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Genovés P, Arias-Mutis ÓJ, Parra G, Such-Miquel L, Zarzoso M, Del Canto I, Soler C, Díaz A, Blanch E, Alberola A, Such L, Chorro FJ. Development and Long-Term Follow-Up of an Experimental Model of Myocardial Infarction in Rabbits. Animals (Basel) 2020; 10:ani10091576. [PMID: 32899601 PMCID: PMC7552163 DOI: 10.3390/ani10091576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/21/2020] [Accepted: 09/01/2020] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Ischemic heart disease is one of the leading causes of death. A series of processes occur during acute myocardial infarction that contribute to the development of ventricular dysfunction, with subsequent heart failure and ventricular arrhythmias, which account for most episodes of sudden cardiac death in these patients. These complications are associated with the adverse cardiac remodeling that occurs during the healing process following an acute episode. The remodeling causes the appearance of a substrate that can trigger life-threatening arrhythmias, such as tachycardia and/or ventricular fibrillation. The development of experimental models for analyzing the basic mechanisms involved in the pathophysiology of myocardial infarction enables the study of different therapeutic approaches aimed at improving the patient´s prognosis. The present study describes the methodology and the results obtained in a 5-week chronic infarction (one hour followed by reperfusion) in a rabbit model. The viability of the model, the care provided, the characteristics and extent of the lesions, the inducibility of arrhythmias, and the reproducibility of the methods and results have been analyzed. Abstract A chronic model of acute myocardial infarction was developed to study the mechanisms involved in adverse postinfarction ventricular remodeling. In an acute myocardial infarction (AMI), the left circumflex coronary artery of New Zealand White rabbits (n = 9) was occluded by ligature for 1 h, followed by reperfusion. A specific care protocol was applied before, during, and after the intervention, and the results were compared with those of a sham operated group (n = 7). After 5 weeks, programmed stimulation and high-resolution mapping were performed on isolated and perfused hearts using the Langendorff technique. The infarct size determined by 2,3,5-triphenyltetrazolium chloride inside of the area at risk (thioflavin-S) was then determined. The area at risk was similar in both groups (54.33% (experimental infarct group) vs. 58.59% (sham group), ns). The infarct size was 73.16% as a percentage of the risk area. The experimental infarct group had a higher inducibility of ventricular arrhythmias (100% vs. 43% in the sham group, p = 0.009). A reproducible chronic experimental model of myocardial infarction is presented in which the extent and characteristics of the lesions enable the study of the vulnerability to develop ventricular arrhythmias because of the remodeling process that occurs during cardiac tissue repair.
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Affiliation(s)
- Patricia Genovés
- INCLIVA, Institute of Health Research, 46010 Valencia, Spain; (P.G.); (Ó.J.A.-M.); (G.P.); (I.D.C.)
- Department of Physiology, Universitat de València, 46010 Valencia, Spain; (C.S.); (A.A.); (L.S.)
| | - Óscar J. Arias-Mutis
- INCLIVA, Institute of Health Research, 46010 Valencia, Spain; (P.G.); (Ó.J.A.-M.); (G.P.); (I.D.C.)
- Department of Physiology, Universitat de València, 46010 Valencia, Spain; (C.S.); (A.A.); (L.S.)
| | - Germán Parra
- INCLIVA, Institute of Health Research, 46010 Valencia, Spain; (P.G.); (Ó.J.A.-M.); (G.P.); (I.D.C.)
- Department of Physiology, Universitat de València, 46010 Valencia, Spain; (C.S.); (A.A.); (L.S.)
| | - Luis Such-Miquel
- Department of Physiotherapy, Universitat de València, 46010 Valencia, Spain; (L.S.-M.); (M.Z.)
- CIBERCV, Carlos III Health Institute, 28029 Madrid, Spain
| | - Manuel Zarzoso
- Department of Physiotherapy, Universitat de València, 46010 Valencia, Spain; (L.S.-M.); (M.Z.)
| | - Irene Del Canto
- INCLIVA, Institute of Health Research, 46010 Valencia, Spain; (P.G.); (Ó.J.A.-M.); (G.P.); (I.D.C.)
