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Mc Loughlin MJ. Genesis of ischemic ST segment changes: A study using precordial bipolar leads and regional vectorcardiograms. J Electrocardiol 2024; 87:153789. [PMID: 39226818 DOI: 10.1016/j.jelectrocard.2024.153789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 08/11/2024] [Accepted: 08/26/2024] [Indexed: 09/05/2024]
Abstract
BACKGROUND Precordial Bipolar Leads (PBLs), Weighted Unipolar Leads (WUL), and Regional Vectorcardiograms (RVCGs) are constructed using the same data recorded by a standard 12‑lead ECG, but they provide additional information not visible in the standard 12‑lead ECG (ECG) tracings. OBJECTIVES In previous studies during balloon occlusion of the LAD and RCA, we observed a complete ischemic inversion of the QRS waves, with folding of the loop and ST segment shift. In the present study, we aim to investigate this abnormality using new ECG methods. We hypothesize that utilizing PBL, WUL, and RVCG in patients with ischemia caused by total acute coronary artery occlusion enables the detection of specific abnormalities-such as changes in waveform time/amplitude, the presence of the omega sign, distortion and folding of RVCG loops, and alterations in loop direction in both the transverse and frontal planes-that are not easily discernible with a standard 12‑lead ECG. This enhanced detection aids in understanding the mechanisms underlying electrocardiographic changes and may assist in managing patients when diagnostic uncertainties arise. METHODS Thirty-three patients undergoing elective PTCA were studied before and after acute LAD (16 patients) or RCA (17 patients) occlusion, and their data were processed with new methods based on PBLs, WULs, and RVCGs. RESULTS 1. In acute ischemia due to occlusion of the LAD and RCA, the most important current of injury occurs in the right to left axis. This axis is underestimated by the standard 12‑lead ECG and only partially complemented by leads V3R and V4R. 2. The two-dimensional presentation detects a new sign (the omega sign), not detectable in the classic ECG, but almost always present in ischemia. It also allows for an accurate identification of the J point. 3. Ischemic R wave peak delay results in distortion and folding of the RVCG loop and causes displacement of the J point and the ST segment. 4. Wave inversion changes the loop direction in the transverse and frontal plane. CONCLUSIONS Precordial bipolar leads, weighted unipolar leads, and regional vectorcardiograms provide essential information omitted by the standard 12‑lead ECG.
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Tallo FS, de Santana PO, Pinto SAG, Lima RY, de Araújo EA, Tavares JGP, Pires-Oliveira M, Nicolau LAD, Medeiros JVR, Taha MO, David AI, Luna-Filho B, Filho CEB, Barbosa AHP, Silva CMC, Wanderley AG, Caixeta A, Caricati-Neto A, Menezes-Rodrigues FS. Pharmacological Modulation of the Ca 2+/cAMP/Adenosine Signaling in Cardiac Cells as a New Cardioprotective Strategy to Reduce Severe Arrhythmias in Myocardial Infarction. Pharmaceuticals (Basel) 2023; 16:1473. [PMID: 37895945 PMCID: PMC10610028 DOI: 10.3390/ph16101473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 10/09/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
Acute myocardial infarction (AMI) is the main cause of morbidity and mortality worldwide and is characterized by severe and fatal arrhythmias induced by cardiac ischemia/reperfusion (CIR). However, the molecular mechanisms involved in these arrhythmias are still little understood. To investigate the cardioprotective role of the cardiac Ca2+/cAMP/adenosine signaling pathway in AMI, L-type Ca2+ channels (LTCC) were blocked with either nifedipine (NIF) or verapamil (VER), with or without A1-adenosine (ADO), receptors (A1R), antagonist (DPCPX), or cAMP efflux blocker probenecid (PROB), and the incidence of ventricular arrhythmias (VA), atrioventricular block (AVB), and lethality (LET) induced by CIR in rats was evaluated. VA, AVB and LET incidences were evaluated by ECG analysis and compared between control (CIR group) and intravenously treated 5 min before CIR with NIF 1, 10, and 30 mg/kg and VER 1 mg/kg in the presence or absence of PROB 100 mg/kg or DPCPX 100 µg/kg. The serum levels of cardiac injury biomarkers total creatine kinase (CK) and CK-MB were quantified. Both NIF and VER treatment were able to attenuate cardiac arrhythmias caused by CIR; however, these antiarrhythmic effects were abolished by pretreatment with PROB and DPCPX. The total serum CK and CK-MB were similar in all groups. These results indicate that the pharmacological modulation of Ca2+/cAMP/ADO in cardiac cells by means of attenuation of Ca2+ influx via LTCC and the activation of A1R by endogenous ADO could be a promising therapeutic strategy to reduce the incidence of severe and fatal arrhythmias caused by AMI in humans.
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Affiliation(s)
- Fernando Sabia Tallo
- Department of Urgency and Emergency Care, Universidade Federal de São Paulo (UNIFESP), São Paulo 04024-000, SP, Brazil
| | - Patricia Oliveira de Santana
- Postgraduate Program in Cardiology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04024-000, SP, Brazil; (P.O.d.S.); (S.A.G.P.); (R.Y.L.); (E.A.d.A.); (B.L.-F.); (C.E.B.F.); (A.H.P.B.); (C.M.C.S.); (A.C.)
| | - Sandra Augusta Gordinho Pinto
- Postgraduate Program in Cardiology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04024-000, SP, Brazil; (P.O.d.S.); (S.A.G.P.); (R.Y.L.); (E.A.d.A.); (B.L.-F.); (C.E.B.F.); (A.H.P.B.); (C.M.C.S.); (A.C.)
| | - Rildo Yamaguti Lima
- Postgraduate Program in Cardiology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04024-000, SP, Brazil; (P.O.d.S.); (S.A.G.P.); (R.Y.L.); (E.A.d.A.); (B.L.-F.); (C.E.B.F.); (A.H.P.B.); (C.M.C.S.); (A.C.)
| | - Erisvaldo Amarante de Araújo
- Postgraduate Program in Cardiology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04024-000, SP, Brazil; (P.O.d.S.); (S.A.G.P.); (R.Y.L.); (E.A.d.A.); (B.L.-F.); (C.E.B.F.); (A.H.P.B.); (C.M.C.S.); (A.C.)
| | - José Gustavo Padrão Tavares
- Department of Pharmacology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04023-062, SP, Brazil; (J.G.P.T.); (A.C.-N.)
| | - Marcelo Pires-Oliveira
- União Metropolitana de Educação e Cultura—School of Medicine (UNIME), Lauro de Freitas 42700-000, BA, Brazil;
| | - Lucas Antonio Duarte Nicolau
- Department of Biotechnology, Universidade Federal do Delta do Parnaíba (UFDPar), Parnaíba 64202-020, PI, Brazil; (L.A.D.N.); (J.V.R.M.)
| | - Jand Venes Rolim Medeiros
- Department of Biotechnology, Universidade Federal do Delta do Parnaíba (UFDPar), Parnaíba 64202-020, PI, Brazil; (L.A.D.N.); (J.V.R.M.)
| | - Murched Omar Taha
- Department of Surgery, Universidade Federal de São Paulo (UNIFESP), São Paulo 04023-900, SP, Brazil; (M.O.T.); (A.I.D.)
| | - André Ibrahim David
- Department of Surgery, Universidade Federal de São Paulo (UNIFESP), São Paulo 04023-900, SP, Brazil; (M.O.T.); (A.I.D.)
| | - Bráulio Luna-Filho
- Postgraduate Program in Cardiology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04024-000, SP, Brazil; (P.O.d.S.); (S.A.G.P.); (R.Y.L.); (E.A.d.A.); (B.L.-F.); (C.E.B.F.); (A.H.P.B.); (C.M.C.S.); (A.C.)
| | - Carlos Eduardo Braga Filho
- Postgraduate Program in Cardiology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04024-000, SP, Brazil; (P.O.d.S.); (S.A.G.P.); (R.Y.L.); (E.A.d.A.); (B.L.-F.); (C.E.B.F.); (A.H.P.B.); (C.M.C.S.); (A.C.)
| | - Adriano Henrique Pereira Barbosa
- Postgraduate Program in Cardiology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04024-000, SP, Brazil; (P.O.d.S.); (S.A.G.P.); (R.Y.L.); (E.A.d.A.); (B.L.-F.); (C.E.B.F.); (A.H.P.B.); (C.M.C.S.); (A.C.)
| | - Célia Maria Camelo Silva
- Postgraduate Program in Cardiology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04024-000, SP, Brazil; (P.O.d.S.); (S.A.G.P.); (R.Y.L.); (E.A.d.A.); (B.L.-F.); (C.E.B.F.); (A.H.P.B.); (C.M.C.S.); (A.C.)
| | - Almir Gonçalves Wanderley
- Department of Pharmaceutical Sciences, Universidade Federal de São Paulo (UNIFESP), Diadema 09913-030, SP, Brazil;
| | - Adriano Caixeta
- Postgraduate Program in Cardiology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04024-000, SP, Brazil; (P.O.d.S.); (S.A.G.P.); (R.Y.L.); (E.A.d.A.); (B.L.-F.); (C.E.B.F.); (A.H.P.B.); (C.M.C.S.); (A.C.)
| | - Afonso Caricati-Neto
- Department of Pharmacology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04023-062, SP, Brazil; (J.G.P.T.); (A.C.-N.)
| | - Francisco Sandro Menezes-Rodrigues
- Postgraduate Program in Cardiology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04024-000, SP, Brazil; (P.O.d.S.); (S.A.G.P.); (R.Y.L.); (E.A.d.A.); (B.L.-F.); (C.E.B.F.); (A.H.P.B.); (C.M.C.S.); (A.C.)
- Department of Surgery, Universidade Federal de São Paulo (UNIFESP), São Paulo 04023-900, SP, Brazil; (M.O.T.); (A.I.D.)
