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Balderas-Villalobos J, Medina-Contreras JML, Lynch C, Kabadi R, Hayles J, Ramirez RJ, Tan AY, Kaszala K, Samsó M, Huizar JF, Eltit JM. Mechanisms of adaptive hypertrophic cardiac remodeling in a large animal model of premature ventricular contraction-induced cardiomyopathy. IUBMB Life 2023; 75:926-940. [PMID: 37427864 PMCID: PMC10592397 DOI: 10.1002/iub.2765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Accepted: 06/13/2023] [Indexed: 07/11/2023]
Abstract
Frequent premature ventricular contractions (PVCs) promoted eccentric cardiac hypertrophy and reduced ejection fraction (EF) in a large animal model of PVC-induced cardiomyopathy (PVC-CM), but the molecular mechanisms and markers of this hypertrophic remodeling remain unexplored. Healthy mongrel canines were implanted with pacemakers to deliver bigeminal PVCs (50% burden with 200-220 ms coupling interval). After 12 weeks, left ventricular (LV) free wall samples were studied from PVC-CM and Sham groups. In addition to reduced LV ejection fraction (LVEF), the PVC-CM group showed larger cardiac myocytes without evident ultrastructural alterations compared to the Sham group. Biochemical markers of pathological hypertrophy, such as store-operated Ca2+ entry, calcineurin/NFAT pathway, β-myosin heavy chain, and skeletal type α-actin were unaltered in the PVC-CM group. In contrast, pro-hypertrophic and antiapoptotic pathways including ERK1/2 and AKT/mTOR were activated and/or overexpressed in the PVC-CM group, which appeared counterbalanced by an overexpression of protein phosphatase 1 and a borderline elevation of the anti-hypertrophic factor atrial natriuretic peptide. Moreover, the potent angiogenic and pro-hypertrophic factor VEGF-A and its receptor VEGFR2 were significantly elevated in the PVC-CM group. In conclusion, a molecular program is in place to keep this structural remodeling associated with frequent PVCs as an adaptive pathological hypertrophy.
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Affiliation(s)
| | - JML Medina-Contreras
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University
| | - Christopher Lynch
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University
| | - Rajiv Kabadi
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States of America
| | - Janée Hayles
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States of America
| | - Rafael J. Ramirez
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University
| | - Alex Y. Tan
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States of America
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, United States of America
| | - Karoly Kaszala
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States of America
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, United States of America
| | - Montserrat Samsó
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University
| | - Jose F. Huizar
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States of America
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, United States of America
| | - Jose M. Eltit
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University
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Lum BX, Liu EH, Tan AY. Excessive N 2O consumption due to pipeline leakages detected through integrated financial and carbon accounting. Can J Anaesth 2023; 70:1707-1708. [PMID: 37656343 DOI: 10.1007/s12630-023-02555-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 05/22/2023] [Accepted: 05/26/2023] [Indexed: 09/02/2023] Open
Affiliation(s)
- B X Lum
- Office of Sustainability, National University Health System, Singapore, Singapore.
| | - E H Liu
- Department of Anaesthesia, National University Hospital, Singapore, Singapore
| | - A Y Tan
- Department of Anaesthesia, Alexandra Hospital, Singapore, Singapore
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Shoureshi P, Kabadi R, James N, Torrado JF, Airapetov S, Hundley W, Kaszala K, Ellenbogen KA, Tan AY, Huizar JF. Left ventricular remodeling in premature ventricular contraction-induced cardiomyopathy: Effect of coupling intervals and atrioventricular dissociation. Heart Rhythm O2 2023; 4:556-564. [PMID: 37744937 PMCID: PMC10513922 DOI: 10.1016/j.hroo.2023.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/26/2023] Open
Abstract
Background Left ventricular dyssynchrony (LVD) and postextrasystolic potentiation (PESP) associated with premature ventricular contractions (PVCs) may play a role in the development of premature ventricular contraction-induced cardiomyopathy (PVC-CM). Long-coupled (LC) PVCs have a greater LVD than short-coupled (SC) PVCs, whereas SC-PVCs have a stronger PESP than LC-PVCs. Objective The purpose of this study was to compare SC-PVCs and LC-PVCs to evaluate the roles of LVD, PESP, and atrioventricular dissociation (AVD) in the development of PVC-CM. Methods Thirty-six canines underwent pacemaker implantation to induce bigeminal right ventricular apical epicardial PVCs (50% burden) for 12 weeks. Telemetry assessed PVC burden and AVD. Animals were grouped as SC-PVC (coupling interval [CI] 200-220ms), LC-PVC (CI 330 ms), or sham (control). Echocardiographic changes, AVD, and hemodynamics were monitored for 12 weeks. Results PVC burden was similar between SC-PVC and LC-PVC groups but was statistically higher in the SC-PVC group (50% vs 47.5%; P = .028). After 12 weeks, left ventricular ejection fraction (LVEF) significantly decreased in both SC-PVC and LC-PVC groups (47.1% ± 1.4% and 45.5% ± 2%, respectively) compared to sham group (61% ± 1.6%; P <.001). Overall AVD was similar between SC-PVC and LC-PVC groups, and there was no significant correlation between AVD and reduction in LVEF at 12 weeks (r = 0.09, P = .5; and r = 0.06, P = .8, respectively). Additionally, both SC-PVC and LC-PVC groups experienced substantial declines in max and min dP/dt after 12 weeks compared to baseline. Conclusion Neither PVC CI nor AVD played an independent role in the development or severity of PVC-CM. LVD and PESP make equal relative contributions to the development of PVC-CM.
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Affiliation(s)
- Pouria Shoureshi
- Department of Internal Medicine, Cardiology Division, Central Virginia VA Health Care System/McGuire Veterans Affairs Medical Center, Richmond, Virginia
- Department of Internal Medicine, Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Rajiv Kabadi
- Department of Internal Medicine, Cardiology Division, Central Virginia VA Health Care System/McGuire Veterans Affairs Medical Center, Richmond, Virginia
| | - Nicholas James
- Department of Internal Medicine, Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Juan F. Torrado
- Department of Internal Medicine, Cardiology Division, Central Virginia VA Health Care System/McGuire Veterans Affairs Medical Center, Richmond, Virginia
| | - Sergei Airapetov
- Department of Internal Medicine, Cardiology Division, Central Virginia VA Health Care System/McGuire Veterans Affairs Medical Center, Richmond, Virginia
- Department of Internal Medicine, Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - William Hundley
- Department of Internal Medicine, Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Karoly Kaszala
- Department of Internal Medicine, Cardiology Division, Central Virginia VA Health Care System/McGuire Veterans Affairs Medical Center, Richmond, Virginia
- Department of Internal Medicine, Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Kenneth A. Ellenbogen
- Department of Internal Medicine, Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Alex Y. Tan
- Department of Internal Medicine, Cardiology Division, Central Virginia VA Health Care System/McGuire Veterans Affairs Medical Center, Richmond, Virginia
- Department of Internal Medicine, Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Jose F. Huizar
- Department of Internal Medicine, Cardiology Division, Central Virginia VA Health Care System/McGuire Veterans Affairs Medical Center, Richmond, Virginia
- Department of Internal Medicine, Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
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Balderas-Villalobos J, Medina-Contreras JML, Lynch C, Kabadi R, Ramirez RJ, Tan AY, Kaszala K, Samsó M, Huizar JF, Eltit JM. Alterations of sarcoplasmic reticulum-mediated Ca 2+ uptake in a model of premature ventricular contraction (PVC)-induced cardiomyopathy. Mol Cell Biochem 2023; 478:1447-1456. [PMID: 36350464 PMCID: PMC10685401 DOI: 10.1007/s11010-022-04605-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/28/2022] [Indexed: 11/11/2022]
Abstract
Premature ventricular contractions (PVCs) are the most frequent ventricular arrhythmias in the overall population. PVCs are known to acutely enhance contractility by the post-extrasystolic potentiation phenomenon, but over time persistent PVCs promote PVC-induced cardiomyopathy (PVC-CM), characterized by a reduction of the left ventricular (LV) ejection fraction. Ca2+ cycling in myocytes commands muscle contraction and in this process, SERCA2 leads the Ca2+ reuptake into the sarcoplasmic reticulum (SR) shaping cytosolic Ca2+ signal decay and muscle relaxation. Altered Ca2+ reuptake can contribute to the contractile dysfunction observed in PVC-CM. To better understand Ca2+ handling using our PVC-CM model (canines with 50% PVC burden for 12 weeks), SR-Ca2+ reuptake was investigated by measuring Ca2+ dynamics and analyzing protein expression. Kinetic analysis of Ca2+ reuptake in electrically paced myocytes showed a ~ 21 ms delay in PVC-CM compared to Sham in intact isolated myocytes, along with a ~ 13% reduction in SERCA2 activity assessed in permeabilized myocytes. Although these trends were not statistically significant between groups using hierarchical statistics, relaxation of myocytes following contraction was significantly slower in PVC-CM vs Sham myocytes. Western blot analyses indicate a 22% reduction in SERCA2 expression, a 23% increase in phospholamban (PLN) expression, and a 50% reduction in PLN phosphorylation in PVC-CM samples vs Sham. Computational analysis simulating a 20% decrease in SR-Ca2+ reuptake resulted in a ~ 22 ms delay in Ca2+ signal decay, consistent with the experimental result described above. In conclusion, SERCA2 and PLB alterations described above have a modest contribution to functional adaptations observed in PVC-CM.
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Affiliation(s)
- Jaime Balderas-Villalobos
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, 1101 E Marshall St, 3-038H, Richmond, VA, 23298, USA
| | - J M L Medina-Contreras
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, 1101 E Marshall St, 3-038H, Richmond, VA, 23298, USA
| | - Christopher Lynch
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, 1101 E Marshall St, 3-038H, Richmond, VA, 23298, USA
| | - Rajiv Kabadi
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, USA
| | - Rafael J Ramirez
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, 1101 E Marshall St, 3-038H, Richmond, VA, 23298, USA
| | - Alex Y Tan
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, USA
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, USA
| | - Karoly Kaszala
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, USA
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, USA
| | - Montserrat Samsó
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, 1101 E Marshall St, 3-038H, Richmond, VA, 23298, USA
| | - Jose F Huizar
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, USA
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, USA
| | - Jose M Eltit
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, 1101 E Marshall St, 3-038H, Richmond, VA, 23298, USA.
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Kapoor K, Fortman E, Matharoo J, Perez-Downes J, Tan AY, Huizar J, Ellenbogen KA, Kaszala K. HIDDEN SECRETS OF THE PR INTERVAL. J Am Coll Cardiol 2023. [DOI: 10.1016/s0735-1097(23)04329-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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Balderas Villalobos J, Medina-Contreras JML, Samso M, Tan AY, Kaszala K, Huizar JF, Eltit JM. Angiogenesis and activated fibroblast in a model of premature ventricular contraction-induced cardiomyopathy. Biophys J 2023; 122:406a. [PMID: 36784069 DOI: 10.1016/j.bpj.2022.11.2207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
| | - J M L Medina-Contreras
- Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Montserrat Samso
- Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Alex Y Tan
- Hunter Holmes McGuire Veterans Administration Medical Center, Richmond, VA, USA
| | - Karoly Kaszala
- Hunter Holmes McGuire Veterans Administration Medical Center, Richmond, VA, USA
| | - Jose F Huizar
- Hunter Holmes McGuire Veterans Administration Medical Center, Richmond, VA, USA
| | - Jose M Eltit
- Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
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Kowlgi GN, Tan AY, Kaszala K, Kontos MC, Lozano P, Ellenbogen KA, Huizar JF. Left ventricular dyssynchrony as marker of early dysfunction in premature ventricular contraction-induced cardiomyopathy. Front Cardiovasc Med 2022; 9:978341. [PMID: 36148047 PMCID: PMC9485544 DOI: 10.3389/fcvm.2022.978341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 08/03/2022] [Indexed: 01/16/2023] Open
Abstract
Background Strain imaging has been suggested as a tool to detect early left ventricular (LV) dysfunction due to frequent premature ventricular contractions (PVCs) in patients with preserved LV ejection fraction (EF). However, the progression of intraventricular dyssynchrony (IVD), radial, and circumferential strain (RS, CS) in PVC-cardiomyopathy (CM) are unknown. The aim of this study was to elucidate the progression patterns of CS, IVD, and electro-mechanical latency (EML) in PVC-CM. Methods and results Pacemakers were implanted in 20 canines to reproduce ventricular bigeminy at 200ms (PVCs n = 11) for 12 weeks and compared to a sham group (n = 9). We obtained echocardiograms at baseline, 4-, 8- and 12-weeks. RS and CS were obtained at the LV mid-cavitary level. IVD was defined as the time between the earliest and latest peak RS. EML was defined as the time between the onset of QRS and the earliest peak RS. LVEF (62 ± 5 to 42 ± 7%, p < 0.01), CS (-18 ± 3 to -12 ± 3, p < 0.01), and EML (219 ± 37 to 283 ± 46ms, p = 0.02) changed significantly in the PVC group. Peak CS (-18 ± 3 to -14 ± 4, p = 0.02) and IVD (49 ± 31 to 122 ± 103, p = 0.05) had a significant change at 4-weeks despite preserved LVEF (51 ± 5%). IVD normalized while EML increased at weeks 8 and 12. Conclusion Our findings consolidate the existing theory that changes in strain precede changes in LVEF in PVC-CM. While IVD becomes abnormal early in the development of PVC-CM, it pseudo-normalizes at advanced stages due to further increases in EML suggestive of cardiac contractility remodeling. These findings are consistent with recent published data where abnormal LV mechanics could be part of a substrate that can predispose to worse outcome in PVC-Cardiomyopathy.
