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Laurita KR, Piktel JS, Irish L, Nassal M, Cheng A, McCauley M, Pawlowski G, Dennis AT, Suen Y, Almahameed S, Ziv O, Gourdie RG, Wilson LD. Spontaneous Repolarization Alternans Causes VT/VF Rearrest That Is Suppressed by Preserving Gap Junctions. JACC Clin Electrophysiol 2024; 10:1271-1286. [PMID: 38752959 DOI: 10.1016/j.jacep.2024.03.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 03/01/2024] [Accepted: 03/07/2024] [Indexed: 06/25/2024]
Abstract
BACKGROUND Ventricular tachycardia (VT)/ventricular fibrillation (VF) rearrest after successful resuscitation is common, and survival is poor. A mechanism of VT/VF, as demonstrated in ex vivo studies, is when repolarization alternans becomes spatially discordant (DIS ALT), which can be enhanced by impaired gap junctions (GJs). However, in vivo spontaneous DIS ALT-induced VT/VF has never been demonstrated, and the effects of GJ on DIS ALT and VT/VF rearrest are unknown. OBJECTIVES This study aimed to determine whether spontaneous VT/VF rearrest induced by DIS ALT occurs in vivo, and if it can be suppressed by preserving Cx43-mediated GJ coupling and/or connectivity. METHODS We used an in vivo porcine model of resuscitation from ischemia-induced cardiac arrest combined with ex vivo optical mapping in porcine left ventricular wedge preparations. RESULTS In vivo, DIS ALT frequently preceded VT/VF and paralleled its incidence at normal (37°C, n = 9) and mild hypothermia (33°C, n = 8) temperatures. Maintaining GJs in vivo with rotigaptide (n = 10) reduced DIS ALT and VT/VF incidence, especially during mild hypothermia, by 90% and 60%, respectively (P < 0.001; P < 0.013). Ex vivo, both rotigaptide (n = 5) and αCT11 (n = 7), a Cx43 mimetic peptide that promotes GJ connectivity, significantly reduced DIS ALT by 60% and 100%, respectively (P < 0.05; P < 0.005), and this reduction was associated with reduced intrinsic heterogeneities of action potential duration rather than changes in conduction velocity restitution. CONCLUSIONS These results provide the strongest in vivo evidence to date suggesting a causal relationship between spontaneous DIS ALT and VT/VF in a clinically realistic scenario. Furthermore, our results suggest that preserving GJs during resuscitation can suppress VT/VF rearrest.
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Affiliation(s)
- Kenneth R Laurita
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA.
| | - Joseph S Piktel
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA; Department of Emergency Medicine, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA
| | - Laken Irish
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA
| | - Michelle Nassal
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA
| | - Aurelia Cheng
- Department of Emergency Medicine, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA
| | - Matthew McCauley
- Department of Emergency Medicine, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA
| | - Gary Pawlowski
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA
| | - Adrienne T Dennis
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA
| | - Yi Suen
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA; Department of Emergency Medicine, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA
| | - Soufian Almahameed
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA
| | - Ohad Ziv
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA
| | - Robert G Gourdie
- Fralin Biomedical Research Institute, Virginia Tech University, Roanoke, Virginia, USA
| | - Lance D Wilson
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA; Department of Emergency Medicine, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA
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Seghetti P, Latrofa S, Biasi N, Giannoni A, Hartwig V, Rossi A, Tognetti A. Electrophysiological patterns and structural substrates of Brugada syndrome: Critical appraisal and computational analyses. J Cardiovasc Electrophysiol 2024. [PMID: 38899376 DOI: 10.1111/jce.16341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 05/24/2024] [Accepted: 06/03/2024] [Indexed: 06/21/2024]
Abstract
Brugada syndrome (BrS) is a cardiac electrophysiological disease with unknown etiology, associated with sudden cardiac death. Symptomatic patients are treated with implanted cardiac defibrillator, but no risk stratification strategy is effective in patients that are at low to medium arrhythmic risk. Cardiac computational modeling is an emerging tool that can be used to verify the hypotheses of pathogenesis and inspire new risk stratification strategies. However, to obtain reliable results computational models must be validated with consistent experimental data. We reviewed the main electrophysiological and structural variables from BrS clinical studies to assess which data could be used to validate a computational approach. Activation delay in the epicardial right ventricular outflow tract is a consistent finding, as well as increased fibrosis and subclinical alterations of right ventricular functional and morphological parameters. The comparison between other electrophysiological variables is hindered by methodological differences between studies, which we commented. We conclude by presenting a recent theory unifying electrophysiological and structural substrate in BrS and illustrate how computational modeling could help translation to risk stratification.
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Affiliation(s)
- Paolo Seghetti
- Health Science Interdisciplinary Center, Scuola Superiore Sant'Anna, Pisa, Italy
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Sara Latrofa
- Health Science Interdisciplinary Center, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Niccolò Biasi
- Department of Information Engineering, Università di Pisa, Pisa, Italy
| | - Alberto Giannoni
- Health Science Interdisciplinary Center, Scuola Superiore Sant'Anna, Pisa, Italy
- Fondazione Toscana 'G. Monasterio', Pisa, Italy
| | - Valentina Hartwig
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
- Fondazione Toscana 'G. Monasterio', Pisa, Italy
| | | | - Alessandro Tognetti
- Department of Information Engineering, Università di Pisa, Pisa, Italy
- Research Center 'Enrico Piaggio', Università di Pisa, Pisa, Italy
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Latrofa S, Hartwig V, Bachi L, Notarstefano P, Garibaldi S, Panchetti L, Nesti M, Seghetti P, Startari U, Mirizzi G, Morelli MS, Modena M, Mazzanti A, Emdin M, Giannoni A, Rossi A. Endocardial repolarization dispersion in BrS: A novel automatic algorithm for mapping activation recovery interval. J Cardiovasc Electrophysiol 2024; 35:965-974. [PMID: 38477371 DOI: 10.1111/jce.16244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 02/20/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024]
Abstract
INTRODUCTION Repolarization dispersion in the right ventricular outflow tract (RVOT) contributes to the type-1 electrocardiographic (ECG) phenotype of Brugada syndrome (BrS), while data on the significance and feasibility of mapping repolarization dispersion in BrS patients are scarce. Moreover, the role of endocardial repolarization dispersion in BrS is poorly investigated. We aimed to assess endocardial repolarization patterns through an automated calculation of activation recovery interval (ARI) estimated on unipolar electrograms (UEGs) in spontaneous type-1 BrS patients and controls; we also investigated the relation between ARI and right ventricle activation time (RVAT), and T-wave peak-to-end interval (Tpe) in BrS patients. METHODS Patients underwent endocardial high-density electroanatomical mapping (HDEAM); BrS showing an overt type-1 ECG were defined as OType1, while those without (latent type-1 ECG and LType1) received ajmaline infusion. BrS patients only underwent programmed ventricular stimulation (PVS). Data were elaborated to obtain ARI corrected with the Bazett formula (ARIc), while RVAT was derived from activation maps. RESULTS 39 BrS subjects (24 OType1 and 15 LTtype1) and 4 controls were enrolled. OType1 and post-ajmaline LType1 showed longer mean ARIc than controls (306 ± 27.3 ms and 333.3 ± 16.3 ms vs. 281.7 ± 10.3 ms, p = .05 and p < .001, respectively). Ajmaline induced a significant prolongation of ARIc compared to pre-ajmaline LTtype1 (333.3 ± 16.3 vs. 303.4 ± 20.7 ms, p < .001) and OType1 (306 ± 27.3 ms, p < .001). In patients with type-1 ECG (OTtype1 and post-ajmaline LType1) ARIc correlated with RVAT (r = .34, p = .04) and Tpec (r = .60, p < .001), especially in OType1 subjects (r = .55, p = .008 and r = .65 p < .001, respectively). CONCLUSION ARIc mapping demonstrates increased endocardial repolarization dispersion in RVOT in BrS. Endocardial ARIc positively correlates with RVAT and Tpec, especially in OType1.
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Affiliation(s)
- Sara Latrofa
- Health Science Interdisciplinary Center, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | - Lorenzo Bachi
- Health Science Interdisciplinary Center, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | | | | | | | - Paolo Seghetti
- Health Science Interdisciplinary Center, Scuola Superiore Sant'Anna, Pisa, Italy
- Institute of Clinical Physiology, Pisa, Italy
| | | | | | | | - Martina Modena
- Health Science Interdisciplinary Center, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Andrea Mazzanti
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Michele Emdin
- Health Science Interdisciplinary Center, Scuola Superiore Sant'Anna, Pisa, Italy
- Fondazione Toscana Gabriele Monasterio, Pisa, Italy
| | - Alberto Giannoni
- Health Science Interdisciplinary Center, Scuola Superiore Sant'Anna, Pisa, Italy
- Fondazione Toscana Gabriele Monasterio, Pisa, Italy
| | - Andrea Rossi
- Fondazione Toscana Gabriele Monasterio, Pisa, Italy
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Ernault AC, Al-Shama RFM, Li J, Devalla HD, de Groot JR, Coronel R, Vigmond E, Boukens BJ. Interpretation of field and LEAP potentials recorded from cardiomyocyte monolayers. Am J Physiol Heart Circ Physiol 2024; 326:H800-H811. [PMID: 38180452 DOI: 10.1152/ajpheart.00463.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 12/04/2023] [Accepted: 01/02/2024] [Indexed: 01/06/2024]
Abstract
Multielectrode arrays (MEAs) are the method of choice for electrophysiological characterization of cardiomyocyte monolayers. The field potentials recorded using an MEA are like extracellular electrograms recorded from the myocardium using conventional electrodes. Nevertheless, different criteria are used to interpret field potentials and extracellular electrograms, which hamper correct interpretation and translation to the patient. To validate the criteria for interpretation of field potentials, we used neonatal rat cardiomyocytes to generate monolayers. We recorded field potentials using an MEA and simultaneously recorded action potentials using sharp microelectrodes. In parallel, we recreated our experimental setting in silico and performed simulations. We show that the amplitude of the local RS complex of a field potential correlated with conduction velocity in silico but not in vitro. The peak time of the T wave in field potentials exhibited a strong correlation with APD90 while the steepest upslope correlated well with APD50. However, this relationship only holds when the T wave displayed a biphasic pattern. Next, we simulated local extracellular action potentials (LEAPs). The shape of the LEAP differed markedly from the shape of the local action potential, but the final duration of the LEAP coincided with APD90. Criteria for interpretation of extracellular electrograms should be applied to field potentials. This will provide a strong basis for the analysis of heterogeneity in conduction velocity and repolarization in cultured monolayers of cardiomyocytes. Finally, a LEAP is not a recording of the local action potential but is generated by intracellular current provided by neighboring cardiomyocytes and is superior to field potential duration in estimating APD90.NEW & NOTEWORTHY We present a physiological basis for the interpretation of multielectrode array-derived, extracellular, electrical signals.
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Affiliation(s)
- Auriane C Ernault
- Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Rushd F M Al-Shama
- Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Jiuru Li
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Harsha D Devalla
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Joris R de Groot
- Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Ruben Coronel
- Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Edward Vigmond
- IHU Liryc, Fondation Bordeaux Université, Bordeaux, France
- University of Bordeaux, Talence, France
| | - Bastiaan J Boukens
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
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van Weperen VYH, Hoang JD, Jani NR, Khaky A, Herring N, Smith C, Vaseghi M. Circulating noradrenaline leads to release of neuropeptide Y from cardiac sympathetic nerve terminals via activation of β-adrenergic receptors. J Physiol 2024. [PMID: 38352977 DOI: 10.1113/jp285945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 01/25/2024] [Indexed: 03/03/2024] Open
Abstract
Cardiac disease is marked by sympathoexcitation and elevated levels of noradrenaline (NA) and cotransmitter neuropeptide Y (NPY). Increased NPY levels are associated with a greater risk of ventricular arrhythmias and mortality. Nonetheless, the factors that cause NPY release remain poorly understood. We hypothesized that circulating catecholamines might lead to NPY release from myocardial sympathetic nerve terminals via a β-receptor-mediated mechanism that enhances sympathoexcitation. Ventricular interstitial NA and NPY levels were measured in six Yorkshire pigs after i.v. administration of NA (1 mg) and before and after propranolol infusion (1 mg/kg). Real-time interstitial NPY levels were measured using ventricular capacitive immunoprobes (CIs) affixed with NPY antibodies and quantified as the change in CI input current (INPY ) upon binding of NPY. Interstitial NA was measured with adjacent fast-scan cyclic voltammetry probes (INA ). A left ventricular pressure catheter and continuous ECGs were used for haemodynamic recordings, and an epicardial 56-electrode sock was used for measurements of activation recovery interval, a surrogate of action potential duration. Upon administration of NA, heart rate and left ventricular pressure increased, and activation recovery interval shortened. Notably, NA significantly increased interstitial myocardial NPY levels. After propranolol, changes in heart rate and activation recovery interval were largely mitigated. The INA increased to a similar extent post-propranolol vs. pre-propranolol, but changes in INPY were significantly reduced post-propranolol. Coronary sinus plasma analyses confirmed fast-scan cyclic voltammetry and CI findings. Hence, this study demonstrates that circulating NA induces NPY release from ventricular sympathetic nerve terminals, the mechanism for which is mediated via β-adrenergic receptors and can be blocked by the non-selective β-blocker, propranolol. KEY POINTS: Cardiovascular disease is characterized by sympathovagal imbalance, with increased plasma noradrenaline (NA) and neuropeptide Y (NPY) concentrations. Increased NPY levels are associated with increased ventricular arrhythmias and mortality in heart failure. Limited data are available on the specific factors that cause NPY release. In this study, fast-scan cyclic voltammetry and capacitive immunoprobes were used to allow for real-time in vivo measurements of interstitial myocardial neurotransmitters and neuropeptides, respectively. Using an in vivo porcine model with cardiac fast-scan cyclic voltammetry and capacitive immunoprobes, it was shown that systemic NA can increase ventricular interstitial NPY levels, suggesting that NA induces NPY release from postganglionic sympathetic nerves. The release of NPY was blocked by administration of the non-selective β-blocker propranolol, suggesting that release of NPY is dependent on activation of β-adrenergic receptors by NA.
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Affiliation(s)
- Valerie Y H van Weperen
- University of California, Los Angeles Cardiac Arrhythmia Center, Los Angeles, CA, USA
- Neurocardiology Research Center of Excellence, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jonathan D Hoang
- University of California, Los Angeles Cardiac Arrhythmia Center, Los Angeles, CA, USA
- Neurocardiology Research Center of Excellence, University of California, Los Angeles, Los Angeles, CA, USA
| | - Neil R Jani
- University of California, Los Angeles Cardiac Arrhythmia Center, Los Angeles, CA, USA
- Neurocardiology Research Center of Excellence, University of California, Los Angeles, Los Angeles, CA, USA
| | - Artin Khaky
- University of California, Los Angeles Cardiac Arrhythmia Center, Los Angeles, CA, USA
- Neurocardiology Research Center of Excellence, University of California, Los Angeles, Los Angeles, CA, USA
| | - Neil Herring
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Corey Smith
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA
| | - Marmar Vaseghi
- University of California, Los Angeles Cardiac Arrhythmia Center, Los Angeles, CA, USA
- Neurocardiology Research Center of Excellence, University of California, Los Angeles, Los Angeles, CA, USA
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van der Waal J, Meijborg V, Coronel R, Dubois R, Oostendorp T. Basis and applicability of noninvasive inverse electrocardiography: a comparison between cardiac source models. Front Physiol 2023; 14:1295103. [PMID: 38152249 PMCID: PMC10752226 DOI: 10.3389/fphys.2023.1295103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 11/30/2023] [Indexed: 12/29/2023] Open
Abstract
The body surface electrocardiogram (ECG) is a direct result of electrical activity generated by the myocardium. Using the body surface ECGs to reconstruct cardiac electrical activity is called the inverse problem of electrocardiography. The method to solve the inverse problem depends on the chosen cardiac source model to describe cardiac electrical activity. In this paper, we describe the theoretical basis of two inverse methods based on the most commonly used cardiac source models: the epicardial potential model and the equivalent dipole layer model. We discuss similarities and differences in applicability, strengths and weaknesses and sketch a road towards improved inverse solutions by targeted use, sequential application or a combination of the two methods.
