The treatment of intractable supraventricular tachycardia after open heart surgery by a continuous infusion of verapamil and ventricular pacing.

Four patients who developed intractable supraventricular tachycardia (SVT) after open heart surgery were treated using a new therapeutic method of creating a pharmacological atrioventricular block by the continuous infusion of verapamil with ventricular pacing. Both the initial dose and the effective dose, being the verapamil dose necessary to maintain pharmacological atrioventricular block to prevent the recurrence of SVT, were surveyed with clinical results. The verapamil-induced hemodynamic changes observed 4 h and 8 h after treatment, as indicated by systolic arterial blood pressure, mean arteral blood pressure, heart rate, cardiac index, and urine volume, were compared with the values 1 h before treatment. After an initial low dose infusion of 0.07 +/- 0.02 mg/kg.h had been given, an effective and safe dose of 0.11 +/- 0.05 mg/kg.h was determined. Good hemodynamic and clinical results were achieved in all four patients who are now leading an active life. These results therefore encourage us to apply this therapeutic method for treating patients with intractable and recurrent SVT after open heart surgery.