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Affiliation(s)
- Gurukripa N. Kowlgi
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, United States
| | - Alex Y. Tan
- Division of Cardiovascular Diseases, Department of Internal Medicine, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, United States
| | - Karoly Kaszala
- Division of Cardiovascular Diseases, Department of Internal Medicine, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, United States
| | - Michael C. Kontos
- Division of Cardiovascular Diseases, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States
| | - Pedro Lozano
- Department of Cardiovascular Diseases, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Kenneth A. Ellenbogen
- Division of Cardiovascular Diseases, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States
| | - Jose F. Huizar
- Division of Cardiovascular Diseases, Department of Internal Medicine, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, United States,Division of Cardiovascular Diseases, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States,*Correspondence: Jose F. Huizar, ; ;
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Kowlgi GN, Ramirez RJ, Kaszala K, Joslyn M, Koneru JN, Ellenbogen KA, Tan AY, Huizar JF. Post-extrasystolic potentiation as a predictor of premature ventricular contraction-cardiomyopathy in an animal model. Europace 2021; 22:813-820. [PMID: 32142121 DOI: 10.1093/europace/euaa025] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 01/21/2020] [Indexed: 12/21/2022] Open
Abstract
AIMS High premature ventricular contractions (PVCs) burden does not always predict the development of PVC-cardiomyopathy (CM). We sought to evaluate post-extrasystolic potentiation (PESP) of left ventricular ejection fraction (LVEF) to predict the severity of PVC-CM in an animal model. METHODS AND RESULTS Right ventricular apical bigeminal PVCs were introduced for 12 weeks in 11 canines to induce PVC-CM. Echocardiograms were performed to obtain LVEF without ectopy (Echo-1) and during PVCs (200 and 350 ms coupling intervals, Echo-2, and Echo-3, respectively), and premature atrial contractions (PACs) (Echo-4) at baseline and after 12 weeks of bigeminal PVCs. PESP was calculated as delta-LVEF between the sinus beat post-ectopy LVEF (Echo-2, -3, and -4, respectively) and LVEF without PVC (Echo-1) at baseline and 12 weeks of high PVC burden. A hyperdynamic LV function (LVEF > 70%) was noted in all animals only with early-coupled PVCs (LVEF at 200 ms: 74.4 ± 6%) at baseline. While PVC PESP at 200 ms had a strong significant correlation with the final 12-week LVEF (R = 0.8, P = 0.003), PVC PESP at 350 ms and PAC PESP had a positive but non-significant correlation (R = 0.53, P = 0.09, and R = 0.29, P = 0.34, respectively). Premature ventricular contraction PESP at 350 ms was significantly higher after PVC-CM had developed (delta-LVEF baseline 2.7 ± 2.9% vs. 12 weeks 18.6 ± 12.3% P < 0.001). CONCLUSION Bigeminal early-coupled PVCs cause hyperdynamic left ventricular function in the structurally normal canine heart due to PESP. The degree of PESP at baseline is inversely proportional to the PVC-CM severity at 12 weeks and maybe a predictor of PVC-CM as it may assess the myocardial adaptation reserve to PVCs.
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Affiliation(s)
- Gurukripa N Kowlgi
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Ste. 4A-100, Richmond, VA 23249, USA
| | - Rafael J Ramirez
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Ste. 4A-100, Richmond, VA 23249, USA
| | - Karoly Kaszala
- Hunter Holmes McGuire Veterans Affairs Medical Center, 1201 Broad Rock Blvd, Richmond, VA, USA
| | - Martha Joslyn
- Hunter Holmes McGuire Veterans Affairs Medical Center, 1201 Broad Rock Blvd, Richmond, VA, USA
| | - Jayanthi N Koneru
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Ste. 4A-100, Richmond, VA 23249, USA
| | - Kenneth A Ellenbogen
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Ste. 4A-100, Richmond, VA 23249, USA
| | - Alex Y Tan
- Hunter Holmes McGuire Veterans Affairs Medical Center, 1201 Broad Rock Blvd, Richmond, VA, USA
| | - Jose F Huizar
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Ste. 4A-100, Richmond, VA 23249, USA.,Hunter Holmes McGuire Veterans Affairs Medical Center, 1201 Broad Rock Blvd, Richmond, VA, USA
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Huizar JF, Tan AY, Kaszala K, Ellenbogen KA. Clinical and translational insights on premature ventricular contractions and PVC-induced cardiomyopathy. Prog Cardiovasc Dis 2021; 66:17-27. [PMID: 33857575 PMCID: PMC9192164 DOI: 10.1016/j.pcad.2021.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 04/06/2021] [Indexed: 12/29/2022]
Abstract
The medical community's understanding of the consequences of premature ventricular contractions (PVCs) and PVC-induced cardiomyopathy has been derived mostly from observational and large population-based studies. Due to the difficulty of predicting the development of PVC-cardiomyopathy, the acute and chronic cardiac effects of PVCs and the mechanism of PVC-cardiomyopathy have been derived from pre-clinical studies with large animal models. Recently, these studies have described myocardial substrates that could potentially increase morbidity and mortality in patients with frequent PVCs and PVC-cardiomyopathy. In this paper, we provide an up-to-date comprehensive review of these pre-clinical and clinical studies.
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Affiliation(s)
- Jose F Huizar
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States of America; Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, United States of America.
| | - Alex Y Tan
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States of America; Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, United States of America
| | - Karoly Kaszala
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States of America; Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, United States of America
| | - Kenneth A Ellenbogen
- Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, United States of America
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Huizar JF, Fisher SG, Ramsey FV, Kaszala K, Tan AY, Moore H, Koneru JN, Kron J, Padala SK, Ellenbogen KA, Singh SN. Outcomes of Premature Ventricular Contraction-Cardiomyopathy in the Veteran Population: A Secondary Analysis of the CHF-STAT Study. JACC Clin Electrophysiol 2021; 7:380-390. [PMID: 33736756 PMCID: PMC9188841 DOI: 10.1016/j.jacep.2020.08.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/05/2020] [Accepted: 08/19/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVES This study sought to assess the rate and outcomes of premature ventricular contractions (PVC)-cardiomyopathy from the CHF-STAT (Survival Trial of Antiarrhythmic Therapy in Congestive Heart Failure) trial, a population with cardiomyopathy (left ventricular [LV] ejection fraction of <40%) and frequent PVCs (>10 PVCs per hour). BACKGROUND PVCs are associated with heart failure and PVC-cardiomyopathy. The prevalence of PVC-cardiomyopathy and outcome benefits of PVC suppression are not clear. METHODS A secondary analysis of the CHF-STAT study was performed to compare the rate of successful PVC suppression (≥80% PVC reduction), LV recovery (defined as improvement in LV ejection fraction of ≥10% points), and PVC-cardiomyopathy between amiodarone and placebo groups at 6 months. PVC-cardiomyopathy was defined if both PVC reduction of ≥80% and LV ejection fraction improvement of ≥10% were present at 6 months. Cardiac events (death or resuscitated cardiac arrest) were compared between PVC-cardiomyopathy versus non-PVC-cardiomyopathy during a 5-year follow-up. RESULTS The rates of successful PVC suppression and LV recovery were significantly higher in the amiodarone (72% and 39%, respectively) when compared to the placebo group (12% and 16%, respectively; p < 0.001), regardless of cardiomyopathy etiology. PVC-cardiomyopathy was present in 29% and 1.8% of patients in the amiodarone and placebo groups, respectively (p < 0.001). Similar PVC-cardiomyopathy rates were found in ischemic (24% amiodarone vs. 2% placebo; p < 0.001) and nonischemic populations (41% amiodarone vs. 1.5% placebo; p < 0.001). Death and resuscitated cardiac arrest were significantly lower in patients with PVC-cardiomyopathy and those treated with amiodarone. CONCLUSIONS The overall prevalence of PVC-cardiomyopathy in the CHF-STAT study was significant regardless of ischemic substrate (29%, overall population; 41%, nonischemic cardiomyopathy). Treatment of PVC-cardiomyopathy with amiodarone is likely to improve survival in this high-risk population.
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Affiliation(s)
- Jose F Huizar
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia, USA; Virginia Commonwealth University/Pauley Heart Center, Richmond, Virginia, USA.
| | - Susan G Fisher
- Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
| | - Frederick V Ramsey
- Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
| | - Karoly Kaszala
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia, USA; Virginia Commonwealth University/Pauley Heart Center, Richmond, Virginia, USA
| | - Alex Y Tan
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia, USA; Virginia Commonwealth University/Pauley Heart Center, Richmond, Virginia, USA
| | - Hans Moore
- Washington Veterans Affairs Medical Center, Washington, DC, USA
| | - Jayanthi N Koneru
- Virginia Commonwealth University/Pauley Heart Center, Richmond, Virginia, USA
| | - Jordana Kron
- Virginia Commonwealth University/Pauley Heart Center, Richmond, Virginia, USA
| | - Santosh K Padala
- Virginia Commonwealth University/Pauley Heart Center, Richmond, Virginia, USA
| | | | - Steven N Singh
- Washington Veterans Affairs Medical Center, Washington, DC, USA
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Torrado J, Kowlgi GN, Ramirez RJ, Balderas-Villalobos J, Jovin D, Parker C, Om E, Airapetov S, Kaszala K, Tan AY, Ellenbogen KA, Huizar JF. Eccentric hypertrophy in an animal model of mid- and long-term premature ventricular contraction-induced cardiomyopathy. Heart Rhythm O2 2021; 2:80-88. [PMID: 34113908 PMCID: PMC8183810 DOI: 10.1016/j.hroo.2020.12.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Tachycardia and heart rate irregularity are proposed triggers of premature ventricular contraction-induced cardiomyopathy (PVC-cardiomyopathy). Bigeminal premature atrial and ventricular contractions (PACs and PVCs) increase heart rate and result in rhythm irregularities but differ in their effects on ventricular synchrony. Comparing chronic bigeminal PACs with PVCs would provide insights into mechanisms of PVC-cardiomyopathy. OBJECTIVE To compare the impact of chronic PACs and PVCs on ventricular hemodynamics, structure, and function. METHODS Pacemakers were implanted in 27 canines to reproduce atrial (PACs, n = 7) or ventricular bigeminy (PVCs, n = 11) for 12 weeks, and compared to sham-operated animals (n = 9). Four additional animals were exposed to long-term bigeminal PVCs (48 weeks). Hemodynamic changes were assessed using a pressure-transducing catheter at baseline and 12 weeks. Cardiac remodeling was monitored by transthoracic echocardiography throughout the 12- and 48-week protocols in the respective groups. RESULTS PVC group demonstrated a significant decrease in left ventricular (LV) ejection fraction and contractility (max dP/dt), impaired LV lusitropy (min dP/dt), and increase in LV dimensions and LV mass at 12 weeks without further deterioration beyond 16 weeks. Despite increased LV mass, relative wall thickness decreased, consistent with eccentric hypertrophy. No significant cardiac remodeling was noted in either sham or PAC groups at 12 weeks. CONCLUSION In contrast to bigeminal PACs, PVCs result in a cardiomyopathy characterized by reduced LV ejection fraction, LV dilation, and eccentric hypertrophy that plateaus between 12 and 16 weeks. The lack of remodeling in chronic PACs suggests that tachycardia and heart rate irregularity do not play a significant role on the development of PVC-cardiomyopathy.