- CIBERCV, Carlos III Health Institute, 28029 Madrid, Spain
- Electronic Engineering Department, Universitat Politècnica de València, 46022 Valencia, Spain
| | - Carlos Soler
- Department of Physiology, Universitat de València, 46010 Valencia, Spain; (C.S.); (A.A.); (L.S.)
| | - Ana Díaz
- UCIM, Universitat de València, 46010 Valencia, Spain; (A.D.); (E.B.)
| | - Eva Blanch
- UCIM, Universitat de València, 46010 Valencia, Spain; (A.D.); (E.B.)
| | - Antonio Alberola
- Department of Physiology, Universitat de València, 46010 Valencia, Spain; (C.S.); (A.A.); (L.S.)
- CIBERCV, Carlos III Health Institute, 28029 Madrid, Spain
| | - Luis Such
- Department of Physiology, Universitat de València, 46010 Valencia, Spain; (C.S.); (A.A.); (L.S.)
- CIBERCV, Carlos III Health Institute, 28029 Madrid, Spain
| | - Francisco J. Chorro
- INCLIVA, Institute of Health Research, 46010 Valencia, Spain; (P.G.); (Ó.J.A.-M.); (G.P.); (I.D.C.)
- CIBERCV, Carlos III Health Institute, 28029 Madrid, Spain
- Cardiology Department, Hospital Clinico Universitario, Universitat de València, Avda. Blasco Ibañez 17, 46010 Valencia, Spain
- Correspondence:
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Del Canto I, Santamaría L, Genovés P, Such-Miquel L, Arias-Mutis O, Zarzoso M, Soler C, Parra G, Tormos Á, Alberola A, Such L, Chorro FJ. Effects of the Inhibition of Late Sodium Current by GS967 on Stretch-Induced Changes in Cardiac Electrophysiology. Cardiovasc Drugs Ther 2019; 32:413-425. [PMID: 30173392 DOI: 10.1007/s10557-018-6822-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE Mechanical stretch increases sodium and calcium entry into myocytes and activates the late sodium current. GS967, a triazolopyridine derivative, is a sodium channel blocker with preferential effects on the late sodium current. The present study evaluates whether GS967 inhibits or modulates the arrhythmogenic electrophysiological effects of myocardial stretch. METHODS Atrial and ventricular refractoriness and ventricular fibrillation modifications induced by acute stretch were studied in Langendorff-perfused rabbit hearts (n = 28) using epicardial multiple electrodes and high-resolution mapping techniques under control conditions and during the perfusion of GS967 at different concentrations (0.03, 0.1, and 0.3 μM). RESULTS On comparing ventricular refractoriness, conduction velocity and wavelength obtained before stretch had no significant changes under each GS967 concentration while atrial refractoriness increased under GS967 0.3 μM. Under GS967, the stretch-induced changes were attenuated, and no significant differences were observed between before and during stretch. GS967 0.3 μM diminished the normal stretch-induced changes resulting in longer (less shortened) atrial refractoriness (138 ± 26 ms vs 95 ± 9 ms; p < 0.01), ventricular refractoriness (155 ± 18 ms vs 124 ± 16 ms; p < 0.01) and increments in spectral concentration (23 ± 5% vs 17 ± 2%; p < 0.01), the fifth percentile of ventricular activation intervals (46 ± 8 ms vs 31 ± 3 ms; p < 0.05), and wavelength of ventricular fibrillation (2.5 ±0.5 cm vs 1.7 ± 0.3 cm; p < 0.05) during stretch. The stretch-induced increments in dominant frequency during ventricular fibrillation (control = 38%, 0.03 μM = 33%, 0.1 μM = 33%, 0.3 μM = 14%; p < 0.01) and the stretch-induced increments in arrhythmia complexity index (control = 62%, 0.03μM = 41%, 0.1 μM = 32%, 0.3 μM = 16%; p < 0.05) progressively decreased on increasing the GS967 concentration. CONCLUSIONS GS967 attenuates stretch-induced changes in cardiac electrophysiology.
