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The impact of a modified anaesthetic protocol on animal survival and the characteristics of ventricular arrhythmias in the course of acute myocardial infarction in a domestic pig model. J Vet Res 2022; 66:435-447. [PMID: 36349138 PMCID: PMC9597936 DOI: 10.2478/jvetres-2022-0046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 08/18/2022] [Indexed: 11/20/2022] Open
Abstract
Abstract
Introduction
Acute myocardial infarction (MI) is one of the most common causes of death in humans in highly developed countries. Among its most frequent complications affecting the patient’s prognosis are cardiac arrhythmias: ventricular tachycardia (VT) and ventricular fibrillation (VF).
Material and Methods
The study aimed to characterise arrhythmias in 19 pigs subjected to experimentally induced MI obtained by occlusion of the proximal left anterior descending (LAD) coronary artery using an angioplasty balloon. The anaesthetic protocol was modified to reduce mortality by including procedures stabilising haemodynamic disorders which develop during episodes of ischaemia and arrhythmia. During 30 min of experimentally induced ischaemia, the heart rhythm was recorded using a 12-lead ECG. The time, frequency, and type of arrhythmias were analysed.
Results
Ventricular arrhythmias were found in 94.74% of the treated pigs. The most common were ventricular premature complexes, reported in 88.89% of pigs with arrhythmia. Ventricular tachycardia was recorded in 66.67% and ventricular fibrillation in 50% of pigs with arrhythmias.
Conclusion
Myocardial infarction due to proximal LAD occlusion is characterised by a high incidence of ventricular arrhythmias, especially VT and VF. Because of the high survival rate, this MI porcine model may serve as a model for research on acute ischaemic ventricular arrhythmias in humans. Additionally, it reduces the total number of animals required for testing while yielding meaningful results, which is in line with the 3R principle.
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Quinn TA, Kohl P. Cardiac Mechano-Electric Coupling: Acute Effects of Mechanical Stimulation on Heart Rate and Rhythm. Physiol Rev 2020; 101:37-92. [PMID: 32380895 DOI: 10.1152/physrev.00036.2019] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The heart is vital for biological function in almost all chordates, including humans. It beats continually throughout our life, supplying the body with oxygen and nutrients while removing waste products. If it stops, so does life. The heartbeat involves precise coordination of the activity of billions of individual cells, as well as their swift and well-coordinated adaption to changes in physiological demand. Much of the vital control of cardiac function occurs at the level of individual cardiac muscle cells, including acute beat-by-beat feedback from the local mechanical environment to electrical activity (as opposed to longer term changes in gene expression and functional or structural remodeling). This process is known as mechano-electric coupling (MEC). In the current review, we present evidence for, and implications of, MEC in health and disease in human; summarize our understanding of MEC effects gained from whole animal, organ, tissue, and cell studies; identify potential molecular mediators of MEC responses; and demonstrate the power of computational modeling in developing a more comprehensive understanding of ‟what makes the heart tick.ˮ.
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Affiliation(s)
- T Alexander Quinn
- Department of Physiology and Biophysics and School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada; Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg/Bad Krozingen, Medical Faculty of the University of Freiburg, Freiburg, Germany; and CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Peter Kohl
- Department of Physiology and Biophysics and School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada; Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg/Bad Krozingen, Medical Faculty of the University of Freiburg, Freiburg, Germany; and CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
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Cameron BA, Kai H, Kaihara K, Iribe G, Quinn TA. Ischemia Enhances the Acute Stretch-Induced Increase in Calcium Spark Rate in Ventricular Myocytes. Front Physiol 2020; 11:289. [PMID: 32372969 PMCID: PMC7179564 DOI: 10.3389/fphys.2020.00289] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 03/16/2020] [Indexed: 12/20/2022] Open
Abstract