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Affiliation(s)
- Juan Torrado
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia
| | | | - Rafael J. Ramirez
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia
| | - Jaime Balderas-Villalobos
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia
| | - Daniel Jovin
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia
| | - Chandler Parker
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia
| | - Evani Om
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia
| | - Sergei Airapetov
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia
| | - Karoly Kaszala
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia
| | - Alex Y. Tan
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia
| | | | - Jose F. Huizar
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia
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12
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Teigeler T, Kolominsky J, Vo C, Shepard RK, Kalahasty G, Kron J, Huizar JF, Kaszala K, Tan AY, Koneru JN, Ellenbogen KA, Padala SK. Intermediate-term performance and safety of His-bundle pacing leads: A single-center experience. Heart Rhythm 2021; 18:743-749. [PMID: 33418127 DOI: 10.1016/j.hrthm.2020.12.031] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/09/2020] [Accepted: 12/27/2020] [Indexed: 01/19/2023]
Abstract
BACKGROUND The short-term safety, feasibility, and performance of His-bundle pacing (HBP) leads have been reported; however, their longer-term performance beyond 1 year remains unclear. OBJECTIVE The purpose of this study was to examine the intermediate-term performance and safety of HBP. METHODS All HBP lead implants at Virginia Commonwealth University between January 2014 and January 2019 were analyzed. HBP was performed using a Medtronic SelectSecure 3830-69 cm pacing lead. RESULTS Of 295 attempts, successful HBP implantation (selective or nonselective) was seen in 274 cases (93%). Mean follow-up duration was 22.8 ± 19.5 months (median 19.5; interquartile range 11-33). Mean age was 69 ± 15 years; 58% were males; and ejection fraction <50% was noted in 30%. Indications for pacemaker included sick sinus syndrome in 41%, atrioventricular block in 36%, cardiac resynchronization therapy in 7%, and refractory atrial fibrillation in 15%. Selective HBP was achieved in 33%. Mean HBP capture threshold at implant was 1.1 ± 0.9 V at 0.8 ± 0.2 ms, which significantly increased at chronic follow-up to 1.7 ± 1.1 V at 0.8 ± 0.3 ms (P <.001). Threshold was ≥2.5 V in 24% of patients, and 28% had an increase in HBP threshold ≥1 V. Loss of His-bundle capture at follow-up (septal right ventricular pacing) was seen in 17%. There was a total of 31 (11%) lead revisions, primarily for unacceptably high thresholds. CONCLUSION Although HBP can prevent or improve pacing-induced cardiomyopathy, the elevated capture thresholds, loss of His-bundle capture, and lead revision rates at intermediate follow-up are of concern. Longer-term follow-up data from multiple centers are needed.
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Affiliation(s)
- Todd Teigeler
- Division of Cardiac Electrophysiology, Virginia Commonwealth University, Richmond, Virginia
| | - Jeffrey Kolominsky
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Chau Vo
- Department of Cardiology, Virginia Commonwealth University, Richmond, Virginia
| | - Richard K Shepard
- Division of Cardiac Electrophysiology, Virginia Commonwealth University, Richmond, Virginia
| | - Gautham Kalahasty
- Division of Cardiac Electrophysiology, Virginia Commonwealth University, Richmond, Virginia
| | - Jordana Kron
- Division of Cardiac Electrophysiology, Virginia Commonwealth University, Richmond, Virginia
| | - Jose F Huizar
- Division of Cardiac Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Karoly Kaszala
- Division of Cardiac Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Alex Y Tan
- Division of Cardiac Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Jayanthi N Koneru
- Division of Cardiac Electrophysiology, Virginia Commonwealth University, Richmond, Virginia
| | - Kenneth A Ellenbogen
- Division of Cardiac Electrophysiology, Virginia Commonwealth University, Richmond, Virginia
| | - Santosh K Padala
- Division of Cardiac Electrophysiology, Virginia Commonwealth University, Richmond, Virginia.
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13
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Tan AY, Ellenbogen KA. Separating the Forest From the Trees: New Tools for a Personalized Sudden Cardiac Death Risk Stratification. J Am Heart Assoc 2020; 9:e018957. [PMID: 33025849 PMCID: PMC7763384 DOI: 10.1161/jaha.120.018957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Alex Y. Tan
- Hunter Holmes McGuire VA Medical Center Richmond VA
- Pauley Heart Center Virginia Commonwealth University Richmond VA
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14
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Keen L, Abbate A, Clark V, Moeller FG, Tan AY. Differences in heart rate among recent marijuana use groups. Minerva Cardiol Angiol 2020. [PMID: 32989967 DOI: 10.23736/s0026-4725.20.05239-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Marijuana use increases cardiac sympathetic activity within minutes of its use and this effect may begin to decrease as soon as one hour after marijuana use. However, the cardiovascular effects of marijuana use more than an hour after use is poorly characterized. The purpose of the current study is to compare heart rate, a marker of cardiac sympathetic activity, across recent marijuana use groups (never used: N.=63; recent use [in the past 24 hours; subacute] N.=13; in the past 7 days, but not in the past 24 hours: N.=17). Overall, the current sample included 93 African American/Black college students, with a mean age of 20.03±2.21 years. METHODS Participants completed a demographic form, a brief battery of psychological questionnaires, and had their heart rate assessed at baseline. RESULTS Analysis of covariance showed that heart rate was statistically significantly lower in the recent use group (62.38 bpm) compared with the non-users group (73.92 bpm). This difference persisted before and after statistically adjusting for demographic covariates. CONCLUSIONS These results suggest that there may be a cardiovascular process that occurs when using marijuana that results in a compensatory, reduced heart rate.
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Affiliation(s)
- Larry Keen
- Department of Psychology, Virginia State University, Petersburg, VA, USA -
| | - Antonio Abbate
- Department of Cardiology, Virginia Commonwealth University, Richmond, VA, USA
| | - Vernessa Clark
- Department of Psychology, Virginia State University, Petersburg, VA, USA
| | - F Gerard Moeller
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA
| | - Alex Y Tan
- Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, VA, USA
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15
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Abstract
BACKGROUND Marijuana use increases cardiac sympathetic activity within minutes of its use and this effect may begin to decrease as soon as one hour after marijuana use. However, the cardiovascular effects of marijuana use more than an hour after use is poorly characterized. The purpose of the current study is to compare heart rate, a marker of cardiac sympathetic activity, across recent marijuana use groups (never used: N.=63; recent use [in the past 24 hours; subacute] N.=13; in the past 7 days, but not in the past 24 hours: N.=17). Overall, the current sample included 93 African American/Black college students, with a mean age of 20.03±2.21 years. METHODS Participants completed a demographic form, a brief battery of psychological questionnaires, and had their heart rate assessed at baseline. RESULTS Analysis of covariance showed that heart rate was statistically significantly lower in the recent use group (62.38 bpm) compared with the non-users group (73.92 bpm). This difference persisted before and after statistically adjusting for demographic covariates. CONCLUSIONS These results suggest that there may be a cardiovascular process that occurs when using marijuana that results in a compensatory, reduced heart rate.
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Affiliation(s)
- Larry Keen
- Department of Psychology, Virginia State University, Petersburg, VA, USA -
| | - Antonio Abbate
- Department of Cardiology, Virginia Commonwealth University, Richmond, VA, USA
| | - Vernessa Clark
- Department of Psychology, Virginia State University, Petersburg, VA, USA
| | - F Gerard Moeller
- Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA
| | - Alex Y Tan
- Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, VA, USA
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16
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Keen L, Tan AY, Abbate A. Inverse associations between parasympathetic activity and cognitive flexibility in African Americans: Preliminary findings. Int J Psychophysiol 2020; 155:204-209. [PMID: 32610053 DOI: 10.1016/j.ijpsycho.2020.06.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 06/23/2020] [Accepted: 06/24/2020] [Indexed: 10/24/2022]
Abstract
Previous research suggests that vagal activity and executive function (EF) are positively associated. However, existing data exploring the relationship between HRV and EF remains limited. Though Blacks may have higher HRV, they remain underrepresented in previous research examining HRV and EF. The current study aimed to determine the relationship between EF and HRV in a sample of 92 Black undergraduates (Mean age = 20.32, SD = 2.28). Participants wore an 6‑lead ambulatory electrocardiographic impedance monitoring system to obtain the root mean square of interbeat interval differences (rMSSD) and Cardiac Sympathetic Index. After baseline autonomic activity assessment, participants completed the Berg Card Sorting Test. Utilizing hierarchical regression analyses, HRV was negatively associated with correct responses (Beta = -0.40, SE = 0.04, p=0.01) and categories experienced (Beta = -0.37, SE = 0.01, p=0.01), and positively associated with total errors (Beta = 0.39, SE =0.04, p=0.01). To further elucidate these findings, participants were assigned to coinhibition (n = 12), parasympathetically dominant (n = 34), sympathetically dominant (n = 35), or coactivation (n = 11) autonomic space subgroups. Participants in the sympathetically dominant subgroup completed more categories (M = 6.86, SD = 2.13) and committed fewer errors (M = 30.63, SD = 11.53) than their parasympathetic counterparts (M = 5.74, SD = 2.44; M = 43.29, SD = 18.83, respectively). This study suggests that a state of sympathetic arousal immediately prior to the administration of an EF task, may aid in better task performance.
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Affiliation(s)
- Larry Keen
- Department of Psychology, Virginia State University, United States of America.
| | - Alex Y Tan
- Division of Cardiology, Hunter Holmes McGuire VA Medical Center, United States of America.
| | - Antonio Abbate
- Pauley Heart Center, Virginia Commonwealth University, United States of America.
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17
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Larsen TR, Sargent D, Moyes M, Huizar JF, Tan AY, Ellenbogen KA, Kaszala K. Proarrhythmic effect of automatic threshold testing algorithm in dual chamber devices. J Cardiovasc Electrophysiol 2020; 31:2078-2085. [PMID: 32510718 DOI: 10.1111/jce.14606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 05/03/2020] [Accepted: 05/21/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Operation of auto-threshold testing (ATT) algorithm in current dual chamber cardiac devices require temporary shortening of atrio-ventricular (AV) delay to accurately measure evoked potential (capture) after a pacing pulse. Near simultaneous AV pacing causes atrial pressure elevation and may be associated with atrial arrhythmias. OBJECTIVE We evaluated the prevalence of atrial arrhythmias induced by ATT in Abbott devices. METHODS Device clinic records were reviewed at a single center for patients with dual chamber Abbott pacemaker/ICD. ATT-induced atrial fibrillation (AF) cases were defined as new appropriate mode switch episodes while the ATT was operating. The auto-capture test trends were defined as unstable if there were deviations >1 V in capture threshold trend events that did not correlate with routine in-office testing. RESULTS One hundred and seventy patients were programmed in dual chamber pacing mode. The ventricular ATT was active in 118 patients and of these 78 had true mode switch episodes. Six patients developed AF during ventricular ATT. Three patients had most recorded atrial arrhythmias in close association with ATT (63%, 66%, 100% vs 2%,9%, 33% in other patients with known prior AF). An unstable auto-capture trend curve was seen in 33 patients (6 showing ATT-induced AF) versus 85 patients with stable auto-capture curve and no ATT-induced AF (P = .0001, the χ2 test). CONCLUSION Ventricular auto-capture algorithm use is associated with induction of AF in dual chamber Abbott devices with a prevalence of over 5%. AF occur more frequently (18%) in patients with erratic ventricular ATT trend results.