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Affiliation(s)
- Irene Del Canto
- CIBER CV. Carlos III Health Institute, Madrid, Spain.,Department of Electronics, Universitat Politècnica de València, Valencia, Spain
| | - Laura Santamaría
- Department of Physiology, Valencia University - Estudi General, Valencia, Spain
| | | | - Luis Such-Miquel
- CIBER CV. Carlos III Health Institute, Madrid, Spain.,Department of Physiotherapy, Valencia University - Estudi General, Valencia, Spain
| | | | - Manuel Zarzoso
- Department of Physiotherapy, Valencia University - Estudi General, Valencia, Spain
| | - Carlos Soler
- Department of Physiology, Valencia University - Estudi General, Valencia, Spain
| | - Germán Parra
- Department of Physiology, Valencia University - Estudi General, Valencia, Spain
| | - Álvaro Tormos
- CIBER CV. Carlos III Health Institute, Madrid, Spain.,Department of Electronics, Universitat Politècnica de València, Valencia, Spain
| | - Antonio Alberola
- CIBER CV. Carlos III Health Institute, Madrid, Spain.,Department of Physiology, Valencia University - Estudi General, Valencia, Spain
| | - Luis Such
- CIBER CV. Carlos III Health Institute, Madrid, Spain.,Department of Physiology, Valencia University - Estudi General, Valencia, Spain
| | - Francisco J Chorro
- CIBER CV. Carlos III Health Institute, Madrid, Spain. .,Service of Cardiology, Valencia University Clinic Hospital, INCLIVA, Valencia, Spain. .,Department of Medicine, Valencia University - Estudi General, Valencia, Spain. .,Servicio de Cardiología, Hospital Clínico Universitario, Avda. Blasco Ibañez 17, 46010, Valencia, Spain.
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Abstract
Electromechanical coupling studies have described the intervention of nitric oxide and S-nitrosylation processes in Ca2+ release induced by stretch, with heterogeneous findings. On the other hand, ion channel function activated by stretch is influenced by nitric oxide, and concentration-dependent biphasic effects upon several cellular functions have been described. The present study uses isolated and perfused rabbit hearts to investigate the changes in mechanoelectric feedback produced by two different concentrations of the nitric oxide carrier S-nitrosoglutathione. Epicardial multielectrodes were used to record myocardial activation at baseline and during and after left ventricular free wall stretch using an intraventricular device. Three experimental series were studied: (a) control (n = 10); (b) S-nitrosoglutathione 10 µM (n = 11); and (c) S-nitrosoglutathione 50 µM (n = 11). The changes in ventricular fibrillation (VF) pattern induced by stretch were analyzed and compared. S-nitrosoglutathione 10 µM did not modify VF at baseline, but attenuated acceleration of the arrhythmia (15.6 ± 1.7 vs. 21.3 ± 3.8 Hz; p < 0.0001) and reduction of percentile 5 of the activation intervals (42 ± 3 vs. 38 ± 4 ms; p < 0.05) induced by stretch. In contrast, at baseline using the 50 µM concentration, percentile 5 was shortened (38 ± 6 vs. 52 ± 10 ms; p < 0.005) and the complexity index increased (1.77 ± 0.18 vs. 1.27 ± 0.13; p < 0.0001). The greatest complexity indices (1.84 ± 0.17; p < 0.05) were obtained during stretch in this series. S-nitrosoglutathione 10 µM attenuates the effects of mechanoelectric feedback, while at a concentration of 50 µM the drug alters the baseline VF pattern and accentuates the increase in complexity of the arrhythmia induced by myocardial stretch.