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Affiliation(s)
- Jeanne van der Waal
- Department of Clinical and Experimental Cardiology, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - Veronique Meijborg
- Department of Clinical and Experimental Cardiology, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - Ruben Coronel
- Department of Clinical and Experimental Cardiology, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - Rémi Dubois
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac, France
| | - Thom Oostendorp
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands
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Kinoshita T, Onda N, Ohno R, Ikeda T, Sugizaki Y, Ohara H, Nakagami T, Yuzawa H, Shimada H, Shimizu K, Ikeda T. Activation recovery interval as an electrocardiographic repolarization index to detect doxorubicin-induced cardiotoxicity. J Cardiol 2023; 82:473-480. [PMID: 37506822 DOI: 10.1016/j.jjcc.2023.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 05/12/2023] [Accepted: 07/21/2023] [Indexed: 07/30/2023]
Abstract
BACKGROUND It has been reported that early detection and treatment of cancer therapy- related cardiac dysfunction (CTRCD) improves its prognosis. The detailed relationships between electrocardiographic repolarization indices and decreased left ventricular function in CTRCD have not been elucidated. We closely assessed such relationships in patients with doxorubicin (DOX)-induced CTRCD. METHODS This retrospective, single-center, cohort study included 471 consecutive patients with malignant lymphoma who received chemotherapy including DOX. Of them, 17 patients with CTRCD and 68 patients without CTRCD who underwent 12‑lead electrocardiogram and an echocardiogram before and after chemotherapy were eventually analyzed. The fluctuations of the following electrocardiographic repolarization indices were evaluated in lead V5: QT, JT, T peak to T end interval (Tp-e), and activation recovery interval (ARI). These indices were corrected by heart rate with the Fridericia formula. RESULTS The median period from the end of chemotherapy to the diagnosis of the CTRCD group was 346 days (IQR 170-1283 days). After chemotherapy, the QT interval was significantly prolonged in both with and without CTRCD groups compared with that before chemotherapy (pre QTc vs. post QTc in CTRCD group, 386 ± 27 ms vs. 411 ± 37 ms, p = 0.03, pre QTc vs. post QTc in non-CTRCD group, 388 ± 24 ms vs. 395 ± 25 ms, p = 0.04, respectively). ARIc after chemotherapy was characteristically observed only in the CTRCD group (pre ARIc vs. post ARIc in CTRCD group, 258 ± 53 ms vs. 211 ± 28 ms, p = 0.03, pre ARIc vs. post ARIc in non-CTRCD group, 221 ± 19 ms vs. 225 ± 23 ms, NS, respectively) and had negative correlations with left ventricular ejection fraction (r = -0.56, p < 0.001). Using the receiver-operating characteristic curve, the relationship between ARIc and CTRCD morbidity was examined. The optimal cut-off point of ARIc prolongation between before and after chemotherapy was 18 ms (sensitivity 75 %, specificity 79 %, area under the curve 0.76). CONCLUSIONS ARIc prolongation may be useful in the early detection of developing late-onset chronic DOX-induced CTRCD and lead to early treatment for cardiac protection.
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Affiliation(s)
- Toshio Kinoshita
- Division of Cardiovascular Medicine, Department of Internal Medicine, Toho University Sakura Medical Center, Chiba, Japan.
| | - Naoki Onda
- Division of Hematology and Oncology, Department of Medicine, Toho University Omori Medical Center, Tokyo, Japan
| | - Ruiko Ohno
- Division of Cardiovascular Medicine, Department of Internal Medicine, Toho University Sakura Medical Center, Chiba, Japan
| | - Takushi Ikeda
- Division of Cardiovascular Medicine, Department of Internal Medicine, Toho University Sakura Medical Center, Chiba, Japan
| | - Yuta Sugizaki
- Division of Cardiovascular Medicine, Department of Internal Medicine, Toho University Sakura Medical Center, Chiba, Japan
| | - Hiroshi Ohara
- Department of Cardiovascular Medicine, Toho University Faculty of Medicine, Tokyo, Japan
| | - Takahiro Nakagami
- Division of Cardiovascular Medicine, Department of Internal Medicine, Toho University Sakura Medical Center, Chiba, Japan
| | - Hitomi Yuzawa
- Division of Cardiology, Mitsui Memorial Hospital, Tokyo, Japan
| | - Hideaki Shimada
- Department of Gastroenterological Surgery and Clinical Oncology, Toho University Graduate School of Medicine, Tokyo, Japan
| | - Kazuhiro Shimizu
- Division of Cardiovascular Medicine, Department of Internal Medicine, Toho University Sakura Medical Center, Chiba, Japan
| | - Takanori Ikeda
- Department of Cardiovascular Medicine, Toho University Faculty of Medicine, Tokyo, Japan
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Elliott MK, Strocchi M, Sieniewicz BJ, Mehta V, Wijesuriya N, deVere F, Howell S, Thorpe A, Martic D, Bishop MJ, Niederer S, Rinaldi CA. Left bundle branch area pacing reduces epicardial dispersion of repolarization compared with biventricular cardiac resynchronization therapy. Heart Rhythm 2023; 20:1629-1636. [PMID: 37516414 DOI: 10.1016/j.hrthm.2023.07.065] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/19/2023] [Accepted: 07/24/2023] [Indexed: 07/31/2023]
Abstract
BACKGROUND Biventricular endocardial pacing (BiV-endo) and left bundle branch area pacing (LBBAP) are novel methods of delivering cardiac resynchronization therapy. These techniques are associated with improved activation times and acute hemodynamic response compared with conventional biventricular epicardial pacing (BiV-epi); however, the effects on repolarization and arrhythmic risk are unknown. OBJECTIVE The purpose of this study was to compare the effects of temporary BiV-epi, BiV-endo, and LBBAP on epicardial left ventricular (LV) repolarization using electrocardiographic imaging (ECGi). METHODS Eleven patients indicated for cardiac resynchronization therapy underwent a temporary pacing protocol with ECGi. BiV-endo was delivered via endocardial stimulation of the LV lateral wall. LBBAP was delivered by pacing the LV septum. Epicardial LV repolarization time (LVRT-95; time taken for 95% of the LV to repolarize), LV RT dispersion, mean LV activation recovery interval (ARI), LV ARI dispersion, and RT gradients were calculated. RESULTS The protocol was completed in 10 patients. During LBBAP, there were significant reductions in LVRT-95 (94.9 ± 17.4 ms vs 125.0 ± 29.4 ms; P = .03) and LV RT dispersion (29.4 ± 6.3 ms vs 40.8 ± 11.4 ms; P = .015) compared with BiV-epi. In contrast, there were no significant differences between baseline, BiV-epi, or BiV-endo. There was a nonsignificant reduction in mean RT gradients between LBBAP and baseline rhythm (0.74 ± 0.22 ms/mm vs 1.01 ± 0.31 ms/mm; P = .07). There were no significant differences in mean LV ARI or LV ARI dispersion between groups. CONCLUSION Temporary LBBAP reduces epicardial dispersion of repolarization compared with conventional BiV-epi. Further study is required to determine whether these repolarization changes on ECGi translate into a reduced risk of ventricular arrhythmia in clinical practice.
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Affiliation(s)
- Mark K Elliott
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom.
| | - Marina Strocchi
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Benjamin J Sieniewicz
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Vishal Mehta
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Nadeev Wijesuriya
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Felicity deVere
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Sandra Howell
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Andrew Thorpe
- Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Dejana Martic
- Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Martin J Bishop
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Steven Niederer
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Christopher A Rinaldi
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
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Vermoortele D, Amoni M, Ingelaere S, Sipido KR, Willems R, Claus P. Electric Field-Based Spatial Analysis of Noncontact Unipolar Electrograms to Map Regional Activation-Repolarization Intervals. JACC Clin Electrophysiol 2023; 9:1217-1231. [PMID: 37558285 DOI: 10.1016/j.jacep.2023.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/30/2023] [Accepted: 02/01/2023] [Indexed: 08/11/2023]
Abstract
BACKGROUND Spatial heterogeneity in repolarization plays an important role in generating and sustaining cardiac arrhythmias. Reliable determination of repolarization times remains challenging. OBJECTIVES The goal of this study was to improve processing of densely sampled noncontact unipolar electrograms to yield reliable high-resolution activation and repolarization maps. METHODS Endocardial noncontact unipolar electrograms were both simulated and recorded in pig left ventricle. Electrical activity on the endocardial surface was processed in terms of a pseudo-electric field. Activation and repolarization times were calculated by using an amplitude-weighted average on QRS and T waves (ie, the E-field method). This was compared vs the conventional Wyatt method on unipolar electrograms. Timing maps were validated against timing on endocardial action potentials in a simulation study. In vivo, activation and repolarization times determined by using this alternative E-field method were validated against simultaneously recorded endocardial monophasic action potentials (MAPs). RESULTS Simulation showed that the E-field method provides viable measurements of local endocardial action potential activation and repolarization times. In vivo, correlation of E-field activation times with MAP activation times (rE = 0.76; P < 0.001) was similar to those of Wyatt (rWyatt = 0.80, P < 0.001; P[h1:rE > rWyatt] = 0.82); for repolarization times, correlation improved significantly (rE = 0.96, P < 0.001; rWyatt = 0.82, P < 0.001; P[h1:rE > rWyatt] < 0.00001). This resulted in improved correlations of activation-repolarization intervals to endocardial action potential duration on MAP (rE = 0.96, P < 0.001; rWyatt = 0.86, P < 0.001; P[h1:rE > rWyatt] < 0.00001). Spatial beat-to-beat variation of repolarization could only be calculated by using the E-field methodology and correlated well with the MAP beat-to-beat variation of repolarization (rE = 0.76; P = 0.001). CONCLUSIONS The E-field method substantially enhances information from endocardial noncontact electrogram data, allowing for dense maps of activation and repolarization times and derived parameters.
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Affiliation(s)
- Dylan Vermoortele
- Department of Cardiovascular Sciences, Cardiovascular Imaging and Dynamics, KU Leuven, Leuven, Belgium
| | - Matthew Amoni
- Department of Cardiovascular Sciences, Experimental Cardiology, KU Leuven, Leuven, Belgium
| | - Sebastian Ingelaere
- Department of Cardiovascular Sciences, Experimental Cardiology, KU Leuven, Leuven, Belgium; Division of Cardiology, University Hospitals Leuven, Leuven, Belgium
| | - Karin R Sipido
- Department of Cardiovascular Sciences, Experimental Cardiology, KU Leuven, Leuven, Belgium
| | - Rik Willems
- Department of Cardiovascular Sciences, Experimental Cardiology, KU Leuven, Leuven, Belgium; Division of Cardiology, University Hospitals Leuven, Leuven, Belgium
| | - Piet Claus
- Department of Cardiovascular Sciences, Cardiovascular Imaging and Dynamics, KU Leuven, Leuven, Belgium.
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Xu L, Zahid S, Khoshknab M, Moss J, Berger RD, Chrispin J, Callans D, Marchlinski FE, Zimmerman SL, Han Y, Desjardins B, Trayanova N, Nazarian S. Conduction Velocity Dispersion Predicts Postinfarct Ventricular Tachycardia Circuit Sites and Associates With Lipomatous Metaplasia. JACC Clin Electrophysiol 2023; 9:1464-1474. [PMID: 37294264 PMCID: PMC11149171 DOI: 10.1016/j.jacep.2023.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 05/09/2023] [Accepted: 05/10/2023] [Indexed: 06/10/2023]
Abstract
BACKGROUND Regional myocardial conduction velocity (CV) dispersion has not been studied in postinfarct patients with ventricular tachycardia (VT). OBJECTIVES This study sought to compare the following: 1) the association of CV dispersion vs repolarization dispersion with VT circuit sites; and 2) myocardial lipomatous metaplasia (LM) vs fibrosis as the anatomic substrate for CV dispersion. METHODS Among 33 postinfarct patients with VT, we characterized dense and border zone infarct tissue by late gadolinium enhancement cardiac magnetic resonance, and LM by computed tomography, with both images registered with electroanatomic maps. Activation recovery interval (ARI) was the time interval from the minimum derivative within the QRS complex to the maximum derivative within the T-wave on unipolar electrograms. CV at each EAM point was the mean CV between that point and 5 adjacent points along the activation wave front. CV and ARI dispersion were the coefficient of variation (CoV) of CV and ARI per American Heart Association (AHA) segment, respectively. RESULTS Regional CV dispersion exhibited a much larger range than ARI dispersion, with median 0.65 vs 0.24; P < 0.001. CV dispersion was a more robust predictor of the number of critical VT sites per AHA segment than ARI dispersion. Regional LM area was more strongly associated with CV dispersion than fibrosis area. LM area was larger (median 0.44 vs 0.20 cm2; P < 0.001) in AHA segments with mean CV <36 cm/s and CoV_CV >0.65 than those with mean CV <36 cm/s and CoV_CV <0.65. CONCLUSIONS Regional CV dispersion more strongly predicts VT circuit sites than repolarization dispersion, and LM is a critical substrate for CV dispersion.
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Affiliation(s)
- Lingyu Xu
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.
| | - Sohail Zahid
- Department of Internal Medicine, NYU Langone Medical Center, New York, New York, USA
| | - Mirmilad Khoshknab
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Juwann Moss
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Ronald D Berger
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA; Department of Cardiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jonathan Chrispin
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA; Department of Cardiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - David Callans
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Francis E Marchlinski
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Stefan L Zimmerman
- Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yuchi Han
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Benoit Desjardins
- Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Natalia Trayanova
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Saman Nazarian
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA. https://twitter.com/Dr_Nazarian_EP
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Xu L, Zahid S, Khoshknab M, Moss J, Berger RD, Chrispin J, Callans D, Marchlinski FE, Zimmerman SL, Han Y, Desjardins B, Trayanova N, Nazarian S. Lipomatous metaplasia prolongs repolarization and increases repolarization dispersion within post-infarct ventricular tachycardia circuit cites. Europace 2023; 25:496-505. [PMID: 36519747 PMCID: PMC9935002 DOI: 10.1093/europace/euac222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 10/20/2022] [Indexed: 12/23/2022] Open
Abstract
AIMS Post-infarct myocardium contains viable corridors traversing scar or lipomatous metaplasia (LM). Ventricular tachycardia (VT) circuitry has been separately reported to associate with corridors that traverse LM and with repolarization heterogeneity. We examined the association of corridor activation recovery interval (ARI) and ARI dispersion with surrounding tissue type. METHODS AND RESULTS The cohort included 33 post-infarct patients from the prospective Intra-Myocardial Fat Deposition and Ventricular Tachycardia in Cardiomyopathy (INFINITY) study. We co-registered scar and corridors from late gadolinium enhanced magnetic resonance, and LM from computed tomography with intracardiac electrogram locations. Activation recovery interval was calculated during sinus or ventricular pacing, as the time interval from the minimum derivative within the QRS to the maximum derivative within the T-wave on unipolar electrograms. Regional ARI dispersion was defined as the standard deviation (SD) of ARI per AHA segment (ARISD). Lipomatous metaplasia exhibited higher ARI than scar [325 (interquartile range 270-392) vs. 313 (255-374), P < 0.001]. Corridors critical to VT re-entry were more likely to traverse through or near LM and displayed prolonged ARI compared with non-critical corridors [355 (319-397) vs. 302 (279-333) ms, P < 0.001]. ARISD was more closely associated with LM than with scar (likelihood ratio χ2 50 vs. 12, and 4.2-unit vs. 0.9-unit increase in 0.01*Log(ARISD) per 1 cm2 increase per AHA segment). Additionally, LM and scar exhibited interaction (P < 0.001) in their association with ARISD. CONCLUSION Lipomatous metaplasia is closely associated with prolonged local action potential duration of corridors and ARI dispersion, which may facilitate the propensity of VT circuit re-entry.
