Arrhythmogenesis after acute myocardial necrosis with and without preceding ischemia in rats.
J Basic Clin Physiol Pharmacol
; 25(2): 143-53, 2014 May 01.
Article
em En
| MEDLINE
| ID: mdl-24114909
BACKGROUND: The relative role of acute myocardial ischemia and infarction in ventricular arrhythmogenesis is incompletely understood. We compared the arrhythmia pattern after ischemia/infarction to that observed after direct myocardial necrosis without preceding ischemia in rats. METHODS: Coagulation necrosis was induced in Wistar rats (n=20, 280±3 g) by radiofrequency current application (for 15 s) from a 4-mm-tip ablation catheter. Myocardial infarction was induced by coronary artery ligation with (n=10) or without (n=10) reperfusion. Using 24-h telemetry recording, we examined ventricular arrhythmias, voluntary motor activity and indices of sympathetic activation. RESULTS: The coagulation-necrosis volume was 24.4%±0.6%, comparable to the infarct size in the absence of reperfusion. Acute left ventricular failure and sympathetic activation were similar in the three groups. Coagulation necrosis induced ventricular fibrillation immediately, followed by a second peak after â¼1 h. Reperfusion decreased ventricular arrhythmias, whereas a second arrhythmogenic period (between the third and the eight hour) was noted in non-reperfused infarcts (mainly monomorphic ventricular tachycardia). CONCLUSIONS: Distinct arrhythmia patterns occur after myocardial infarction (with or without reperfusion) and after direct necrosis. They are not produced by differences in sympathetic activation and are likely related to the evolution of myocardial injury. The necrosis rat model may be useful in studies of arrhythmogenesis.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Arritmias Cardíacas
/
Infarto do Miocárdio
/
Miocárdio
Tipo de estudo:
Etiology_studies
Limite:
Animals
Idioma:
En
Revista:
J Basic Clin Physiol Pharmacol
Assunto da revista:
FARMACOLOGIA
/
FISIOLOGIA
Ano de publicação:
2014
Tipo de documento:
Article