Rapidly Recurring Supraventricular Tachycardia

Reciprocating tachycardias were diagnosed on the basis of previously established ECG criteria in seven patients with recurrent tachycardia but without WPW. In each patient we could record the onset of arrhythmia because tachycardia recurred within minutes of its termination. Treatment with propranolol alone or with digitalis, or digitalis and quinidine, prevented tachycardia in five patients and slowed it in one. Our cases suggest the following: (1) Recurrent supraventricular tachycardia in patients without the WPW syndrome may frequently be caused by a reciprocal mechanism. (2) The diagnosis of reciprocating tachycardia should be suspected when (a) the tachycardia recurs within minutes of its termination, (b) the onset follows prolongation of the P-R or R-P interval, (c) the P wave during the tachycardia is superiorly directed and different from the P wave which initiates the tachycardia, and (d) at least one other criterion for the diagnosis is met. (3) Propranolol is the drug of choice for the treatment of recurrent supraventricular tachycardias which satisfy the criteria for reciprocating tachycardia.