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Affiliation(s)
- Lingyu Xu
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Sohail Zahid
- Department of Internal Medicine, NYU Langone Medical Center, New York, NY, USA
| | - Mirmilad Khoshknab
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Juwann Moss
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Ronald D Berger
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Cardiology, Johns Hopkins University, Baltimore, MD, USA
| | - Jonathan Chrispin
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Cardiology, Johns Hopkins University, Baltimore, MD, USA
| | - David Callans
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Francis E Marchlinski
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Stefan L Zimmerman
- Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Yuchi Han
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA 19104, USA
| | - Benoit Desjardins
- Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Natalia Trayanova
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Saman Nazarian
- Cardiovascular Medicine Division, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA 19104, USA
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12
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Stoks J, Bear LR, Vijgen J, Dendale P, Peeters R, Volders PGA, Cluitmans MJM. Understanding repolarization in the intracardiac unipolar electrogram: A long-lasting controversy revisited. Front Physiol 2023; 14:1158003. [PMID: 37089414 PMCID: PMC10119409 DOI: 10.3389/fphys.2023.1158003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 03/24/2023] [Indexed: 04/25/2023] Open
Abstract
Background: The optimal way to determine repolarization time (RT) from the intracardiac unipolar electrogram (UEG) has been a topic of debate for decades. RT is typically determined by either the Wyatt method or the "alternative method," which both consider UEG T-wave slope, but differently. Objective: To determine the optimal method to measure RT on the UEG. Methods: Seven pig hearts surrounded by an epicardial sock with 100 electrodes were Langendorff-perfused with selective cannulation of the left anterior descending (LAD) coronary artery and submersed in a torso-shaped tank containing 256 electrodes on the torso surface. Repolarization was prolonged in the non-LAD-regions by infusing dofetilide and shortened in the LAD-region using pinacidil. RT was determined by the Wyatt (tWyatt) and alternative (tAlt) methods, in both invasive (recorded with epicardial electrodes) and in non-invasive UEGs (reconstructed with electrocardiographic imaging). tWyatt and tAlt were compared to local effective refractory period (ERP). Results: With contact mapping, mean absolute error (MAE) of tWyatt and tAlt vs. ERP were 21 ms and 71 ms, respectively. Positive T-waves typically had an earlier ERP than negative T-waves, in line with theory. tWyatt -but not tAlt-shortened by local infusion of pinacidil. Similar results were found for the non-invasive UEGs (MAE of tWyatt and tAlt vs. ERP were 30 ms and 92 ms, respectively). Conclusion: The Wyatt method is the most accurate to determine RT from (non) invasive UEGs, based on novel and historical analyses. Using it to determine RT could unify and facilitate repolarization assessment and amplify its role in cardiac electrophysiology.
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Affiliation(s)
- Job Stoks
- Department of Cardiology, CARIM, Maastricht University Medical Center+, Maastricht, Netherlands
- Department of Advanced Computing Sciences, Maastricht University, Maastricht, Netherlands
- Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Laura R. Bear
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Bordeaux, France
| | - Johan Vijgen
- Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Paul Dendale
- Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Ralf Peeters
- Department of Advanced Computing Sciences, Maastricht University, Maastricht, Netherlands
| | - Paul G. A. Volders
- Department of Cardiology, CARIM, Maastricht University Medical Center+, Maastricht, Netherlands
| | - Matthijs J. M. Cluitmans
- Department of Cardiology, CARIM, Maastricht University Medical Center+, Maastricht, Netherlands
- *Correspondence: Matthijs J. M. Cluitmans,
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13
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Cluitmans MJM, Bayer J, Bear LR, ter Bekke RMA, Heijman J, Coronel R, Volders PGA. The circle of reentry: Characteristics of trigger-substrate interaction leading to sudden cardiac arrest. Front Cardiovasc Med 2023; 10:1121517. [PMID: 37139119 PMCID: PMC10150924 DOI: 10.3389/fcvm.2023.1121517] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 03/28/2023] [Indexed: 05/05/2023] Open
Abstract
Sudden cardiac death is often caused by ventricular arrhythmias driven by reentry. Comprehensive characterization of the potential triggers and substrate in survivors of sudden cardiac arrest has provided insights into the trigger-substrate interaction leading to reentry. Previously, a "Triangle of Arrhythmogenesis", reflecting interactions between substrate, trigger and modulating factors, has been proposed to reason about arrhythmia initiation. Here, we expand upon this concept by separating the trigger and substrate characteristics in their spatial and temporal components. This yields four key elements that are required for the initiation of reentry: local dispersion of excitability (e.g., the presence of steep repolarization time gradients), a critical relative size of the region of excitability and the region of inexcitability (e.g., a sufficiently large region with early repolarization), a trigger that originates at a time when some tissue is excitable and other tissue is inexcitable (e.g., an early premature complex), and which occurs from an excitable region (e.g., from a region with early repolarization). We discuss how these findings yield a new mechanistic framework for reasoning about reentry initiation, the "Circle of Reentry." In a patient case of unexplained ventricular fibrillation, we then illustrate how a comprehensive clinical investigation of these trigger-substrate characteristics may help to understand the associated arrhythmia mechanism. We will also discuss how this reentry initiation concept may help to identify patients at risk, and how similar reasoning may apply to other reentrant arrhythmias.
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Affiliation(s)
- Matthijs J. M. Cluitmans
- Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands
- Philips Research, Eindhoven, Netherlands
- Correspondence: Matthijs J. M. Cluitmans
| | | | | | - Rachel M. A. ter Bekke
- Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands
| | - Jordi Heijman
- Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands
| | - Ruben Coronel
- Department of Experimental Cardiology, Amsterdam University Medical Centre, Amsterdam, Netherlands
| | - Paul G. A. Volders
- Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands
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14
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Han H, Cheng LK, Paskaranandavadivel N. High-resolution in vivo monophasic gastric slow waves to quantify activation and recovery profiles. Neurogastroenterol Motil 2022; 34:e14422. [PMID: 35726361 PMCID: PMC10078408 DOI: 10.1111/nmo.14422] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/29/2022] [Accepted: 05/23/2022] [Indexed: 12/07/2022]
Abstract
BACKGROUND Gastric bio-electrical slow waves are, in part, responsible for coordinating motility. Spatial dynamics about the recovery phase of slow wave recordings have not been thoroughly investigated due to the lack of suitable experimental techniques. METHODS A high-resolution multi-channel suction electrode array was developed and applied in pigs to acquire monophasic gastric slow waves. Signal characteristics were verified against biphasic slow waves recorded by conventional surface contact electrode arrays. Monophasic slow wave events were categorized into two groups based on their morphological characteristics, after which their amplitudes, activation to recovery intervals, and gradients were quantified and compared. Coverage of activation and recovery maps for both electrode types were calculated and compared. KEY RESULTS Monophasic slow waves had a more pronounced recovery phase with a higher gradient than biphasic slow waves (0.5 ± 0.1 vs. 0.3 ± 0.1 mV·s-1 ). Between the 2 groups of monophasic slow waves, there was a significant difference in amplitude (1.8 ± 0.5 vs. 1.1 ± 0.2 mV), activation time gradient (0.8 ± 0.2 vs. 0.3 ± 0.1 mV·s-1 ), and recovery time gradient (0.5 ± 0.1 vs. 0.3 ± 0.1 mV·s-1 ). For the suction and conventional contact electrode arrays, the recovery maps had reduced coverage compared to the activation maps (4 ± 6% and 43 ± 11%, respectively). CONCLUSIONS AND INFERENCES A novel high-resolution multi-channel suction electrode array was developed and applied in vivo to record monophasic gastric slow waves. Slow wave recovery phase analysis could be performed more efficiently on monophasic signals compared with biphasic signals, due to the more identifiable recovery phases.
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Affiliation(s)
- Henry Han
- Auckland Bioengineering Institute, The University of Auckland, New Zealand
| | - Leo K Cheng
- Auckland Bioengineering Institute, The University of Auckland, New Zealand.,Department of Surgery, Vanderbilt University, Nashville, Tennessee, USA
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15
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Ovechkin AO, Vaykshnorayte MA, Sedova KA, Shmakov DN, Shumikhin KV, Medvedeva SY, Danilova IG, Azarov JE. Beta-Receptor Blockade Reproduces Electrophysiological Effects of Early Diabetes Mellitus in Ventricular Myocardium. J EVOL BIOCHEM PHYS+ 2022. [PMCID: PMC9910273 DOI: 10.1134/s0022093022070080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- A. O. Ovechkin
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
- Institute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
| | - M. A. Vaykshnorayte
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - K. A. Sedova
- Faculty of Biomedical Engineering, Czech Technical University, Kladno, Czech Republic
| | - D. N. Shmakov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - K. V. Shumikhin
- Institute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
| | - S. Yu. Medvedeva
- Department of morphology and biochemistry, Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russia
| | - I. G. Danilova
- Department of morphology and biochemistry, Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russia
| | - J. E. Azarov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
- Institute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
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16
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Chokesuwattanaskul R, Nademanee K. Advances in Ventricular Arrhythmia Ablation for Brugada Syndrome. Card Electrophysiol Clin 2022; 14:685-692. [PMID: 36396185 DOI: 10.1016/j.ccep.2022.08.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Three decades have passed since the Brugada syndrome (BrS) clinical entity was introduced in the early 1990s. During the first 2 decades, treatment of patients with BrS was challenging because there were limited treatment options, and an implantable cardioverter-defibrillator was the only choice for high-risk patients with BrS, that is, those who had aborted sudden cardiac death or had previous ventricular fibrillation episodes. In this article, the authors focus on these advances and how to treat patients with BrS with catheter ablation.
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Affiliation(s)
- Ronpichai Chokesuwattanaskul
- Department of Medicine, Center of Excellence in Arrhythmia Research Chulalongkorn University, 1873 Rama IV Road, Pathumwan, Bangkok 10330 Thailand
| | - Koonlawee Nademanee
- Department of Medicine, Center of Excellence in Arrhythmia Research Chulalongkorn University, 1873 Rama IV Road, Pathumwan, Bangkok 10330 Thailand; Bumrungrad Hospital, Bangkok and Pacific Rim Electrophysiology Research Institute, Bangkok, Thailand; Las Vegas, NV, USA.
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17
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van der Waal J, Bear L, Meijborg V, Dubois R, Cluitmans M, Coronel R. Steep repolarization time gradients in pig hearts cause distinct changes in composite electrocardiographic T‐wave parameters. Ann Noninvasive Electrocardiol 2022; 27:e12994. [DOI: 10.1111/anec.12994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/09/2022] [Accepted: 06/20/2022] [Indexed: 11/30/2022] Open
Affiliation(s)
- Jeanne van der Waal
- Department of Experimental and Clinical Cardiology Amsterdam UMC, Location AMC Amsterdam The Netherlands
| | - Laura Bear
- IHU Liryc, Electrophysiology and Heart Modeling Institute Fondation Bordeaux Université Pessac France
- Université de Bordeaux Pessac France
- Inserm, Cardio‐Thoracix Research Centre of Bordeaux Pessac France
| | - Veronique Meijborg
- Department of Experimental and Clinical Cardiology Amsterdam UMC, Location AMC Amsterdam The Netherlands
| | - Rémi Dubois
- IHU Liryc, Electrophysiology and Heart Modeling Institute Fondation Bordeaux Université Pessac France
- Université de Bordeaux Pessac France
- Inserm, Cardio‐Thoracix Research Centre of Bordeaux Pessac France
| | - Matthijs Cluitmans
- CARIM School for Cardiovascular Diseases Maastricht University Medical Centre Maastricht The Netherlands
| | - Ruben Coronel
- Department of Experimental and Clinical Cardiology Amsterdam UMC, Location AMC Amsterdam The Netherlands
- Université de Bordeaux Pessac France
- Inserm, Cardio‐Thoracix Research Centre of Bordeaux Pessac France
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18
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Elliott MK, Strocchi M, Mehta VS, Wijesuriya N, Mannakkara NN, Jackson T, Pereira H, Behar JM, Bishop MJ, Niederer S, Rinaldi CA. Dispersion of repolarization increases with cardiac resynchronization therapy and is associated with left ventricular reverse remodeling. J Electrocardiol 2022; 72:120-127. [PMID: 35468456 PMCID: PMC10171825 DOI: 10.1016/j.jelectrocard.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 12/20/2022]
Abstract
PURPOSE Cardiac resynchronization therapy (CRT) reduces ventricular activation times and electrical dyssynchrony, however the effect on repolarization is unclear. In this study, we sought to investigate the effect of CRT and left ventricular (LV) remodeling on dispersion of repolarization using electrocardiographic imaging (ECGi). METHODS 11 patients with heart failure and electrical dyssynchrony underwent ECGi 1-day and 6-months post CRT. Reconstructed epicardial electrograms were used to create maps of activation time, repolarization time (RT) and activation recovery intervals (ARI) and calculate measures of RT, ARI and their dispersion. ARI was corrected for heart rate (cARI). RESULTS Compared to baseline rhythm, LV cARI dispersion was significantly higher at 6 months (28.2 ± 7.7 vs 36.4 ± 7.2 ms; P = 0.03) but not after 1 day (28.2 ± 7.7 vs 34.4 ± 6.8 ms; P = 0.12). There were no significant differences from baseline to CRT for mean LV cARI or RT metrics. Significant LV remodeling (>15% reduction in end-systolic volume) was an independent predictor of increase in LV cARI dispersion (P = 0.04) and there was a moderate correlation between the degree of LV remodeling and the relative increase in LV cARI dispersion (R = -0.49) though this was not statistically significant (P = 0.12). CONCLUSION CRT increases LV cARI dispersion, but this change was not fully apparent until 6 months post implant. The effects of CRT on LV cARI dispersion appeared to be dependent on LV reverse remodeling, which is in keeping with evidence that the risk of ventricular arrhythmia after CRT is higher in non-responders compared to responders.
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Affiliation(s)
- Mark K Elliott
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, UK.
| | - Marina Strocchi
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK
| | - Vishal S Mehta
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Nadeev Wijesuriya
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Nilanka N Mannakkara
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Tom Jackson
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Helder Pereira
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Jonathan M Behar
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Martin J Bishop
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK
| | - Steven Niederer
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK
| | - Christopher A Rinaldi
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK; Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, UK
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Graham AJ, Orini M, Zacur E, Dhillon G, Jones D, Prabhu S, Pugliese F, Lowe M, Ahsan S, Earley MJ, Chow A, Sporton S, Dhinoja M, Hunter RJ, Schilling RJ, Lambiase PD. Assessing Noninvasive Delineation of Low-Voltage Zones Using ECG Imaging in Patients With Structural Heart Disease. JACC Clin Electrophysiol 2022; 8:426-436. [PMID: 35450597 DOI: 10.1016/j.jacep.2021.11.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 11/12/2021] [Accepted: 11/16/2021] [Indexed: 11/16/2022]
Abstract
OBJECTIVES This study sought to assess the association between electrocardiographic imaging (ECGI) parameters and voltage from simultaneous electroanatomic mapping (EAM). BACKGROUND ECGI offers noninvasive assessment of electrophysiologic features relevant for mapping ventricular arrhythmia and its substrate, but the accuracy of ECGI in the delineation of scar is unclear. METHODS Sixteen patients with structural heart disease underwent simultaneous ECGI (CardioInsight, Medtronic) and contact EAM (CARTO, Biosense-Webster) during ventricular tachycardia catheter ablation, with 7 mapped epicardially. ECGI and EAM geometries were coregistered using anatomic landmarks. ECGI points were paired to the closest site on the EAM within 10 mm. The association between EAM voltage and ECGI features from reconstructed epicardial unipolar electrograms was assessed by mixed-effects regression models. The classification of low-voltage regions was performed using receiver-operating characteristic analysis. RESULTS A total of 9,541 ECGI points (median: 596; interquartile range: 377-737 across patients) were paired to an EAM site. Epicardial EAM voltage was associated with ECGI features of signal fractionation and local repolarization dispersion (N = 7; P < 0.05), but they poorly classified sites with bipolar voltage of <1.5 mV or <0.5 mV thresholds (median area under the curve across patients: 0.50-0.62). No association was found between bipolar EAM voltage and low-amplitude reconstructed epicardial unipolar electrograms or ECGI-derived bipolar electrograms. Similar results were found in the combined cohort (n = 16), including endocardial EAM voltage compared to epicardial ECGI features (n = 9). CONCLUSIONS Despite a statistically significant association between ECGI features and EAM voltage, the accuracy of the delineation of low-voltage zones was modest. This may limit ECGI use for pr-procedural substrate analysis in ventricular tachycardia ablation, but it could provide value in risk assessment for ventricular arrhythmias.
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Affiliation(s)
- Adam J Graham
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom
| | - Michele Orini
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Ernesto Zacur
- Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Gurpreet Dhillon
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom
| | - Daniel Jones
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom
| | - Sandeep Prabhu
- Department of Cardiology, The Alfred Hospital, Melbourne, Australia
| | - Francesca Pugliese
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom
| | - Martin Lowe
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom
| | - Syed Ahsan
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom
| | - Mark J Earley
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom
| | - Anthony Chow
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom
| | - Simon Sporton
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom
| | - Mehul Dhinoja
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom
| | - Ross J Hunter
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom
| | - Richard J Schilling
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom
| | - Pier D Lambiase
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom.
