Acute hemodynamic and electrophysiologic effects of propranolol in patients receiving diltiazem

Because the combined use of a beta-adrenergic blocking agent and a calcium antagonist may be beneficial in some patients with severe angina, the acute hemodynamic and electrophysiologic effects of intravenous propranolol in the presence and absence of oral diltiazem treatment was studied. In 22 patients (11 men, 11 women, mean age 50 years), 12 receiving diltiazem (mean 243 mg/day, range 180 to 360) and 10 not receiving diltiazem, hemodynamic and electrophysiologic variables were measured before and 5 minutes after intravenous propranolol (0.1 mg/kg). Cardiac index (by thermodilution) and left ventricular (LV) peak dP/dt fell and LV end-diastolic pressure increased similarly in both groups. Mean systemic arterial pressure was unchanged. Coronary sinus blood flow (by thermodilution) decreased slightly in patients receiving diltiazem and was unchanged in those not receiving it. Propranolol caused a similar reduction in heart rate and increase in atrio-His conduction in both groups. Thus, when intravenous propranolol is given to patients with normal or only mildly depressed LV systolic function, the hemodynamic and electrophysiologic effects are similar in those receiving and not receiving oral diltiazem.