Introduction: In ventricular myocytes, spontaneous release of calcium (Ca2+) from the sarcoplasmic reticulum via ryanodine receptors (“Ca2+ sparks”) is acutely increased by stretch, due to a stretch-induced increase of reactive oxygen species (ROS). In acute regional ischemia there is stretch of ischemic tissue, along with an increase in Ca2+ spark rate and ROS production, each of which has been implicated in arrhythmogenesis. Yet, whether there is an impact of ischemia on the stretch-induced increase in Ca2+ sparks and ROS has not been investigated. We hypothesized that ischemia would enhance the increase of Ca2+ sparks and ROS that occurs with stretch. Methods: Isolated ventricular myocytes from mice (male, C57BL/6J) were loaded with fluorescent dye to detect Ca2+ sparks (4.6 μM Fluo-4, 10 min) or ROS (1 μM DCF, 20 min), exposed to normal Tyrode (NT) or simulated ischemia (SI) solution (hyperkalemia [15 mM potassium], acidosis [6.5 pH], and metabolic inhibition [1 mM sodium cyanide, 20 mM 2-deoxyglucose]), and subjected to sustained stretch by the carbon fiber technique (~10% increase in sarcomere length, 15 s). Ca2+ spark rate and rate of ROS production were measured by confocal microscopy. Results: Baseline Ca2+ spark rate was greater in SI (2.54 ± 0.11 sparks·s−1·100 μm−2; n = 103 cells, N = 10 mice) than NT (0.29 ± 0.05 sparks·s−1·100 μm−2; n = 33 cells, N = 9 mice; p < 0.0001). Stretch resulted in an acute increase in Ca2+ spark rate in both SI (3.03 ± 0.13 sparks·s−1·100 μm−2; p < 0.0001) and NT (0.49 ± 0.07 sparks·s−1·100 μm−2; p < 0.0001), with the increase in SI being greater than NT (+0.49 ± 0.04 vs. +0.20 ± 0.04 sparks·s−1·100 μm−2; p < 0.0001). Baseline rate of ROS production was also greater in SI (1.01 ± 0.01 normalized slope; n = 11, N = 8 mice) than NT (0.98 ± 0.01 normalized slope; n = 12, N = 4 mice; p < 0.05), but there was an acute increase with stretch only in SI (+12.5 ± 2.6%; p < 0.001). Conclusion: Ischemia enhances the stretch-induced increase of Ca2+ sparks in ventricular myocytes, with an associated enhancement of stretch-induced ROS production. This effect may be important for premature excitation and/or in the development of an arrhythmogenic substrate in acute regional ischemia.
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Affiliation(s)
- Breanne A Cameron
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Hiroaki Kai
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Keiko Kaihara
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Gentaro Iribe
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, Japan.,Department of Physiology, Asahikawa Medical University, Asahikawa, Japan
| | - T Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada.,School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada
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Qi K, Li X, Geng Y, Cui H, Jin C, Wang P, Li Y, Yang Y. Tongxinluo attenuates reperfusion injury in diabetic hearts by angiopoietin-like 4-mediated protection of endothelial barrier integrity via PPAR-α pathway. PLoS One 2018; 13:e0198403. [PMID: 29912977 PMCID: PMC6005559 DOI: 10.1371/journal.pone.0198403] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 05/20/2018] [Indexed: 12/02/2022] Open
Abstract
Objective Endothelial barrier function in the onset and Tongxinluo (TXL) protection of myocardial ischemia/reperfusion (I/R) injury, and TXL can induce the secretion of Angiopoietin-like 4 (Angptl4) in human cardiac microvascular endothelial cells during hypoxia/reoxygenation. We intend to demonstrate whether TXL can attenuate myocardial I/R injury in diabetes, characterized with microvascular endothelial barrier disruption, by induction of Angptl4-mediated protection of endothelial barrier integrity. Methods and results I/R injury was created by coronary ligation in ZDF diabetic and non-diabetic control rats. The animals were anesthetized and randomized to sham operation or I/R injury with or without the exposure to insulin, rhAngptl4, TXL, Angptl4 siRNA, and the PPAR-α inhibitor MK886. Tongxinluo, insulin and rhAngptl4 have the similar protective effect on diabetic hearts against I/R injury. In I/R-injured diabetic hearts, TXL treatment remarkably reduced the infarct size, and protected endothelial barrier integrity demonstrated by decreased endothelial cells apoptosis, microvascular permeability, and myocardial hemorrhage, fortified tight junction, and upregulated expression of JAM-A, integrin-α5, and VE-cadherin, and these effects of TXL were as effective as insulin and rhAngptl4. However, Angptl4 knock-down with siRNA interference and inhibition of PPAR-α with MK886 partially diminished these beneficial effects of TXL and rhAngptl4. TXL induced the expression of Angptl4 in I/R-injured diabetic hearts, and was canceled by Angptl4 siRNA and MK886. TXL treatment increased myocardial PPAR-α activity, and was abolished by MK886 but not by Angptl4 siRNA. Conclusions TXL protects diabetic hearts against I/R injury by activating Angptl4-mediated restoration of endothelial barrier integrity via the PPAR-α pathway.
