Focal atrial tachycardia originating from the pulmonary vein with onset later than 3 years of age might have a better prognosis, possibly converting in adolescence.

Two cases of focal atrial tachycardia probably originating from the pulmonary vein with onset later than 3 years of age are presented. Both cases had associated variable atrioventricular conduction and showed no signs of heart failure, and they converted to sinus rhythm at the time of puberty. In cases of focal atrial tachycardia originating from the pulmonary vein with onset later than 3 years of age, drug therapy may be effective. Even if drug therapy is not effective, changes in the autonomic nervous system are reflected strongly in the pulmonary veins, so that changes in autonomic nervous system regulation with growth might terminate focal atrial tachycardia. Therefore, focal atrial tachycardia originating from the pulmonary vein with onset later than 3 years of age might have a better prognosis.