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del Canto I, Such-Miquel L, Brines L, Soler C, Zarzoso M, Calvo C, Parra G, Tormos Á, Alberola A, Millet J, Such L, Chorro FJ. Effects of JTV-519 on stretch-induced manifestations of mechanoelectric feedback. Clin Exp Pharmacol Physiol 2016; 43:1062-1070. [DOI: 10.1111/1440-1681.12630] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 07/16/2016] [Accepted: 08/01/2016] [Indexed: 12/29/2022]
Affiliation(s)
- Irene del Canto
- Department of Medicine; Valencia University “Estudi General”; Valencia Spain
| | - Luis Such-Miquel
- Department of Physiotherapy; Valencia University “Estudi General”; Valencia Spain
| | - Laia Brines
- Department of Physiology; Valencia University “Estudi General”; Valencia Spain
| | - Carlos Soler
- Department of Physiology; Valencia University “Estudi General”; Valencia Spain
| | - Manuel Zarzoso
- Department of Physiotherapy; Valencia University “Estudi General”; Valencia Spain
| | - Conrado Calvo
- Department of Electronic Engineering; Valencia Polytechnic University; Valencia Spain
| | - Germán Parra
- Department of Physiology; Valencia University “Estudi General”; Valencia Spain
| | - Álvaro Tormos
- Department of Electronic Engineering; Valencia Polytechnic University; Valencia Spain
| | - Antonio Alberola
- Department of Physiology; Valencia University “Estudi General”; Valencia Spain
| | - José Millet
- Department of Electronic Engineering; Valencia Polytechnic University; Valencia Spain
| | - Luis Such
- Department of Physiology; Valencia University “Estudi General”; Valencia Spain
| | - Francisco J. Chorro
- Department of Medicine; Valencia University “Estudi General”; Valencia Spain
- Department of Cardiology; Valencia University Clinic Hospital; INCLIVA; Valencia Spain
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Ranolazine Attenuates the Electrophysiological Effects of Myocardial Stretch in Langendorff-Perfused Rabbit Hearts. Cardiovasc Drugs Ther 2016; 29:231-41. [PMID: 26138210 DOI: 10.1007/s10557-015-6587-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE Mechanical stretch is an arrhythmogenic factor found in situations of cardiac overload or dyssynchronic contraction. Ranolazine is an antianginal agent that inhibits the late Na (+) current and has been shown to exert a protective effect against arrhythmias. The present study aims to determine whether ranolazine modifies the electrophysiological responses induced by acute mechanical stretch. METHODS The ventricular fibrillation modifications induced by acute stretch were studied in Langendorff-perfused rabbit hearts using epicardial multiple electrodes under control conditions (n = 9) or during perfusion of the late Na(+) current blocker ranolazine 5 μM (n = 9). Spectral and mapping techniques were used to establish the ventricular fibrillation dominant frequency, the spectral concentration and the complexity of myocardial activation in three situations: baseline, stretch and post-stretch. RESULTS Ranolazine attenuated the increase in ventricular fibrillation dominant frequency produced by stretch (23.0 vs 40.4 %) (control: baseline =13.6 ± 2.6 Hz, stretch = 19.1 ± 3.1 Hz, p < 0.0001; ranolazine: baseline = 1.4 ± 1.8 Hz, stretch =14.0 ± 2.4 Hz, p < 0.05 vs baseline, p < 0.001 vs control). During stretch, ventricular fibrillation was less complex in the ranolazine than in the control series, as evaluated by the lesser percentage of complex maps and the greater spectral concentration of ventricular fibrillation. These changes were associated to an increase in the fifth percentile of VV intervals during ventricular fibrillation (50 ± 8 vs 38 ± 5 ms, p < .01) and in the wavelength of the activation (2.4 ± 0.3 vs 1.9 ± 0.2 cm, p < 0.001) under ranolazine. CONCLUSIONS The late inward Na(+) current inhibitor ranolazine attenuates the electrophysiological effects responsible for the acceleration and increase in complexity of ventricular fibrillation produced by myocardial stretch.
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Chorro FJ, Canto ID, Brines L, Such-Miquel L, Calvo C, Soler C, Zarzoso M, Trapero I, Tormos Á, Such L. Estudio experimental de los efectos de EIPA, losartán y BQ-123 sobre las modificaciones electrofisiológicas inducidas por el estiramiento miocárdico. Rev Esp Cardiol 2015. [DOI: 10.1016/j.recesp.2014.12.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Álvarez-Álvarez B, Bouzas-Cruz N, Abu-Assi E, Raposeiras-Roubin S, López-López A, González Cambeiro MC, Peña-Gil C, García-Acuña JM, González-Juanatey JR. Impacto de la fibrilación ventricular que complica el curso de un síndrome coronario agudo en la incidencia a largo plazo de muerte súbita cardiaca. Rev Esp Cardiol 2015. [DOI: 10.1016/j.recesp.2014.11.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Álvarez-Álvarez B, Bouzas-Cruz N, Abu-Assi E, Raposeiras-Roubin S, López-López A, González Cambeiro MC, Peña-Gil C, García-Acuña JM, González-Juanatey JR. Impact of Acute Coronary Syndrome Complicated by Ventricular Fibrillation on Long-term Incidence of Sudden Cardiac Death. REVISTA ESPANOLA DE CARDIOLOGIA (ENGLISH ED.) 2015; 68:878-884. [PMID: 25800166 DOI: 10.1016/j.rec.2014.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 11/03/2014] [Indexed: 06/04/2023]
