Attenuation of conduction delay by ischemic preconditioning reduces ischemia-induced ventricular arrhythmias

Kui Hong, Kengo Fukushima Kusano, Hiroshi Morita, Yoshihisa Fujimoto, Xian Wang, Hiroshi Yamanari, Tohru Ohe

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Ischemic preconditioning has been acknowledged as a powerful method of decreasing ischemic injury. However, the antiarrhythmic mechanism of ischemic preconditioning during ischemia is unclear. We studied the effects of ischemic preconditioning on arrhythmias and cardiac electrophysiology during ischemia in Langendorff rat hearts (n = 44). In the non-preconditioned group (PC(-); n = 24), the hearts underwent 5-min zero-flow global ischemia without any prior ischemic preconditioning. In the preconditioned group (PC(+); n = 20), the hearts were preconditioned by three cycles of 3-min zero-flow global ischemia and 5-min reperfusion before undergoing 5-min global ischemia. Ischemic preconditioning reduced the incidence of ischemia-induced arrhythmias (PC(-): 38.9%, PC(+): 8.3%, p < 0.05), shortened monophasic action potential duration (MAPD, P < 0.05), attenuated conduction delay (conduction time; PC(-): 234.2%, PC(+): 173.4%, P < 0.05) and increased the ventricular fibrillation threshold. Although the shortening of MAPD in PC(-) hearts was not influenced by the presence or absence of arrhythmias, conduction time prolongation at 3-min was more obvious in PC(-) hearts with arrhythmia than in PC(-) hearts without arrhythmia (PC(-) with arrhythmia: 220.2%, PC(-) without arrhythmia: 190.7%, P < 0.05). We concluded that ischemic preconditioning could protect the rat hearts from ischemia-induced arrhythmias and postulated that attenuation of conduction delay during ischemia might be an important factor in the antiarrhythmic action of ischemic preconditioning.

Original languageEnglish
Pages (from-to)233-238
Number of pages6
JournalActa medica Okayama
Volume53
Issue number5
Publication statusPublished - Dec 1 1999

Keywords

  • Arrhythmia
  • Ischemia
  • Preconditioning

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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    Hong, K., Kusano, K. F., Morita, H., Fujimoto, Y., Wang, X., Yamanari, H., & Ohe, T. (1999). Attenuation of conduction delay by ischemic preconditioning reduces ischemia-induced ventricular arrhythmias. Acta medica Okayama, 53(5), 233-238.