Twenty-nine consecutive spontaneous attacks of paroxysmal supraventricular tachycardia (PSVT) in 14 infants (mean age 4.4 months) were treated with verapamil. No infant had associated heart disease. Verapamil 1-2 mg i.v was administered over 30 seconds. The dosage varied according to the weight of the infant. Within 60 seconds sinus rhythm was obtained in 28 instances (96.5%). No significant co...