Studies in a newborn infant with supraventricular tachycardia and Wolff-Parkinson-White syndrome.

A neonatal patient with Wolff-Parkinson-White type A and supraventricular tachycardia is described. Demonstration of the mechanism of the tachycardia and its termination were achieved using intracardiac electrography and cardiac pacing. Quantitative left ventricular angiography and echocardiography showed impaired left ventricular function following the arrhythmia. Serial echocardiograms demonstrated the subsequent return to normal left ventricular performance.