[Simultaneous supraventricular tachycardia in twin premature newborns of a monochorionic pregnancy].

Supraventricular tachycardia (SVT) is the most common pediatric arrhythmia. SVT occurs more frequently in infants under 1 year of age, most of whom have structurally normal hearts. Pejorative predisposing factors such as congenital heart disease exist in only a few patients. In patients with a healthy heart, SVT is due to re-entry via an accessory pathway. Some articles describe occurrence of SVT in 1 of the fetuses or newborns from multiple gestation pregnancies, but few cases report simultaneous start of SVT in twins. This observation describes simultaneous occurrence of SVT in both premature infants from a monochorionic twin gestation. Successful emergency treatment consisted in physical maneuvers increasing vagal activity. The twin neonates then received a prolonged anti-arrhythmic amiodarone treatment. Both of their electrocardiograms were normal, without Wolf-Parkinson-White syndrome. Both of their echocardiography results showed aneurysms of the atrial septum. At 6 months of age, SVT had not recurred. This case describes an original presentation of simultaneous SVT in twins and highlights the efficacy of vagal maneuvers to manage stable patients. We discuss the existence of benign predisposing heart structural abnormalities.