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Affiliation(s)
- Timothy R Larsen
- Division of Cardiology, Section of Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia.,Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Donna Sargent
- Division of Cardiology, Section of Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Meredith Moyes
- Division of Cardiology, Section of Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Jose F Huizar
- Division of Cardiology, Section of Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia.,Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Alex Y Tan
- Division of Cardiology, Section of Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia.,Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Kenneth A Ellenbogen
- Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Karoly Kaszala
- Division of Cardiology, Section of Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia.,Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
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18
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Tan AY, Elharrif K, Cardona-Guarache R, Mankad P, Ayers O, Joslyn M, Das A, Kaszala K, Lin SF, Ellenbogen KA, Minisi AJ, Huizar JF. Persistent Proarrhythmic Neural Remodeling Despite Recovery From Premature Ventricular Contraction-Induced Cardiomyopathy. J Am Coll Cardiol 2020; 75:1-13. [PMID: 31918815 PMCID: PMC7006705 DOI: 10.1016/j.jacc.2019.10.046] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/30/2019] [Accepted: 10/21/2019] [Indexed: 11/23/2022]
Abstract
BACKGROUND The presence and significance of neural remodeling in premature ventricular contraction-induced cardiomyopathy (PVC-CM) remain unknown. OBJECTIVES This study aimed to characterize cardiac sympathovagal balance and proarrhythmia in a canine model of PVC-CM. METHODS In 12 canines, the investigators implanted epicardial pacemakers and radiotelemetry units to record cardiac rhythm and nerve activity (NA) from the left stellate ganglion (SNA), left cardiac vagus (VNA), and arterial blood pressure. Bigeminal PVCs (200 ms coupling) were applied for 12 weeks to induce PVC-CM in 7 animals then disabled for 4 weeks to allow complete recovery of left ventricular ejection fraction (LVEF), versus 5 sham controls. RESULTS After 12 weeks of PVCs, LVEF (p = 0.006) and dP/dT (p = 0.007) decreased. Resting SNA (p = 0.002) and VNA (p = 0.04), exercise SNA (p = 0.01), SNA response to evoked PVCs (p = 0.005), heart rate (HR) at rest (p = 0.003), and exercise (p < 0.04) increased, whereas HR variability (HRV) decreased (p = 0.009). There was increased spontaneous atrial (p = 0.02) and ventricular arrhythmias (p = 0.03) in PVC-CM. Increased SNA preceded both atrial (p = 0.0003) and ventricular (p = 0.009) arrhythmia onset. Clonidine suppressed SNA and abolished all arrhythmias. After disabling PVC for 4 weeks, LVEF (p = 0.01), dP/dT (p = 0.047), and resting VNA (p = 0.03) recovered to baseline levels. However, SNA, resting HR, HRV, and atrial (p = 0.03) and ventricular (p = 0.03) proarrhythmia persisted. There was sympathetic hyperinnervation in stellate ganglia (p = 0.02) but not ventricles (p = 0.2) of PVC-CM and recovered animals versus sham controls. CONCLUSIONS Neural remodeling in PVC-CM is characterized by extracardiac sympathetic hyperinnervation and sympathetic neural hyperactivity that persists despite normalization of LVEF. The altered cardiac sympathovagal balance is an important trigger and substrate for atrial and ventricular proarrhythmia.
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Affiliation(s)
- Alex Y Tan
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia; Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia.
| | - Khalid Elharrif
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia; Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Ricardo Cardona-Guarache
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia; Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Pranav Mankad
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia; Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Owen Ayers
- Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Martha Joslyn
- Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Anindita Das
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Karoly Kaszala
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia; Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Shien-Fong Lin
- Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kenneth A Ellenbogen
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia; Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Anthony J Minisi
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia; Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Jose F Huizar
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia; Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
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19
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Affiliation(s)
- Jordana Kron
- Pauley Heart Center, Virginia Commonwealth University (J.K.)
| | - Alex Y Tan
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA (A.Y.T.)
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20
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Larsen TR, Saini A, Moore J, Huizar JF, Tan AY, Ellenbogen KA, Kaszala K. Fluoroscopy reduction during device implantation by using three-dimensional navigation. A single-center experience. J Cardiovasc Electrophysiol 2019; 30:2027-2033. [PMID: 31392815 DOI: 10.1111/jce.14102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 05/21/2019] [Accepted: 08/02/2019] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVES The use of nonfluoroscopic three-dimensional electroanatomic mapping (3DM) systems reduces radiation exposure during ablation procedures. In this study, we sought to determine the value of 3DM during routine device implant procedures. METHODS Seventy nonselected patients underwent implantation of a single chamber, dual chamber, or biventricular device guided by Ensite (Abbott Laboratories) to limit fluoroscopy use and compared with 70 consecutive patients, who underwent matching procedures with standard fluoroscopy use (FL) in the period immediately preceding the use of 3DM. The venous anatomy, right atrium, and ventricle and coronary sinus were mapped with 0.035 inch J-wire, quadripolar catheter, and/or angioplasty wire. The leads were advanced under real-time visualization in Ensite. RESULTS 3DM reduced both fluoroscopy time and dose. Median fluoroscopy time for FL vs 3DM was 5.5 minutes (interquartile range [IQR]: 3.8-8.1) vs 0.9 minutes (IQR: 0.6-1.9) (P < .001) for single chamber devices, 6.3 minutes (IQR: 5.1-7.9) vs 3.3 minutes (IQR: 1.9-4) (P < .001) for dual-chamber devices, and 28.6 minutes (IQR: 19.6-36.2) to 14.7 minutes (IQR: 10.4-22.3) (P = .009) for biventricular devices, respectively. The median air kerma for FL vs 3DM was 15.4 mGy (IQR: 8.1-30.2) vs 4 mGy (IQR: 1.8-8) (P < .001) for single chamber devices, 16 mGy (IQR: 12-18.5) to 9.4 mGy (IQR: 7.5-11.3) (P = .001) for dual-chamber devices, and 324 mGy (IQR: 143-668.7) to 115 mGy (IQR:77-204) (P = .014) for biventricular devices, respectively. There were no procedural complications. At 3-month follow-up, there was no difference in voltage threshold measurements between the groups. CONCLUSION The use of 3DM leads to significantly reduced fluoroscopy time and fluoroscopy dose during routine device implantation.
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Affiliation(s)
- Timothy R Larsen
- Pauley Heart Center, Medical College of Virginia Hospitals, Virginia Commonwealth University, Richmond, Virginia
| | - Aditya Saini
- Pauley Heart Center, Medical College of Virginia Hospitals, Virginia Commonwealth University, Richmond, Virginia
| | - Jessica Moore
- Division of Cardiac Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Jose F Huizar
- Pauley Heart Center, Medical College of Virginia Hospitals, Virginia Commonwealth University, Richmond, Virginia.,Division of Cardiac Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Alex Y Tan
- Pauley Heart Center, Medical College of Virginia Hospitals, Virginia Commonwealth University, Richmond, Virginia.,Division of Cardiac Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Kenneth A Ellenbogen
- Pauley Heart Center, Medical College of Virginia Hospitals, Virginia Commonwealth University, Richmond, Virginia
| | - Karoly Kaszala
- Pauley Heart Center, Medical College of Virginia Hospitals, Virginia Commonwealth University, Richmond, Virginia.,Division of Cardiac Electrophysiology, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
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21
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Gunda S, Akyeampong D, Gomez-Arroyo J, Jovin DG, Kowlgi NG, Kaszala K, Tan AY, Koneru JN, Kron J, Ellenbogen KA, Huizar JF. Consequences of chronic frequent premature atrial contractions: Association with cardiac arrhythmias and cardiac structural changes. J Cardiovasc Electrophysiol 2019; 30:1952-1959. [PMID: 31310360 DOI: 10.1111/jce.14067] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 05/22/2019] [Accepted: 06/24/2019] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Frequent premature ventricular contractions (PVCs) can cause cardiomyopathy (CM). Postextrasystolic potentiation (PESP) and irregularity have been in implicated as triggers of PVC-CM. Because both phenomena can also be found in premature atrial contractions (PACs), it is speculated that frequent PACs have similar consequences. METHODS AND RESULTS A single-center, retrospective study included all consecutive patients undergoing a 14-day Holter monitors (November 2014 to October 2016). Patients were divided into four groups by ectopy burden group 1 (<1%) and remaining by tertiles (group 2-4). Echocardiographic and arrhythmic data were compared between PAC and PVC burdens. In addition, a translational PAC animal model was used to assess the chronic effects of frequent PACs. A total 846 patients were reviewed. In contrast to PVCs, we found no difference in left ventricular ejection fraction (LVEF), end-systolic and end-diastolic dimensions and presence of CM (LVEF <50%) between different PAC groups. Multivariate regression analysis demonstrated that only PVC burden predicted low EF (odds ratio, 1.1; confidence interval, 1.03-1.13; P = .001). While there was a weak correlation between PAC burden and supraventricular tachycardia (SVT) episodes and atrial fibrillation (AF) burden (r = 0.19; P < .001), there was no correlation between PAC burden and LVEF or CM. Finally, atrial bigeminy in our animal model did not significantly decrease LVEF after 3 months. CONCLUSION PAC burden is associated with increased AF and SVT episodes. In contrast to a high PVC burden, a high PAC burden is not associated with CM. Our findings suggest that heart rate irregularity and/or PESP may play a minimal role in the pathophysiology of PVC-CM.
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Affiliation(s)
- Sampath Gunda
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Daniel Akyeampong
- Cardiology Division, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia
| | - Jose Gomez-Arroyo
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia.,Cardiology Division, University of Cincinnati Medical Center, Cincinnati, Ohio
| | - Daniel G Jovin
- Cardiology Division, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia
| | - Narayan G Kowlgi
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Karoly Kaszala
- Cardiology Division, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia
| | - Alex Y Tan
- Cardiology Division, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia
| | - Jayanthi N Koneru
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Jordana Kron
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | | | - Jose F Huizar
- Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia.,Cardiology Division, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia
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O'Quinn MP, Dormer KJ, Huizar JF, Nguyen KT, Kaszala K, Sima A, Ellenbogen KA, Tan AY. Epicardial injection of nanoformulated calcium into cardiac ganglionic plexi suppresses autonomic nerve activity and postoperative atrial fibrillation. Heart Rhythm 2019; 16:597-605. [PMID: 30929671 PMCID: PMC6446939 DOI: 10.1016/j.hrthm.2018.10.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Imbalanced activation of the cardiac autonomic nervous system triggers postoperative atrial fibrillation (POAF). Neuronal calcium overload induces apoptosis. We hypothesize that epicardial injection of timed-release nanoformulated CaCl2 (nCaCl2) into left atrial ganglionic plexi (GP) modulates autonomic function and suppresses POAF. OBJECTIVE The purpose of this study was to determine whether nCaCl2 GP therapy suppresses POAF. METHODS We used a novel canine model of POAF with implanted radiotelemetry to record nerve activity (NA) from the left stellate ganglion (SNA), left cardiac vagus nerve, and GP. At week 3, nCaCl2 (n = 7) or vehicle control (sham; n = 3) was injected into left pulmonary vein GP (LGP), followed by right pulmonary vein GP at week 4. Atrial effective refractory period (AERP) and atrial fibrillation vulnerability (AFV) were assessed in vivo. Resting and exercise NA and heart rate (HR) were assessed before and after LGP treatment. RESULTS AERP decreased (P < .0001) and AFV increased (P = .008) at week 3 vs baseline. However, nCaCl2-LGP treatment reversed these changes and restored them to baseline after 1 week (P = .04). Subsequent nCaCl2-right pulmonary vein GP treatment further reduced AFV (P = .03). In contrast, AFV increased (P = .001) and AERP remained decreased (P = .01) 1 week after sham-LGP treatment vs baseline. nCaCl2-LGP treatment reduced NA from GP (P < .02) and NA from the left cardiac vagus nerve (P < .05) and increased SNA (P < .02). Despite increased SNA, HR was decreased (P < .01) with loss of HR-SNA correlation (R = 0.62). After sham-LGP treatment, NA was unchanged and HR-SNA remained correlated (R = 0.95). Histology confirmed nCaCl2-GP colocalization, apoptosis, and loss of immunoreactivity in nCaCl2-treated somas. CONCLUSION Epicardial injection of nCaCl2 into left atrial GP induced neuroapoptosis and modulated autonomic function. This reversed a postoperative reduction in AERP and suppressed POAF.
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Affiliation(s)
- Michael P O'Quinn
- Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VAMC, Richmond, Virginia; Pauley Heart Center, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Kenneth J Dormer
- Liberty University College of Osteopathic Medicine, Lynchburg, Virginia
| | - Jose F Huizar
- Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VAMC, Richmond, Virginia; Pauley Heart Center, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | | | - Karoly Kaszala
- Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VAMC, Richmond, Virginia; Pauley Heart Center, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Adam Sima
- Department of Biostatistics, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Kenneth A Ellenbogen
- Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VAMC, Richmond, Virginia
| | - Alex Y Tan
- Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VAMC, Richmond, Virginia; Pauley Heart Center, Virginia Commonwealth University Medical Center, Richmond, Virginia.