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Affiliation(s)
- Kang Qi
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiangdong Li
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yongjian Geng
- Division of Cardiovascular Medicine, University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Hehe Cui
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Chen Jin
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Peihe Wang
- Peking Key Laboratory for Pre-clinical Evaluation of Cardiovascular Implant Material, State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Animal Experimental Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yue Li
- Peking Key Laboratory for Pre-clinical Evaluation of Cardiovascular Implant Material, State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Animal Experimental Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yuejin Yang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- * E-mail:
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Porta A, Barrabés JA, Candell-Riera J, Agulló L, Aguadé-Bruix S, de León G, Figueras J, Garcia-Dorado D. Plasma B-type natriuretic peptide levels are poorly related to the occurrence of ischemia or ventricular arrhythmias during symptom-limited exercise in low-risk patients. Arch Med Sci 2016; 12:341-8. [PMID: 27186178 PMCID: PMC4848363 DOI: 10.5114/aoms.2016.59258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 02/03/2015] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION The usefulness of B-type natriuretic peptide (BNP) as a marker of ischemia is controversial. BNP levels have predicted arrhythmias in various settings, but it is unknown whether they are related to exercise-induced ischemic ventricular arrhythmias. MATERIAL AND METHODS We analyzed in 63 patients (64 ±14 years, 65% male, 62% with known coronary disease) undergoing exercise stress single-photon emission computed tomography (SPECT) the association between plasma BNP values (before and 15 min after exercise) and the occurrence of ischemia or ventricular arrhythmias during the test. RESULTS Exercise test (8.1 ±2.7 min, 7.4 ±8.1 metabolic equivalents, 82 ±12% of maximal predicted heart rate) induced reversible perfusion defects in 23 (36%) patients. Eight (13%) patients presented significant arrhythmias (≥ 7 ventricular premature complexes/min, couplets, or non-sustained ventricular tachycardia during exercise or in the first minute of recovery). Median baseline BNP levels were 17.5 (12.4-66.4) pg/ml in patients developing scintigraphic ischemia and 45.6 (13.2-107.4) pg/ml in those without ischemia (p = 0.137). The BNP levels increased after exercise (34.4 (15.3-65.4)% increment over baseline, p < 0.001), but the magnitude of this increase was not related to SPECT positivity (35.7 (18.8-65.4)% vs. 27.9 (5.6-64.0)% in patients with and without ischemia, respectively, p = 0.304). No significant association was found between BNP values (at baseline or their change during the test) and ventricular arrhythmias. CONCLUSIONS Plasma BNP values - at baseline or after exercise - were not associated with myocardial ischemia or with ventricular arrhythmia during exercise SPECT. These results highlight the limited usefulness of this biomarker to assess acute ischemia.
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Affiliation(s)
- Andreu Porta
- Servicio de Cardiología, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - José A Barrabés
- Servicio de Cardiología, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jaume Candell-Riera
- Servicio de Cardiología, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Luis Agulló
- Servicio de Cardiología, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Santiago Aguadé-Bruix
- Servicio de Medicina Nuclear, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Gustavo de León
- Servicio de Medicina Nuclear, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jaume Figueras
- Servicio de Cardiología, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - David Garcia-Dorado
- Servicio de Cardiología, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain
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Barrabés JA, Inserte J, Agulló L, Rodríguez-Sinovas A, Alburquerque-Béjar JJ, Garcia-Dorado D. Effects of the Selective Stretch-Activated Channel Blocker GsMtx4 on Stretch-Induced Changes in Refractoriness in Isolated Rat Hearts and on Ventricular Premature Beats and Arrhythmias after Coronary Occlusion in Swine. PLoS One 2015; 10:e0125753. [PMID: 25938516 PMCID: PMC4418727 DOI: 10.1371/journal.pone.0125753] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 03/26/2015] [Indexed: 01/19/2023] Open
Abstract
Mechanical factors may contribute to ischemic ventricular arrhythmias. GsMtx4 peptide, a selective stretch-activated channel blocker, inhibits stretch-induced atrial arrhythmias. We aimed to assess whether GsMtx4 protects against ventricular ectopy and arrhythmias following coronary occlusion in swine. First, the effects of 170-nM GsMtx4 on the changes in the effective refractory period (ERP) induced by left ventricular (LV) dilatation were assessed in 8 isolated rat hearts. Then, 44 anesthetized, open-chest pigs subjected to 50-min left anterior descending artery occlusion and 2-h reperfusion were blindly allocated to GsMtx4 (57 μg/kg iv. bolus and 3.8 μg/kg/min infusion, calculated to attain the above concentration in plasma) or saline, starting 5-min before occlusion and continuing until after reflow. In rat hearts, LV distension induced progressive reductions in ERP (35±2, 32±2, and 29±2 ms at 0, 20, and 40 mmHg of LV end-diastolic pressure, respectively, P<0.001) that were prevented by GsMTx4 (33±2, 33±2, and 32±2 ms, respectively, P=0.002 for the interaction with LV end-diastolic pressure). Pigs receiving GsMtx4 had similar number of ventricular premature beats during the ischemic period as control pigs (110±28 vs. 103±21, respectively, P=0.842). There were not significant differences among treated and untreated animals in the incidence of ventricular fibrillation (13.6 vs. 22.7%, respectively, P=0.696) or tachycardia (36.4 vs. 50.0%, P=0.361) or in the number of ventricular tachycardia episodes during the occlusion period (1.8±0.7 vs. 5.5±2.6, P=0.323). Thus, GsMtx4 administered under these conditions does not suppress ventricular ectopy following coronary occlusion in swine. Whether it might protect against malignant arrhythmias should be tested in studies powered for these outcomes.