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20
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Elliott MK, Costa CM, Whitaker J, Gemmell P, Mehta VS, Sidhu BS, Gould J, Williams SE, O'Neill M, Razavi R, Niederer S, Bishop MJ, Rinaldi CA. Effect of scar and pacing location on repolarization in a porcine myocardial infarction model. Heart Rhythm O2 2022; 3:186-195. [PMID: 35496454 PMCID: PMC9043407 DOI: 10.1016/j.hroo.2022.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Background The effect of chronic ischemic scar on repolarization is unclear, with conflicting results from human and animal studies. An improved understanding of electrical remodeling within scar and border zone tissue may enhance substrate-guided ablation techniques for treatment of ventricular tachycardia. Computational modeling studies have suggested increased dispersion of repolarization during epicardial, but not endocardial, left ventricular pacing, in close proximity to scar. However, the effect of endocardial pacing near scar in vivo is unknown. Objective The purpose of this study was to investigate the effect of scar and pacing location on local repolarization in a porcine myocardial infarction model. Methods Six model pigs underwent late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging followed by electroanatomic mapping of the left ventricular endocardium. LGE-CMR images were registered to the anatomic shell and scar defined by LGE. Activation recovery intervals (ARIs), a surrogate for action potential duration, and local ARI gradients were calculated from unipolar electrograms within areas of late gadolinium enhancement (aLGE) and healthy myocardium. Results There was no significant difference between aLGE and healthy myocardium in mean ARI (304.20 ± 19.44 ms vs 300.59 ± 19.22 ms; P = .43), ARI heterogeneity (23.32 ± 11.43 ms vs 24.85 ± 12.99 ms; P = .54), or ARI gradients (6.18 ± 2.09 vs 5.66 ± 2.32 ms/mm; P = .39). Endocardial pacing distance from scar did not affect ARI gradients. Conclusion Our findings suggest that changes in ARI are not an intrinsic property of surviving myocytes within scar, and endocardial pacing close to scar does not affect local repolarization.
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Affiliation(s)
- Mark K Elliott
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Caroline Mendonca Costa
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - John Whitaker
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Philip Gemmell
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Vishal S Mehta
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Baldeep S Sidhu
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Justin Gould
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Steven E Williams
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Mark O'Neill
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Reza Razavi
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Steven Niederer
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Martin J Bishop
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Christopher A Rinaldi
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Department of Cardiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
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21
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Aras K, Gams A, Faye R, Brennan J, Goldrick K, Li J, Zhong Y, Chiang CH, Smith EH, Poston MD, Chivers J, Hanna P, Mori S, Ajijola OA, Shivkumar K, Hoover DB, Viventi J, Rogers JA, Bernus O, Efimov IR. Electrophysiology and Arrhythmogenesis in the Human Right Ventricular Outflow Tract. Circ Arrhythm Electrophysiol 2022; 15:e010630. [PMID: 35238622 PMCID: PMC9052172 DOI: 10.1161/circep.121.010630] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 02/17/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Right ventricular outflow tract (RVOT) is a common source of ventricular tachycardia, which often requires ablation. However, the mechanisms underlying the RVOT's unique arrhythmia susceptibility remain poorly understood due to lack of detailed electrophysiological and molecular studies of the human RVOT. METHODS We conducted optical mapping studies in 16 nondiseased donor human RVOT preparations subjected to pharmacologically induced adrenergic and cholinergic stimulation to evaluate susceptibility to arrhythmias and characterize arrhythmia dynamics. RESULTS We found that under control conditions, RVOT has shorter action potential duration at 80% repolarization relative to the right ventricular apical region. Treatment with isoproterenol (100 nM) shortened action potential duration at 80% repolarization and increased incidence of premature ventricular contractions (P=0.003), whereas acetylcholine (100 μM) stimulation alone had no effect on action potential duration at 80% repolarization or premature ventricular contractions. However, acetylcholine treatment after isoproterenol stimulation reduced the incidence of premature ventricular contractions (P=0.034) and partially reversed action potential duration at 80% repolarization shortening (P=0.029). Immunolabeling of RVOT (n=4) confirmed the presence of cholinergic marker VAChT (vesicular acetylcholine transporter) in the region. Rapid pacing revealed RVOT susceptibility to both concordant and discordant alternans. Investigation into transmural arrhythmia dynamics showed that arrhythmia wave fronts and phase singularities (rotors) were relatively more organized in the endocardium than in the epicardium (P=0.006). Moreover, there was a weak but positive spatiotemporal autocorrelation between epicardial and endocardial arrhythmic wave fronts and rotors. Transcriptome analysis (n=10 hearts) suggests a trend that MAPK (mitogen-activated protein kinase) signaling, calcium signaling, and cGMP-PKG (protein kinase G) signaling are among the pathways that may be enriched in the male RVOT, whereas pathways of neurodegeneration may be enriched in the female RVOT. CONCLUSIONS Human RVOT electrophysiology is characterized by shorter action potential duration relative to the right ventricular apical region. Cholinergic right ventricular stimulation attenuates the arrhythmogenic effects of adrenergic stimulation, including increase in frequency of premature ventricular contractions and shortening of wavelength. Right ventricular arrhythmia is characterized by positive spatial-temporal autocorrelation between epicardial-endocardial arrhythmic wave fronts and rotors that are relatively more organized in the endocardium.
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Affiliation(s)
- Kedar Aras
- Department of Biomedical Engineering, the George Washington University, Washington, DC
- Department of Materials Science and Engineering, Ohio State University, Columbus, OH
| | - Anna Gams
- Department of Biomedical Engineering, the George Washington University, Washington, DC
| | - Rokhaya Faye
- Department of Biomedical Engineering, the George Washington University, Washington, DC
- LIRYC Institute, Bordeaux University, France
| | - Jaclyn Brennan
- Department of Biomedical Engineering, the George Washington University, Washington, DC
| | - Katherine Goldrick
- Department of Biomedical Engineering, the George Washington University, Washington, DC
| | - Jinghua Li
- Department of Biomedical Engineering, Northwestern University, Evanston, IL
- Department of Materials Science and Engineering, Ohio State University, Columbus, OH
| | - Yishan Zhong
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, IL
| | - Chia-Han Chiang
- Department of Biomedical Engineering, Duke University, Durham, NC
| | - Elizabeth H. Smith
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN
| | - Megan D. Poston
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN
| | - Jacqueline Chivers
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN
| | - Peter Hanna
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA
| | - Shumpei Mori
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA
| | - Olujimi A. Ajijola
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA
| | - Donald B. Hoover
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN
| | - Jonathan Viventi
- Department of Biomedical Engineering, Duke University, Durham, NC
| | - John A. Rogers
- Department of Biomedical Engineering, Northwestern University, Evanston, IL
| | | | - Igor R. Efimov
- Department of Biomedical Engineering, the George Washington University, Washington, DC
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22
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Vaykshnorayte MA, Vityazev VA, Azarov JE. Seasonal changes of electrophysiological heterogeneities in the rainbow trout ventricular myocardium. Curr Res Physiol 2022; 5:93-98. [PMID: 35198999 PMCID: PMC8844795 DOI: 10.1016/j.crphys.2022.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 01/09/2022] [Accepted: 02/04/2022] [Indexed: 11/28/2022] Open
Abstract
Introduction Thermal adaptation in fish is accompanied by morphological and electrophysiological changes in the myocardium. Little is known regarding seasonal changes of spatiotemporal organization of ventricular excitation and repolarization processes. We aimed to evaluate transmural and apicobasal heterogeneity of depolarization and repolarization characteristics in the rainbow trout in-situ ventricular myocardium in summer and winter conditions. Methods The experiments were done in summer-acclimatized (SA, 18°C, n = 8) and winter-acclimatized (WA, 3°C, n = 8) rainbow trout (Oncorhynchus mykiss). 24 unipolar electrograms were recorded with 3 plunge needle electrodes (eight lead terminals each) impaled into the ventricular wall. Activation time (AT), end of repolarization time (RT), and activation-repolarization interval (ARI, a surrogate for action potential duration) were determined as dV/dt min during QRS-complex, dV/dt max during T-wave, and RT-AT difference, respectively. Results The SA fish demonstrated relatively flat apicobasal and transmural AT and ARI profiles. In the WA animals, ATs and ARIs were longer as compared to SA animals (p≤0.001), ARIs were shorter in the compact layer than in the spongy layer (p≤0.050), and within the compact layer, the apical region had shorter ATs and longer ARIs as compared to the basal region (p≤0.050). In multiple linear regression analysis, ARI duration was associated with RR-interval and AT in SA and WA animals. The WA animals additionally demonstrated an independent association of ARIs with spatial localization across the ventricle. Conclusion Cold conditions led to the spatial redistribution of repolarization durations in the rainbow trout ventricle and the formation of repolarization gradients typically observed in mammalian myocardium. Spatiotemporal electrophysiological pattern is essential for cardiac function. A role of this pattern is unclear, specifically in seasonal changes in fish. Transmural repolarization gradients develop in cold conditions in rainbow trout.
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23
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Cluitmans M, Coll-Font J, Erem B, Bear L, Nguyên UC, Ter Bekke R, Volders PGA, Brooks D. Spatiotemporal approximation of cardiac activation and recovery isochrones. J Electrocardiol 2021; 71:1-9. [PMID: 34979408 DOI: 10.1016/j.jelectrocard.2021.12.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 12/15/2021] [Accepted: 12/21/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND The sequence of myocardial activation and recovery can be studied in detail by invasive catheter recordings of cardiac electrograms (EGMs), or noninvasive inverse reconstructions thereof with electrocardiographic imaging (ECGI). Local activation and recovery times are obtained from a unipolar EGM by the moment of maximum downslope of the QRS complex or maximum upslope of the T wave, respectively. However, both invasive and noninvasive recordings of intracardiac EGMs may suffer from noise and fractionation, making reliable detection of these deflections nontrivial. METHODS Here, we introduce a novel method that benefits from the spatial coupling of these processes, and incorporate not only the temporal EGM deflection, but also the spatial gradients. We validated this approach in computer simulations, in animal data with ECGI and invasive electrode recordings, and illustrated its use in a clinical case. RESULTS In the simulated data, the spatiotemporal approach was able to incorporate spatial information to better select the correct deflection in artificially fractionated EGMs and outperformed the traditional temporal-only method. In experimental data, the accuracy of time estimation from ECGI compared to invasive recordings significantly increased from R = 0.73 (activation) and R = 0.58 (recovery) with the temporal-only method to R = 0.79 (activation) and R = 0.72 (recovery) with the novel approach. Localization of the pacing origin of paced beats improved significantly from 36 mm mean error with the temporal-only approach to 23 mm with the spatiotemporal approach. CONCLUSION The spatiotemporal method to compute activation and recovery times from EGMs outperformed the traditional temporal-only approach in which spatial information was not taken into account.
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Affiliation(s)
- Matthijs Cluitmans
- Cardiovascular Research Institute Maastricht, Maastricht University, the Netherlands.
| | - Jaume Coll-Font
- Computational Radiology Laboratory, Boston Children's Hospital, Boston, MA, USA
| | | | | | - Uyên Châu Nguyên
- Cardiovascular Research Institute Maastricht, Maastricht University, the Netherlands
| | - Rachel Ter Bekke
- Cardiovascular Research Institute Maastricht, Maastricht University, the Netherlands
| | - Paul G A Volders
- Cardiovascular Research Institute Maastricht, Maastricht University, the Netherlands
| | - Dana Brooks
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA, USA
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24
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van der Waal JG, Meijborg VMF, Belterman CNW, Streekstra GJ, Oostendorp TF, Coronel R. Ex vivo Validation of Noninvasive Epicardial and Endocardial Repolarization Mapping. Front Physiol 2021; 12:737609. [PMID: 34744778 PMCID: PMC8569864 DOI: 10.3389/fphys.2021.737609] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 09/21/2021] [Indexed: 11/17/2022] Open
Abstract
Background: The detection and localization of electrophysiological substrates currently involve invasive cardiac mapping. Electrocardiographic imaging (ECGI) using the equivalent dipole layer (EDL) method allows the noninvasive estimation of endocardial and epicardial activation and repolarization times (AT and RT), but the RT validation is limited to in silico studies. We aimed to assess the temporal and spatial accuracy of the EDL method in reconstructing the RTs from the surface ECG under physiological circumstances and situations with artificially induced increased repolarization heterogeneity. Methods: In four Langendorff-perfused pig hearts, we simultaneously recorded unipolar electrograms from plunge needles and pseudo-ECGs from a volume-conducting container equipped with 61 electrodes. The RTs were computed from the ECGs during atrial and ventricular pacing and compared with those measured from the local unipolar electrograms. Regional RT prolongation (cooling) or shortening (pinacidil) was achieved by selective perfusion of the left anterior descending artery (LAD) region. Results: The differences between the computed and measured RTs were 19.0 ± 17.8 and 18.6 ± 13.7 ms for atrial and ventricular paced beats, respectively. The region of artificially delayed or shortened repolarization was correctly identified, with minimum/maximum RT roughly in the center of the region in three hearts. In one heart, the reconstructed region was shifted by ~2.5 cm. The total absolute difference between the measured and calculated RTs for all analyzed patterns in selectively perfused hearts (n = 5) was 39.6 ± 27.1 ms. Conclusion: The noninvasive ECG repolarization imaging using the EDL method of atrial and ventricular paced beats allows adequate quantitative reconstruction of regions of altered repolarization.
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Affiliation(s)
- Jeanne G van der Waal
- Department of Experimental and Clinical Cardiology, Amsterdam University Medical Centers, Location Academic Medical Center, Amsterdam, Netherlands
| | - Veronique M F Meijborg
- Department of Experimental and Clinical Cardiology, Amsterdam University Medical Centers, Location Academic Medical Center, Amsterdam, Netherlands
| | - Charly N W Belterman
- Department of Experimental and Clinical Cardiology, Amsterdam University Medical Centers, Location Academic Medical Center, Amsterdam, Netherlands
| | - Geert J Streekstra
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Centers, Location Academic Medical Center, Amsterdam, Netherlands
| | - Thom F Oostendorp
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Ruben Coronel
- Department of Experimental and Clinical Cardiology, Amsterdam University Medical Centers, Location Academic Medical Center, Amsterdam, Netherlands.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France
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25
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Mechanism of the Effects of Sodium Channel Blockade on the Arrhythmogenic Substrate of Brugada Syndrome. Heart Rhythm 2021; 19:407-416. [PMID: 34742919 DOI: 10.1016/j.hrthm.2021.10.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND The mechanisms by which sodium channel blockade and high-rate pacing modify electrogram substrates of Brugada syndrome (BrS) have not been elucidated. OBJECTIVES To determine the effect of ajmaline and high pacing rate on the BrS substrates. METHODS Thirty-two BrS patients (age 40 ± 12 years) with frequent ventricular fibrillation (VF) episodes underwent right ventricular outflow tract (RVOT) substrate electroanatomical and electrocardiogram imaging (ECGI) mapping before and after ajmaline administration and during high-rate atrial pacing. In 4 patients, epicardial mapping was performed using open thoracotomy with targeted biopsies. RESULTS Ajmaline increased the activation time delay in the substrate (33%; p = 0.002), ST elevation in the right precordial leads (74%; p < 0.0001), and the area of delayed activation (170%; p < 0.0001), coinciding with increased substrate size (75%; p < 0.0001). High atrial pacing rate increased the abnormal electrogram (EGM) duration at the RVOT areas from 112 ± 48 to 143 ± 66 ms (p = 0.003) and produced intermittent conduction block and/or excitation failure at the substrate sites, especially after ajmaline. Biopsies from the 4 patients with thoracotomy showed epicardial fibrosis where EGMs were normal at baseline but became fractionated after ajmaline. In some areas, local activation was absent and unipolar EGMs had a monophasic morphology resembling the shape of the action potential. CONCLUSIONS INa reduction with ajmaline severely compromises impulse conduction at the BrS fibrotic substrates by producing fractionated EGMs, conduction block, or excitation failure, leading to the Brugada ECG pattern and favoring VF genesis.
