Haemodynamic and metabolic effects of the antiarrhythmic drug melperone during acute left ventricular failure in dogs.

Haemodynamic and metabolic effects of the new antiarrhythmic drug melperone were studied during acute ischaemic left ventricular failure in closed-chest anaesthetized dogs. Embolisation of the left main coronary artery with 50 micrometer plastic microspheres induced severe depression of left ventricular performance as evidenced by a marked increase in left ventricular end-diastolic pressure and a marked reduction in the maximum rate of left ventricular pressure rise (LVdP/dtmax), cardiac output, and stroke volume. Six dogs received intravenous melperone 1.0 and 2.5 mg . kg-1 (cumulative dose) 90 and 115 min after the embolisation, respectively. Six other dogs received no treatment and served as controls. Melperone effected a marked reduction in left ventricular end-diastolic pressure, a slight but transient increase in LVdP/dtmax, a moderate reduction in heart rate, a moderate reduction in mean aortic blood pressure and total peripheral resistance and a moderate increase in stroke volume. Melperone moderately decreased myocardial O2-consumption, while myocardial lactate uptake remained unchanged. In conclusion, in contrast to commonly used antiarrhythmic drugs which may all induce cardiodepression, melperone improved left ventricular function in dogs with acute ischaemic left ventricular failure.