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Larsen TR, Kaszala K, Tan AY, Ellenbogen KA, Huizar JF. Paradoxical reflex bradycardia after epinephrine infusion for arrhythmia induction in the electrophysiology laboratory. HeartRhythm Case Rep 2018; 4:455-458. [PMID: 30364668 PMCID: PMC6197463 DOI: 10.1016/j.hrcr.2018.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- Timothy R Larsen
- Hunter Holmes McGuire VA Medical Center, Richmond, Virginia.,Virginia Commonwealth University Medical Center, VCU Pauley Heart Center, Richmond, Virginia
| | - Karoly Kaszala
- Hunter Holmes McGuire VA Medical Center, Richmond, Virginia.,Virginia Commonwealth University Medical Center, VCU Pauley Heart Center, Richmond, Virginia
| | - Alex Y Tan
- Hunter Holmes McGuire VA Medical Center, Richmond, Virginia.,Virginia Commonwealth University Medical Center, VCU Pauley Heart Center, Richmond, Virginia
| | - Kenneth A Ellenbogen
- Virginia Commonwealth University Medical Center, VCU Pauley Heart Center, Richmond, Virginia
| | - Jose F Huizar
- Hunter Holmes McGuire VA Medical Center, Richmond, Virginia.,Virginia Commonwealth University Medical Center, VCU Pauley Heart Center, Richmond, Virginia
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Tan AY, Nearing BD, Rosenberg M, Nezafat R, Josephson ME, Verrier RL. Interlead heterogeneity of R- and T-wave morphology in standard 12-lead ECGs predicts sustained ventricular tachycardia/fibrillation and arrhythmic death in patients with cardiomyopathy. J Cardiovasc Electrophysiol 2017; 28:1324-1333. [DOI: 10.1111/jce.13288] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 06/15/2017] [Accepted: 06/27/2017] [Indexed: 11/28/2022]
Affiliation(s)
- Alex Y. Tan
- Electrophysiology Section, Division of Cardiology; Hunter Holmes McGuire VA Medical Center; Pauley Heart Center; Virginia Commonwealth University School of Medicine; Richmond VA USA
- Division of Cardiovascular Medicine; Department of Medicine, Beth Israel Deaconess Medical Center; Harvard Medical School; Boston MA USA
| | - Bruce D. Nearing
- Division of Cardiovascular Medicine; Department of Medicine, Beth Israel Deaconess Medical Center; Harvard Medical School; Boston MA USA
| | - Michael Rosenberg
- Division of Cardiovascular Medicine; Department of Medicine, Beth Israel Deaconess Medical Center; Harvard Medical School; Boston MA USA
- Division of Cardiology, Department of Medicine; University of Colorado School of Medicine; Denver CO USA
| | - Reza Nezafat
- Division of Cardiovascular Medicine; Department of Medicine, Beth Israel Deaconess Medical Center; Harvard Medical School; Boston MA USA
| | - Mark E. Josephson
- Division of Cardiovascular Medicine; Department of Medicine, Beth Israel Deaconess Medical Center; Harvard Medical School; Boston MA USA
| | - Richard L. Verrier
- Division of Cardiovascular Medicine; Department of Medicine, Beth Israel Deaconess Medical Center; Harvard Medical School; Boston MA USA
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Koneru JN, Swerdlow CD, Ploux S, Sharma PS, Kaszala K, Tan AY, Huizar JF, Vijayaraman P, Kenigsberg D, Ellenbogen KA. Mechanisms of Undersensing by a Noise Detection Algorithm That Utilizes Far-Field Electrograms With Near-Field Bandpass Filtering. J Cardiovasc Electrophysiol 2016; 28:224-232. [PMID: 27957764 DOI: 10.1111/jce.13143] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 10/29/2016] [Accepted: 11/06/2016] [Indexed: 11/29/2022]
Abstract
BACKGROUND Implantable cardioverter defibrillators (ICDs) must establish a balance between delivering appropriate shocks for ventricular tachyarrhythmias and withholding inappropriate shocks for lead-related oversensing ("noise"). To improve the specificity of ICD therapy, manufacturers have developed proprietary algorithms that detect lead noise. The SecureSenseTM RV Lead Noise discrimination (St. Jude Medical, St. Paul, MN, USA) algorithm is designed to differentiate oversensing due to lead failure from ventricular tachyarrhythmias and withhold therapies in the presence of sustained lead-related oversensing. METHODS AND RESULTS We report 5 patients in whom appropriate ICD therapy was withheld due to the operation of the SecureSense algorithm and explain the mechanism for inhibition of therapy in each case. Limitations of algorithms designed to increase ICD therapy specificity, especially for the SecureSense algorithm, are analyzed. CONCLUSION The SecureSense algorithm can withhold appropriate therapies for ventricular arrhythmias due to design and programming limitations. Electrophysiologists should have a thorough understanding of the SecureSense algorithm before routinely programming it and understand the implications for ventricular arrhythmia misclassification.
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Affiliation(s)
- Jayanthi N Koneru
- Virginia Commonwealth University/Pauley Heart Center, Richmond, Virginia, USA
| | | | - Sylvain Ploux
- Bordeaux University Hospital (CHU), Pessac, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, Pessac-Bordeaux, France
| | - Parikshit S Sharma
- Virginia Commonwealth University/Pauley Heart Center, Richmond, Virginia, USA
| | - Karoly Kaszala
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia, USA
| | - Alex Y Tan
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia, USA
| | - Jose F Huizar
- Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia, USA
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Abstract
Idiopathic ventricular tachycardia is often considered a benign form of ventricular arrhythmia in patients without apparent structural heart disease. However, a subset of patients may develop malignant ventricular arrhythmias and present with syncope and sudden cardiac arrest. Survivors of cardiac arrest are candidates for implantable cardiac defibrillators (ICDs). The indications for ICDs in patients with less than a full-blown cardiac arrest presentation but with electrocardiographically high-risk ectopy features remain uncertain. This article addresses some of the uncertainties and pitfalls in ICD risk stratification in this patient group and explores potential mechanisms for malignant conversion of benign premature ventricular complexes to sustained arrhythmia.
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Affiliation(s)
- Alex Y Tan
- Electrophysiology Section, Division of Cardiology, Hunter Holmes McGuire VA Medical Center, 1201 Broad Rock Boulevard, Richmond, VA 23249, USA; VCU Pauley Heart Center, Medical College of Virginia, Virginia Commonwealth University School of Medicine, 1250 E Marshall Street, Richmond, VA 23298, USA.
| | - Kenneth Ellenbogen
- VCU Pauley Heart Center, Medical College of Virginia, Virginia Commonwealth University School of Medicine, 1250 E Marshall Street, Richmond, VA 23298, USA
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Chinda K, Tsai WC, Chan YH, Lin AYT, Patel J, Zhao Y, Tan AY, Shen MJ, Lin H, Shen C, Chattipakorn N, Rubart-von der Lohe M, Chen LS, Fishbein MC, Lin SF, Chen Z, Chen PS. Intermittent left cervical vagal nerve stimulation damages the stellate ganglia and reduces the ventricular rate during sustained atrial fibrillation in ambulatory dogs. Heart Rhythm 2015; 13:771-80. [PMID: 26607063 DOI: 10.1016/j.hrthm.2015.11.031] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Indexed: 11/24/2022]
Abstract
BACKGROUND The effects of intermittent open-loop vagal nerve stimulation (VNS) on the ventricular rate (VR) during atrial fibrillation (AF) remain unclear. OBJECTIVE The purpose of this study was to test the hypothesis that VNS damages the stellate ganglion (SG) and improves VR control during persistent AF. METHODS We performed left cervical VNS in ambulatory dogs while recording the left SG nerve activity (SGNA) and vagal nerve activity. Tyrosine hydroxylase (TH) staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were used to assess neuronal cell death in the SG. RESULTS We induced persistent AF by atrial pacing in 6 dogs, followed by intermittent VNS with short ON-time (14 seconds) and long OFF-time (66 seconds). The integrated SGNA and VR during AF were 4.84 mV·s (95% confidence interval [CI] 3.08-6.60 mV·s) and 142 beats/min (95% CI 116-168 beats/min), respectively. During AF, VNS reduced the integrated SGNA and VR, respectively, to 3.74 mV·s (95% CI 2.27-5.20 mV·s; P = .021) and 115 beats/min (95% CI 96-134 beats/min; P = .016) during 66-second OFF-time and to 4.07 mV·s (95% CI 2.42-5.72 mV·s; P = .037) and 114 beats/min (95% CI 83-146 beats/min; P = .039) during 3-minute OFF-time. VNS increased the frequencies of prolonged (>3 seconds) pauses during AF. TH staining showed large confluent areas of damage in the left SG, characterized by pyknotic nuclei, reduced TH staining, increased percentage of TH-negative ganglion cells, and positive TUNEL staining. Occasional TUNEL-positive ganglion cells were also observed in the right SG. CONCLUSION VNS damaged the SG, leading to reduced SGNA and better rate control during persistent AF.
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Affiliation(s)
- Kroekkiat Chinda
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana; Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Department of Physiology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Wei-Chung Tsai
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana; Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Hsin Chan
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana; Division of Cardiology, The First Department of Medicine, Chang-Gung Memorial Hospital, Taipei, Taiwan
| | - Andrew Y-T Lin
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jheel Patel
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Ye Zhao
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana; Department of Cardiac Surgery, The First Affiliated Hospital of China Medical University, Shenyang, People's Republic of China
| | - Alex Y Tan
- Division of Cardiology, Hunter Holmes McGuire VA Medical Center, Virginia Commonwealth University, Richmond, Virginia
| | - Mark J Shen
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Hongbo Lin
- Department of Biostatistics, Indiana University School of Medicine and the Fairbanks School of Public Health, Indianapolis, Indiana
| | - Changyu Shen
- Department of Biostatistics, Indiana University School of Medicine and the Fairbanks School of Public Health, Indianapolis, Indiana
| | - Nipon Chattipakorn
- Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | | | - Lan S Chen
- The Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Michael C Fishbein
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Shien-Fong Lin
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana; Institute of Biomedical Engineering, National Chiao-Tung University, Hsin-Chu, Taiwan
| | - Zhenhui Chen
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Peng-Sheng Chen
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana.
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Tan AY, Hu YL, Potfay J, Kaszala K, Howren M, Sima AP, Shultz M, Koneru JN, Ellenbogen KA, Huizar JF. Impact of ventricular ectopic burden in a premature ventricular contraction-induced cardiomyopathy animal model. Heart Rhythm 2015; 13:755-61. [PMID: 26586453 DOI: 10.1016/j.hrthm.2015.11.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Indexed: 11/27/2022]
Abstract
BACKGROUND Frequent premature ventricular contractions (PVCs) have been associated with PVC-induced cardiomyopathy (CM) in some patients. OBJECTIVE The purpose of this study was to understand the cardiac consequences of different PVC burdens and the minimum burden required to induce left ventricular (LV) dysfunction. METHODS Right ventricular apical PVCs at a coupling interval of 240 ms were introduced at different PVC burdens in 9 mongrel canines. A stepwise increase in PVC burden was implemented every 8 weeks from 0% (baseline), 7%, 14%, 25%, 33% to 50% using our premature pacing algorithm. Echocardiogram and 24-hour Holter were obtained at 4- and 8-week period for each PVC burden with a single blinded reader assessing all echocardiographic parameters including those assessed by speckle tracking imaging (EchoPAC workstation, General Electric). CM was defined as left ventricular ejection fraction (LVEF) <50% or LVEF drop >10% points. Interleukin-6 and pro-brain natriuretic peptide levels were obtained at the end of each PVC burden. RESULTS The mean LVEF (mean heart rate) at 8 weeks for each PVC burden (0%, 7%, 14%, 33%, and 50%) were 57% ± 2.9% (85 ± 13 beats/min), 54.4% ± 3% (81 ± 10 beats/min), 53.3% ± 5% (77 ± 12 beats/min), 51.1% ± 4.2% (79 ± 14 beats/min), 47.7% ± 3.8% (80 ± 14 beats/min), and 44.7% ± 1.9% (157 ± 43 beats/min). PVC-induced CM was present in 11.1%, 44.4%, and 100% of animals with 25%, 33%, and 50% PVC burden, respectively. E/A ratio and radial strain decreased while left atrial size increased beyond 33% PVC burden. No changes in pro-brain natriuretic peptide and interleukin-6 levels were noted at any PVC burden. CONCLUSION LV systolic function (LVEF and radial strain) declined linearly as PVC burden increased. PVC-induced CM developed in some canines with 25% and 33% PVC burden, but developed in all animals with 50% PVC burden.