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Wang X, Wei L, Wu Y, Yan J, Zhao L, Yue X, Gao C. ST-segment elevation predicts the occurrence of malignant ventricular arrhythmia events in patients with acute ST-segment elevation myocardial infarction. BMC Cardiovasc Disord 2023; 23:61. [PMID: 36732698 PMCID: PMC9896671 DOI: 10.1186/s12872-023-03099-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND ST-segment elevation (STE) represents a repolarization dispersion marker underlying arrhythmogenesis in ST-segment elevation myocardial infarction (STEMI); however, its value for predicting malignant ventricular arrhythmia events (MVAEs) remains uncertain. METHODS In total, 285 patients with STEMI and those with or without MVAEs who presented within 6 h of symptom onset were enrolled. The relationships between STE and clinical characteristics of MVAEs (defined as ventricular tachycardia or ventricular fibrillation) were analyzed using t-test, chi-square test, binary multivariate logistic regression, and receiver operating characteristic curve analysis. RESULTS Patients with STEMI and MVAEs had a shorter time from symptom onset to balloon time (p = 0.0285) and greater STE (p < 0.01) than those without MVAEs. The symptom-to-balloon time, age, and STE were associated with MVAEs after stepwise regression analysis in all cases. Only STE was significantly associated with the occurrence of MVAEs (all, p < 0.01). The area under the curve (AUC) of STE for predicting MVAEs was 0.905, and the cut-off value was 4.5 mV. When only infarct-related arteries were included in the analysis, the AUC of the left anterior descending artery was 0.925 with a cut-off value of 4.5 mV, that of the right coronary artery was 0.915 with a cut-off value of 4.5 mV, and that of the left circumflex artery was 0.929 with a cut-off value of 4.0 mV. CONCLUSIONS In patients with STEMI presenting within 6 h of symptom onset, age, symptom-to-balloon time, and STE were the main predictors for MVAEs. However, among these, STE was the strongest predictor for MVAEs and was an index for repolarization dispersion of cardiomyocytes in infarcted and non-infarcted areas.
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Affiliation(s)
- Xianpei Wang
- Department of Cardiology, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou University Central China Fuwai Hospital, No. 1 Fuwai Avenue, Zhengdong New District, Zhengzhou, Henan Province, China.
| | - Lifang Wei
- grid.414011.10000 0004 1808 090XDepartment of Cardiology, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou University Central China Fuwai Hospital, No. 1 Fuwai Avenue, Zhengdong New District, Zhengzhou, Henan Province China
| | - Ying Wu
- grid.414011.10000 0004 1808 090XHenan Provincial Key Lab for Control of Coronary Heart Disease, Zhengzhou University Central China Fuwai Hospital, People’s Hospital of Zhengzhou University, Zhengzhou, Henan Province China
| | - Juanjuan Yan
- grid.414011.10000 0004 1808 090XDepartment of Cardiology, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou University Central China Fuwai Hospital, No. 1 Fuwai Avenue, Zhengdong New District, Zhengzhou, Henan Province China
| | - Linwei Zhao
- grid.414011.10000 0004 1808 090XDepartment of Cardiology, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou University Central China Fuwai Hospital, No. 1 Fuwai Avenue, Zhengdong New District, Zhengzhou, Henan Province China
| | - Xinjie Yue
- grid.414011.10000 0004 1808 090XDepartment of Cardiology, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou University Central China Fuwai Hospital, No. 1 Fuwai Avenue, Zhengdong New District, Zhengzhou, Henan Province China
| | - Chuanyu Gao
- grid.414011.10000 0004 1808 090XDepartment of Cardiology, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou University Central China Fuwai Hospital, No. 1 Fuwai Avenue, Zhengdong New District, Zhengzhou, Henan Province China ,grid.414011.10000 0004 1808 090XHenan Provincial Key Lab for Control of Coronary Heart Disease, Zhengzhou University Central China Fuwai Hospital, People’s Hospital of Zhengzhou University, Zhengzhou, Henan Province China
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Mc Loughlin MJ, Di Diego JM. Pathophysiology of myocardial currents of injury revisited. J Electrocardiol 2022; 74:54-58. [PMID: 35994822 DOI: 10.1016/j.jelectrocard.2022.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/20/2022] [Accepted: 08/08/2022] [Indexed: 12/13/2022]
Affiliation(s)
| | - José M Di Diego
- Lankenau Institute for Medical Research, Wynnewood, PA, United States of America.
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Xu X, Yin Y, Li D, Yao B, Zhao L, Wang H, Wang H, Dong J, Zhang J, Peng R. Vicious LQT induced by a combination of factors different from hERG inhibition. Front Pharmacol 2022; 13:930831. [PMID: 35935820 PMCID: PMC9354841 DOI: 10.3389/fphar.2022.930831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/28/2022] [Indexed: 11/13/2022] Open
Abstract
Clinically, drug-induced torsades de pointes (TdP) are rare events, whereas the reduction of the human ether-à-go-go-related gene (hERG) current is common. In this study, we aimed to explore the specific factors that contribute to the deterioration of hERG inhibition into malignant ventricular arrhythmias. Cisapride, a drug removed from the market because it caused long QT (LQT) syndrome and torsade de pointes (TdP), was used to induce hERG inhibition. The effects of cisapride on the hERG current were evaluated using a whole-cell patch clamp. Based on the dose-response curve of cisapride, models of its effects at different doses (10, 100, and 1,000 nM) on guinea pig heart in vitro were established. The effects of cisapride on electrocardiogram (ECG) signals and QT interval changes in the guinea pigs were then comprehensively evaluated by multi-channel electrical mapping and high-resolution fluorescence mapping, and changes in the action potential were simultaneously detected. Cisapride dose-dependently inhibited the hERG current with a half inhibitory concentration (IC50) of 32.63 ± 3.71 nM. The complete hERG suppression by a high dose of cisapride (1,000 nM) prolonged the action potential duration (APD), but not early after depolarizations (EADs) and TdP occurred. With 1 μM cisapride and lower Mg2+/K+, the APD exhibited triangulation, dispersion, and instability. VT was induced in two of 12 guinea pig hearts. Furthermore, the combined administration of isoproterenol was not therapeutic and increased susceptibility to ventricular fibrillation (VF) development. hERG inhibition alone led to QT and ERP prolongation and exerted an anti-arrhythmic effect. However, after the combination with low concentrations of magnesium and potassium, the prolonged action potential became unstable, triangular, and dispersed, and VT was easy to induce. The combination of catecholamines shortened the APD, but triangulation and dispersion still existed. At this time, VF was easily induced and sustained.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Jing Zhang
- *Correspondence: Jing Zhang, ; Ruiyun Peng,
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Olson M, Li JM, Adabag S, Benditt DG, Sakaguchi S. Transmural conduction delay and block producing a pseudo-infarction ECG during treatment of anaphylaxis. HeartRhythm Case Rep 2022; 8:453-457. [PMID: 35774203 PMCID: PMC9237354 DOI: 10.1016/j.hrcr.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/23/2022] [Accepted: 04/01/2022] [Indexed: 10/26/2022] Open
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Zagidullin NS, Motloch LJ, Musin TI, Bagmanova ZA, Lakman IA, Tyurin AV, Gumerov RM, Enikeev D, Cai B, Gareeva DF, Davtyan PA, Gareev DA, Talipova HM, Badykov MR, Jirak P, Kopp K, Hoppe UC, Pistulli R, Pavlov VN. J-waves in acute COVID-19: A novel disease characteristic and predictor of mortality? PLoS One 2021; 16:e0257982. [PMID: 34648510 PMCID: PMC8516278 DOI: 10.1371/journal.pone.0257982] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 09/14/2021] [Indexed: 12/14/2022] Open
Abstract
Background J-waves represent a common finding in routine ECGs (5–6%) and are closely linked to ventricular tachycardias. While arrhythmias and non-specific ECG alterations are a frequent finding in COVID-19, an analysis of J-wave incidence in acute COVID-19 is lacking. Methods A total of 386 patients consecutively, hospitalized due to acute COVID-19 pneumonia were included in this retrospective analysis. Admission ECGs were analyzed, screened for J-waves and correlated to clinical characteristics and 28-day mortality. Results J-waves were present in 12.2% of patients. Factors associated with the presence of J-waves were old age, female sex, a history of stroke and/or heart failure, high CRP levels as well as a high BMI. Mortality rates were significantly higher in patients with J-waves in the admission ECG compared to the non-J-wave cohort (J-wave: 14.9% vs. non-J-wave 3.8%, p = 0.001). After adjusting for confounders using a multivariable cox regression model, the incidence of J-waves was an independent predictor of mortality at 28-days (OR 2.76 95% CI: 1.15–6.63; p = 0.023). J-waves disappeared or declined in 36.4% of COVID-19 survivors with available ECGs for 6–8 months follow-up. Conclusion J-waves are frequently and often transiently found in the admission ECG of patients hospitalized with acute COVID-19. Furthermore, they seem to be an independent predictor of 28-day mortality.
