The beneficial actions of bepridil in acute myocardial infarction in anaesthetized dogs.

1 When administered intravenously shortly before acute coronary ligation in dogs anaesthetized with chloralose, bepridil (5 mg/kg) produced immediate and transient falls in coronary and systemic vascular resistance which were accompanied by marked decreases in myocardial oxygen extraction. These effects were followed by sustained decreases in heart rate and myocardial oxygen consumption. 2 This dose of bepridil reduced the number of premature ventricular beats and abolished fibrillation induced by coronary artery ligation without modifying the haemodynamic or metabolic consequences (lactate production) of myocardial ischaemia. 3 When administered 1.5-2 h after ligation, bepridil did not compromise the critical perfusion of the acutely ischaemic zone but reduced the lactate production and ST-segment elevation in the ischaemic zone. 4 These results suggest that bepridil may be a useful drug in the chronic treatment of angina pectoris and in this respect may possess advantages over beta-adrenoceptor antagonists.