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Affiliation(s)
- José A. Barrabés
- Servicio de Cardiología, Hospital Universitari Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
- * E-mail:
| | - Javier Inserte
- Servicio de Cardiología, Hospital Universitari Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Luis Agulló
- Servicio de Cardiología, Hospital Universitari Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Antonio Rodríguez-Sinovas
- Servicio de Cardiología, Hospital Universitari Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Juan J. Alburquerque-Béjar
- Servicio de Cardiología, Hospital Universitari Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - David Garcia-Dorado
- Servicio de Cardiología, Hospital Universitari Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
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Barrabés JA, Mirabet M, Agulló L, Figueras J, Pizcueta P, Garcia-Dorado D. Platelet deposition in remote cardiac regions after coronary occlusion. Eur J Clin Invest 2007; 37:939-46. [PMID: 17971174 DOI: 10.1111/j.1365-2362.2007.01883.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Activated platelets might contribute to endothelial dysfunction in non-ischaemic territories during acute myocardial infarction. We assessed platelet deposition, coronary flow reserve and contractile function in remote cardiac regions after transient coronary occlusion and their association with systemic platelet activation. MATERIALS AND METHODS In 10 pigs (series A) subjected to 48-min occlusion of the left anterior descending coronary artery (LAD), 99mTc-platelet content in the right coronary artery (RCA) and its dependent myocardium was counted after reflow. In 10 pigs (series B) receiving the same occlusion of the RCA, the hyperaemic response at the LAD and systolic shortening in LAD-dependent myocardium were monitored after reperfusion. P-selectin expression on circulating platelets was assessed in both series by flow cytometry. RESULTS In series A, platelet counts in the RCA and non-ischaemic myocardium were correlated with platelet content, polymorphonuclear leukocyte infiltration and infarct size in the reperfused zone, as well as with the percentage of P-selectin-positive platelets after reflow. In series B, a transient reduction in peak hyperaemic response in the LAD and sustained contractile dysfunction in non-ischemic myocardium were observed after releasing the RCA occlusion, these changes being also correlated with platelet activation status. CONCLUSIONS Ischaemic injury triggers macro- and microvascular platelet deposition and causes an impairment in coronary flow reserve and contractile function in distant regions of the heart, which are related to activation of circulating platelets.
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Affiliation(s)
- J A Barrabés
- Servicio de Cardiología, Hospital Universitari Vall d'Hebron, Barcelona, Spain
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Barrabés JA, Garcia-Dorado D, Agulló L, Rodríguez-Sinovas A, Padilla F, Trobo L, Soler-Soler J. Intracoronary infusion of Gd3+ into ischemic region does not suppress phase Ib ventricular arrhythmias after coronary occlusion in swine. Am J Physiol Heart Circ Physiol 2005; 290:H2344-50. [PMID: 16387793 DOI: 10.1152/ajpheart.00917.2005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Increased mechanical tension in the ischemic region during acute coronary occlusion might favor the occurrence of phase Ib ventricular arrhythmias. We aimed to investigate whether intracoronary administration of Gd(3+), a stretch-activated channel blocker, into the ischemic zone reduces the incidence of these arrhythmias. In thiopental-anesthetized, open-chest pigs, the left anterior descending coronary artery (LAD) was ligated for 45 or 48 min. Phosphate-free, HEPES-buffered saline bubbled with 100% N(2) was infused into the ischemic region for 4 min, starting 5 min (series A; n = 16) or 20 min (series B; n = 16) after coronary occlusion, at a rate doubling the baseline blood flow. Animals were blindly allocated to receive 40 muM Gd(3+) or only the buffer during the final 2 min of the infusion. There were no differences between groups with respect to hemodynamic variables, plasma K(+) levels, or size of the ischemic region. In neither series was the number of phase Ib premature ventricular beats reduced by Gd(3+) (46 +/- 20 in untreated vs. 91 +/- 37 in Gd(3+)-treated animals in series A and 19 +/- 7 vs. 22 +/- 13, respectively, in series B; both P = not significant). The occurrence of ventricular tachycardia or fibrillation was significantly associated with the magnitude of early ischemic expansion of the LAD region, as measured by ultrasonic crystals, but was also not prevented by Gd(3+). These results argue against a major role of stretch-activated channels inside the area at risk in the genesis of phase Ib ischemic ventricular arrhythmias.
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Affiliation(s)
- José A Barrabés
- Servicio de Cardiología, Hospital Universitari Vall d'Hebron, Pg. Vall d'Hebron 119-129, E-08035 Barcelona, Spain
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