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Affiliation(s)
- Naufal Shamilevich Zagidullin
- Department of Internal Medicine I, Bashkir State Medical University, Ufa, Russian Federation
- Department of Biomedical Engineering of Ufa State Aviation Technical University, Ufa, Russian Federation
- * E-mail:
| | - Lukas J. Motloch
- Clinic II for Internal Medicine, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Timur Ilgamovich Musin
- Department of Internal Medicine I, Bashkir State Medical University, Ufa, Russian Federation
| | | | - Irina Alexandrovna Lakman
- Department of Biomedical Engineering of Ufa State Aviation Technical University, Ufa, Russian Federation
- Department of Economics, Finance and Business, Bashkir State University, Ufa, Russian Federation
| | | | | | - Dinar Enikeev
- Department of Biomedical Engineering of Ufa State Aviation Technical University, Ufa, Russian Federation
| | - Benzhi Cai
- Department of Pharmacy at The Second Affiliated Hospital, and Department of Pharmacology (The Key Laboratory of Cardiovascular Medicine Research, Ministry of Education) at College of Pharmacy, Harbin Medical University, Harbin, China
| | | | | | - Damir Aidarovich Gareev
- Department of Internal Medicine I, Bashkir State Medical University, Ufa, Russian Federation
| | | | | | - Peter Jirak
- Clinic II for Internal Medicine, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Kristen Kopp
- Clinic II for Internal Medicine, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Uta C. Hoppe
- Clinic II for Internal Medicine, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Rudin Pistulli
- Department of Cardiology I, Coronary and Peripheral Vascular Disease, Heart Failure, University Hospital Münster, Münster, Germany
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Van Malderen SCH, Schultz CJ, Jordaens L. Case report: Synergetic effect of ischaemia and increased vagal tone inducing ventricular fibrillation in a patient with Brugada syndrome. Eur Heart J Case Rep 2020; 4:1-5. [PMID: 32974459 PMCID: PMC7501915 DOI: 10.1093/ehjcr/ytaa202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/15/2019] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Brugada syndrome (BS) is a hereditary channelopathy associated with syncope, malignant ventricular arrhythmia, and sudden cardiac death. Right ventricular ischaemia and BS have similar underlying substrates precipitating ventricular tachycardia or fibrillation (VF). CASE SUMMARY A 72-year-old woman with BS and a stenosis on the proximal right coronary artery received several subsequent implantable cardioverter-defibrillator shocks due to VF during an episode of extreme nausea with vomiting. DISCUSSION This case report emphasizes on the synergetic effect of mild ischaemia and increased vagal tone on the substrate responsible for BS to create pathophysiological changes precipitating VF.
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Affiliation(s)
- Sophie C H Van Malderen
- Department of Cardiology, Erasmus MC, Dr. Molewaterplein 40. 3015 GD, Rotterdam, The Netherlands
- Department of Cardiology, AZ Monica, Florent Pauwelslei 1, 2100, Deurne, Belgium
| | - Carl J Schultz
- School of Medicine, University of Western Australia, Perth, Western Australia, Australia
- Department of Cardiology, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Luc Jordaens
- Department of Cardiology, Erasmus MC, Dr. Molewaterplein 40. 3015 GD, Rotterdam, The Netherlands
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Okada JI, Fujiu K, Yoneda K, Iwamura T, Washio T, Komuro I, Hisada T, Sugiura S. Ionic mechanisms of ST segment elevation in electrocardiogram during acute myocardial infarction. J Physiol Sci 2020; 70:36. [PMID: 32660418 PMCID: PMC10717899 DOI: 10.1186/s12576-020-00760-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/30/2020] [Indexed: 11/10/2022]
Abstract
ST elevation on an electrocardiogram is a hallmark of acute transmural ischemia. However, the underlying mechanism remains unclear. We hypothesized that high ischemic sensitivities of epicardial adenosine triphosphate-sensitive potassium (IKATP) and sodium (INa) currents play key roles in the genesis of ST elevation. Using a multi-scale heart simulation under moderately ischemic conditions, transmural heterogeneities of IKATP and INa created a transmural gradient, opposite to that observed in subendocardial injury, leading to ST elevation. These heterogeneities also contributed to the genesis of hyper-acute T waves under mildly ischemic conditions. By contrast, under severely ischemic conditions, although action potentials were suppressed transmurally, the potential gradient at the boundary between the ischemic and normal regions caused ST elevation without a contribution from transmural heterogeneity. Thus, transmural heterogeneities of ion channel properties may contribute to the genesis of ST-T changes during mild or moderate transmural ischemia, while ST elevation may be induced without the contribution of heterogeneity under severe ischemic conditions.
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Grants
- hp150260 Ministry of Education, Culture, Sports, Science and Technology
- hp160209 Ministry of Education, Culture, Sports, Science and Technology
- hp170233 Ministry of Education, Culture, Sports, Science and Technology
- hp180210 Ministry of Education, Culture, Sports, Science and Technology
- hp150260 Ministry of Education, Culture, Sports, Science and Technology
- hp160209 Ministry of Education, Culture, Sports, Science and Technology
- hp170233 Ministry of Education, Culture, Sports, Science and Technology
- hp180210 Ministry of Education, Culture, Sports, Science and Technology
- hp150260 Ministry of Education, Culture, Sports, Science and Technology
- hp160209 Ministry of Education, Culture, Sports, Science and Technology
- hp170233 Ministry of Education, Culture, Sports, Science and Technology
- hp180210 Ministry of Education, Culture, Sports, Science and Technology
- hp150260 Ministry of Education, Culture, Sports, Science and Technology
- hp160209 Ministry of Education, Culture, Sports, Science and Technology
- hp170233 Ministry of Education, Culture, Sports, Science and Technology
- hp180210 Ministry of Education, Culture, Sports, Science and Technology
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Affiliation(s)
- Jun-Ichi Okada
- UT-Heart Inc., 3-25-8 Nozawa, Setagaya, Tokyo, 154-0003, Japan.
- Future Center Initiative, The University of Tokyo, 178-4-4 Wakashiba, Kashiwa, Chiba, 277-0871, Japan.
| | - Katsuhiko Fujiu
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo, 113-8655, Japan
- Department of Advanced Cardiology, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo, 113-8655, Japan
| | - Kazunori Yoneda
- Healthcare Solutions Unit, Fujitsu Limited, Minato, Tokyo, 108-0075, Japan
| | - Takashi Iwamura
- Healthcare Solutions Unit, Fujitsu Limited, Minato, Tokyo, 108-0075, Japan
| | - Takumi Washio
- UT-Heart Inc., 3-25-8 Nozawa, Setagaya, Tokyo, 154-0003, Japan
- Future Center Initiative, The University of Tokyo, 178-4-4 Wakashiba, Kashiwa, Chiba, 277-0871, Japan
| | - Issei Komuro
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo, 113-8655, Japan
| | - Toshiaki Hisada
- UT-Heart Inc., 3-25-8 Nozawa, Setagaya, Tokyo, 154-0003, Japan
| | - Seiryo Sugiura
- UT-Heart Inc., 3-25-8 Nozawa, Setagaya, Tokyo, 154-0003, Japan
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10
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Menezes-Rodrigues FS, Tavares JGP, Vasques ER, Errante PR, Araújo EAD, Pires-Oliveira M, Scorza CA, Scorza FA, Taha MO, Caricati-Neto A. Cardioprotective effects of pharmacological blockade of the mitochondrial calcium uniporter on myocardial ischemia-reperfusion injury. Acta Cir Bras 2020; 35:e202000306. [PMID: 32692797 PMCID: PMC7251977 DOI: 10.1590/s0102-865020200030000006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Accepted: 02/22/2020] [Indexed: 05/13/2023] Open
Abstract
PURPOSE To evaluate whether the attenuation of mitochondrial Ca2+ overload produced by pharmacological blockade of mitochondrial Ca2+ uniporter (MCU) protects the myocardium against injuries caused by cardiac ischemia and reperfusion (CIR). METHODS CIR was induced in adult male Wistar rats (300-350 g) by occlusion of the left anterior descendent coronary artery (10 min), followed by reperfusion (120 min). Rats were treated with different doses of MCU blocker ruthenium red (RuR), administered 5 min before ischemia or reperfusion. RESULTS In untreated rats, the incidences of ventricular arrhythmias (VA), atrioventricular block (AVB) and the lethality (LET) induced by CIR were 85%, 79% and 70%, respectively. In rats treated with RuR before ischemia, the incidences of VA, AVB and LET were significantly reduced to 62%, 25% and 25%, respectively. In rats treated with RuR after ischemia, the incidences of VA, AVB and LET were significantly reduced to 50%, 25% and 25%, respectively. CONCLUSION The significant reduction of the incidence of CIR-induced VA, AVB and LET produced by the treatment with RuR indicates that the attenuation of mitochondrial Ca2+ overload produced by pharmacological blockade of MCU can protect the myocardium against injuries caused by CIR.
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11
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Wang X, Zhang L, Gao C, Wu S, Zhu J. ST-segment elevation and the Tpeak-Tend/QT ratio predict the occurrence of malignant arrhythmia events in patients with vasospastic angina. J Electrocardiol 2019; 53:52-56. [DOI: 10.1016/j.jelectrocard.2019.01.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 12/15/2018] [Accepted: 01/01/2019] [Indexed: 10/27/2022]
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12
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Almer J, Jennings RB, Ringborn M, Engblom H. Ischemic QRS prolongation as a predictor of ventricular fibrillation in a canine model. SCAND CARDIOVASC J 2018; 52:262-267. [PMID: 30182762 PMCID: PMC6397935 DOI: 10.1080/14017431.2018.1494304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 06/08/2018] [Accepted: 06/15/2018] [Indexed: 10/28/2022]
Abstract
OBJECTIVES An acute coronary occlusion and its possible subsequent complications is one of the most common causes of death. One such complication is ventricular fibrillation (VF) due to myocardial ischemia. The severity of ischemia is related to the amount of coronary arterial collateral flow. In dog studies collateral flow has also been shown to be associated with QRS prolongation. The aim of this study was to investigate whether ischemic QRS prolongation (IQP) is associated with impending VF in an experimental acute ischemia dog model. METHODS Degree of IQP and occurrence of VF were measured in dogs (n = 21) during coronary occlusion for 15 min and also during subsequent reperfusion (experiments conducted in 1984). RESULTS There was a significant difference in absolute IQP between dogs which developed VF during reperfusion (47 ± 29 ms, mean ± SD) and those which did not (12 ± 10 ms; p = .001). CONCLUSIONS IQP during acute coronary occlusion is associated with reperfusion VF in an experimental dog model and might therefore be a potential predictor of malignant arrhythmias in patients with acute coronary syndrome.
