[Disorders of supraventricular rhythm in children]

In children with otherwise normal heart, reentry is the most common cause of supraventricular tachycardia. The tachycardia is stopped by vagal stimulation, and digoxin is then given to prevent recurrences; in patients with Wolff-Parkinson-White syndrome, transeosophageal stimulation is performed to examine properties of anterograde condution across the accessory connection, and to select the most appropriate treatment. Radiofrequency ablation is selected only in children with refractory supraventricular tachycardia or who were admitted for syncope due to rapid conduction over an accessory pathway. Neonatal junctional ectopic tachycardia may be very severe and even results is death when the heart rate is not slowed down; amiodarone is the safest and the most effective drug. Atrial flutter is encountered in 2 groups of children: neonates, in whom it is converted by rapid transeosophageal pacing, with excellent prognosis, and children who have had atrial surgery (Mustard and Senning operations). These patients have sinus failure, with paroxysmal atrial flutter possibly responsible for sudden death when rapidly conducted to the ventricles. It is a new and concerning pathology, as these children have chronic arrhythmias requiring aggressive therapy such as amiodarone and cardiac stimulation.