Combined verapamil and propranolol for supraventricular tachycardia.

The electrophysiologic effects of intravenous verapamil and propranolol were compared alone and in combination in 14 patients (aged 21 to 69 years) with paroxysmal supraventricular tachycardia (SVT). Ten patients had atrioventricular (AV) reentry utilizing a manifest (7 patients) or concealed (3 patients) accessory pathway. Four patients had AV nodal reentry. Electrophysiology studies were performed using standard techniques in the control state and after verapamil (0.15 mg/kg intravenous bolus and 0.005 mg/kg/min). The next day, studies were repeated after propranolol (0.1 mg/kg) and a combination of verapamil and propranolol. No adverse effects occurred with the drug combination. Each drug intervention prolonged anterograde functional refractory period of the AV node (control, 370 +/- 50 ms; verapamil, 446 +/- 90 ms; propranolol, 436 +/- 92, p less than 0.05), with the greatest increase occurring after the drug combination (502 +/- 103 ms, p less than 0.001). In 2 patients prolonged sinus node recovery time developed after the drug combination. Verapamil or propranolol prevented SVT induction in 7 patients (50%). However, only the drug combination prevented reinduction of sustained SVT in 6 patients. These 6 patients were treated chronically with verapamil and propranolol, with no recurrence of SVT in any patient after 2 to 26 months.