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Affiliation(s)
- Jakob Almer
- Department of Clinical physiology and Nuclear medicine, Skåne University Hospital and Lund
University, Lund, Sweden
| | | | | | - Henrik Engblom
- Department of Clinical physiology and Nuclear medicine, Skåne University Hospital and Lund
University, Lund, Sweden
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13
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Cipriani A, D'Amico G, Brunello G, Perazzolo Marra M, Migliore F, Cacciavillani L, Tarantini G, Bauce B, Iliceto S, Corrado D, Zorzi A. The electrocardiographic “triangular QRS-ST-T waveform” pattern in patients with ST-segment elevation myocardial infarction: Incidence, pathophysiology and clinical implications. J Electrocardiol 2018; 51:8-14. [DOI: 10.1016/j.jelectrocard.2017.08.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Indexed: 11/17/2022]
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14
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Tse G, Liu T, Li KHC, Laxton V, Chan YWF, Keung W, Li RA, Yan BP. Electrophysiological Mechanisms of Brugada Syndrome: Insights from Pre-clinical and Clinical Studies. Front Physiol 2016; 7:467. [PMID: 27803673 PMCID: PMC5067537 DOI: 10.3389/fphys.2016.00467] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 09/27/2016] [Indexed: 12/19/2022] Open
Abstract
Brugada syndrome (BrS), is a primary electrical disorder predisposing affected individuals to sudden cardiac death via the development of ventricular tachycardia and fibrillation (VT/VF). Originally, BrS was linked to mutations in the SCN5A, which encodes for the cardiac Na+ channel. To date, variants in 19 genes have been implicated in this condition, with 11, 5, 3, and 1 genes affecting the Na+, K+, Ca2+, and funny currents, respectively. Diagnosis of BrS is based on ECG criteria of coved- or saddle-shaped ST segment elevation and/or T-wave inversion with or without drug challenge. Three hypotheses based on abnormal depolarization, abnormal repolarization, and current-load-mismatch have been put forward to explain the electrophysiological mechanisms responsible for BrS. Evidence from computational modeling, pre-clinical, and clinical studies illustrates that molecular abnormalities found in BrS lead to alterations in excitation wavelength (λ), which ultimately elevates arrhythmic risk. A major challenge for clinicians in managing this condition is the difficulty in predicting the subset of patients who will suffer from life-threatening VT/VF. Several repolarization risk markers have been used thus far, but these neglect the contributions of conduction abnormalities in the form of slowing and dispersion. Indices incorporating both repolarization and conduction and based on the concept of λ have recently been proposed. These may have better predictive values than the existing markers.
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Affiliation(s)
- Gary Tse
- Department of Medicine and Therapeutics, Chinese University of Hong KongHong Kong, Hong Kong
- Li Ka Shing Institute of Health Sciences, Chinese University of Hong KongHong Kong, Hong Kong
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical UniversityTianjin, China
| | - Ka H. C. Li
- Faculty of Medicine, Newcastle UniversityNewcastle, UK
| | - Victoria Laxton
- Intensive Care Department, Royal Brompton and Harefield NHS TrustLondon, UK
| | - Yin W. F. Chan
- School of Biological Sciences, University of CambridgeCambridge, UK
| | - Wendy Keung
- Stem Cell and Regenerative Medicine Consortium, Li Ka Shing Faculty of Medicine, The University of Hong KongPokfulam, Hong Kong
| | - Ronald A. Li
- Ming Wai Lau Centre for Reparative Medicine, Karolinska InstitutetSolna, Sweden
| | - Bryan P. Yan
- Department of Medicine and Therapeutics, Chinese University of Hong KongHong Kong, Hong Kong
- Department of Epidemiology and Preventive Medicine, Monash UniversityMelbourne, VIC, Australia
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15
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Mayourian J, Savizky RM, Sobie EA, Costa KD. Modeling Electrophysiological Coupling and Fusion between Human Mesenchymal Stem Cells and Cardiomyocytes. PLoS Comput Biol 2016; 12:e1005014. [PMID: 27454812 PMCID: PMC4959759 DOI: 10.1371/journal.pcbi.1005014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 06/08/2016] [Indexed: 01/16/2023] Open
Abstract
Human mesenchymal stem cell (hMSC) delivery has demonstrated promise in preclinical and clinical trials for myocardial infarction therapy; however, broad acceptance is hindered by limited understanding of hMSC-human cardiomyocyte (hCM) interactions. To better understand the electrophysiological consequences of direct heterocellular connections between hMSCs and hCMs, three original mathematical models were developed, representing an experimentally verified triad of hMSC families with distinct functional ion channel currents. The arrhythmogenic risk of such direct electrical interactions in the setting of healthy adult myocardium was predicted by coupling and fusing these hMSC models to the published ten Tusscher midcardial hCM model. Substantial variations in action potential waveform—such as decreased action potential duration (APD) and plateau height—were found when hCMs were coupled to the two hMSC models expressing functional delayed rectifier-like human ether à-go-go K+ channel 1 (hEAG1); the effects were exacerbated for fused hMSC-hCM hybrid cells. The third family of hMSCs (Type C), absent of hEAG1 activity, led to smaller single-cell action potential alterations during coupling and fusion, translating to longer tissue-level mean action potential wavelength. In a simulated 2-D monolayer of cardiac tissue, re-entry vulnerability with low (5%) hMSC insertion was approximately eight-fold lower with Type C hMSCs compared to hEAG1-functional hMSCs. A 20% decrease in APD dispersion by Type C hMSCs compared to hEAG1-active hMSCs supports the claim of reduced arrhythmogenic potential of this cell type with low hMSC insertion. However, at moderate (15%) and high (25%) hMSC insertion, the vulnerable window increased independent of hMSC type. In summary, this study provides novel electrophysiological models of hMSCs, predicts possible arrhythmogenic effects of hMSCs when directly coupled to healthy hCMs, and proposes that isolating a subset of hMSCs absent of hEAG1 activity may offer increased safety as a cell delivery cardiotherapy at low levels of hMSC-hCM coupling. Myocardial infarction—better known as a heart attack—strikes on average every 43 seconds in America. An emerging approach to treat myocardial infarction patients involves the delivery of human mesenchymal stem cells (hMSCs) to the damaged heart. While clinical trials of this therapeutic approach have yet to report adverse effects on heart electrical rhythm, such consequences have been implicated in simpler experimental systems and thus remain a concern. In this study, we utilized mathematical modeling to simulate electrical interactions arising from direct coupling between hMSCs and human heart cells to develop insight into the possible adverse effects of this therapeutic approach on human heart electrical activity, and to assess a novel strategy for reducing some potential risks of this therapy. We developed the first mathematical models of electrical activity of three families of hMSCs based on published experimental data, and integrated these with previously established mathematical models of human heart cell electrical activity. Our computer simulations demonstrated that one particular family of hMSCs minimized the disturbances in cardiac electrical activity both at the single-cell and tissue levels, suggesting that isolating this specific sub-population of hMSCs for myocardial delivery could potentially increase the safety of future hMSC-based heart therapies.
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Affiliation(s)
- Joshua Mayourian
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Ruben M. Savizky
- Department of Chemistry, The Cooper Union, New York, New York, United States of America
| | - Eric A. Sobie
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Kevin D. Costa
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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16
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Kalinauskiene E, Balnyte R, Naudziunas A. A constant ST segment elevation in leads II, III, AVF: An electrocardiographic, echocardiographic, clinical, exercise test, laboratory and multi-slice computed tomography angiographic study. J Electrocardiol 2016; 49:610-3. [PMID: 27212143 DOI: 10.1016/j.jelectrocard.2016.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Indexed: 10/21/2022]
Abstract
A constant ST-elevation was more often described in precordial leads. We presented it in leads II, III, AVF in 16 consecutive patients seeking to establish a link between it and clinical, laboratory, echocardiography, exercise test, and multi-slice computed tomography angiography data. Main complaint of these obese middle-age men was angina pectoris (68.75%). They usually had hypertension, dyslipidemia, concentric left ventricular hypertrophy and non-pathological exercise test. Coronary stenosis >50% was only in one case (6.25%). Despite the typical pain and risk factors, the constant ST-elevation in leads II, III, AVF usually was not associated with coronary stenosis.
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Affiliation(s)
- Egle Kalinauskiene
- Department of Internal Diseases, Lithuanian University of Health Sciences, Josvainiu 2, Kaunas, Lithuania.
| | - Ruta Balnyte
- Department of Internal Diseases, Lithuanian University of Health Sciences, Josvainiu 2, Kaunas, Lithuania
| | - Albinas Naudziunas
- Department of Internal Diseases, Lithuanian University of Health Sciences, Josvainiu 2, Kaunas, Lithuania
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17
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Yochai B, Nikus K, Birnbaum Y. About QRS prolongation, distortion and the acuteness score. J Electrocardiol 2016; 49:265-71. [PMID: 26972846 DOI: 10.1016/j.jelectrocard.2016.02.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Indexed: 01/25/2023]
Affiliation(s)
- Birnbaum Yochai
- The Section of Cardiology, the Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Kjell Nikus
- Cardiology Department, Heart Center, Tampere University Hospital and School of Medicine, University of Tampere, Finland
| | - Yochai Birnbaum
- The Section of Cardiology, the Department of Medicine, Baylor College of Medicine, Houston, TX, USA.
