Atrial flutter in the fetus and young infant: an association with accessory connections.

OBJECTIVE To highlight the association between atrial flutter and accessory connections in the fetus and young infant. DESIGN A retrospective review from January 1985 to January 1990. PATIENTS Fetuses, neonates, and young infants with atrial flutter. RESULTS Four fetuses and five infants presented with atrial flutter. In two fetuses and one infant sinus rhythm returned spontaneously. The other six required cardioversion. Three of them developed orthodromic atrioventricular re-entry tachycardia and each had evidence of an accessory connection. CONCLUSIONS Because atrial flutter in the fetus and neonate is rare, the high incidence of accessory connections in this group points to a possible aetiology of "idiopathic" atrial flutter in this age group.