Hemodynamic effects of verapamil and practolol in man

The hemodynamic effects of verapamil and practolol were investigated in a group of 10 selected patients (7 with coronary artery disease) undergoing cardiac catherization. The drugs were given i.v. in a dose of 0.1 mg/kg, alone or in combination, before and after controling the heart rate by atrial pacing. Measured hemodynamic parameters included aortic and left ventricular pressure and its first derivative, cardiac output, and echocardiographically derived left ventricular dimensions. Each drug given individually caused minor hemodynamic changes, but the combination of practolol and verapamil when the heart rate was fixed by atrial pacing invaribly caused a reduction in LV dp/dt max which was independent of preload and afterload. It is concluded that both drugs have a mildly negative inotropic effect when administered at this dose intravenously to patients with normal or mildly impaired left ventricular function. The myocardial depression was more apparent when practolol preceded verpamil. Caution must be exercised when using these drugs in combination in patients with impaired myocardial function.