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18
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Reply to the Editor-Regarding Dynamic ECG Abnormalities at the Junction of QRS Complex and ST Segment as Indicators of Arrhythmia Risk During Acute Ischemia. Heart Rhythm 2016; 13:e239-e240. [PMID: 26775797 DOI: 10.1016/j.hrthm.2016.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Indexed: 11/24/2022]
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19
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The Osborn wave: what have we learned? Herz 2015; 41:48-56. [DOI: 10.1007/s00059-015-4338-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 06/22/2015] [Accepted: 06/29/2015] [Indexed: 11/28/2022]
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20
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Oguro T, Fujii M, Fuse K, Takahashi M, Fujita S, Kitazawa H, Sato M, Ikeda Y, Okabe M, Aizawa Y. Electrical alternans induced by a brief period of myocardial ischemia during percutaneous coronary intervention: The characteristic ECG morphology and relationship to mechanical alternans. Heart Rhythm 2015; 12:2272-7. [PMID: 26091855 DOI: 10.1016/j.hrthm.2015.06.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Indexed: 11/18/2022]
Abstract
BACKGROUND Electrical alternans (EA) has not been fully studied in the current percutaneous coronary intervention (PCI) procedure. OBJECTIVE The purpose of this study was to evaluate visible EA and the morphology of ST segment during PCI. METHODS The incidence of visible EA and ST-segment morphology were studied while the coronary artery was occluded for 20 seconds. When data were available, the relationship between EA and blood pressure was analyzed. The clinical and electrocardiographic data were compared with those of the age- and sex-matched controls. RESULTS During balloon inflation, visible EA was observed in 5 of 306 patients (1.6%) in the last 2 years. EA was limited to PCI in the proximal left anterior descending artery. The ST segment elevated to 10.1 ± 3.2 mm, followed by an alternating QRS complex with a lower ST segment (5.6 ± 1.9 mm; P = .0047) with characteristic ST-segment morphology, which is known as lambda pattern. The mean age of the 5 patients was 68 ± 20 years, and 4(80%). were men. After the release of inflation, the ST-segment level returned rapidly to baseline, followed by normalization of J point. Compared with controls, the maximal elevated ST segment was significantly higher in patients with EA (5.7 ± 2.7 mm; P = .0028). The occlusion of the proximal left anterior descending artery with more severe ischemia seemed to be a prerequisite for developing EA. A higher ST segment was associated with a lower blood pressure and vice versa. CONCLUSION A short period of ischemia during PCI may induce visible EA and alternating QRS complexes with a characteristic ST-segment morphology. A higher ST segment was associated with a lower blood pressure and vice versa.
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Affiliation(s)
- Takeo Oguro
- Department of Cardiology, Tachikawa General Hospital, Nagaoka, Japan
| | - Masatsune Fujii
- Department of Cardiology, Tachikawa General Hospital, Nagaoka, Japan
| | - Koichi Fuse
- Department of Cardiology, Tachikawa General Hospital, Nagaoka, Japan
| | - Minoru Takahashi
- Department of Cardiology, Tachikawa General Hospital, Nagaoka, Japan
| | - Satoru Fujita
- Department of Cardiology, Tachikawa General Hospital, Nagaoka, Japan
| | - Hitoshi Kitazawa
- Department of Cardiology, Tachikawa General Hospital, Nagaoka, Japan
| | - Masahito Sato
- Department of Cardiology, Tachikawa General Hospital, Nagaoka, Japan
| | - Yoshio Ikeda
- Department of Cardiology, Tachikawa General Hospital, Nagaoka, Japan
| | - Masaaki Okabe
- Department of Cardiology, Tachikawa General Hospital, Nagaoka, Japan
| | - Yoshifusa Aizawa
- Department of Research and Development Tachikawa Medical Center, Nagaoka, Japan.
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21
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Tavares JGP, Vasques ER, Arida RM, Cavalheiro EA, Cabral FR, Torres LB, Menezes-Rodrigues FS, Jurkiewicz A, Caricati-Neto A, Godoy CMG, Gomes da Silva S. Epilepsy-induced electrocardiographic alterations following cardiac ischemia and reperfusion in rats. ACTA ACUST UNITED AC 2015; 48:140-5. [PMID: 25590352 PMCID: PMC4321219 DOI: 10.1590/1414-431x20144311] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 11/06/2014] [Indexed: 11/22/2022]
Abstract
The present study evaluated electrocardiographic alterations in rats with epilepsy
submitted to an acute myocardial infarction (AMI) model induced by cardiac ischemia
and reperfusion. Rats were randomly divided into two groups: control (n=12) and
epilepsy (n=14). It was found that rats with epilepsy presented a significant
reduction in atrioventricular block incidence following the ischemia and reperfusion
procedure. In addition, significant alterations were observed in electrocardiogram
intervals during the stabilization, ischemia, and reperfusion periods of rats with
epilepsy compared to control rats. It was noted that rats with epilepsy presented a
significant increase in the QRS interval during the stabilization period in relation
to control rats (P<0.01). During the ischemia period, there was an increase in the
QRS interval (P<0.05) and a reduction in the P wave and QT intervals (P<0.05
for both) in rats with epilepsy compared to control rats. During the reperfusion
period, a significant reduction in the QT interval (P<0.01) was verified in the
epilepsy group in relation to the control group. Our results indicate that rats
submitted to an epilepsy model induced by pilocarpine presented electrical
conductivity alterations of cardiac tissue, mainly during an AMI episode.
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Affiliation(s)
- J G P Tavares
- Departamento de Farmacologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil
| | - E R Vasques
- Departamento de Gastroenterologia, LIM 37, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brasil
| | - R M Arida
- Departamento de Fisiologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil
| | - E A Cavalheiro
- Departamento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo, São Paulo, SP, Brasil
| | - F R Cabral
- Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP, Brasil
| | - L B Torres
- Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP, Brasil
| | - F S Menezes-Rodrigues
- Departamento de Farmacologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil
| | - A Jurkiewicz
- Departamento de Farmacologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil
| | - A Caricati-Neto
- Departamento de Farmacologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil
| | - C M G Godoy
- Departamento de Ciência e Tecnologia, Universidade Federal de São Paulo, São José dos Campos, SP, Brasil
| | - S Gomes da Silva
- Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP, Brasil
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22
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Demidova MM, Martín-Yebra A, van der Pals J, Koul S, Erlinge D, Laguna P, Martínez JP, Platonov PG. Transient and rapid QRS-widening associated with a J-wave pattern predicts impending ventricular fibrillation in experimental myocardial infarction. Heart Rhythm 2014; 11:1195-201. [PMID: 24691451 DOI: 10.1016/j.hrthm.2014.03.048] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Certain types of the early repolarization phenomenon, previously considered to be benign, have been reported to be associated with ventricular fibrillation (VF), both in population-based studies and in the myocardial infarction (MI) settings. OBJECTIVE To analyze whether QRS widening and appearance of a J-wave pattern in experimental MI settings is predictive of VF. METHODS MI was induced in 32 pigs by 40-minute inflation of an angioplasty balloon in the left descending artery, and electrocardiogram was continuously recorded. Multilead QRS boundaries were computed, and QRS duration was calculated on a beat-to-beat basis during the occlusion period for each pig. An association between QRS widening and subsequent VF was studied using receiver operating characteristic curve analysis. Electrocardiograms at maximum QRS duration were reviewed for the presence of a J-wave pattern. RESULTS Sixteen animals had VF episodes during the occlusion period. Two peaks of QRS widening were found in all animals: the first peak immediately on left descending artery occlusion and the second peak 19.1 ± 4.0 minutes later. The magnitude of changes in the QRS width over time had significant interindividual differences. A QRS widening of ≥28 ms during a 3-minute time window was observed in 14 animals and predicted impending VF (selectivity 80%, specificity 73%, positive predictive value 57%, and negative predictive value 89%; P = .008). In 10 of 14 (71%) pigs, a J-wave pattern appeared at maximal QRS duration. The appearance of a J-wave pattern predicted VF with selectivity 80%, specificity 68%, positive predictive value 53%, and negative predictive value 88% (P = .02). CONCLUSION Transient QRS widening, commonly associated with a J-wave pattern, appears to predict impending VF in acute ischemia settings and motivates further clinical studies for monitoring immediate risk of VF in MI.
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Affiliation(s)
- Marina M Demidova
- Department of Cardiology, Lund University, Lund, Sweden; Federal Centre of Heart, Blood and Endocrinology, St. Petersburg, Russia.
| | - Alba Martín-Yebra
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy; Aragon Institute of Engineering Research, IIS Aragón, Universidad de Zaragoza, Aragon, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
| | | | - Sasha Koul
- Department of Cardiology, Lund University, Lund, Sweden
| | - David Erlinge
- Department of Cardiology, Lund University, Lund, Sweden
| | - Pablo Laguna
- Aragon Institute of Engineering Research, IIS Aragón, Universidad de Zaragoza, Aragon, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
| | - Juan Pablo Martínez
- Aragon Institute of Engineering Research, IIS Aragón, Universidad de Zaragoza, Aragon, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
| | - Pyotr G Platonov
- Department of Cardiology, Lund University, Lund, Sweden; Arrhythmiaclinic, Skåne University Hospital, Lund, Sweden
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23
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Di Diego JM, Antzelevitch C. Acute myocardial ischemia: cellular mechanisms underlying ST segment elevation. J Electrocardiol 2014; 47:486-90. [PMID: 24742586 DOI: 10.1016/j.jelectrocard.2014.02.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Indexed: 10/25/2022]
Abstract
The electrocardiogram (ECG) is an essential tool for the diagnosis of acute myocardial ischemia in the emergency department, as well as for that of an evolving acute myocardial infarction (AMI). Changes in the surface ECG in leads whose positive poles face the ischemic region are known to be related to injury currents flowing across the boundaries between the ischemic and the surrounding normal myocardium. Although experimental studies have also shown an endocardium to epicardium differential sensitivity to the effect of acute ischemia, the important contribution of this transmural heterogeneous response to the changes observed in the surface ECG is less appreciated by the clinical cardiologist. This review briefly discusses our current knowledge regarding the electrophysiology of the ischemic myocardium focusing primarily on the electrophysiologic changes underlying the ECG alterations observed at the onset of a transmural AMI.
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24
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Abstract
An early repolarization (ER) pattern in the ECG, consisting of J point elevation, distinct J wave with or without ST segment elevation or slurring of the terminal part of the QRS, was long considered a benign electrocardiographic manifestation. Experimental studies a dozen years ago suggested that an ER is not always benign, but may be associated with malignant arrhythmias. Validation of this hypothesis derives from recent case-control and population-based studies showing that an ER pattern in inferior or infero-lateral leads is associated with increased risk for life-threatening arrhythmias, termed early repolarization syndrome (ERS). Because accentuated J waves characterize both Brugada syndrome (BrS) and ERS, these syndromes have been grouped under the heading of J wave syndromes. BrS and ERS appear to share common ECG characteristics, clinical outcomes, risk factors as well as a common arrhythmic platform related to amplification of Ito-mediated J waves. However, they differ with respect to the magnitude and lead location of abnormal J waves and can be considered to represent a continuous spectrum of phenotypic expression. Recent studies support the hypothesis that BrS and ERS are caused by a preferential accentuation of the AP notch in right or left ventricular epicardium, respectively, and that this repolarization defect is accentuated by cholinergic agonists. Quinidine, cilostazol and isoproterenol exert ameliorative effects by reversing these repolarization abnormalities. Identifying subjects truly at risk is the challenge ahead. Our goal here is to review the clinical and genetic aspects as well as the cellular and molecular mechanisms underlying the J wave syndromes.
