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 language | English |
|---|---|
| Pages (from-to) | 233-238 |
| Number of pages | 6 |
| Journal | Acta Medica Okayama |
| Volume | 53 |
| Issue number | 5 |
| Publication status | Published - 1999 |
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Keywords
- Arrhythmia
- Ischemia
- Preconditioning
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Medicine(all)
Cite this
Attenuation of conduction delay by ischemic preconditioning reduces ischemia-induced ventricular arrhythmias. / Hong, Kui; Kusano, Kengo Fukushima; Morita, Hiroshi; Fujimoto, Yoshihisa; Wang, Xian; Yamanari, Hiroshi; Ohe, Tohru.
In: Acta Medica Okayama, Vol. 53, No. 5, 1999, p. 233-238.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Attenuation of conduction delay by ischemic preconditioning reduces ischemia-induced ventricular arrhythmias
AU - Hong, Kui
AU - Kusano, Kengo Fukushima
AU - Morita, Hiroshi
AU - Fujimoto, Yoshihisa
AU - Wang, Xian
AU - Yamanari, Hiroshi
AU - Ohe, Tohru
PY - 1999
Y1 - 1999
N2 - 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.
AB - 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.
KW - Arrhythmia
KW - Ischemia
KW - Preconditioning
UR - http://www.scopus.com/inward/record.url?scp=0033209439&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033209439&partnerID=8YFLogxK
M3 - Article
C2 - 10561732
AN - SCOPUS:0033209439
VL - 53
SP - 233
EP - 238
JO - Acta Medica Okayama
JF - Acta Medica Okayama
SN - 0386-300X
IS - 5
ER -