Long-term control of reciprocating paroxysmal tachycardia by ventricular pacing in a case of Wolff-Parkinson-White syndrome.

A patient is described with a complex electrocardiographic pattern, including preexcitation, grade 1 atrioventricular block, reciprocal rhythm of atrial origin, and frequent attacks of reciprocating tachycardia at a rate of about 135 beats per minute. Long-term control of these attacks was obtained by synchronous ventricular pacing at 80 beats a minute, which was below the rate during the attacks of tachycardia and above the spontaneous heart rate between the attacks.