Abstract
INTRODUCTION AND OBJECTIVES There is little information on the effect of acute coronary syndrome complicated by ventricular fibrillation on the long-term incidence of sudden cardiac death. We analyzed this effect in a contemporary cohort of patients with acute coronary syndrome. METHODS We studied 5302 consecutive patients with acute coronary syndrome between December 2003 and December 2012. We compared mortality during and after hospitalization according to the presence or absence of ventricular fibrillation. RESULTS Ventricular fibrillation was observed in 163 (3.1%) patients, and was early onset in 72.4% of these patients. In-hospital mortality was 36.2% in the group with ventricular fibrillation and 4.7% in the group without (p<.001). After a mean follow-up of 4.7 years (standard deviation, 2.6 years), mortality was 30.7% in the ventricular fibrillation group and 24.7% in the other group (P=.23). After adjusting for confounding variables, the presence of ventricular fibrillation was not associated with an increased risk of death in the follow-up period (hazard ratio=1.29; 95% confidence interval, 0.90-1.87). The cause of death was established in 72% of patients. The incidence of sudden death was 12.9% in the ventricular fibrillation group and 11.9% in the other group (P=.71). Cardiovascular-cause mortality was also similar between the 2 groups (35.5% and 34.4%, respectively. CONCLUSIONS Patients with acute coronary syndrome complicated by ventricular fibrillation who survive the in-hospital phase do not appear to be at an increased risk of sudden cardiac death or other cardiovascular-cause death.
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Affiliation(s)
- Belén Álvarez-Álvarez
- Servicio de Cardiología y Unidad Coronaria, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, Spain.
| | - Noelia Bouzas-Cruz
- Servicio de Cardiología y Unidad Coronaria, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - Emad Abu-Assi
- Servicio de Cardiología y Unidad Coronaria, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - Sergio Raposeiras-Roubin
- Servicio de Cardiología y Unidad Coronaria, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - Andrea López-López
- Servicio de Cardiología y Unidad Coronaria, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - María Cristina González Cambeiro
- Servicio de Cardiología y Unidad Coronaria, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - Carlos Peña-Gil
- Servicio de Cardiología y Unidad Coronaria, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - José María García-Acuña
- Servicio de Cardiología y Unidad Coronaria, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
| | - José Ramón González-Juanatey
- Servicio de Cardiología y Unidad Coronaria, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, A Coruña, Spain
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Chorro FJ, Canto ID, Brines L, Such-Miquel L, Calvo C, Soler C, Zarzoso M, Trapero I, Tormos Á, Such L. Experimental Study of the Effects of EIPA, Losartan, and BQ-123 on Electrophysiological Changes Induced by Myocardial Stretch. ACTA ACUST UNITED AC 2015; 68:1101-10. [PMID: 25985899 DOI: 10.1016/j.rec.2014.12.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 12/12/2014] [Indexed: 11/26/2022]
Abstract
INTRODUCTION AND OBJECTIVES Mechanical response to myocardial stretch has been explained by various mechanisms, which include Na(+)/H(+) exchanger activation by autocrine-paracrine system activity. Drug-induced changes were analyzed to investigate the role of these mechanisms in the electrophysiological responses to acute myocardial stretch. METHODS Multiple epicardial electrodes and mapping techniques were used to analyze changes in ventricular fibrillation induced by acute myocardial stretch in isolated perfused rabbit hearts. Four series were studied: control (n = 9); during perfusion with the angiotensin receptor blocker losartan (1 μM, n = 8); during perfusion with the endothelin A receptor blocker BQ-123 (0.1 μM, n = 9), and during perfusion with the Na(+)/H(+) exchanger inhibitor EIPA (5-[N-ethyl-N-isopropyl]-amiloride) (1 μM, n = 9). RESULTS EIPA attenuated the increase in the dominant frequency of stretch-induced fibrillation (control=40.4%; losartan=36% [not significant]; BQ-123=46% [not significant]; and EIPA=22% [P<.001]). During stretch, the activation maps were less complex (P<.0001) and the spectral concentration of the arrhythmia was greater (greater regularity) in the EIPA series: control=18 (3%); EIPA = 26 (9%) (P < .02); losartan=18 (5%) (not significant); and BQ-123=18 (4%) (not significant). CONCLUSIONS The Na(+)/H(+) exchanger inhibitor EIPA attenuated the electrophysiological effects responsible for the acceleration and increased complexity of ventricular fibrillation induced by acute myocardial stretch. The angiotensin II receptor antagonist losartan and the endothelin A receptor blocker BQ-123 did not modify these effects.