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26
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Tajarenejad H, Ansari MA, Akbari S, Yazdanfar H, Hamidi SM. Optical neural stimulation using the thermoplasmonic effect of gold nano-hexagon. BIOMEDICAL OPTICS EXPRESS 2021; 12:6013-6023. [PMID: 34745718 PMCID: PMC8548018 DOI: 10.1364/boe.438593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/23/2021] [Accepted: 08/26/2021] [Indexed: 06/13/2023]
Abstract
The use of nanoparticle photothermal effect as adjuvants in neuromodulation has recently received much attention, with many open questions about new nanostructures' effect on the action potential. The photothermal properties of hexagonal gold nanoparticles are investigated in this work, including the absorption peak wavelength and light-heat conversion rate, using both experimental and simulation methods. Furthermore, the ability to use these nanostructures in axonal neural stimulation and cardiac stimulation by measuring temperature changes of gold nano-hexagons under 532 nm laser irradiation is studied. In addition, their thermal effect on neural responses is investigated by modeling small-diameter unmyelinated axons and heart pacemaker cells. The results show that the increase in temperature caused by these nano-hexagons can successfully stimulate the small diameter axon and produce an action potential. Experiments have also demonstrated that the heat created by gold nano-hexagons affects toad cardiac rhythm and increases T wave amplitude. An increase in T wave amplitude on toad heart rhythm shows the thermal effect of nano hexagons heat on heart pacemaker cells and intracellular ion flows. This work demonstrates the feasibility of utilizing these nanostructures to create portable and compact medical devices, such as optical pacemakers or cardiac stimulation.
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27
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Excitation and Contraction of the Failing Human Heart In Situ and Effects of Cardiac Resynchronization Therapy: Application of Electrocardiographic Imaging and Speckle Tracking Echo-Cardiography. HEARTS 2021. [DOI: 10.3390/hearts2030027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Despite the success of cardiac resynchronization therapy (CRT) for treating heart failure (HF), the rate of nonresponders remains 30%. Improvements to CRT require understanding of reverse remodeling and the relationship between electrical and mechanical measures of synchrony. The objective was to utilize electrocardiographic imaging (ECGI, a method for noninvasive cardiac electrophysiology mapping) and speckle tracking echocardiography (STE) to study the physiology of HF and reverse remodeling induced by CRT. We imaged 30 patients (63% male, mean age 63.7 years) longitudinally using ECGI and STE. We quantified CRT-induced remodeling of electromechanical parameters and evaluated a novel index, the electromechanical delay (EMD, the delay from activation to peak contraction). We also measured dyssynchrony using ECGI and STE and compared their effectiveness for predicting response to CRT. EMD values were elevated in HF patients compared to controls. However, the EMD values were dependent on the activation sequence (CRT-paced vs. un-paced), indicating that the EMD is not intrinsic to the local tissue, but is influenced by factors such as opposing wall contractions. After 6 months of CRT, patients had increased contraction in native rhythm compared to baseline pre-CRT (baseline: −8.55%, 6 months: −10.14%, p = 0.008). They also had prolonged repolarization at the location of the LV pacing lead. The pre-CRT delay between mean lateral LV and RV electrical activation time was the best predictor of beneficial reduction in LV end systolic volume by CRT (Spearman’s Rho: −0.722, p < 0.001); it outperformed mechanical indices and 12-lead ECG criteria. HF patients have abnormal EMD. The EMD depends upon the activation sequence and is not predictive of response to CRT. ECGI-measured LV activation delay is an effective index for CRT patient selection. CRT causes persistent improvements in contractile function.
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28
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Aronis KN, Prakosa A, Bergamaschi T, Berger RD, Boyle PM, Chrispin J, Ju S, Marine JE, Sinha S, Tandri H, Ashikaga H, Trayanova NA. Characterization of the Electrophysiologic Remodeling of Patients With Ischemic Cardiomyopathy by Clinical Measurements and Computer Simulations Coupled With Machine Learning. Front Physiol 2021; 12:684149. [PMID: 34335294 PMCID: PMC8317643 DOI: 10.3389/fphys.2021.684149] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 06/22/2021] [Indexed: 11/13/2022] Open
Abstract
Rationale Patients with ischemic cardiomyopathy (ICMP) are at high risk for malignant arrhythmias, largely due to electrophysiological remodeling of the non-infarcted myocardium. The electrophysiological properties of the non-infarcted myocardium of patients with ICMP remain largely unknown. Objectives To assess the pro-arrhythmic behavior of non-infarcted myocardium in ICMP patients and couple computational simulations with machine learning to establish a methodology for the development of disease-specific action potential models based on clinically measured action potential duration restitution (APDR) data. Methods and Results We enrolled 22 patients undergoing left-sided ablation (10 ICMP) and compared APDRs between ICMP and structurally normal left ventricles (SNLVs). APDRs were clinically assessed with a decremental pacing protocol. Using genetic algorithms (GAs), we constructed populations of action potential models that incorporate the cohort-specific APDRs. The variability in the populations of ICMP and SNLV models was captured by clustering models based on their similarity using unsupervised machine learning. The pro-arrhythmic potential of ICMP and SNLV models was assessed in cell- and tissue-level simulations. Clinical measurements established that ICMP patients have a steeper APDR slope compared to SNLV (by 38%, p < 0.01). In cell-level simulations, APD alternans were induced in ICMP models at a longer cycle length compared to SNLV models (385–400 vs 355 ms). In tissue-level simulations, ICMP models were more susceptible for sustained functional re-entry compared to SNLV models. Conclusion Myocardial remodeling in ICMP patients is manifested as a steeper APDR compared to SNLV, which underlies the greater arrhythmogenic propensity in these patients, as demonstrated by cell- and tissue-level simulations using action potential models developed by GAs from clinical measurements. The methodology presented here captures the uncertainty inherent to GAs model development and provides a blueprint for use in future studies aimed at evaluating electrophysiological remodeling resulting from other cardiac diseases.
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Affiliation(s)
- Konstantinos N Aronis
- Section of Electrophysiology, Division of Cardiology, Johns Hopkins Hospital, Baltimore, MD, United States.,Department of Biomedical Engineering, The Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Adityo Prakosa
- Department of Biomedical Engineering, The Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Teya Bergamaschi
- Department of Biomedical Engineering, The Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Ronald D Berger
- Section of Electrophysiology, Division of Cardiology, Johns Hopkins Hospital, Baltimore, MD, United States
| | - Patrick M Boyle
- Department of Biomedical Engineering, The Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Jonathan Chrispin
- Section of Electrophysiology, Division of Cardiology, Johns Hopkins Hospital, Baltimore, MD, United States
| | - Suyeon Ju
- Department of Biomedical Engineering, The Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Joseph E Marine
- Section of Electrophysiology, Division of Cardiology, Johns Hopkins Hospital, Baltimore, MD, United States
| | - Sunil Sinha
- Section of Electrophysiology, Division of Cardiology, Johns Hopkins Hospital, Baltimore, MD, United States
| | - Harikrishna Tandri
- Section of Electrophysiology, Division of Cardiology, Johns Hopkins Hospital, Baltimore, MD, United States
| | - Hiroshi Ashikaga
- Section of Electrophysiology, Division of Cardiology, Johns Hopkins Hospital, Baltimore, MD, United States
| | - Natalia A Trayanova
- Section of Electrophysiology, Division of Cardiology, Johns Hopkins Hospital, Baltimore, MD, United States.,Department of Biomedical Engineering, The Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, United States
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29
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Srinivasan NT, Garcia J, Schilling RJ, Ahsan S, Hunter RJ, Lowe M, Chow AW, Lambiase PD. Dynamic spatial dispersion of repolarization is present in regions critical for ischemic ventricular tachycardia ablation. Heart Rhythm O2 2021; 2:280-289. [PMID: 34337579 PMCID: PMC8322930 DOI: 10.1016/j.hroo.2021.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The presence of dynamic substrate changes may facilitate functional block and reentry in ventricular tachycardia (VT). OBJECTIVE We aimed to study dynamic ventricular repolarization changes in critical regions of the VT circuit during sensed single extrastimulus pacing known as the Sense Protocol (SP). METHODS Twenty patients (aged 67 ± 9 years, 17 male) underwent VT ablation. A bipolar voltage map was obtained during sinus rhythm (SR) and right ventricular SP pacing at 20 ms above ventricular effective refractory period. Ventricular repolarization maps were constructed. Ventricular repolarization time (RT) was calculated from unipolar electrogram T waves, using the Wyatt method, as the dV/dtmax of the unipolar T wave. Entrainment or pace mapping confirmed critical sites for ablation. RESULTS The median global repolarization range (max-min RT per patient) was 166 ms (interquartile range [IQR] 143-181 ms) during SR mapping vs 208 ms (IQR 182-234) during SP mapping (P = .0003 vs intrinsic rhythm). Regions of late potentials (LP) had a longer RT during SP mapping compared to regions without LP (mean 394 ± 40 ms vs 342 ± 25 ms, P < .001). In paired regions of normal myocardium there was no significant spatial dispersion of repolarization (SDR)/10 mm2 during SP mapping vs SR mapping (SDR 11 ± 6 ms vs 10 ± 6 ms, P = .54). SDR/10 mm2 was greater in critical areas of the VT circuit during SP mapping 63 ± 29 ms vs SR mapping 16 ± 9 ms (P < .001). CONCLUSION Ventricular repolarization is prolonged in regions of LP and increases dynamically, resulting in dynamic SDR in critical areas of the VT circuit. These dynamic substrate changes may be an important factor that facilitates VT circuits.
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Affiliation(s)
- Neil T. Srinivasan
- Department of Cardiac Electrophysiology, The Essex Cardiothoracic Centre, Basildon, Essex, United Kingdom
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew’s Hospital, London, United Kingdom
- Institute of Cardiovascular Science, University College London, London, United Kingdom
- Circulatory Health Research Group, Medical Technology Research Centre, School of Medicine, Anglia Ruskin University, Essex, United Kingdom
| | - Jason Garcia
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew’s Hospital, London, United Kingdom
| | - Richard J. Schilling
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew’s Hospital, London, United Kingdom
| | - Syed Ahsan
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew’s Hospital, London, United Kingdom
| | - Ross J. Hunter
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew’s Hospital, London, United Kingdom
| | - Martin Lowe
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew’s Hospital, London, United Kingdom
| | - Anthony W. Chow
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew’s Hospital, London, United Kingdom
| | - Pier D. Lambiase
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew’s Hospital, London, United Kingdom
- Institute of Cardiovascular Science, University College London, London, United Kingdom
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30
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Taggart P, Pueyo E, Duijvenboden SV, Porter B, Bishop M, Sampedro-Puente DA, Orini M, Hanson B, Rinaldi CA, Gill JS, Lambiase P. Emerging evidence for a mechanistic link between low-frequency oscillation of ventricular repolarization measured from the electrocardiogram T-wave vector and arrhythmia. Europace 2021; 23:1350-1358. [PMID: 33880542 PMCID: PMC8427352 DOI: 10.1093/europace/euab009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Indexed: 11/17/2022] Open
Abstract
Strong recent clinical evidence links the presence of prominent oscillations of ventricular repolarization in the low-frequency range (0.04–0.15 Hz) to the incidence of ventricular arrhythmia and sudden death in post-MI patients and patients with ischaemic and non-ischaemic cardiomyopathy. It has been proposed that these oscillations reflect oscillations of ventricular action potential duration at the sympathetic nerve frequency. Here we review emerging evidence to support that contention and provide insight into possible underlying mechanisms for this association.
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Affiliation(s)
- Peter Taggart
- Department of Cardiovascular Sciences, University College London, London, UK
| | - Esther Pueyo
- BSICOS Group, 13A, 11S, Aragon, University of Zaragoza, Spain.,CIBER-BBN, Zaragoza, Spain
| | | | - Bradley Porter
- Department of Imaging Sciences and Biomedical Engineering, KCL, London, UK
| | - Martin Bishop
- Department of Imaging Sciences and Biomedical Engineering, KCL, London, UK
| | | | - M Orini
- Department of Cardiovascular Sciences, University College London, London, UK
| | - B Hanson
- UCL Mechanical Engineering, University College London, London, UK
| | | | | | - Pier Lambiase
- Department of Cardiovascular Sciences, University College London, London, UK
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31
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Langfield P, Feng Y, Bear LR, Duchateau J, Sebastian R, Abell E, Dubois R, Labrousse L, Rogier J, Hocini M, Haissaguerre M, Vigmond E. A novel method to correct repolarization time estimation from unipolar electrograms distorted by standard filtering. Med Image Anal 2021; 72:102075. [PMID: 34020081 DOI: 10.1016/j.media.2021.102075] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 03/30/2021] [Accepted: 04/02/2021] [Indexed: 11/30/2022]
Abstract
Reliable patient-specific ventricular repolarization times (RTs) can identify regions of functional block or afterdepolarizations, indicating arrhythmogenic cardiac tissue and the risk of sudden cardiac death. Unipolar electrograms (UEs) record electric potentials, and the Wyatt method has been shown to be accurate for estimating RT from a UE. High-pass filtering is an important step in processing UEs, however, it is known to distort the T-wave phase of the UE, which may compromise the accuracy of the Wyatt method. The aim of this study was to examine the effects of high-pass filtering, and improve RT estimates derived from filtered UEs. We first generated a comprehensive set of UEs, corresponding to early and late activation and repolarization, that were then high-pass filtered with settings that mimicked the CARTO filter. We trained a deep neural network (DNN) to output a probabilistic estimation of RT and a measure of confidence, using the filtered synthetic UEs and their true RTs. Unfiltered ex-vivo human UEs were also filtered and the trained DNN used to estimate RT. Even a modest 2 Hz high-pass filter imposes a significant error on RT estimation using the Wyatt method. The DNN outperformed the Wyatt method in 62.75% of cases, and produced a significantly lower absolute error (p=8.99E-13), with a median of 16.91 ms, on 102 ex-vivo UEs. We also applied the DNN to patient UEs from CARTO, from which an RT map was computed. In conclusion, DNNs trained on synthetic UEs improve the RT estimation from filtered UEs, which leads to more reliable repolarization maps that help to identify patient-specific repolarization abnormalities.
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Affiliation(s)
- Peter Langfield
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France; Univ. Bordeaux, IMB UMR 5251, Talence F-33400, France.
| | - Yingjing Feng
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France; Univ. Bordeaux, IMB UMR 5251, Talence F-33400, France.
| | - Laura R Bear
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France
| | - Josselin Duchateau
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France; Bordeaux University Hospital (CHU), Cardiac Electrophysiology and Cardiac Stimulation Team, Pessac, France
| | - Rafael Sebastian
- CoMMLab, Dept. Computer Sciences, Universitat de Valencia, Valencia, Spain
| | - Emma Abell
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France
| | - Remi Dubois
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France
| | - Louis Labrousse
- Bordeaux University Hospital (CHU), Cardiac Electrophysiology and Cardiac Stimulation Team, Pessac, France
| | - Julien Rogier
- Bordeaux University Hospital (CHU), Cardiac Electrophysiology and Cardiac Stimulation Team, Pessac, France
| | - Meleze Hocini
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France; Bordeaux University Hospital (CHU), Cardiac Electrophysiology and Cardiac Stimulation Team, Pessac, France
| | - Michel Haissaguerre
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France; Bordeaux University Hospital (CHU), Cardiac Electrophysiology and Cardiac Stimulation Team, Pessac, France
| | - Edward Vigmond
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France; Univ. Bordeaux, IMB UMR 5251, Talence F-33400, France
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32
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Campos FO, Orini M, Arnold R, Whitaker J, O'Neill M, Razavi R, Plank G, Hanson B, Porter B, Rinaldi CA, Gill J, Lambiase PD, Taggart P, Bishop MJ. Assessing the ability of substrate mapping techniques to guide ventricular tachycardia ablation using computational modelling. Comput Biol Med 2021; 130:104214. [PMID: 33476992 DOI: 10.1016/j.compbiomed.2021.104214] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 01/05/2021] [Accepted: 01/05/2021] [Indexed: 01/19/2023]
Abstract
BACKGROUND Identification of targets for ablation of post-infarction ventricular tachycardias (VTs) remains challenging, often requiring arrhythmia induction to delineate the reentrant circuit. This carries a risk for the patient and may not be feasible. Substrate mapping has emerged as a safer strategy to uncover arrhythmogenic regions. However, VT recurrence remains common. GOAL To use computer simulations to assess the ability of different substrate mapping approaches to identify VT exit sites. METHODS A 3D computational model of the porcine post-infarction heart was constructed to simulate VT and paced rhythm. Electroanatomical maps were constructed based on endocardial electrogram features and the reentry vulnerability index (RVI - a metric combining activation (AT) and repolarization timings to identify tissue susceptibility to reentry). Since scar transmurality in our model was not homogeneous, parameters derived from all signals (including dense scar regions) were used in the analysis. Potential ablation targets obtained from each electroanatomical map during pacing were compared to the exit site detected during VT mapping. RESULTS Simulation data showed that voltage cut-offs applied to bipolar electrograms could delineate the scar, but not the VT circuit. Electrogram fractionation had the highest correlation with scar transmurality. The RVI identified regions closest to VT exit site but was outperformed by AT gradients combined with voltage cut-offs. The performance of all metrics was affected by pacing location. CONCLUSIONS Substrate mapping could provide information about the infarct, but the directional dependency on activation should be considered. Activation-repolarization metrics have utility in safely identifying VT targets, even with non-transmural scars.