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25
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QRS complex and ST segment manifestations of ventricular ischemia: The effect of regional slowing of ventricular activation. J Electrocardiol 2013; 46:497-504. [DOI: 10.1016/j.jelectrocard.2013.08.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Indexed: 11/22/2022]
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26
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González-Torrecilla E, Arenal A, Sosa V, Fernández-Avilés F. Exercise-induced vasospasm and the J-wave syndrome. Heart Rhythm 2013; 10:770-1. [DOI: 10.1016/j.hrthm.2011.12.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Indexed: 10/14/2022]
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27
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Noonan AM, Eisch RA, Liewehr DJ, Sissung TM, Venzon DJ, Flagg TP, Haigney MC, Steinberg SM, Figg WD, Piekarz RL, Bates SE. Electrocardiographic studies of romidepsin demonstrate its safety and identify a potential role for K(ATP) channel. Clin Cancer Res 2013; 19:3095-104. [PMID: 23589175 DOI: 10.1158/1078-0432.ccr-13-0109] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Romidepsin is a histone deacetylase inhibitor (HDI) approved for the treatment of both cutaneous and peripheral T-cell lymphoma (CTCL and PTCL). During development, a thorough assessment of cardiac toxicity was conducted. EXPERIMENTAL DESIGN A phase II single-agent nonrandomized study of romidepsin was conducted in patients with CTCL or PTCL who had progressed after at least 1 prior systemic therapy. RESULTS Results for the first 42 patients enrolled on the NCI 1312 phase II study of romidepsin in CTCL or PTCL showed no cardiac toxicity based on serial electrocardiograms (ECG), troponins, and MUGA scans/echocardiograms. The cardiac assessments reported herein confirm the safety of romidepsin among 131 enrolled patients, while supporting a role for electrolyte replacement. Heart rate increased an average 11 bpm following romidepsin infusion; there was no evidence of increased arrhythmia. Criteria for potassium/magnesium replacement were met before 55% of 1365 romidepsin doses; an association with hypoalbuminemia was confirmed. We propose a mechanism for ST segment flattening and depression, the most common ECG abnormalities observed: HDI-induced alteration of the activity or expression of KATP channels. In addition, examination of the variants of the active transporter of romidepsin, ABCB1, showed a trend toward smaller heart rate changes in the peri-infusion period among wild-type than variant diplotypes. CONCLUSIONS We conclude that in the context of appropriate attention to electrolyte levels, the data support the cardiac safety of romidepsin.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- Adult
- Aged
- Aged, 80 and over
- Antibiotics, Antineoplastic/adverse effects
- Depsipeptides/adverse effects
- Electrocardiography/drug effects
- Female
- Genotype
- Heart Rate/drug effects
- Histone Deacetylase Inhibitors/adverse effects
- Humans
- Lymphoma, T-Cell, Cutaneous/drug therapy
- Lymphoma, T-Cell, Cutaneous/genetics
- Lymphoma, T-Cell, Cutaneous/metabolism
- Lymphoma, T-Cell, Peripheral/drug therapy
- Lymphoma, T-Cell, Peripheral/genetics
- Lymphoma, T-Cell, Peripheral/metabolism
- Magnesium/blood
- Male
- Middle Aged
- Potassium/blood
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Affiliation(s)
- Anne M Noonan
- Medical Oncology Branch, National Cancer Institute, NIH, Bethesda, Maryland 20892, USA
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28
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Extramiana F. ST segment elevation: a common ECG sign for different diseases and different mechanism. J Electrocardiol 2013; 46:90-1. [PMID: 23332419 DOI: 10.1016/j.jelectrocard.2013.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Indexed: 12/14/2022]
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29
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Di Diego JM, Sicouri S, Myles RC, Burton FL, Smith GL, Antzelevitch C. Optical and electrical recordings from isolated coronary-perfused ventricular wedge preparations. J Mol Cell Cardiol 2012; 54:53-64. [PMID: 23142540 DOI: 10.1016/j.yjmcc.2012.10.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 10/22/2012] [Accepted: 10/29/2012] [Indexed: 01/06/2023]
Abstract
The electrophysiological heterogeneity that exists across the ventricular wall in the mammalian heart has long been recognized, but remains an area that is incompletely understood. Experimental studies of the mechanisms of arrhythmogenesis in the whole heart often examine the epicardial surface in isolation and thereby disregard transmural electrophysiology. Significant heterogeneity exists in the electrophysiological properties of cardiomyocytes isolated from different layers of the ventricular wall, and given that regional heterogeneities of membrane repolarization properties can influence the electrophysiological substrate for re-entry, the diversity of cell types and characteristics spanning the ventricular wall is important in the study of arrhythmogenesis. For these reasons, coronary-perfused left ventricular wedge preparations have been developed to permit the study of transmural electrophysiology in the intact ventricle. Since the first report by Yan and Antzelevitch in 1996, electrical recordings from the transmural surface of canine wedge preparations have provided a wealth of data regarding the cellular basis for the electrocardiogram, the role of transmural heterogeneity in arrhythmogenesis, and differences in the response of the different ventricular layers to drugs and neurohormones. Use of the wedge preparation has since been expanded to other species and more recently it has also been widely used in optical mapping studies. The isolated perfused wedge preparation has become an important tool in cardiac electrophysiology. In this review, we detail the methodology involved in recording both electrical and optical signals from the coronary-perfused wedge preparation and review the advances in cardiac electrophysiology achieved through study of the wedge.
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Affiliation(s)
- José M Di Diego
- Masonic Medical Research Laboratory, 2150 Bleecker St., Utica, NY 13501, USA
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30
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Characteristics of electrocardiographic repolarization in acute myocardial infarction complicated by ventricular fibrillation. J Electrocardiol 2012; 45:252-9. [DOI: 10.1016/j.jelectrocard.2011.11.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Indexed: 11/22/2022]
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31
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Bernikova OG, Sedova KA, Azarov YE, Shmakov DN. Ventricular myocardial repolarization in acute coronary occlusion and reperfusion in cats. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2011; 437:69-71. [PMID: 21562947 DOI: 10.1134/s0012496611020037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Indexed: 05/30/2023]
Affiliation(s)
- O G Bernikova
- Institute of Physiology, Komi Scientific Center, Ural Division of the Russian Academy of Sciences, Syktyvkar, Russia
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32
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Karebsheh S, Michaels AD. Acoustic cardiographic indices of transmyocardial ischemia during percutaneous coronary intervention. ACTA ACUST UNITED AC 2011; 13:3-8. [PMID: 21244232 DOI: 10.3109/17482941.2010.532222] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Shadi Karebsheh
- Division of Cardiology, University of Utah, Salt Lake City, USA
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33
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Henao ÓA, Ferrero de Loma-Osorio JM, Sáiz J, Reynolds J. Arritmias potenciadas por isquemia sub-epicárdica en pared transmural heterogénea cardiaca: un estudio teórico de simulación. REVISTA COLOMBIANA DE CARDIOLOGÍA 2011. [DOI: 10.1016/s0120-5633(11)70164-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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34
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Current-to-load mismatch, Brugada ECG pattern, and the associated arrhythmogenesis. Heart Rhythm 2011; 8:119-20. [DOI: 10.1016/j.hrthm.2010.09.083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2010] [Indexed: 11/20/2022]
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35
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Balci B. Tombstoning ST-Elevation Myocardial Infarction. Curr Cardiol Rev 2010; 5:273-8. [PMID: 21037844 PMCID: PMC2842959 DOI: 10.2174/157340309789317869] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Revised: 03/18/2009] [Accepted: 03/31/2009] [Indexed: 11/22/2022] Open
Abstract
Tombstoning ST elevation myocardial infarction can be described as a STEMI characterized by tombstoning ST-segment elevation. This myocardial infarction is associated with extensive myocardial damage, reduced left ventricle function, serious hospital complications and poor prognosis. Tombstoning ECG pattern is a notion beyond morphological difference and is associated with more serious clinical results.Despite the presence of a few reports on tombstoning ST elevation, there is no report which reviews STEMI demonstrating this electrocardiographic pattern.
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Affiliation(s)
- Bahattin Balci
- Department of Cardiology, Van Specialist Trainig Education & Research Hospital, Van, Turkey
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36
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Wilde AAM, Postema PG, Di Diego JM, Viskin S, Morita H, Fish JM, Antzelevitch C. The pathophysiological mechanism underlying Brugada syndrome: depolarization versus repolarization. J Mol Cell Cardiol 2010; 49:543-53. [PMID: 20659475 DOI: 10.1016/j.yjmcc.2010.07.012] [Citation(s) in RCA: 253] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 07/13/2010] [Accepted: 07/19/2010] [Indexed: 12/29/2022]
Abstract
This Point/Counterpoint presents a scholarly debate of the mechanisms underlying the electrocardiographic and arrhythmic manifestations of Brugada syndrome (BrS), exploring in detail the available evidence in support of the repolarization vs. depolarization hypothesis.
