Paroxysmal atrial tachycardia in infancy: long-term follow-up study of 49 subjects. 
A follow-up study of 49 individuals with paroxysmal atrial tachycardia in infancy is reported.  Forty subjects had supraventricular tachycardia and nine had atrial flutter/fibrillation.  The mean follow-up period was 24 years.  Males whose ECGs showed preexcitation displayed the highest rate of recurrences (approximately 60%) in the long-term follow-up.  Approximately 30% of the subjects without preexcitation in the ECG displayed episodes of supraventricular tachycardia in their third decade.  Eight-six percent of the children of the subjects in the present series were males.  The prognosis is good in the absence of congenital heart disease.