The effects of antiplatelet agents in the prevention of ventricular tachyarrhythmias during acute myocardial ischemia in rats

Experiments were performed in rat models to study the effectiveness of vari ous antiplatelet agents in the prevention of ventricular tachyarrhythmias d uring acute myocardial ischemia. The time to the onset of ST-segment elevation and initiating ventricular ar rhythmias, frequency and incidence of ventricular arrhythmias, and mortalit y rates were observed during acute myocardial ischemia (20 minutes) induced by ligation of the proximal left anterior descending coronary artery (LAD) in anesthetized rats. Four groups were studied: Control group (n = 10, not pretreated); Aspirin pretreated group (n = 10, 300 mg/kg po for 1 wk); Tic lopidine pretreated group (n = 10, 200 mg/kg po for 1 wk); and Abciximab (P latelet glycoprotein IIb/IIIa receptor antagonist) pretreated group (n = 10 , 2 mg/kg iv 10-20 minutes before an experiment). No significant difference was observed in the time to the onset of ST-segment elevation and ventricu lar arrhythmias between the groups. The incidence of ventricular tachycardi a (VT) in the abciximab group was significantly lower than in the control g roup (p < 0.05) and ventricular fibrillation (VF) in the aspirin and ticlop idine group was significantly lower than in the control group (p < 0.05). T he mortality rate in the ticlopidine group was significantly lower than in the control group (p < 0.01). This study suggests aspirin, ticlopidine, and abciximab can effectively pre vent VT or VF during acute myocardial ischemia induced by nonthrombotic occ lusion and its antiarrhythmic effect may lead to prolonged survival.