Supraventricular arrhythmias in neonates are rare and mostly not related to structural heart defects. We present the first case of a newborn with a supraventricular microreentrant tachycardia possibly associated with an atrial septum aneurysm and emphasize the importance of a thorough diagnostic workup allowing a fast and adequate therapy.
Keywords: Aneurysmatic atrial septum; atrial flutter; ectopic atrial tachycardia; microreentry tachycardia; newborn; supraventricular arrhythmia.