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Affiliation(s)
- Fernando O Campos
- School of Biomedical Engineering and Imaging Sciences, Rayne Institute, 4th Floor, Lambeth Wing, St. Thomas' Hospital, Westminster Bridge Road, London, SE1 7EH, United Kingdom.
| | - Michele Orini
- Institute of Cardiovascular Science, University College London, London, United Kingdom; Electrophysiology Department, Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom
| | - Robert Arnold
- Gottfried Schatz Research Center (for Cell Signaling, Metabolism and Aging), Division of Biophysics, Graz, Austria
| | - John Whitaker
- School of Biomedical Engineering and Imaging Sciences, Rayne Institute, 4th Floor, Lambeth Wing, St. Thomas' Hospital, Westminster Bridge Road, London, SE1 7EH, United Kingdom
| | - Mark O'Neill
- School of Biomedical Engineering and Imaging Sciences, Rayne Institute, 4th Floor, Lambeth Wing, St. Thomas' Hospital, Westminster Bridge Road, London, SE1 7EH, United Kingdom
| | - Reza Razavi
- School of Biomedical Engineering and Imaging Sciences, Rayne Institute, 4th Floor, Lambeth Wing, St. Thomas' Hospital, Westminster Bridge Road, London, SE1 7EH, United Kingdom
| | - Gernot Plank
- Gottfried Schatz Research Center (for Cell Signaling, Metabolism and Aging), Division of Biophysics, Graz, Austria
| | - Ben Hanson
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Bradley Porter
- School of Biomedical Engineering and Imaging Sciences, Rayne Institute, 4th Floor, Lambeth Wing, St. Thomas' Hospital, Westminster Bridge Road, London, SE1 7EH, United Kingdom; Department of Cardiology, Guys and St Thomas' NHS Trust, London, United Kingdom
| | | | - Jaswinder Gill
- School of Biomedical Engineering and Imaging Sciences, Rayne Institute, 4th Floor, Lambeth Wing, St. Thomas' Hospital, Westminster Bridge Road, London, SE1 7EH, United Kingdom; Department of Cardiology, Guys and St Thomas' NHS Trust, London, United Kingdom
| | - Pier D Lambiase
- Institute of Cardiovascular Science, University College London, London, United Kingdom; Electrophysiology Department, Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom
| | - Peter Taggart
- Institute of Cardiovascular Science, University College London, London, United Kingdom; Electrophysiology Department, Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom
| | - Martin J Bishop
- School of Biomedical Engineering and Imaging Sciences, Rayne Institute, 4th Floor, Lambeth Wing, St. Thomas' Hospital, Westminster Bridge Road, London, SE1 7EH, United Kingdom
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33
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Orini M, Yanni J, Taggart P, Hanson B, Hayward M, Smith A, Zhang H, Colman M, Jones G, Jie X, Dobrzynski H, Boyett MR, Lambiase PD. Mechanistic insights from targeted molecular profiling of repolarization alternans in the intact human heart. Europace 2020; 21:981-989. [PMID: 30753421 PMCID: PMC6545501 DOI: 10.1093/europace/euz007] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 10/17/2018] [Accepted: 01/21/2019] [Indexed: 02/05/2023] Open
Abstract
AIMS Action potential duration (APD) alternans is an established precursor or arrhythmia and sudden cardiac death. Important differences in fundamental electrophysiological properties relevant to arrhythmia exist between experimental models and the diseased in vivo human heart. To investigate mechanisms of APD alternans using a novel approach combining intact heart and cellular cardiac electrophysiology in human in vivo. METHODS AND RESULTS We developed a novel approach combining intact heart electrophysiological mapping during cardiac surgery with rapid on-site data analysis to guide myocardial biopsies for laboratory analysis, thereby linking repolarization dynamics observed at the organ level with underlying ion channel expression. Alternans-susceptible and alternans-resistant regions were identified by an incremental pacing protocol. Biopsies from these sites (n = 13) demonstrated greater RNA expression in Calsequestrin (CSQN) and Ryanodine (RyR) and ion channels underlying IK1 and Ito at alternans-susceptible sites. Electrical restitution properties (n = 7) showed no difference between alternans-susceptible and resistant sites, whereas spatial gradients of repolarization were greater in alternans-susceptible than in alternans-resistant sites (P = 0.001). The degree of histological fibrosis between alternans-susceptible and resistant sites was equivalent. Mathematical modelling of these changes indicated that both CSQN and RyR up-regulation are key determinants of APD alternans. CONCLUSION Combined intact heart and cellular electrophysiology show that regions of myocardium in the in vivo human heart exhibiting APD alternans are associated with greater expression of CSQN and RyR and show no difference in restitution properties compared to non-alternans regions. In silico modelling identifies up-regulation and interaction of CSQN with RyR as a major mechanism underlying APD alternans.
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Affiliation(s)
- Michele Orini
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Electrophysiology, Barts Heart Centre at St Bartholomew's Hospital, London, UK
| | - Joseph Yanni
- Division of Cardiovascular Science, University of Manchester, Manchester, UK
| | - Peter Taggart
- Institute of Cardiovascular Science, University College London, London, UK
| | - Ben Hanson
- Department of Mechanical Engineering, University College London, UK
| | - Martin Hayward
- Department of Cardiothoracic Surgery, The Heart Hospital, University College London Hospitals, London, UK
| | - Andrew Smith
- Department of Electrophysiology, Barts Heart Centre at St Bartholomew's Hospital, London, UK
| | - Henggui Zhang
- Division of Cardiovascular Science, University of Manchester, Manchester, UK.,School of Physics and Astronomy, University of Manchester, Manchester, UK
| | | | - Gareth Jones
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | - Xiao Jie
- Institute of Cardiovascular Science, University College London, London, UK
| | - Halina Dobrzynski
- Division of Cardiovascular Science, University of Manchester, Manchester, UK
| | - Mark R Boyett
- Division of Cardiovascular Science, University of Manchester, Manchester, UK
| | - Pier D Lambiase
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Electrophysiology, Barts Heart Centre at St Bartholomew's Hospital, London, UK
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34
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Srinivasan NT, Orini M, Providencia R, Dhinoja MB, Lowe MD, Ahsan SY, Chow AW, Hunter RJ, Schilling RJ, Taggart P, Lambiase PD. Prolonged action potential duration and dynamic transmural action potential duration heterogeneity underlie vulnerability to ventricular tachycardia in patients undergoing ventricular tachycardia ablation. Europace 2020; 21:616-625. [PMID: 30500897 PMCID: PMC6452309 DOI: 10.1093/europace/euy260] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 10/16/2018] [Indexed: 12/30/2022] Open
Abstract
Aims Differences of action potential duration (APD) in regions of myocardial scar and their borderzones are poorly defined in the intact human heart. Heterogeneities in APD may play an important role in the generation of ventricular tachycardia (VT) by creating regions of functional block. We aimed to investigate the transmural and planar differences of APD in patients admitted for VT ablation. Methods and results Six patients (median age 53 years, five male); (median ejection fraction 35%), were studied. Endocardial (Endo) and epicardial (Epi) 3D electroanatomic mapping was performed. A bipolar voltage of <0.5 mV was defined as dense scar, 0.5–1.5 mV as scar borderzone, and >1.5 mV as normal. Decapolar catheters were positioned transmurally across the scar borderzone to assess differences of APD and repolarization time (RT) during restitution pacing from Endo and Epi. Epi APD was 173 ms in normal tissue vs. 187 ms at scar borderzone and 210 ms in dense scar (P < 0.001). Endocardial APD was 210 ms in normal tissue vs. 222 ms in the scar borderzone and 238 ms in dense scar (P < 0.01). This resulted in significant transmural RT dispersion (ΔRT 22 ms across dense transmural scar vs. 5 ms in normal transmural tissue, P < 0.001), dependent on the scar characteristics in the Endo and Epi, and the pacing site. Conclusion Areas of myocardial scar have prolonged APD compared with normal tissue. Heterogeneity of regional transmural and planar APD result in localized dispersion of repolarization, which may play an important role in initiating VT.
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Affiliation(s)
- Neil T Srinivasan
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew's Hospital, West Smithfield, London, UK.,Institute of Cardiovascular Science, University College London, London, UK
| | - Michele Orini
- Institute of Cardiovascular Science, University College London, London, UK
| | - Rui Providencia
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew's Hospital, West Smithfield, London, UK
| | - Mehul B Dhinoja
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew's Hospital, West Smithfield, London, UK
| | - Martin D Lowe
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew's Hospital, West Smithfield, London, UK
| | - Syed Y Ahsan
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew's Hospital, West Smithfield, London, UK
| | - Anthony W Chow
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew's Hospital, West Smithfield, London, UK
| | - Ross J Hunter
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew's Hospital, West Smithfield, London, UK
| | - Richard J Schilling
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew's Hospital, West Smithfield, London, UK
| | - Peter Taggart
- Institute of Cardiovascular Science, University College London, London, UK
| | - Pier D Lambiase
- Department of Cardiac Electrophysiology, The Barts Heart Center, St Bartholomew's Hospital, West Smithfield, London, UK.,Institute of Cardiovascular Science, University College London, London, UK
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35
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Tsvetkova AS, Azarov JE, Bernikova OG, Ovechkin AO, Vaykshnorayte MA, Demidova MM, Platonov PG. Contribution of Depolarization and Repolarization Changes to J-Wave Generation and Ventricular Fibrillation in Ischemia. Front Physiol 2020; 11:568021. [PMID: 33101054 PMCID: PMC7556294 DOI: 10.3389/fphys.2020.568021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 09/14/2020] [Indexed: 01/11/2023] Open
Abstract
Background: Activation delay in ischemic myocardium has been found to contribute to J-wave appearance and to predict ventricular fibrillation (VF) in experimental myocardial infarction. However, the role of ischemia-related repolarization abnormalities in J-wave generation remains unclear. Objectives: The objective of our study was to assess a contribution of myocardial repolarization changes to J-wave generation in the body surface ECG and VF in a porcine acute myocardial infarction model. Methods: In 22 anesthetized pigs, myocardial ischemia was induced by occlusion of the left anterior descending coronary artery (LAD, n = 14) and right coronary artery (RCA, n = 8). Body surface ECGs were recorded simultaneously with intramyocardial unipolar electrograms led from flexible electrodes positioned across the left ventricular (LV) wall, interventricular septum (IVS), and right ventricular (RV) wall at apical, middle and basal levels of the ventricles (a total of 48 leads). Local activation times (ATs) and activation-repolarization intervals (ARIs, differences between dV/dt maximum during T-wave and dV/dt minimum during QRS) were measured. Results: J-waves appeared in left precordial leads (in 11 out of 14 animals with LAD occlusion) and right precordial leads (in six out of eight animals with RCA occlusion). During ischemic exposure, ATs prolonged, and the activation delay was associated with J-wave development (OR = 1.108 95% CI 1.072-1.144; p < 0.001) and VF incidence (OR = 1.039 95% CI 1.008-1.072; p = 0.015). ARIs shortened in the ischemic regions (in the IVS under LAD-occlusion and the lateral RV base under RCA-occlusion). The difference between maximal ARI in normal zones and ARI in the ischemic zones (ΔARI) was associated with J-wave appearance (OR = 1.025 95% CI 1.016-1.033, p < 0.001) independently of AT delay in multivariate logistic regression analysis. Conclusions: Both AT delay and increase of ΔARIs contributed to the development of J-wave in body surface ECG. However, only AT delay was associated with VF occurrence.
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Affiliation(s)
- Alena S Tsvetkova
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Jan E Azarov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia.,Department of Cardiology, Clinical Sciences, Lund University, Lund, Sweden.,Department of Biochemistry and Physiology, Institute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
| | - Olesya G Bernikova
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Alexey O Ovechkin
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia.,Department of Biochemistry and Physiology, Institute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
| | - Marina A Vaykshnorayte
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
| | - Marina M Demidova
- Department of Therapy, Institute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia.,V. A. Almazov National Medical Research Center, Saint Petersburg, Russia
| | - Pyotr G Platonov
- Department of Cardiology, Clinical Sciences, Lund University, Lund, Sweden.,Arrhythmia Clinic, Skåne University Hospital, Lund, Sweden
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36
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Smoczyńska A, Sprenkeler DJ, Aranda A, Beekman JDM, Bossu A, Dunnink A, Wijers SC, Stegemann B, Meine M, Vos MA. Evaluation of a Fully Automatic Measurement of Short-Term Variability of Repolarization on Intracardiac Electrograms in the Chronic Atrioventricular Block Dog. Front Physiol 2020; 11:1005. [PMID: 32973549 PMCID: PMC7472439 DOI: 10.3389/fphys.2020.01005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/23/2020] [Indexed: 11/29/2022] Open
Abstract
Background: Short-term variability (STV) of repolarization of the monophasic action potential duration (MAPD) or activation recovery interval (ARI) on the intracardiac electrogram (EGM) increases abruptly prior to the occurrence of ventricular arrhythmias in the chronic AV-block (CAVB) dog model. Therefore, this parameter might be suitable for continuous monitoring of imminent arrhythmias using the EGM stored on an implanted device. However, 24/7 monitoring would require automatic STVARI measurement by the device. Objective: To evaluate a newly developed automatic measurement of STVARI for prediction of dofetilide-induced torsade de pointes (TdP) arrhythmias in the CAVB-dog. Methods: Two retrospective analyses were done on data from recently performed dog experiments. (1) In seven anesthetized CAVB-dogs, the new automatic STVARI method was compared with the gold standard STVMAPD at baseline and after dofetilide administration (0.025 mg/kg in 5 min). (2) The predictive value of the automatic method was compared to currently used STVARI methods, i.e., slope method and fiducial segment averaging (FSA) method, in 11 inducible (≥3 TdP arrhythmias) and 10 non-inducible CAVB-dogs. Results: (1) The automatic measurement of STVARI had good correlation with STVMAPD (r2 = 0.89; p < 0.001). Bland-Altman analysis showed a small bias of 0.06 ms with limits of agreement between −0.63 and 0.76 ms. (2) STVARI of all three methods was significantly different between inducible and non-inducible dogs after dofetilide. The automatic method showed the highest predictive performance with an area under the ROC-curve of 0.93, compared to 0.85 and 0.87 of the slope and FSA methods, respectively. With a threshold of STV set at 1.69 ms, STVARI measured with the automatic method had a sensitivity of 0.91 and specificity of 0.90 in differentiating inducible from non-inducible subjects. Conclusion: We developed a fully-automatic method for measurement of STVARI on the intracardiac EGM that can accurately predict the occurrence of ventricular arrhythmias in the CAVB-dog. Future integration of this method into implantable devices could provide the opportunity for 24/7 monitoring of arrhythmic risk.
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Affiliation(s)
- Agnieszka Smoczyńska
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - David J Sprenkeler
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Alfonso Aranda
- Medtronic Bakken Research Center, Maastricht, Netherlands
| | - Jet D M Beekman
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Alexandre Bossu
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Albert Dunnink
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Sofieke C Wijers
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, Netherlands
| | | | - Mathias Meine
- Department of Cardiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Marc A Vos
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, Netherlands
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37
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Blok M, Boukens BJ. Mechanisms of Arrhythmias in the Brugada Syndrome. Int J Mol Sci 2020; 21:ijms21197051. [PMID: 32992720 PMCID: PMC7582368 DOI: 10.3390/ijms21197051] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/15/2020] [Accepted: 09/21/2020] [Indexed: 12/13/2022] Open
Abstract
Arrhythmias in Brugada syndrome patients originate in the right ventricular outflow tract (RVOT). Over the past few decades, the characterization of the unique anatomy and electrophysiology of the RVOT has revealed the arrhythmogenic nature of this region. However, the mechanisms that drive arrhythmias in Brugada syndrome patients remain debated as well as the exact site of their occurrence in the RVOT. Identifying the site of origin and mechanism of Brugada syndrome would greatly benefit the development of mechanism-driven treatment strategies.