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Affiliation(s)
- Arthur A M Wilde
- Department of Cardiology, Academic Medical Center Amsterdam, Amsterdam, The Netherlands
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37
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Shumilova TE, Shereshkov VI, Yanvareva IN, Nozdrachev AD. Peculiarities of myocardial electrogenesis in laboratory rats under conditions of acute nitrite intoxication. J EVOL BIOCHEM PHYS+ 2010. [DOI: 10.1134/s0022093010020079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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38
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Sicouri S, Glass A, Ferreiro M, Antzelevitch C. Transseptal dispersion of repolarization and its role in the development of Torsade de Pointes arrhythmias. J Cardiovasc Electrophysiol 2009; 21:441-7. [PMID: 19909385 DOI: 10.1111/j.1540-8167.2009.01641.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE This study was designed to quantitate transseptal dispersion of repolarization (DR) and delineate its role in arrhythmogenesis using the calcium agonist BayK 8644 to mimic the gain of function of calcium channel current responsible for Timothy syndrome. BACKGROUND Amplification of transmural dispersion of repolarization (TDR) has been shown to contribute to development of Torsade de Pointes (TdP) arrhythmias under long-QT conditions. METHODS An arterially perfused septal wedge preparation was developed via cannulation of the septal artery. Action potentials (APs) were recorded using floating microelectrodes together with a transseptal electrocardiogram (ECG). These data were compared to those recorded from arterially perfused canine left ventricular (LV) wedge preparations. RESULTS Under control conditions, the shortest AP duration measured at 90% repolarization (APD(90)) was observed in right ventricular (RV) endocardium (181.8 +/- 15 ms), APD(90) peaked close to midseptum (278.0 +/- 32 ms), and abbreviated again as LV endocardium was approached (207.3 +/- 9 ms). Transseptal DR averaged 106 +/- 24 ms and T(peak)-T(end) 84 +/- 7 ms (n = 6). TDR and T(peak)-T(end) recorded from LV wedge were 36 +/- 9 ms and 34 +/- 19 ms, respectively (n = 30). BayK 8644 increased transseptal DR to 123.2 +/- 35 ms (n = 5) and induced early and delayed afterdepolarizations (3/5), rate-dependent ST-T-wave alternans (5/5), and TdP arrhythmias (3/5). CONCLUSIONS Our data indicate that dispersion of repolarization across the interventricular septum is twice that of the LV free wall, predisposing to development of TdP under long-QT conditions. Our findings suggest that the coronary-perfused ventricular septal preparation may be a sensitive model in which to assess the potential arrhythmogenic effects of drugs and pathophysiological conditions.
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Affiliation(s)
- Serge Sicouri
- Masonic Medical Research Laboratory, Utica, New York 13501, USA.
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39
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SCN5A mutation associated with acute myocardial infarction. Leg Med (Tokyo) 2009; 11 Suppl 1:S206-9. [PMID: 19345130 DOI: 10.1016/j.legalmed.2009.02.044] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Accepted: 02/02/2009] [Indexed: 11/23/2022]
Abstract
Ventricular tachycardia and fibrillation (VT/VF) complicating Brugada syndrome, a genetic disorder linked to SCN5A mutations, and VF complicating acute myocardial infarction (AMI) have both been linked to phase 2 reentry. Because of these mechanistic similarities in arrhythmogenesis, we examined the contribution of SCN5A mutations to VT/VF complicating AMI. Nineteen consecutive patients developing VF during AMI were enrolled. Wild-type (WT) and mutant SCN5A genes were co-expressed with SCN1B in TSA201 cells and studied using whole-cell patch-clamp techniques. One missense mutation (G400A) in SCN5A was detected in a conserved region among the cohort of 19 patients. A H558R polymorphism was detected on the same allele. Unlike the other 18 patients who each developed 1-2 VF episodes during acute MI, the mutation carrier developed six episodes of VT/VF within the first 12 hours. All VT/VF episodes were associated with ST segment changes and were initiated by short-coupled extrasystoles. We describe the first sodium channel mutation to be associated with the development of an arrhythmic storm during acute ischemia. These findings suggest that a loss of function in SCN5A may predispose to ischemia induced arrhythmic storm. These results could be very useful for forensic implications regarding genetic screening in relatives.
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40
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Peng Y, Xu L, Wang X. Heart rate variability in myocardial ischemic periods. IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE : THE QUARTERLY MAGAZINE OF THE ENGINEERING IN MEDICINE & BIOLOGY SOCIETY 2008; 27:14-19. [PMID: 18799385 DOI: 10.1109/memb.2008.923954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Yi Peng
- Department of Biomedical Engineering, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, 5 Beijing 100005, China.
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41
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Cordeiro JM, Mazza M, Goodrow R, Ulahannan N, Antzelevitch C, Di Diego JM. Functionally distinct sodium channels in ventricular epicardial and endocardial cells contribute to a greater sensitivity of the epicardium to electrical depression. Am J Physiol Heart Circ Physiol 2008; 295:H154-62. [PMID: 18456729 DOI: 10.1152/ajpheart.01327.2007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A greater depression of the action potential (AP) of the ventricular epicardium (Epi) versus endocardium (Endo) is readily observed in experimental models of acute ischemia and Brugada syndrome. Endo and Epi differences in transient outward K(+) current and/or ATP-sensitive K(+) channel current are believed to contribute to the differential response. The present study tested the hypothesis that the greater sensitivity of Epi is due in part to its functionally distinct early fast Na(+) current (I(Na)). APs were recorded from isolated Epi and Endo tissue slices and coronary-perfused wedge preparations before and after exposures to elevated extracellular K(+) concentration ([K(+)](o); 6-12 mM). I(Na) was recorded from Epi and Endo myocytes using whole cell patch-clamp techniques. In tissue slices, increasing [K(+)](o) to 12 mM reduced V(max) to 51.1 +/- 5.3% and 26.8 +/- 9.6% of control in Endo (n = 9) and Epi (n = 14), respectively (P < 0.05). In wedge preparations (n = 12), the increase in [K(+)](o) caused selective depression of Epi APs and transmural conduction slowing and block. I(Na) density was not significantly different between Epi (n = 14) and Endo (n = 15) cells, but Epi cells displayed a more negative half-inactivation voltage [-83.6 +/- 0.1 and -75.5 +/- 0.3 mV for Epi (n = 16) and Endo (n = 16), respectively, P < 0.05]. Our data suggest that reduced I(Na) availability in ventricular Epi may contribute to its greater sensitivity to electrical depression and thus may contribute to the R-ST segment changes observed under a variety of clinical conditions including acute myocardial ischemia, severe hyperkalemia, and Brugada syndrome.
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Affiliation(s)
- J M Cordeiro
- Masonic Medical Research Laboratory, Utica, NY 13504, USA
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42
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Ortega Carnicer J. [Acute inferior myocardial infarction masking the J wave syndrome. Based on four observations]. Med Intensiva 2008; 32:48-53. [PMID: 18221713 DOI: 10.1016/s0210-5691(08)70902-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The J wave syndrome is characterized by a prominent J wave accompanied by ST-segment elevation in the absence of structural heart disease. It includes the benign early repolarization syndrome, the highly arrhythmogenic Brugada syndrome and idiopathic ventricular fibrillation. Although acute coronary syndromes are one of the leading causes of ST-segment deviation, no clinical reports that specifically describe the modulating effects of an ischemic injury current on the ECG manifestations of the J wave syndrome have been found. This report describes four cases of patients with acute inferior ST-segment elevation myocardial infarction who had J wave (or negative deplacement of the J point) and ST-segment depression in the right precordial leads. Later, these precordial ECG alterations disappeared and were progressively replaced by prominent J (R') waves and anterior ST-segment elevations, suggesting the presence of a J wave syndrome. In conclusion, the J wave syndrome may be obscured by an acute inferior myocardial infarction with concomitant ST-segment depression in the right precordial leads. In such circumstances, early detection of the J wave (or depressed J point) may be used as ECG marker of the early repolarization syndrome or Brugada syndrome.
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Affiliation(s)
- J Ortega Carnicer
- Servicio de Medicina Intensiva, Hospital General de Ciudad Real, España.
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43
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Hu D, Viskin S, Oliva A, Cordeiro JM, Guerchicoff A, Pollevick GD, Antzelevitch C. Genetic predisposition and cellular basis for ischemia-induced ST-segment changes and arrhythmias. J Electrocardiol 2008; 40:S26-9. [PMID: 17993325 DOI: 10.1016/j.jelectrocard.2007.05.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Accepted: 05/14/2007] [Indexed: 11/19/2022]
Abstract
Recent reports have highlighted the importance of a family history of sudden death as a risk for ventricular fibrillation (VF) in patients experiencing acute myocardial infarction (AMI), pointing to the possibility of a genetic predisposition. This report briefly reviews 2 recent studies designed to examine the hypothesis that there is a genetic predisposition to the development of arrhythmias associated with AMI. Ventricular tachycardia and VF (VT/VF) complicating AMI as well as arrhythmias associated with Brugada syndrome, a genetic disorder linked to SCN5A mutations, have both been linked to phase 2 reentry. Because of these mechanistic similarities in arrhythmogenesis, we examined the contribution of SCN5A mutations to VT/VF complicating AMI in patients developing VF during AMI. A missense mutation in SCN5A was found in a patient who developed an arrhythmic electrical storm during an evolving myocardial infarction. All VT/VF episodes were associated with ST-segment changes and were initiated by short-coupled extrasystoles. G400A mutation and H558R polymorphism were on the same allele, and functional expression in TSA201 demonstrated loss of function of sodium channel activity. These results suggest that a subclinical mutation in SCN5A resulting in a loss of function may predispose to life-threatening arrhythmias during acute ischemia. In another cohort of patients who developed long-QT intervals and torsade de pointes arrhythmias in days 2 to 11 after an AMI, a genetic screening of all long-QT genes was performed. Of 8 patients in this group, 6 (75%) displayed the same polymorphism in KCNH2, which encodes the alpha-subunit of the rapidly activating delayed rectifier potassium current, I(Kr). The K897T polymorphism was detected in only 3 of 14 patients with uncomplicated myocardial infarction and has been detected in 33% of the white population. Expression of this polymorphism has previously been shown to cause a loss of function in HERG current consistent with the long-QT phenotype. These observations suggest a genetic predisposition to the development of long-QT intervals and torsade de pointes in the days after an AMI. These preliminary studies provide support for the hypothesis that there is a genetic predisposition to the type and severity of arrhythmias that develop during and after an AMI, and that additional studies are warranted.