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Affiliation(s)
- Francisco J Chorro
- Servicio de Cardiología, Hospital Clínico Universitario de Valencia, INCLIVA, Valencia, Spain; Departamento de Medicina, Universidad de Valencia-Estudi General, Valencia, Spain.
| | - Irene Del Canto
- Departamento de Medicina, Universidad de Valencia-Estudi General, Valencia, Spain
| | - Laia Brines
- Departamento de Fisiología, Universidad de Valencia-Estudi General, Valencia, Spain
| | - Luis Such-Miquel
- Departamento de Fisioterapia, Universidad de Valencia-Estudi General, Valencia, Spain
| | - Conrado Calvo
- Departamento de Electrónica, Universidad Politécnica de Valencia, Valencia, Spain
| | - Carlos Soler
- Departamento de Fisiología, Universidad de Valencia-Estudi General, Valencia, Spain
| | - Manuel Zarzoso
- Departamento de Fisioterapia, Universidad de Valencia-Estudi General, Valencia, Spain
| | - Isabel Trapero
- Departamento de Enfermería, Universidad de Valencia-Estudi General, Valencia, Spain
| | - Álvaro Tormos
- Departamento de Electrónica, Universidad Politécnica de Valencia, Valencia, Spain
| | - Luis Such
- Departamento de Fisiología, Universidad de Valencia-Estudi General, Valencia, Spain
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Quintanilla JG, Moreno J, Archondo T, Chin A, Pérez-Castellano N, Usandizaga E, García-Torrent MJ, Molina-Morúa R, González P, Rodríguez-Bobada C, Macaya C, Pérez-Villacastín J. KATP channel opening accelerates and stabilizes rotors in a swine heart model of ventricular fibrillation. Cardiovasc Res 2013; 99:576-85. [PMID: 23612586 DOI: 10.1093/cvr/cvt093] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS The mechanisms underlying ventricular fibrillation (VF) are still disputed. Recent studies have highlighted the role of KATP-channels. We hypothesized that, under certain conditions, VF can be driven by stable and epicardially detectable rotors in large hearts. To test our hypothesis, we used a swine model of accelerated VF by opening KATP-channels with cromakalim. METHODS AND RESULTS Optical mapping, spectral analysis, and phase singularity tracking were performed in eight perfused swine hearts during VF. Pseudo-bipolar electrograms were computed. KATP-channel opening almost doubled the maximum dominant frequency (14.3 ± 2.2 vs. 26.5 ± 2.8 Hz, P < 0.001) and increased the maximum regularity index (0.82 ± 0.05 vs. 0.94 ± 0.04, P < 0.001), the density of rotors (2.0 ± 1.4 vs. 16.0 ± 7.0 rotors/cm²×s, P < 0.001), and their maximum lifespans (medians: 368 vs. ≥3410 ms, P < 0.001). Persistent rotors (≥1 movie = 3410 ms) were found in all hearts after cromakalim (mostly coinciding with the fastest and highest organized areas), but they were not epicardially visible at baseline VF. A 'beat phenomenon' ruled by inter-domain frequency gradients was observed in all hearts after cromakalim. Acceleration of VF did not reveal any significant regional preponderance. Complex fractionated electrograms were not found in areas near persistent rotors. CONCLUSION Upon KATP-channel opening, VF consisted of rapid and highly organized domains mainly due to stationary rotors, surrounded by poorly organized areas. A 'beat phenomenon' due to the quasi-periodic onset of drifting rotors was observed. These findings demonstrate the feasibility of a VF driven by stable rotors in hearts whose size is similar to the human heart. Our model also showed that complex fractionation does not seem to localize stationary rotors.
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Affiliation(s)
- Jorge G Quintanilla
- Optical Mapping Laboratory, Arrhythmia Unit, Cardiovascular Institute, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), CP 28040, Madrid, Spain.
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