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Affiliation(s)
- Michiel Blok
- Department of Medical Biology, Amsterdam University Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Bastiaan J. Boukens
- Department of Medical Biology, Amsterdam University Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
- Correspondence: ; Tel.: +31-(0)20-566-4659
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38
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Boukens BJ, Benjacholamas V, van Amersfoort S, Meijborg VM, Schumacher C, Jensen B, Haissaguerre M, Wilde A, Prechawat S, Huntrakul A, Nademanee K, Coronel R. Structurally Abnormal Myocardium Underlies Ventricular Fibrillation Storms in a Patient Diagnosed With the Early Repolarization Pattern. JACC Clin Electrophysiol 2020; 6:1395-1404. [PMID: 33121669 DOI: 10.1016/j.jacep.2020.06.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/12/2020] [Accepted: 06/16/2020] [Indexed: 01/23/2023]
Abstract
OBJECTIVES The aim of this study was to investigate the mechanism underlying QRS-slurring in a patient with the early repolarization pattern in the electrocardiogram (ECG) and ventricular fibrillation (VF) storms. BACKGROUND The early repolarization pattern refers to abnormal ending of the QRS complex in subjects with structurally normal hearts and has been associated with VF. METHODS We studied a patient with slurring of the QRS complex in leads II, III, and aVF of the ECG and recurrent episodes of VF. Echocardiographic and imaging studies did not reveal any abnormalities. Endocardial mapping was normal but subxyphoidal epicardial access was not possible. Open chest epicardial mapping was performed. RESULTS Mapping showed that the inferior right ventricular free wall activated the latest with local J-waves in unipolar electrograms. The last moment of epicardial activation concurred with QRS-slurring in the ECG whereas the J-waves in the local unipolar electrograms occurred in the ST-segment of the ECG. Myocardial biopsies obtained from the late activated tissue showed severe fibrofatty alterations in the inferior right ventricular wall where fractionation and local J-waves were present. After ablation, the early repolarization pattern in the ECG disappeared and arrhythmias have been absent since (follow-up 18 months). CONCLUSIONS In this patient, the electrocardiographic early repolarization pattern was caused by late activation due to structurally abnormal myocardium. The late activated areas were marked by J-waves in local electrograms. Ablation of these regions prevented arrhythmia recurrence and normalized the ECG.
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Affiliation(s)
- Bastiaan J Boukens
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam University Medical Centers, Amsterdam, the Netherlands; Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Vichai Benjacholamas
- Division of Cardiothoracic Surgery, Department of Surgery, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Shirley van Amersfoort
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Veronique M Meijborg
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Cees Schumacher
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Bjarke Jensen
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Michel Haissaguerre
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France
| | - Arthur Wilde
- Department of Cardiology, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Somchai Prechawat
- Division of Cardiovascular Medicine, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Anurut Huntrakul
- Division of Cardiovascular Medicine, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Koonlawee Nademanee
- Division of Cardiovascular Medicine, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Cardiac Center, King Chulalongkorn Memorial Hospital, Bangkok, Thailand
| | - Ruben Coronel
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam University Medical Centers, Amsterdam, the Netherlands; IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France.
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39
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Preventive Administration of Melatonin Attenuates Electrophysiological Consequences of Myocardial Ischemia. Bull Exp Biol Med 2020; 169:328-331. [PMID: 32743782 DOI: 10.1007/s10517-020-04881-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Indexed: 10/23/2022]
Abstract
The effect of preventive administration of melatonin on the arrhythmogenic substrate in the myocardium was studied in the rabbit model of acute ischemia/reperfusion in vivo. The animals treated with melatonin 60 min before ischemia induction had shorter median activation time compared to the control group (p=0.039), less pronounced shortening of repolarization durations in the ischemic zone during coronary occlusion (p=0.008), and more complete recovery of repolarization during reperfusion (p=0.027). In the melatonin group, the dispersion of repolarization was less than in the control group during both ischemic period (p=0.043) and reperfusion (p=0.038). Thus, preventive administration of melatonin mitigated the arrhythmogenic substrate in the heart under conditions of ischemia/reperfusion.
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40
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Hoang JD, Salavatian S, Yamaguchi N, Swid MA, David H, Vaseghi M. Cardiac sympathetic activation circumvents high-dose beta blocker therapy in part through release of neuropeptide Y. JCI Insight 2020; 5:135519. [PMID: 32493842 DOI: 10.1172/jci.insight.135519] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 04/30/2020] [Indexed: 01/14/2023] Open
Abstract
The sympathetic nervous system plays an important role in the occurrence of ventricular tachycardia (VT). Many patients, however, experience VT despite maximal doses of beta blocker therapy, possibly due to the effects of sympathetic cotransmitters such as neuropeptide Y (NPY). The purpose of this study was to determine, in a porcine model, whether propranolol at doses higher than clinically recommended could block ventricular electrophysiological effects of sympathoexcitation via stellate ganglia stimulation, and if any residual effects are mediated by NPY. Greater release of cardiac NPY was observed at higher sympathetic stimulation frequencies (10 and 20 vs. 4 Hz). Despite treatment with even higher doses of propranolol (1.0 mg/kg), electrophysiological effects of sympathetic stimulation remained, with residual shortening of activation recovery interval (ARI), a surrogate of action potential duration (APD). Adjuvant treatment with the NPY Y1 receptor antagonist BIBO 3304, however, reduced these electrophysiological effects while augmenting inotropy. These data demonstrate that high-dose beta blocker therapy is insufficient to block electrophysiological effects of sympathoexcitation, and a portion of these electrical effects in vivo are mediated by NPY. Y1 receptor blockade may represent a promising adjuvant therapy to beta-adrenergic receptor blockade.
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Affiliation(s)
- Jonathan D Hoang
- UCLA Cardiac Arrhythmia Center.,Neurocardiology Center for Excellence, and.,UCLA Molecular Cellular and Integrative Physiology Interdepartmental Program, UCLA, Los Angeles, California, USA
| | - Siamak Salavatian
- UCLA Cardiac Arrhythmia Center.,Neurocardiology Center for Excellence, and
| | - Naoko Yamaguchi
- UCLA Cardiac Arrhythmia Center.,Neurocardiology Center for Excellence, and
| | - Mohammed Amer Swid
- UCLA Cardiac Arrhythmia Center.,Neurocardiology Center for Excellence, and
| | - Hamon David
- UCLA Cardiac Arrhythmia Center.,Neurocardiology Center for Excellence, and
| | - Marmar Vaseghi
- UCLA Cardiac Arrhythmia Center.,Neurocardiology Center for Excellence, and.,UCLA Molecular Cellular and Integrative Physiology Interdepartmental Program, UCLA, Los Angeles, California, USA
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41
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Blom LJ, Groeneveld SA, Wulterkens BM, van Rees B, Nguyen UC, Roudijk RW, Cluitmans M, Volders PGA, Hassink RJ. Novel use of repolarization parameters in electrocardiographic imaging to uncover arrhythmogenic substrate. J Electrocardiol 2020; 59:116-121. [PMID: 32062380 DOI: 10.1016/j.jelectrocard.2020.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/23/2020] [Accepted: 02/06/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND Measuring repolarization characteristics is challenging and has been reserved for experienced physicians. In electrocardiographic imaging (ECGI), activation-recovery interval (ARI) is used as a measure of local cardiac repolarization duration. We hypothesized that repolarization characteristics, such as local electrogram morphology and local and global dispersion of repolarization timing and duration could be of significance in ECGI. OBJECTIVE To further explore their potential in arrhythmic risk stratification we investigated the use of novel repolarization parameters in ECGI. MATERIALS AND METHODS We developed and compared methods for T-peak and T-end detection in reconstructed potentials. All methods were validated on annotated reconstructed electrograms (EGMs). Characteristics of the reconstructed EGMs and epicardial substrate maps in IVF patients were analyzed by using data recorded during sinus rhythm. The ECGI data were analyzed for EGM morphology, conduction, and repolarization. RESULTS We acquired ECGI data from 8 subjects for this study. In all patients we evaluated four repolarization parameters: Repolarization time, T-wave area, Tpeak-Tend interval, and T-wave alternans. Most prominent findings were steep repolarization time gradients in regions with flat EGMs. These regions were also characterized by low T-wave area and large differences in Tpeak-Tend interval. CONCLUSIONS Measuring novel repolarization parameters in reconstructed electrograms acquired with ECGI is feasible, can be done in a fully automated manner and may provide additional information on underlying arrhythmogenic substrate for risk stratification. Further studies are needed to investigate their potential use and clinical application.
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Affiliation(s)
- L J Blom
- Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands.
| | - S A Groeneveld
- Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - B M Wulterkens
- Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - B van Rees
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, Maastricht, the Netherlands
| | - U C Nguyen
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, Maastricht, the Netherlands
| | - R W Roudijk
- Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - M Cluitmans
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, Maastricht, the Netherlands
| | - P G A Volders
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, Maastricht, the Netherlands
| | - R J Hassink
- Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands
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42
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Duijvenboden SV, Porter B, Pueyo E, Sampedro-Puente DA, Fernandez-Bes J, Sidhu B, Gould J, Orini M, Bishop MJ, Hanson B, Lambiase P, Razavi R, Rinaldi CA, Gill JS, Taggart P. Complex Interaction Between Low-Frequency APD Oscillations and Beat-to-Beat APD Variability in Humans Is Governed by the Sympathetic Nervous System. Front Physiol 2020; 10:1582. [PMID: 32038279 PMCID: PMC6987475 DOI: 10.3389/fphys.2019.01582] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 12/17/2019] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Recent clinical, experimental and modeling studies link oscillations of ventricular repolarization in the low frequency (LF) (approx. 0.1 Hz) to arrhythmogenesis. Sympathetic provocation has been shown to enhance both LF oscillations of action potential duration (APD) and beat-to-beat variability (BVR) in humans. We hypothesized that beta-adrenergic blockade would reduce LF oscillations of APD and BVR of APD in humans and that the two processes might be linked. METHODS AND RESULTS Twelve patients with normal ventricles were studied during routine electrophysiological procedures. Activation-recovery intervals (ARI) as a conventional surrogate for APD were recorded from 10 left and 10 right ventricular endocardial sites before and after acute beta-adrenergic adrenergic blockade. Cycle length was maintained constant with right ventricular pacing. Oscillatory behavior of ARI was quantified by spectral analysis and BVR as the short-term variability. Beta-adrenergic blockade reduced LF ARI oscillations (8.6 ± 4.5 ms2 vs. 5.5 ± 3.5 ms2, p = 0.027). A significant correlation was present between the initial control values and reduction seen following beta-adrenergic blockade in LF ARI (r s = 0.62, p = 0.037) such that when initial values are high the effect is greater. A similar relationship was also seen in the beat-to beat variability of ARI (r s = 0.74, p = 0.008). There was a significant correlation between the beta-adrenergic blockade induced reduction in LF power of ARI and the witnessed reduction of beat-to-beat variability of ARI (r s = 0.74, p = 0.01). These clinical results accord with recent computational modeling studies which provide mechanistic insight into the interactions of LF oscillations and beat-to-beat variability of APD at the cellular level. CONCLUSION Beta-adrenergic blockade reduces LF oscillatory behavior of APD (ARI) in humans in vivo. Our results support the importance of LF oscillations in modulating the response of BVR to beta-adrenergic blockers, suggesting that LF oscillations may play role in modulating beta-adrenergic mechanisms underlying BVR.
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Affiliation(s)
| | - Bradley Porter
- School of Imaging Sciences and Biomedical Engineering, King’s College London, London, United Kingdom
| | - Esther Pueyo
- BSICOS Group, I3A, IIS Aragón, University of Zaragoza, Zaragoza, Spain
- CIBER-BBN, Madrid, Spain
| | | | | | - Baldeep Sidhu
- School of Imaging Sciences and Biomedical Engineering, King’s College London, London, United Kingdom
| | - Justin Gould
- School of Imaging Sciences and Biomedical Engineering, King’s College London, London, United Kingdom
| | - Michele Orini
- Department of Clinical Pharmacology, Queen Mary University of London, London, United Kingdom
| | - Martin J. Bishop
- School of Imaging Sciences and Biomedical Engineering, King’s College London, London, United Kingdom
| | - Ben Hanson
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Pier Lambiase
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Reza Razavi
- School of Imaging Sciences and Biomedical Engineering, King’s College London, London, United Kingdom
| | | | | | - Peter Taggart
- Institute of Cardiovascular Science, University College London, London, United Kingdom
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43
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Graham AJ, Orini M, Zacur E, Dhillon G, Daw H, Srinivasan NT, Martin C, Lane J, Mansell JS, Cambridge A, Garcia J, Pugliese F, Segal O, Ahsan S, Lowe M, Finlay M, Earley MJ, Chow A, Sporton S, Dhinoja M, Hunter RJ, Schilling RJ, Lambiase PD. Evaluation of ECG Imaging to Map Hemodynamically Stable and Unstable Ventricular Arrhythmias. Circ Arrhythm Electrophysiol 2020; 13:e007377. [PMID: 31934784 DOI: 10.1161/circep.119.007377] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND ECG imaging (ECGI) has been used to guide treatment of ventricular ectopy and arrhythmias. However, the accuracy of ECGI in localizing the origin of arrhythmias during catheter ablation of ventricular tachycardia (VT) in structurally abnormal hearts remains to be fully validated. METHODS During catheter ablation of VT, simultaneous mapping was performed using electroanatomical mapping (CARTO, Biosense-Webster) and ECGI (CardioInsight, Medtronic) in 18 patients. Sites of entrainment, pace-mapping, and termination during ablation were used to define the VT site of origin (SoO). Distance between SoO and the site of earliest activation on ECGI were measured using co-registered geometries from both systems. The accuracy of ECGI versus a 12-lead surface ECG algorithm was compared. RESULTS A total of 29 VTs were available for comparison. Distance between SoO and sites of earliest activation in ECGI was 22.6, 13.9 to 36.2 mm (median, first to third quartile). ECGI mapped VT sites of origin onto the correct AHA segment with higher accuracy than a validated 12-lead ECG algorithm (83.3% versus 38.9%; P=0.015). CONCLUSIONS This simultaneous assessment demonstrates that CardioInsight localizes VT circuits with sufficient accuracy to provide a region of interest for targeting mapping for ablation. Resolution is not sufficient to guide discrete radiofrequency lesion delivery via catheter ablation without concomitant use of an electroanatomical mapping system but may be sufficient for segmental ablation with radiotherapy.
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Affiliation(s)
- Adam J Graham
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Michele Orini
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.).,Institute of Cardiovascular Science, University College London, United Kingdom (M.O., P.D.L.)
| | - Ernesto Zacur
- Institute of Biomedical Engineering, University of Oxford, United Kingdom (E.Z.)
| | - Gurpreet Dhillon
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Holly Daw
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Neil T Srinivasan
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Claire Martin
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Jem Lane
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Josephine S Mansell
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Alex Cambridge
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Jason Garcia
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Francesca Pugliese
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Oliver Segal
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Syed Ahsan
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Martin Lowe
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Malcolm Finlay
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Mark J Earley
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Anthony Chow
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Simon Sporton
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Mehul Dhinoja
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Ross J Hunter
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Richard J Schilling
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.)
| | - Pier D Lambiase
- Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom (A.J.G., M.O., G.D., H.D., N.T.S., C.M., J.L., J.S.M., A.C., J.G., F.P., O.S., S.A., M.L., M.F., M.J.E., A.C., S.S., M.D., R.J.H., R.J.S., P.D.L.).,Institute of Cardiovascular Science, University College London, United Kingdom (M.O., P.D.L.)
