Ventricular arrhythmias associated with coronary artery occlusion and reperfusion in the isolated perfused rat heart: a model for assessment of antifibrillatory action of antiarrhythmic agents.

The isolated Langendorff-perfused rat heart, subjected to coronary artery occlusion and reperfusion consistently developed ventricular arrhythmias. The incidence of hearts with ventricular premature extrasystoles, ventricular tachycardia, and fibrillatioon ventricular fibrillation could be abolished in the presence of an extracellular potassium concentration of 12 mmol-litre--1, whereas with 4.5 mmol-litre--1 all hearts developed all the ventricular arrhythmias including fibrillation. This predictable occurrence of ventricular arrhythmias was used to assess the antiarrhythmic effect of lignocaine with particular reference to its effect on the spontaneously occurring reperfusion ventricular fibrillation. Lignocaine decreased the incidence of all ventricular arrhythmias both during ischaemia and on reperfusion in a concentration-related fashion.