Robert A Kloner1, Joan Dow, Anil Bhandari. 1. Heart Institute, Good Samaritan Hospital and Division of Cardiovascular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90017, USA. rkloner@goodsam.org
Abstract
BACKGROUND: Brief periods of reocclusion (postconditioning) during early reperfusion reduce myocardial infarct size. Whether postconditioning has an effect on lethal ventricular arrhythmias independent of infarction in an in-vivo regional ischemia model is unknown. The purpose of this study was to determine if postconditioning limited reperfusion arrhythmias in a necrosis-free model. METHODS: Anesthetized rats were subjected to 5 minutes of proximal coronary artery occlusion; they were randomized to a control group (n = 15) that underwent reperfusion alone or a postconditioning group (n = 15) that received four cycles of 20 seconds reperfusion, 20 seconds reocclusion before final reperfusion. RESULTS: During the final reperfusion phase, ventricular arrhythmias occurred in 14 of 15 control rats and 8 of 15 postconditioning rats (P = .017). Ventricular tachycardia occurred in 10 of 15 control rats vs 4 of 15 postconditioning rats (P = .028). Control rats demonstrated 1.3 runs of ventricular tachycardia per minute vs 0.4 runs in postconditioning rats (P = .026). The average duration of ventricular tachycardia runs was 8.8 +/- 3.2 seconds in the control group vs 5.0 +/- 3.9 seconds in postconditioning rats (P = NS). CONCLUSION: This in-vivo study showed that postconditioning markedly attenuates ventricular arrhythmia after regional ischemia in a noninfarct model.
BACKGROUND: Brief periods of reocclusion (postconditioning) during early reperfusion reduce myocardial infarct size. Whether postconditioning has an effect on lethal ventricular arrhythmias independent of infarction in an in-vivo regional ischemia model is unknown. The purpose of this study was to determine if postconditioning limited reperfusion arrhythmias in a necrosis-free model. METHODS: Anesthetized rats were subjected to 5 minutes of proximal coronary artery occlusion; they were randomized to a control group (n = 15) that underwent reperfusion alone or a postconditioning group (n = 15) that received four cycles of 20 seconds reperfusion, 20 seconds reocclusion before final reperfusion. RESULTS: During the final reperfusion phase, ventricular arrhythmias occurred in 14 of 15 control rats and 8 of 15 postconditioning rats (P = .017). Ventricular tachycardia occurred in 10 of 15 control rats vs 4 of 15 postconditioning rats (P = .028). Control rats demonstrated 1.3 runs of ventricular tachycardia per minute vs 0.4 runs in postconditioning rats (P = .026). The average duration of ventricular tachycardia runs was 8.8 +/- 3.2 seconds in the control group vs 5.0 +/- 3.9 seconds in postconditioning rats (P = NS). CONCLUSION: This in-vivo study showed that postconditioning markedly attenuates ventricular arrhythmia after regional ischemia in a noninfarct model.
Authors: Ming Cai; Yuanjing Li; Yi Xu; Harold M Swartz; Chwen-Lih Chen; Yeong-Renn Chen; Guanglong He Journal: Am J Physiol Heart Circ Physiol Date: 2011-01-07 Impact factor: 4.733
Authors: Andreas Spannbauer; Denise Traxler; Dominika Lukovic; Katrin Zlabinger; Johannes Winkler; Alfred Gugerell; Péter Ferdinandy; Derek J Hausenloy; Noemi Pavo; Maximilian Y Emmert; Simon P Hoerstrup; Andras Jakab; Mariann Gyöngyösi; Martin Riesenhuber Journal: Int J Mol Sci Date: 2019-04-30 Impact factor: 5.923