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Affiliation(s)
- Alex Y Tan
- Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia; Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Yuhning L Hu
- Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Jonathan Potfay
- Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia; Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Karoly Kaszala
- Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia; Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Maureen Howren
- Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Adam P Sima
- Department of Biostatistics, Virginia Commonwealth University, Richmond, Virginia
| | - Michael Shultz
- Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Jayanthi N Koneru
- Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Kenneth A Ellenbogen
- Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Jose F Huizar
- Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia; Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia.
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Tan AY, Ellenbogen KA, Kaszala K, Huizar J. Sustained Multiple Railroad Tracks on Implantable Cardiac Defibrillator Interval Plots: Mechanisms and Management. Circ Arrhythm Electrophysiol 2015; 8:1284-8. [PMID: 26487623 DOI: 10.1161/circep.114.002633] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Alex Y Tan
- From the Pauley Heart Center, Virginia Commonwealth University Medical Center (A.Y.T., K.A.E., K.K., J.H.); Division of Cardiology, Hunter Holmes McGuire Veterans Affairs Medical Center (A.Y.T., K.K., J.H.); and Virginia Commonwealth University School of Medicine (A.Y.T., K.A.E., K.K., J.H.), Richmond, VA.
| | - Kenneth A Ellenbogen
- From the Pauley Heart Center, Virginia Commonwealth University Medical Center (A.Y.T., K.A.E., K.K., J.H.); Division of Cardiology, Hunter Holmes McGuire Veterans Affairs Medical Center (A.Y.T., K.K., J.H.); and Virginia Commonwealth University School of Medicine (A.Y.T., K.A.E., K.K., J.H.), Richmond, VA
| | - Karoly Kaszala
- From the Pauley Heart Center, Virginia Commonwealth University Medical Center (A.Y.T., K.A.E., K.K., J.H.); Division of Cardiology, Hunter Holmes McGuire Veterans Affairs Medical Center (A.Y.T., K.K., J.H.); and Virginia Commonwealth University School of Medicine (A.Y.T., K.A.E., K.K., J.H.), Richmond, VA
| | - Jose Huizar
- From the Pauley Heart Center, Virginia Commonwealth University Medical Center (A.Y.T., K.A.E., K.K., J.H.); Division of Cardiology, Hunter Holmes McGuire Veterans Affairs Medical Center (A.Y.T., K.K., J.H.); and Virginia Commonwealth University School of Medicine (A.Y.T., K.A.E., K.K., J.H.), Richmond, VA
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Potfay J, Kaszala K, Tan AY, Sima AP, Gorcsan J, Ellenbogen KA, Huizar JF. Abnormal Left Ventricular Mechanics of Ventricular Ectopic Beats: Insights Into Origin and Coupling Interval in Premature Ventricular Contraction-Induced Cardiomyopathy. Circ Arrhythm Electrophysiol 2015; 8:1194-200. [PMID: 26297787 DOI: 10.1161/circep.115.003047] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 08/03/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Left ventricular (LV) dyssynchrony caused by premature ventricular contractions (PVCs) has been proposed as a mechanism of PVC-induced cardiomyopathy. We sought to understand the impact of different PVC locations and coupling intervals (prematurity) on LV regional mechanics and global function of the PVC beat itself. METHODS AND RESULTS Using our premature pacing algorithm, pentageminal PVCs at coupling intervals of 200 to 375 ms were delivered from the epicardial right ventricular apex, RV outflow tract, and LV free wall, as well as premature atrial contractions, from the left atrial appendage at a coupling interval of 200 ms in 7 healthy canines. LV short-axis echocardiographic images, LV stroke volume, and dP/dtmax were obtained during all ectopic beats and ventricular pacing. LV dyssynchrony was assessed by dispersion of QRS-to-peak strain (earliest-last QRS-to-peak strain) between 6 different LV segments during each of the aforementioned beats (GE, EchoPac). LV dyssynchrony was greater during long-coupled rather than short-coupled PVCs and PVCs at 375 ms compared with rapid ventricular pacing at 400 ms (P<0.0001), whereas no difference was found between PVC locations. Longer PVC coupling intervals were associated with greater stroke volume and dP/dtmax despite more pronounced dyssynchrony (P<0.001). CONCLUSIONS PVCs with longer coupling intervals demonstrate more pronounced LV dyssynchrony, whereas PVC location has minimal impact. LV dyssynchrony cannot be attributed to prematurity or abnormal ventricular activation alone, but rather to a combination of both. This study suggests that late-coupled PVCs may cause a more severe cardiomyopathy if dyssynchrony is the leading mechanism responsible for PVC-induced cardiomyopathy.
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Affiliation(s)
- Jonathan Potfay
- From the Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, VA (J.P., K.K., A.Y.T., J.F.H.); Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond (J.P., K.K., A.Y.T., K.A.E., J.F.H.); School of Biostatistics, Virginia Commonwealth University, Richmond (A.P.S.); and Cardiology Division, University of Pittsburgh Medical Center, PA (J.G. III)
| | - Karoly Kaszala
- From the Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, VA (J.P., K.K., A.Y.T., J.F.H.); Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond (J.P., K.K., A.Y.T., K.A.E., J.F.H.); School of Biostatistics, Virginia Commonwealth University, Richmond (A.P.S.); and Cardiology Division, University of Pittsburgh Medical Center, PA (J.G. III)
| | - Alex Y Tan
- From the Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, VA (J.P., K.K., A.Y.T., J.F.H.); Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond (J.P., K.K., A.Y.T., K.A.E., J.F.H.); School of Biostatistics, Virginia Commonwealth University, Richmond (A.P.S.); and Cardiology Division, University of Pittsburgh Medical Center, PA (J.G. III)
| | - Adam P Sima
- From the Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, VA (J.P., K.K., A.Y.T., J.F.H.); Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond (J.P., K.K., A.Y.T., K.A.E., J.F.H.); School of Biostatistics, Virginia Commonwealth University, Richmond (A.P.S.); and Cardiology Division, University of Pittsburgh Medical Center, PA (J.G. III)
| | - John Gorcsan
- From the Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, VA (J.P., K.K., A.Y.T., J.F.H.); Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond (J.P., K.K., A.Y.T., K.A.E., J.F.H.); School of Biostatistics, Virginia Commonwealth University, Richmond (A.P.S.); and Cardiology Division, University of Pittsburgh Medical Center, PA (J.G. III)
| | - Kenneth A Ellenbogen
- From the Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, VA (J.P., K.K., A.Y.T., J.F.H.); Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond (J.P., K.K., A.Y.T., K.A.E., J.F.H.); School of Biostatistics, Virginia Commonwealth University, Richmond (A.P.S.); and Cardiology Division, University of Pittsburgh Medical Center, PA (J.G. III)
| | - Jose F Huizar
- From the Cardiology Division, Hunter Holmes McGuire VA Medical Center, Richmond, VA (J.P., K.K., A.Y.T., J.F.H.); Cardiology Division/Pauley Heart Center, Virginia Commonwealth University, Richmond (J.P., K.K., A.Y.T., K.A.E., J.F.H.); School of Biostatistics, Virginia Commonwealth University, Richmond (A.P.S.); and Cardiology Division, University of Pittsburgh Medical Center, PA (J.G. III).
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Sharma PS, Tan AY, Ellenbogen KA, Huizar JF. Violation of Lower Rate Limit: What Is the Mechanism? J Cardiovasc Electrophysiol 2015; 26:909-911. [PMID: 25828955 DOI: 10.1111/jce.12677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 03/30/2015] [Indexed: 11/26/2022]
Affiliation(s)
- Parikshit S Sharma
- Virginia Commonwealth University Medical Center, Richmond, Virginia, USA.,Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia, USA
| | - Alex Y Tan
- Virginia Commonwealth University Medical Center, Richmond, Virginia, USA
| | | | - Jose F Huizar
- Virginia Commonwealth University Medical Center, Richmond, Virginia, USA
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Rosenberg MA, Gandhavadi M, Tan AY. To the Editor—Spontaneous conversion of a long RP to short RP tachycardia: what is the mechanism? Heart Rhythm 2014; 11:E5. [DOI: 10.1016/j.hrthm.2014.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Indexed: 11/26/2022]
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Tan AY, Blumenfeld J, Michaeel A, Donahue S, Bobb W, Parker T, Levine D, Rennert H. Autosomal dominant polycystic kidney disease caused by somatic and germline mosaicism. Clin Genet 2014; 87:373-7. [PMID: 24641620 DOI: 10.1111/cge.12383] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 03/11/2014] [Accepted: 03/16/2014] [Indexed: 12/11/2022]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is a heterogeneous genetic disorder caused by loss of function mutations of PKD1 or PKD2 genes. Although PKD1 is highly polymorphic and the new mutation rate is relatively high, the role of mosaicism is incompletely defined. Herein, we describe the molecular analysis of ADPKD in a 19-year-old female proband and her father. The proband had a PKD1 truncation mutation c.10745dupC (p.Val3584ArgfsX43), which was absent in paternal peripheral blood lymphocytes (PBL). However, very low quantities of this mutation were detected in the father's sperm DNA, but not in DNA from his buccal cells or urine sediment. Next generation sequencing (NGS) analysis determined the level of this mutation in the father's PBL, buccal cells and sperm to be ∼3%, 4.5% and 10%, respectively, consistent with somatic and germline mosaicism. The PKD1 mutation in ∼10% of her father's sperm indicates that it probably occurred early in embryogenesis. In ADPKD cases where a de novo mutation is suspected because of negative PKD gene testing of PBL, additional evaluation with more sensitive methods (e.g. NGS) of the proband PBL and paternal sperm can enhance detection of mosaicism and facilitate genetic counseling.
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Affiliation(s)
- A Y Tan
- Department of Pathology and Laboratory Medicine, New York, NY, USA
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Hellyer J, George Akingba A, Rhee KS, Tan AY, Lane KA, Shen C, Patel J, Fishbein MC, Chen PS. Autonomic nerve activity and blood pressure in ambulatory dogs. Heart Rhythm 2013; 11:307-13. [PMID: 24275433 DOI: 10.1016/j.hrthm.2013.11.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Indexed: 12/01/2022]
Abstract
BACKGROUND The relationship between cardiac autonomic nerve activity and blood pressure (BP) changes in ambulatory dogs is unclear. OBJECTIVE The purpose of this study was to test the hypotheses that simultaneous termination of stellate ganglion nerve activity (SGNA) and vagal nerve activity (VNA) predisposes to spontaneous orthostatic hypotension and that specific β₂-adrenoceptor blockade prevents the hypotensive episodes. METHODS We used a radiotransmitter to record SGNA, VNA, and BP in eight ambulatory dogs. Video imaging was used to document postural changes. RESULTS Of these eight dogs, five showed simultaneous sympathovagal discharges in which the minute-by-minute integrated SGNA correlated with integrated VNA in a linear pattern (group 1). In these dogs, abrupt termination of simultaneous SGNA-VNA at the time of postural changes (as documented by video imaging) was followed by abrupt (>20 mm Hg over four beats) drops in BP. Dogs without simultaneous on/off firing (group 2) did not have drastic drops in pressure. ICI-118,551 (ICI, a specific β₂-blocker) infused at 3 µg/kg/h for 7 days significantly increased BP from 126 mm Hg (95% confidence interval 118-133) to 133 mm Hg (95% confidence interval 125-141; P = .0001). The duration of hypotension (mean systolic BP <100 mm Hg) during baseline accounted for 7.1% of the recording. The percentage was reduced by ICI to 1.3% (P = .01). CONCLUSION Abrupt simultaneous termination of SGNA-VNA was observed at the time of orthostatic hypotension in ambulatory dogs. Selective β₂-adrenoceptor blockade increased BP and reduced the duration of hypotension in this model.