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Affiliation(s)
- Dan Hu
- Masonic Medical Research Laboratory, Utica, NY, USA
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44
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Fish JM, Antzelevitch C. Cellular mechanism and arrhythmogenic potential of T-wave alternans in the Brugada syndrome. J Cardiovasc Electrophysiol 2007; 19:301-8. [PMID: 18031511 DOI: 10.1111/j.1540-8167.2007.01025.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION T-wave alternans (TWA) is characterized by beat to beat alteration in the amplitude, polarity and/or morphology of the electrocardiographic T wave. TWA has been reported in patients with the Brugada syndrome (BS) and is thought to be associated with an increased risk for development of VT/VF. The cellular mechanisms involved are not well-defined and are the subject of this investigation. METHODS In an experimental model of BS composed of an arterially perfused canine right ventricular wedge preparation pretreated with verapamil (1-7 microM), an agent with sodium and calcium channel blocking activity, we simultaneously recorded transmembrane action potentials from two epicardial and one endocardial site, together with a pseudo-ECG. At select frequencies, verapamil induced alternans of both the T-wave amplitude and QT interval. The alternans resulted from either loss of the epicardial action potential dome on alternate beats or concealed phase 2 reentry within the epicardium on alternate beats. Loss of the epicardial action potential dome significantly increased transmural dispersion of repolarization (TDR) when compared with control (18.0 +/- 7.8 ms vs. 82.1 +/- 16.8 ms, P < 0.001, n = 8). During alternans, TDR was greater in beats displaying a more negative T wave (55.1 +/- 45.2 ms vs. 89.8 +/- 39.3 ms, P < 0.001, n = 22 data points from 8 preparations). CONCLUSIONS Our data indicate that TWA in an experimental model of the Brugada syndrome is due to alternating loss of the epicardial AP dome and/or concealed phase 2 reentry, both serving to increase TDR and create the substrate for the development VT/VF.
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Affiliation(s)
- Jeffrey M Fish
- Masonic Medical Research Laboratory, Utica, New York 13501-1787, USA.
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45
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Regulation of ion channels and arrhythmias in the ischemic heart. J Electrocardiol 2007; 40:S37-41. [DOI: 10.1016/j.jelectrocard.2007.05.020] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2007] [Accepted: 05/14/2007] [Indexed: 02/06/2023]
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46
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Shinde R, Rituparna S, Shinde S, Suresh S, Makhale C, Chandrashekhar M, Grant P, Purvez G, Sathe S, Sunil S, Durairaj M, Durairaj M, Lokhandwala Y, Yash L, Di Diego J, DI Diego JM, Antzelevitch C, Charles A. Occurrence of "J waves" in 12-lead ECG as a marker of acute ischemia and their cellular basis. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2007; 30:817-9. [PMID: 17547622 PMCID: PMC1989774 DOI: 10.1111/j.1540-8159.2007.00760.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The "J wave" (also referred to as "the Osborn wave,""the J deflection," or "the camel's hump") is a distinctive deflection occurring at the QRS-ST junction. In 1953, Dr. John Osborn described the "J wave" as an "injury current" resulting in ventricular fibrillation during experimental hypothermia. Although "J Wave" is supposed to be pathognomonic of hypothermia, it is seen in a host of other conditions such as hypercalcemia, brain injury, subarachnoid hemorrhage, cardiopulmonary arrest from over sedation, the Brugada syndrome, vasospastic angina, and idiopathic ventricular fibrillation. However, there is paucity of literature data as regards to ischemic etiology of "J Wave." In this article, we present a case where "J waves" were probably induced by ischemia. We also discuss the mechanism of ischemia-induced "J wave" accentuation and its prognostic implications.
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Affiliation(s)
- Rituparna Shinde
- Department of Cardiology, Grant Medical Foundation, Ruby Hall Clinic, Pune, Maharashtra 411001, India
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47
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Abstract
This lecture examines the hypothesis that amplification of spatial dispersion of repolarization in the form of transmural dispersion of repolarization (TDR) underlies the development of life-threatening ventricular arrhythmias associated with inherited ion channelopathies, including the long QT, short QT, and Brugada syndromes as well as catecholaminergic polymorphic ventricular tachycardia. In the long QT syndrome, amplification of TDR often is secondary to preferential prolongation of the action potential duration of M cells, whereas in Brugada syndrome, it is thought to be due to selective abbreviation of the action potential duration of right ventricular epicardium. In the short QT syndrome, preferential abbreviation of action potential duration of either endocardium or epicardium appears to be responsible for amplification of TDR. In catecholaminergic polymorphic ventricular tachycardia, reversal of the direction of activation of the ventricular wall is responsible for the increase in TDR. Thus, the long QT, short QT, Brugada, and catecholaminergic ventricular tachycardia syndromes are pathologies with very different phenotypes and etiologies. However, these syndromes share a common final pathway in their predisposition to sudden cardiac death.
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48
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Antzelevitch C. Role of spatial dispersion of repolarization in inherited and acquired sudden cardiac death syndromes. Am J Physiol Heart Circ Physiol 2007; 293:H2024-38. [PMID: 17586620 PMCID: PMC2085107 DOI: 10.1152/ajpheart.00355.2007] [Citation(s) in RCA: 185] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This review examines the role of spatial electrical heterogeneity within the ventricular myocardium on the function of the heart in health and disease. The cellular basis for transmural dispersion of repolarization (TDR) is reviewed, and the hypothesis that amplification of spatial dispersion of repolarization underlies the development of life-threatening ventricular arrhythmias associated with inherited ion channelopathies is evaluated. The role of TDR in long QT, short QT, and Brugada syndromes, as well as catecholaminergic polymorphic ventricular tachycardia (VT), is critically examined. In long QT syndrome, amplification of TDR is often secondary to preferential prolongation of the action potential duration (APD) of M cells; in Brugada syndrome, however, it is thought to be due to selective abbreviation of the APD of the right ventricular epicardium. Preferential abbreviation of APD of the endocardium or epicardium appears to be responsible for the amplification of TDR in short QT syndrome. In catecholaminergic polymorphic VT, reversal of the direction of activation of the ventricular wall is responsible for the increase in TDR. In conclusion, long QT, short QT, Brugada, and catecholaminergic polymorphic VT syndromes are pathologies with very different phenotypes and etiologies, but they share a common final pathway in causing sudden cardiac death.
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Affiliation(s)
- Charles Antzelevitch
- Masonic Medical Research Laboratory, 2150 Bleecker St., Utica, NY 13501-1787, USA.
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49
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Hu D, Viskin S, Oliva A, Carrier T, Cordeiro JM, Barajas-Martinez H, Wu Y, Burashnikov E, Sicouri S, Brugada R, Rosso R, Guerchicoff A, Pollevick GD, Antzelevitch C. Novel mutation in the SCN5A gene associated with arrhythmic storm development during acute myocardial infarction. Heart Rhythm 2007; 4:1072-80. [PMID: 17675083 PMCID: PMC1978483 DOI: 10.1016/j.hrthm.2007.03.040] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Accepted: 03/29/2007] [Indexed: 11/25/2022]
Abstract
BACKGROUND Ventricular tachycardia (VT) and ventricular fibrillation (VF) complicating Brugada syndrome, a genetic disorder linked to SCN5A mutations, and VF complicating acute myocardial infarction (AMI) both have been linked to phase 2 reentry. OBJECTIVE Given the mechanistic similarities in arrhythmogenesis, the purpose of this study was to examine the contribution of SCN5A mutations to VT/VF complicating AMI. METHODS Nineteen consecutive patients developing VF during AMI were enrolled in the study. Wild-type (WT) and mutant SCN5A genes were coexpressed with SCN1B in TSA201 cells and studied using whole-cell patch clamp techniques. RESULTS Among the cohort of 19 patients, one missense mutation (G400A) in SCN5A was detected in a conserved region. An H558R polymorphism was detected on the same allele. Unlike the other 18 patients, who each developed 1-2 VF episodes during AMI, the mutation carrier developed six episodes of VT/VF within the first 12 hours. All VT/VF episodes were associated with ST-segment changes and were initiated by short-coupled extrasystoles. Flecainide and adenosine challenge performed to unmask Brugada and long QT syndromes both were negative. Peak G400A and G400A+H558R current were 70.7% and 88.4% less than WT current at -35 mV (P </=.001). G400A current decay was accelerated and steady-state inactivation was shifted -6.39 mV (V(1/2) = -98.9 +/- 0.1 mV vs -92.5 +/- 0.1 mV, P </=.001). No mutations were detected in KCNH2, KCNQ1, KCNE1, or KCNE2 in the G400A patient. CONCLUSION We describe the first sodium channel mutation to be associated with the development of an arrhythmic storm during acute ischemia. These findings suggest that a loss of function in SCN5A may predispose to ischemia-induced arrhythmic storm.
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Affiliation(s)
- Dan Hu
- Masonic Medical Research Laboratory, Utica, New York, USA
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Sami Viskin
- Department of Cardiology, Tel-Aviv Sourasky Medical Center, and Sackler School of Medicine, Tel-Aviv University, Israel
| | - Antonio Oliva
- Masonic Medical Research Laboratory, Utica, New York, USA
- Institute of Forensic Medicine, Catholic University, Rome, Italy
| | | | | | - Hector Barajas-Martinez
- Masonic Medical Research Laboratory, Utica, New York, USA
- South University Center (CUSUR) and Human Genetics Programs of the University of Guadalajara (CIBO-CUCS), Cd. Guzman, Jalisco, México
| | - Yuesheng Wu
- Masonic Medical Research Laboratory, Utica, New York, USA
| | | | - Serge Sicouri
- Masonic Medical Research Laboratory, Utica, New York, USA
| | - Ramon Brugada
- Masonic Medical Research Laboratory, Utica, New York, USA
| | - Rafael Rosso
- Institute of Forensic Medicine, Catholic University, Rome, Italy
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