Cardiac Rhythm Disturbances and the Release of Catecholamines After Acute Coronary Occlusion in Dogs

Acute occlusion of the anterior descending branch of the left coronary artery in dogs led to a development of ventricular arrhythmias in 39 of 68 animals examined. In 35 of these 39 dogs ventricular arrhythmias were associated with an increased release of catecholamines into the bloodstream. In dogs which failed to secrete catecholamines and showed no ectopic activity after coronary ligation, intravenous infusions of adrenaline provoked ventricular arrhythmias after coronary ligation, but not before. The specific β-receptor blocking agents, propranolol and I.C.I. 50 172, suppressed arrhythmias after coronary occlusion.