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Sedova KA, Bernikova OG, Cuprova JI, Ivanova AD, Kutaeva GA, Pliss MG, Lopatina EV, Vaykshnorayte MA, Diez ER, Azarov JE. Association Between Antiarrhythmic, Electrophysiological, and Antioxidative Effects of Melatonin in Ischemia/Reperfusion. Int J Mol Sci 2019; 20:ijms20246331. [PMID: 31847485 PMCID: PMC6941092 DOI: 10.3390/ijms20246331] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 01/08/2023] Open
Abstract
Melatonin is assumed to confer cardioprotective action via antioxidative properties. We evaluated the association between ventricular tachycardia and/or ventricular fibrillation (VT/VF) incidence, oxidative stress, and myocardial electrophysiological parameters in experimental ischemia/reperfusion under melatonin treatment. Melatonin was given to 28 rats (10 mg/kg/day, orally, for 7 days) and 13 animals received placebo. In the anesthetized animals, coronary occlusion was induced for 5 min followed by reperfusion with recording of unipolar electrograms from ventricular epicardium with a 64-lead array. Effects of melatonin on transmembrane potentials were studied in ventricular preparations of 7 rats in normal and “ischemic” conditions. Melatonin treatment was associated with lower VT/VF incidence at reperfusion, shorter baseline activation times (ATs), and activation-repolarization intervals and more complete recovery of repolarization times (RTs) at reperfusion (less baseline-reperfusion difference, ΔRT) (p < 0.05). Superoxide dismutase (SOD) activity was higher in the treated animals and associated with ΔRT (p = 0.001), whereas VT/VF incidence was associated with baseline ATs (p = 0.020). In vitro, melatonin led to a more complete restoration of action potential durations and resting membrane potentials at reoxygenation (p < 0.05). Thus, the antioxidative properties of melatonin were associated with its influence on repolarization duration, whereas the melatonin-related antiarrhythmic effect was associated with its oxidative stress-independent action on ventricular activation.
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Affiliation(s)
- Ksenia A. Sedova
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna sq. 3105, 27201 Kladno, Czech Republic;
| | - Olesya G. Bernikova
- Institute of Physiology, Federal Research Centre, Komi Science Centre, Ural Branch of Russian Academy of Sciences, Pervomayskaya st. 50, 167982 Syktyvkar, Russia; (M.A.V.); (J.E.A.)
- Correspondence: ; Tel.: +79042716438
| | - Julia I. Cuprova
- Department of Health Care Disciplines and Population Protection, Faculty of Biomedical Engineering, Czech Technical University in Prague, Sportovcu st. 2311, 27201 Kladno, Czech Republic;
| | - Alexandra D. Ivanova
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, 119234 Moscow, Russia;
| | - Galina A. Kutaeva
- Department of Physiology, Institute of Medicine of Pitirim Sorokin Syktyvkar State University, Starovskii st., 55, 167001 Syktyvkar, Russia;
| | - Michael G. Pliss
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Akkuratov st., 2, 197341 St Petersburg, Russia;
| | - Ekaterina V. Lopatina
- Department of Normal Physiology, Pavlov First State Medical University of Saint Petersburg, Lev Tolstoy st., 6-8, 197022 St Petersburg, Russia;
| | - Marina A. Vaykshnorayte
- Institute of Physiology, Federal Research Centre, Komi Science Centre, Ural Branch of Russian Academy of Sciences, Pervomayskaya st. 50, 167982 Syktyvkar, Russia; (M.A.V.); (J.E.A.)
| | - Emiliano R. Diez
- Instituto de Medicina y Biología Experimental de Cuyo (IMBECU), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), CP 5500 Mendoza, Argentina;
- Instituto de Fisiología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Av. Libertador 80, Centro Universitario, CP 5500 Mendoza, Argentina
| | - Jan E. Azarov
- Institute of Physiology, Federal Research Centre, Komi Science Centre, Ural Branch of Russian Academy of Sciences, Pervomayskaya st. 50, 167982 Syktyvkar, Russia; (M.A.V.); (J.E.A.)
- Department of Physiology, Institute of Medicine of Pitirim Sorokin Syktyvkar State University, Starovskii st., 55, 167001 Syktyvkar, Russia;
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Evaluation of the reentry vulnerability index to predict ventricular tachycardia circuits using high-density contact mapping. Heart Rhythm 2019; 17:576-583. [PMID: 31751771 PMCID: PMC7105818 DOI: 10.1016/j.hrthm.2019.11.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Indexed: 11/24/2022]
Abstract
Background Identifying arrhythmogenic sites to improve ventricular tachycardia (VT) ablation outcomes remains unresolved. The reentry vulnerability index (RVI) combines activation and repolarization timings to identify sites critical for reentrant arrhythmia initiation without inducing VT. Objective The purpose of this study was to provide the first assessment of RVI’s capability to identify VT sites of origin using high-density contact mapping and comparison with other activation-repolarization markers of functional substrate. Methods Eighteen VT ablation patients (16 male; 72% ischemic) were studied. Unipolar electrograms were recorded during ventricular pacing and analyzed offline. Activation time (AT), activation–recovery interval (ARI), and repolarization time (RT) were measured. Vulnerability to reentry was mapped based on RVI and spatial distribution of AT, ARI, and RT. The distance from sites identified as vulnerable to reentry to the VT site of origin was measured, with distances <10 mm and >20 mm indicating accurate and inaccurate localization, respectively. Results The origins of 18 VTs (6 entrainment, 12 pace-mapping) were identified. RVI maps included 1012 (408–2098) (median, 1st–3rd quartiles) points per patient. RVI accurately localized 72.2% VT sites of origin, with median distance of 5.1 (3.2–10.1) mm. Inaccurate localization was significantly less frequent for RVI than AT (5.6% vs 33.3%; odds ratio 0.12; P = .035). Compared to RVI, distance to VT sites of origin was significantly larger for sites showing prolonged RT and ARI and were nonsignificantly larger for sites showing highest AT and ARI gradients. Conclusion RVI identifies vulnerable regions closest to VT sites of origin. Activation-repolarization metrics may improve VT substrate delineation and inform novel ablation strategies.
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Orini M, Srinivasan N, Graham AJ, Taggart P, Lambiase PD. Further Evidence on How to Measure Local Repolarization Time Using Intracardiac Unipolar Electrograms in the Intact Human Heart. Circ Arrhythm Electrophysiol 2019; 12:e007733. [PMID: 31698934 DOI: 10.1161/circep.119.007733] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Michele Orini
- Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom (M.O., N.S., A.J.G., P.D.L.)
- Institute of Cardiovascular Science, University College London, United Kingdom (M.O., P.T., P.D.L.)
| | - Neil Srinivasan
- Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom (M.O., N.S., A.J.G., P.D.L.)
| | - Adam J Graham
- Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom (M.O., N.S., A.J.G., P.D.L.)
| | - Peter Taggart
- Institute of Cardiovascular Science, University College London, United Kingdom (M.O., P.T., P.D.L.)
| | - Pier D Lambiase
- Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom (M.O., N.S., A.J.G., P.D.L.)
- Institute of Cardiovascular Science, University College London, United Kingdom (M.O., P.T., P.D.L.)
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Orini M, Graham AJ, Martinez-Naharro A, Andrews CM, de Marvao A, Statton B, Cook SA, O'Regan DP, Hawkins PN, Rudy Y, Fontana M, Lambiase PD. Noninvasive Mapping of the Electrophysiological Substrate in Cardiac Amyloidosis and Its Relationship to Structural Abnormalities. J Am Heart Assoc 2019; 8:e012097. [PMID: 31496332 PMCID: PMC6818012 DOI: 10.1161/jaha.119.012097] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background The relationship between structural pathology and electrophysiological substrate in cardiac amyloidosis is unclear. Differences between light‐chain (AL) and transthyretin (ATTR) cardiac amyloidosis may have prognostic implications. Methods and Results ECG imaging and cardiac magnetic resonance studies were conducted in 21 cardiac amyloidosis patients (11 AL and 10 ATTR). Healthy volunteers were included as controls. With respect to ATTR, AL patients had lower amyloid volume (51.0/37.7 versus 73.7/16.4 mL, P=0.04), lower myocardial cell volume (42.6/19.1 versus 58.5/17.2 mL, P=0.021), and higher T1 (1172/64 versus 1109/80 ms, P=0.022) and T2 (53.4/2.9 versus 50.0/3.1 ms, P=0.003). ECG imaging revealed differences between cardiac amyloidosis and control patients in virtually all conduction‐repolarization parameters. With respect to ATTR, AL patients had lower epicardial signal amplitude (1.07/0.46 versus 1.83/1.26 mV, P=0.026), greater epicardial signal fractionation (P=0.019), and slightly higher dispersion of repolarization (187.6/65 versus 158.3/40 ms, P=0.062). No significant difference between AL and ATTR patients was found using the standard 12‐lead ECG. T1 correlated with epicardial signal amplitude (cc=−0.78), and extracellular volume with epicardial signal fractionation (cc=0.48) and repolarization time (cc=0.43). Univariate models based on single features from both cardiac magnetic resonance and ECG imaging classified AL and ATTR patients with an accuracy of 70% to 80%. Conclusions In this exploratory study cardiac amyloidosis was associated with ventricular conduction and repolarization abnormalities, which were more pronounced in AL than in ATTR. Combined ECG imaging–cardiac magnetic resonance analysis supports the hypothesis that additional mechanisms beyond infiltration may contribute to myocardial damage in AL amyloidosis. Further studies are needed to assess the clinical impact of this approach.
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Affiliation(s)
- Michele Orini
- Barts Heart Centre Barts Health NHS Trust London United Kingdom.,Institute of Cardiovascular Science University College London London United Kingdom
| | - Adam J Graham
- Barts Heart Centre Barts Health NHS Trust London United Kingdom
| | | | - Christopher M Andrews
- Cardiac Bioelectricity and Arrhythmia Center Washington University in St Louis St. Louis MO
| | - Antonio de Marvao
- MRC London Institute of Medical Sciences Imperial College London London United Kingdom
| | - Ben Statton
- MRC London Institute of Medical Sciences Imperial College London London United Kingdom
| | - Stuart A Cook
- MRC London Institute of Medical Sciences Imperial College London London United Kingdom
| | - Declan P O'Regan
- MRC London Institute of Medical Sciences Imperial College London London United Kingdom
| | - Philip N Hawkins
- The Royal Free Hospital UCL Hospitals Trust London United Kingdom
| | - Yoram Rudy
- Cardiac Bioelectricity and Arrhythmia Center Washington University in St Louis St. Louis MO
| | - Marianna Fontana
- The Royal Free Hospital UCL Hospitals Trust London United Kingdom
| | - Pier D Lambiase
- Barts Heart Centre Barts Health NHS Trust London United Kingdom.,Institute of Cardiovascular Science University College London London United Kingdom
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Parreira L, Carmo P, Adragão P, Pinho J, Budanova M, Zubarev S, Cavaco D, Marinheiro R, Carmo J, Costa F, Marques H, Goncalves P. Non-invasive electrocardiographic imaging in patients with idiopathic premature ventricular contractions from the right ventricular outflow tract: New insights into arrhythmia substrate. J Electrocardiol 2019; 57:69-76. [PMID: 31514015 DOI: 10.1016/j.jelectrocard.2019.08.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/19/2019] [Accepted: 08/30/2019] [Indexed: 11/17/2022]
Abstract
AIMS The aim of this study was to use non-invasive electrocardiographic imaging (ECGI) to study the electrophysiological properties of right ventricular outflow tract (RVOT) in patients with frequent premature ventricular contractions (PVCs) from the RVOT and in controls. METHODS ECGI is a combined application of body surface electrocardiograms and computed tomography or magnetic resonance imaging data. Unipolar electrograms are reconstructed on the epicardial and endocardial surfaces. Activation time (AT) was defined as the time of maximal negative slope of the electrogram (EGM) during QRS, recovery time (RT) as the time of maximal positive slope of the EGM during T wave, Activation recovery interval (ARI) was defined as the difference between RT and AT. ARI dispersion (Δ ARI) and RT dispersion (Δ RT) were calculated as the difference between maximal and minimal ARI and RT respectively. We evaluated those parameters in patients with frequent PVCs from the RVOT, defined as >10.000 per 24 h, and in a control group. RESULTS We studied 7 patients with frequent RVOT PVCs and 17 controls. Patients with PVCs from the RVOT had shorter median RT than controls, in the endocardium and in the epicardium, respectively 380 (239-397) vs 414 (372-448) ms, p = 0.047 and 275 (236-301) vs 330 (263-418) ms, p = 0.047. The dispersion of ARI and of RT in the epicardium was higher than in controls, Δ ARI of 145 (68-216) vs 17 (3-48) ms, p = 0.001 and Δ RT of 201 (160-235) vs 115 (65-177), p = 0.019. CONCLUSION In this group of patients we found a shorter median RT in the endocardium and in the epicardium of the RVOT and a higher dispersion of the ARI and RT across the epicardium in patients with PVCs from the RVOT when comparing to controls.
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Affiliation(s)
| | - Pedro Carmo
- Hospital Luz Lisboa, Av Lusiada 1500-650, Lisboa, Portugal
| | - Pedro Adragão
- Hospital Luz Lisboa, Av Lusiada 1500-650, Lisboa, Portugal
| | - Joana Pinho
- Hospital Luz Lisboa, Av Lusiada 1500-650, Lisboa, Portugal
| | | | - Stepan Zubarev
- Hospital Luz Lisboa, Av Lusiada 1500-650, Lisboa, Portugal
| | - Diogo Cavaco
- Hospital Luz Lisboa, Av Lusiada 1500-650, Lisboa, Portugal
| | | | - João Carmo
- Hospital Luz Lisboa, Av Lusiada 1500-650, Lisboa, Portugal
| | | | - Hugo Marques
- Hospital Luz Lisboa, Av Lusiada 1500-650, Lisboa, Portugal
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Prolongation of The Activation Time in Ischemic Myocardium is Associated with J-wave Generation in ECG and Ventricular Fibrillation. Sci Rep 2019; 9:12202. [PMID: 31434969 PMCID: PMC6704253 DOI: 10.1038/s41598-019-48710-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 06/17/2019] [Indexed: 12/16/2022] Open
Abstract
J-wave pattern has been recognized as an arrhythmic risk marker, particularly in myocardial infarction patients. Mechanisms underlying J-wave development in ischemia remain unknown. In myocardial infarction model, we evaluated activation time delay as a prerequisite of J-wave appearance and predictor of ventricular fibrillation. Body surface ECGs and myocardial unipolar electrograms were recorded in 14 anesthetized pigs. 48 intramural leads were positioned across ventricular free walls and interventricular septum. Myocardial ischemia was induced by ligation of the left anterior descending coronary artery and the recordings were done during 40-minute coronary occlusion. The local activation times were determined as instants of dV/dt minimum during QRS complex in unipolar electrograms. During occlusion, ventricular local activation time prolonged in the middle portion of the left ventricular free wall, and basal and middle portions of septum, while J-waves appeared in precordial leads in 11 animals. In logistic regression and ROC curve analyses, activation time delay at a given time-point was associated with J-wave development, and a longer activation time was associated with ventricular fibrillation appearance. In experimental coronary occlusion, activation delay in ischemic myocardium was associated with generation of the J waves in the body surface ECG and predicted ventricular fibrillation.
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The Electrophysiological Substrate of Early Repolarization Syndrome: Noninvasive Mapping in Patients. JACC Clin Electrophysiol 2019; 3:894-904. [PMID: 29130071 DOI: 10.1016/j.jacep.2016.12.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Background The early repolarization (ER) pattern is a common ECG finding. Recent studies established a definitive clinical association between ER and fatal ventricular arrhythmias. However, the arrhythmogenic substrate of ER in the intact human heart has not been characterized. Objectives To map the epicardial electrophysiological (EP) substrate in ER syndrome patients using noninvasive Electrocardiographic Imaging (ECGI), and to characterize substrate properties that support arrhythmogenicity. Methods Twenty-nine ER syndrome patients were enrolled, 17 of which had a malignant syndrome. Characteristics of the abnormal EP substrate were analyzed using data recorded during sinus rhythm. The EP mapping data were analyzed for electrogram morphology, conduction and repolarization. Seven normal subjects provided control data. Results The abnormal EP substrate in ER syndrome patients has the following properties: (1) Abnormal epicardial electrograms characterized by presence of J-waves in localized regions; (2) Absence of conduction abnormalities, including delayed activation, conduction block, or fractionated electrograms; (3) Marked abbreviation of ventricular repolarization in areas with J-waves. The action potential duration (APD) was significantly shorter than normal (196±19 vs. 235±21 ms, p<0.05). Shortening of APD occurred heterogeneously, leading to steep repolarization gradients compared to normal control (45±17 vs.7±5 ms/cm, p<0.05). Premature ventricular contractions (PVCs) were recorded in 2 patients. The PVC sites of origin were closely related to the abnormal EP substrate with J-waves and steep repolarization gradients. Conclusions Early Repolarization is associated with steep repolarization gradients caused by localized shortening of APD. Results suggest association of PVC initiation sites with areas of repolarization abnormalities. Conduction abnormalities were not observed.
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