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Affiliation(s)
- Jessica Hellyer
- Division of Cardiology, Department of Medicine, Krannert Institute of Cardiology, Indianapolis, Indiana
| | - A George Akingba
- Division of Cardiology, Department of Medicine, Krannert Institute of Cardiology, Indianapolis, Indiana; Division of Vascular Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kyoung-Suk Rhee
- Division of Cardiology, Department of Medicine, Krannert Institute of Cardiology, Indianapolis, Indiana
| | - Alex Y Tan
- Hunter Holmes McGuire VA Medical Center, Virginia Commonwealth University, Richmond, Virginia
| | - Kathleen A Lane
- Department of Biostatistics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Changyu Shen
- Department of Biostatistics, Indiana University School of Medicine, Indianapolis, Indiana; Fairbanks School of Public Health, School of Medicine, Indiana University, Indianapolis, Indiana
| | - Jheel Patel
- Division of Cardiology, Department of Medicine, Krannert Institute of Cardiology, Indianapolis, Indiana
| | - Michael C Fishbein
- Division of Cardiology, Department of Medicine, Krannert Institute of Cardiology, Indianapolis, Indiana; Department of Pathology and Laboratory Medicine, University of California, Los Angeles, California
| | - Peng-Sheng Chen
- Division of Cardiology, Department of Medicine, Krannert Institute of Cardiology, Indianapolis, Indiana.
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Tan AY, Rosenberg MA. LOWERING THE RISK FOR THROMBUS AND STROKE IN ATRIAL FIBRILLATION PATIENTS: Will Dabigatran Replace Warfarin? Clin Med Rev Vasc Health 2013; 5:1-8. [PMID: 25253992 PMCID: PMC4170944 DOI: 10.4137/cmrvh.s6415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The use of oral anticoagulation to reduce stroke risk from thromboembolism has become the cornerstone of management of atrial fibrillation. Dabigatran is a direct thrombin inhibitor, which in contrast to warfarin, does not require regular blood draws for monitoring effect. Randomized controlled studies suggest that dabigatran may be more effective than warfarin at higher doses without an increased bleeding risk, and equally effective at lower doses, with lower bleeding risk. With these apparent advantages comes a higher cost, and limited use in patients with underlying renal or liver disease. In addition, the inability to measure anticoagulant effect, as with warfarin, presents a double-edged sword for clinical use of dabigatran. In this review, we discuss the mechanisms of action, clinical effect, and place in therapy of dabigatran as a possible replacement for warfarin.
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Affiliation(s)
- Alex Y Tan
- Division of Cardiac Electrophysiology, Beth Israel Deaconess Medical Center, Boston, MA
| | - Michael A Rosenberg
- Division of Cardiac Electrophysiology, Beth Israel Deaconess Medical Center, Boston, MA
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Roujol S, Tan AY, Anter E, Josephson ME, Nezafat R. Towards cardiac and respiratory motion characterization from electrophysiology data for improved real time MR-integration. J Cardiovasc Magn Reson 2013. [PMCID: PMC3560001 DOI: 10.1186/1532-429x-15-s1-p68] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Abstract
Autonomic nervous system activity exerts potent and diverse effects on cardiac rhythm through elaborate neurocircuitry that is integrated at multiple levels. Adrenergic activity such as is associated with mental or physical stress or as a reflex response to myocardial ischemia is capable of generating significant rhythm abnormalities including ventricular fibrillation, the arrhythmia responsible for sudden cardiac death. With respect to the ventricles, vagus nerve activity is generally antiarrhythmic as it inhibits the profibrillatory effects of sympathetic nerve activation, whereas atrial arrhythmias generally derive from heightened levels of both vagus and sympathetic nerve activity. Containment of neural influences by pharmacological and electrical targeted neuromodulation is being pursued as an antiarrhythmic modality.
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Affiliation(s)
- Alex Y Tan
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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Roujol S, Basha TA, Tan AY, Anter E, Buxton AE, Josephson ME, Nezafat R. Feasibility of real time integration of high-resolution scar images with invasive electrograms in electro-anatomical mapping system in patients undergoing ventricular tachycardia ablation. J Cardiovasc Magn Reson 2013. [PMCID: PMC3559393 DOI: 10.1186/1532-429x-15-s1-e94] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Tan AY, Abdi S, Buxton AE, Anter E. Percutaneous stellate ganglia block for acute control of refractory ventricular tachycardia. Heart Rhythm 2012; 9:2063-7. [DOI: 10.1016/j.hrthm.2012.07.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Indexed: 10/28/2022]
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Phua J, Ho BC, Tee A, Chan KP, Johan A, Loo S, So CR, Chia N, Tan AY, Tham HM, Chan YH, Koh Y. The impact of clinical protocols in the management of severe sepsis: a prospective cohort study. Anaesth Intensive Care 2012; 40:663-74. [PMID: 22813495 DOI: 10.1177/0310057x1204000413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This study aimed to assess the availability of clinical protocols and their effect on compliance to the Surviving Sepsis Campaign bundles and on mortality in severe sepsis in ten Singaporean adult teaching intensive care units (ICU). The presence of 11 protocols in the ICUs, steps taken based on the Johns Hopkins University Quality and Safety Research Group's model to translate protocols into practice, and organisational characteristics were assessed. Clinical and research personnel recorded characteristics of patients with severe sepsis who were admitted in July 2009, the achievement of sepsis bundle targets and outcomes. Hospital mortality was 39% for 128 patients. Fewer than half of the ICUs had protocols for early goal-directed therapy, blood cultures, antibiotics, steroids, lung-protective ventilation and weaning. Compliance rates with the resuscitation and management bundles were 18 and 3% respectively. Units with protocols were generally not more likely to achieve associated bundle targets. Steps from the Johns Hopkins model to measure performance, engage teams and sustain and extend interventions were taken in fewer than half of the available protocols. However, on logistic regression analysis, the number of protocols available per ICU was independently and inversely associated with mortality. In conclusion, clinical protocols are infrequently available in Singapore's ICUs and when present do not generally improve compliance to the sepsis bundles. These protocols may, however, be a surrogate marker of the quality of care as they are independently associated with decreased mortality. The use of an integrated and multifaceted approach to translate protocols into practice should be considered.
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Affiliation(s)
- J Phua
- Singapore Society of Intensive Care Medicine's National Investigators for Clinical Epidemiology and Research, Singapore.
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Shen MJ, Choi EK, Tan AY, Han S, Shinohara T, Maruyama M, Chen LS, Shen C, Hwang C, Lin SF, Chen PS. Patterns of baseline autonomic nerve activity and the development of pacing-induced sustained atrial fibrillation. Heart Rhythm 2010; 8:583-9. [PMID: 21118728 DOI: 10.1016/j.hrthm.2010.11.040] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2010] [Accepted: 11/23/2010] [Indexed: 12/17/2022]
Abstract
BACKGROUND Whether autonomic nerve activity is important in the development of pacing-induced sustained atrial fibrillation (AF) is unclear. OBJECTIVE The purpose of this study was to test the hypothesis that patterns of baseline autonomic nerve activity are important in the development of pacing-induced sustained AF. METHODS Radiotransmitters were implanted in 12 ambulatory dogs to record left stellate ganglion nerve activity (SGNA) and vagal nerve activity (VNA). Sustained (>48 hours) AF was induced with intermittent rapid atrial pacing. RESULTS At baseline (before pacing), 1-minute integrated nerve activity between SGNA and VNA demonstrated either a single linear relationship with excellent correlation (group 1, N = 3, r = 0.816 ± 0.105) or nonlinear relationships with poor correlation (group 2, N = 9, r = 0.316 ± 0.162, P <.05 vs group 1). Group 1 dogs had higher VNA (97.0 ± 11.5 mV-s) compared to group 2 (33.4 ± 21.7 mV-s, P <.001). Group 1 dogs had more frequent sympathovagal co-activation episodes than did group 2 (50 ± 19 per day vs 15 ± 6 per day, P <.05) and more paroxysmal atrial tachycardia (PAT; 5 ± 1 per day vs 2 ± 1 per day, P <.05) at baseline. Sustained AF occurred after 16 ± 4 days (range 13-20 days) of pacing in group 1 and after 46 ± 18 days (range 23-72 days) of pacing in group 2 (P <.05). In the week before development of sustained AF, VNA of group 2 dogs was significantly increased compared to baseline (P <.05). CONCLUSION Ambulatory dogs with good linear sympathovagal correlation and higher vagal tone at baseline have more PAT episodes at baseline and faster induction of sustained AF by rapid pacing. Rapid atrial pacing increased the VNA of the remaining dogs before induction of sustained AF.
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Affiliation(s)
- Mark J Shen
- Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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Shen MJ, Choi EK, Tan AY, Han S, Shinohara T, Maruyama M, Chen LS, Shen C, Hwang C, Lin SF, Chen PS. Baseline Autonomic Nerve Activity Predicts the Vulnerability to Sustained Atrial Fibrillation in Ambulatory Dogs. Heart Rhythm 2010. [DOI: 10.1016/j.hrthm.2010.09.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Tan AY, Zhou S, Ogawa M, Song J, Chu M, Li H, Fishbein MC, Lin SF, Chen LS, Chen PS. Neural mechanisms of paroxysmal atrial fibrillation and paroxysmal atrial tachycardia in ambulatory canines. Circulation 2008; 118:916-25. [PMID: 18697820 DOI: 10.1161/circulationaha.108.776203] [Citation(s) in RCA: 234] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND The relationship between autonomic activation and the mechanisms of paroxysmal atrial fibrillation remains unclear. METHODS AND RESULTS We implanted a pacemaker and a radio transmitter in 7 dogs (group 1). After baseline recording, we paced the left atrium at 20 Hz for 1 week and then monitored left stellate ganglion nerve activity, left vagal nerve activity, and left atrial electrogram without pacing for 24 hours. This protocol repeated itself until sustained atrial fibrillation (>48 hours) was induced in 3+/-1 weeks. In another 6 dogs (group 2), we cryoablated left and right stellate ganglia and the cardiac branch of the left vagal nerve during the first surgery and then repeated the same pacing protocol until sustained atrial fibrillation was induced in 7+/-4 weeks (P=0.01). There were 4+/-2 episodes of paroxysmal atrial fibrillation per day and 10+/-3 episodes of paroxysmal atrial tachycardia per day in group 1. Simultaneous sympathovagal discharges were observed to immediately precede the onset of atrial arrhythmias in 73% of episodes. In comparison, group 2 dogs had no paroxysmal atrial fibrillation (P=0.046) or paroxysmal atrial tachycardia (P<0.001) episodes. Nerve sprouting, sympathetic hyperinnervation, and a massive elevation of transcardiac norepinephrine levels occurred in both groups. CONCLUSIONS Intermittent rapid left atrial pacing results in sympathetic hyperinnervation, paroxysmal atrial fibrillation, and paroxysmal atrial tachycardia. Simultaneous sympathovagal discharges are common triggers of these arrhythmias. Cryoablation of extrinsic sympathovagal nerves eliminated paroxysmal atrial fibrillation and paroxysmal atrial tachycardia, which suggests that simultaneous sympathovagal discharges and these arrhythmias are causally related. Because cryoablation only delayed but did not prevent sustained atrial fibrillation, autonomic nerve activity is not the only factor that determines atrial fibrillation maintenance.
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Affiliation(s)
- Alex Y Tan
- Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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Tan AY, Zhou S, Jung BC, Ogawa M, Chen LS, Fishbein MC, Chen PS. Ectopic atrial arrhythmias arising from canine thoracic veins during in vivo stellate ganglia stimulation. Am J Physiol Heart Circ Physiol 2008; 295:H691-8. [PMID: 18539751 DOI: 10.1152/ajpheart.01321.2007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of the present study was to determine whether thoracic veins may act as ectopic pacemakers and whether nodelike cells and rich sympathetic innervation are present at the ectopic sites. We used a 1,792-electrode mapping system with 1-mm resolution to map ectopic atrial arrhythmias in eight normal dogs during in vivo right and left stellate ganglia (SG) stimulation before and after sinus node crushing. SG stimulation triggered significant elevations of transcardiac norepinephrine levels, sinus tachycardia in all dogs, and atrial tachycardia in two of eight dogs. Sinus node crushing resulted in a slow junctional rhythm (51 +/- 6 beats/min). Subsequent SG stimulation induced 20 episodes of ectopic beats in seven dogs and seven episodes of pulmonary vein tachycardia in three dogs (cycle length 273 +/- 35 ms, duration 16 +/- 4 s). The ectopic beats arose from the pulmonary vein (n = 11), right atrium (n = 5), left atrium (n = 2), and the vein of Marshall (n = 2). There was no difference in arrhythmogenic effects of left vs. right SG stimulation (13/29 vs. 16/29 episodes, P = nonsignificant). There was a greater density of periodic acid Schiff-positive cells (P < 0.05) and sympathetic nerves (P < 0.05) at the ectopic sites compared with other nonectopic atrial sites. We conclude that, in the absence of a sinus node, thoracic veins may function as subsidiary pacemakers under heightened sympathetic tone, becoming the dominant sites of initiation of focal atrial arrhythmias that arise from sites with abundant sympathetic nerves and periodic acid Schiff-positive cells.
