Effect of bretylium on cardiovascular changes induced by coronary occlusion in the cat

The influence of bretylium pretreatment on the heart rate, blood pressure, contractile force and cardiac rhythm changes produced by occlusion of the anterior descending coronary artery was evaluated in chloralose-anesthetized cats. Bretylium pretreatment shortened the duration of the ventricular arrhythmia. This drug however had no effect on the other cardiovascular changes evoked by coronary occlusion. These results suggest that the sympathetic nervous system has a role in maintaining electrical instability after experimentally induced myocardial infarction.