[Polymorphic atrial tachycardia and Wolff-Parkinson-White syndrome in a newborn infant].

The authors report a case of polymorphic supraventricular tachycardia in a premature neonate born at 33 weeks by caesarean section because of foeto-placental insufficiency and hydramnios due to foetal tachycardia diagnosed in utero. This arrhythmia was of interest because of the association of chaotic atrial tachycardia and the Wolff-Parkinson-White syndrome (WPW), which has rarely been described in the neonate. The mechanism of atrial tachycardia in the WPW syndrome is variable. In our case, there was retrograde atrial activation by the accessory pathway with atrial desynchronisation aided by left atrial dilatation. Digoxin, an effective anti arrhythmic agent in neonatal tachycardia, should not be used in cases of atrial tachycardia associated with ventricular preexcitation because of the risk of dangerous ventricular tachycardia.