Haemodynamic effects of sulphinpyrazone in experimental myocardial ischaemia.

The effect of sulphinpyrazone (30 mg/kg i.v.) on heart rate, blood pressure and ventricular arrhythmias was studied in open-chested anaesthetized dogs during sequential 10 min occlusions of the left anterior descending coronary artery. An increased duration of occlusion without ventricular fibrillation and reduction in epicardial activation delay in the central ischaemic region were observed after intravenous sulphinpyrazone (n = 7). These effects were associated with a progressive and significant reduction in intrinsic heart rate (up to 15 beats/min) but no change in blood pressure. These findings suggest that heart rate changes alone may account for the observed protective effect of sulphinpyrazone against early ventricular fibrillation during acute experimental myocardial ischaemia.