Changes of monophasic action potential duration and effective refractory period of three layers myocardium of canine during acute ischemia in vivo.
J Huazhong Univ Sci Technolog Med Sci
; 25(5): 497-500, 2005.
Article
em En
| MEDLINE
| ID: mdl-16463655
ABSTRACT
The effect of acute ischemia on the electrophysiological characteristics of the three layers myocardium of canine in vivo was investigated. Twelve canines were divided into two groups randomly acute ischemia (AI) group and sham operation (SO) group. By using the monophasic action potential (MAP) technique, MAP and effective refractory period (ERP) of the three layers myocardium were measured by specially designed plunge needle electrodes and the transmural dispersion of repolarization (TDR) and transmural dispersion of ERP (TDE) were analyzed. The results showed that in the AI group, MAP duration (MAPD) was shortened from 201.67 +/- 21.42 ms to 169.50 +/- 13.81 ms (P < 0.05), but ERP prolonged to varying degrees and TDE increased during ischemia. In the SO group, MAPD and ERP did not change almost. Among of the three layers myocardium of canine, MAPD was coincident in two groups. It was concluded that during acute ischemia, MAPD was shortened sharply, but there was no significant difference among of the three layers myocardium. The prolonged ERP was concomitant with increased TDE during acute ischemia, which may play an important role in the occurrence of arrhythmias induced by acute ischemia. These findings may have important implications in arrhythmogenesis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Período Refratário Eletrofisiológico
/
Potenciais de Ação
/
Isquemia Miocárdica
/
Miocárdio
Limite:
Animals
Idioma:
En
Revista:
J Huazhong Univ Sci Technolog Med Sci
Assunto da revista:
MEDICINA
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
China