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Affiliation(s)
- Alex Y Tan
- Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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Chou CC, Nguyen BL, Tan AY, Chang PC, Lee HL, Lin FC, Yeh SJ, Fishbein MC, Lin SF, Wu D, Wen MS, Chen PS. Intracellular calcium dynamics and acetylcholine-induced triggered activity in the pulmonary veins of dogs with pacing-induced heart failure. Heart Rhythm 2008; 5:1170-7. [PMID: 18554987 DOI: 10.1016/j.hrthm.2008.04.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2007] [Accepted: 04/09/2008] [Indexed: 11/19/2022]
Abstract
BACKGROUND Heart failure increases autonomic nerve activities and changes intracellular calcium (Ca(i)) dynamics. OBJECTIVE The purpose of this study was to investigate the hypothesis that abnormal Ca(i) dynamics are responsible for triggered activity in the pulmonary veins (PVs) during acetylcholine infusion in a canine model of heart failure. METHODS Simultaneous optical mapping of Ca(i) and membrane potential was performed in isolated Langendorff-perfused PV-left atrial (LA) preparations from nine dogs with ventricular pacing-induced heart failure. Mapping was performed at baseline, during acetylcholine (1 micromol/L) infusion (N = 9), and during thapsigargin and ryanodine infusion (N = 6). RESULTS Acetylcholine abbreviated the action potential. In four tissues, long pauses were followed by elevated diastolic Ca(i), late phase 3 early afterdepolarizations, and atrial fibrillation (AF). The incidence of PV focal discharges during AF was increased by acetylcholine from 2.4 +/- 0.6 beats/s (N = 4) to 6.5 +/- 2.2 beats/s (N = 8; P = .003). PV focal discharge and PV-LA microreentry coexisted in 6 of 9 preparations. The spatial distribution of dominant frequency demonstrated a focal source pattern, with the highest dominant frequency areas colocalized with PV focal discharge sites in 35 (95%) of 37 cholinergic AF episodes (N = 8). Thapsigargin and ryanodine infusion eliminated focal discharges in 6 of 6 preparations and suppressed the inducibility of AF in 4 of 6 preparations. PVs with focal discharge have higher densities of parasympathetic nerves than do PVs without focal discharges (P = .01), and periodic acid-Schiff (PAS)-positive cells were present at the focal discharge sites. CONCLUSION Ca(i) dynamics are important in promoting triggered activity during acetylcholine infusion in PVs from pacing-induced heart failure. PV focal discharge sites have PAS-positive cells and high densities of parasympathetic nerves.
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Affiliation(s)
- Chung-Chuan Chou
- Department of Medicine, Second Section of Cardiology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan
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Zhou S, Tan AY, Paz O, Ogawa M, Chou CC, Hayashi H, Nihei M, Fishbein MC, Chen LS, Lin SF, Chen PS. Antiarrhythmic effects of beta3-adrenergic receptor stimulation in a canine model of ventricular tachycardia. Heart Rhythm 2007; 5:289-97. [PMID: 18242556 DOI: 10.1016/j.hrthm.2007.10.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Accepted: 10/06/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND Beta3-adrenergic receptor (beta3-AR) stimulation inhibits cardiac contractility. OBJECTIVE This study sought to test the hypothesis that beta3-AR stimulation is antiarrhythmic. METHODS We implanted a radio transmitter for continuous electrocardiogram monitoring in 18 dogs with a tendency for high incidence of spontaneous ventricular tachycardia (VT). Ten of 18 had subcutaneous continuous BRL37344 (beta3-AR agonist) infusion (experimental group) for 1 month. The other dogs were controls. Western blotting studies were performed on tissues sampled from the noninfarcted left ventricular free wall of all dogs that survived the 60-day follow-up period. RESULTS Phase 2 VT appeared significantly later in the experimental group than in the control group (P <.05). The number of VT episodes in the experimental group was significantly lower than in the control group during both the first month (0.5 +/- 0.95 episodes/day vs. 2.6 +/- 2.3 episodes/day) and the second month (0.2 +/- 0.2 episode/day vs. 1.2 +/- 1.1 episodes/day, P <.05 for both). The experimental group had shorter QTc than control (P <.002). The experimental group had decreased protein levels for sodium calcium exchanger and dihydropyridine receptor, increased beta3-AR expression, without changes in beta1-AR, beta2-AR. The average heart weight and the left ventricular free wall thickness in the experimental group (226 +/- 17 g and 15.1 +/- 1.2 mm, respectively) was significantly lower than in the control group (265 +/- 21 g and 17.4 +/- 2.5 mm, respectively, P <.05 for both). There was no difference in the incidences of sudden cardiac death in these 2 groups of dogs. CONCLUSION Beta3-AR stimulation significantly reduces the occurrence of ventricular tachycardia.
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Affiliation(s)
- Shengmei Zhou
- Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
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Zhou S, Jung BC, Tan AY, Trang VQ, Gholmieh G, Han SW, Lin SF, Fishbein MC, Chen PS, Chen LS. Spontaneous stellate ganglion nerve activity and ventricular arrhythmia in a canine model of sudden death. Heart Rhythm 2007; 5:131-9. [PMID: 18055272 DOI: 10.1016/j.hrthm.2007.09.007] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2007] [Accepted: 09/06/2007] [Indexed: 12/16/2022]
Abstract
BACKGROUND Little information is available on the temporal relationship between instantaneous sympathetic nerve activity and ventricular arrhythmia in ambulatory animals. OBJECTIVE The purpose of this study was to determine if increased sympathetic nerve activity precedes the onset of ventricular arrhythmia. METHODS Simultaneous continuous long-term recording of left stellate ganglion (LSG) nerve activity and electrocardiography was performed in eight dogs with nerve growth factor infusion to the LSG, atrioventricular block, and myocardial infarction (experimental group) and in six normal dogs (control group). RESULTS LSG nerve activity included low-amplitude burst discharge activity (LABDA) and high-amplitude spike discharge activity (HASDA). Both LABDA and HASDA accelerated heart rate. In the experimental group, most ventricular tachycardia (86.3%) and sudden cardiac death were preceded within 15 seconds by either LABDA or HASDA. The closer to onset of ventricular tachycardia, the higher the nerve activity. The majority of HASDA was followed immediately by either ventricular arrhythmia (21%) or QRS morphology changes (65%). HASDA occurred in a circadian pattern. HASDA occurred twice as often in the experimental group than in the control group. Electrical stimulation of LSG increased transmural heterogeneity of repolarization (Tpeak-end intervals) and induced either ventricular tachycardia or fibrillation in the experimental group but not in the control group. Immunohistochemical studies revealed increased synaptogenesis and nerve sprouting in the LSG in the experimental group. CONCLUSION Two distinct types of LSG nerve activity (HASDA and LABDA) are present in the LSG of ambulatory dogs. The majority of malignant ventricular arrhythmias are preceded by either HASDA or LABDA, with HASDA particularly arrhythmogenic.
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Affiliation(s)
- Shengmei Zhou
- Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
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Ogawa M, Zhou S, Tan AY, Song J, Gholmieh G, Fishbein MC, Luo H, Siegel RJ, Karagueuzian HS, Chen LS, Lin SF, Chen PS. Left Stellate Ganglion and Vagal Nerve Activity and Cardiac Arrhythmias in Ambulatory Dogs With Pacing-Induced Congestive Heart Failure. J Am Coll Cardiol 2007; 50:335-43. [PMID: 17659201 DOI: 10.1016/j.jacc.2007.03.045] [Citation(s) in RCA: 173] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 02/20/2007] [Accepted: 03/06/2007] [Indexed: 11/27/2022]
Abstract
OBJECTIVES The purpose of this study was to determine the patterns of autonomic nerve activity in congestive heart failure (CHF). BACKGROUND The relationship between autonomic nerve activity and cardiac arrhythmias in CHF is unclear. METHODS We implanted radiotransmitters in 6 dogs for continuous (24/7) simultaneous monitoring of left stellate ganglion nerve activity (SGNA), vagal nerve activity (VNA), and electrocardiography before and after pacing-induced CHF. RESULTS Congestive heart failure increased both SGNA and VNA. The SGNA but not VNA manifested a circadian variation pattern. There was extensive sinus node fibrosis. We analyzed 2,263 episodes of prolonged (>3 s) sinus pauses (PSP) and 1,420 long (>10 s) episodes of paroxysmal atrial tachycardia (PAT). Most (95.3%) PSP episodes occurred at night, and 56% were preceded by a short burst of SGNA that induced transient sinus tachycardia. Long PAT episodes were typically (83%) induced by simultaneous SGNA and VNA discharge, followed by VNA withdrawal. Premature ventricular contractions and ventricular tachycardia were preceded by elevated SGNA. CONCLUSIONS The reduction of sympathovagal balance at night in ambulatory dogs was due to reduced sympathetic discharge rather than a net increase of vagal discharge. The tachybrady syndrome in CHF might be triggered by an intermittent short burst of SGNA that resulted in tachycardia and sinus node suppression. Simultaneous sympathovagal discharge is a cause of long PAT episodes. These data indicate that there is an association between the specific patterns of autonomic nerve discharges and cardiac arrhythmia during CHF.
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Affiliation(s)
- Masahiro Ogawa
- Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
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Abstract
Rapid repetitive activities arising from pulmonary veins may initiate atrial fibrillation. The basis of these rapid repetitive activities remains unclear, but recent evidence suggests that the autonomic nervous system plays an important role in their formation. Pulmonary veins and the adjoining left atrium are highly innervated structures. This review summarizes recent developments in the understanding of the anatomy of autonomic nerves in and around pulmonary veins and their implications for atrial fibrillation.
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Affiliation(s)
- Alex Y. Tan
- Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California
| | - Peng-Sheng Chen
- Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California
| | - Lan S. Chen
- Los Angeles Children’s Hospital, USC Keck School of Medicine, Los Angeles, California
| | - Michael C. Fishbein
- Division of Anatomical Pathology and Laboratory Medicine, Department of Pathology, David Geffen School of Medicine, University of California Los Angeles, and Division of Cardiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
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50
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Abstract
This review focuses on the importance of autonomic nervous system (ANS) activity in the induction of paroxysmal atrial fibrillation (PAF). Clinical studies suggest that both sympathetic and parasympathetic nervous systems are important in mediating PAF. Consistent with that hypothesis, heart rate variability analyses showed that sympathovagal imbalance is present before the onset of PAF episodes. The importance of the ANS in PAF is further supported by animal experiments and recent clinical studies showing that vagal denervation enhances the efficacy of circumferential pulmonary vein ablation in preventing AF recurrence. In vitro studies show that ANS activation facilitates early afterdepolarization and triggered activity by simultaneously prolonging the intracellular calcium (Ca(i)) transient (sympathetic effect) and shortening the action potential duration (parasympathetic effect). By simultaneously mapping the membrane potential and Ca(i) transient in canine pulmonary vein during sympathetic stimulation, we demonstrated that spontaneous (voltage-independent) sarcoplasmic reticulum calcium release underlies the mechanisms of focal discharges. We developed and studied canine models of PAF induced by electrical, structural, and neural remodeling. We also have developed methods for long-term continuous recording of sympathetic and vagal nerve activity in ambulatory dogs. Preliminary results show that simultaneous sympathovagal discharges precede the onset of PAF in these dogs. ANS activity and Ca(i) transient dynamics are important in the development of PAF. These studies suggest that new methods or drugs aimed at modification of cardiac ANS activity may lead to new opportunities for AF control.
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Affiliation(s)
- Peng-Sheng Chen
- Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center and David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA.
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