Immediate haemodynamic effects of verapamil in man.

The effect of the antiarrhythmic drug verapamil (Isoptin) on circulatory dynamics and myocardial contractility was studied in six patients in sinus rhythm: three patients were control subjects and three had underlying rheumatic valvular disease. The drug was given as an intravenous bolus (10 mg) and measurements made in the control state and repeated 1, 3, 5 and 10 min after administration of verapamil. Left ventricular (LV) systolic pressure fell by 18% 1 min after intravenous verapamil (p less than 0.01) and returned twoards the range of normal after 10 min. Heart rate increased and cardiac and stroke index were not altered 5 and 10 min after administration of the drug. Peak LVdp/dt and Vmax were reduced while LV end-diastolic pressure increased reflecting a decrease in LV contractility. The hemodynamic effects were similar in digitalised and nondigitalised patients.