[Supraventricular arrhythmia in newborn infants and interatrial septal aneurysm].

Three neonates with relapsing supraventricular arrhythmia, diagnosed in utero in one case, presented with aneurysm of the atrial septum (AAS) found at TM and bidimensional echocardiographic examination. Arrhythmia consisted of atrial flutter 1/1 or 2/1 (1 case) or supraventricular extrasystoles with episodes of supraventricular tachycardia (2 cases). Although AAS not associated with congenital heart disease related with a downstream obstacle on the right or left heart is considered a rare condition, it is likely that echocardiography will disclose it more frequently. Anyhow, it seems worthwhile searching for it in cases with apparently primary supraventricular arrhythmias. Although the precise relationships between arrhythmia and AAS are not yet known, one could suggest that this organic anomaly is susceptible of originating and of maintaining the arrhythmia longer, if not in a more sever fashion, than in neonatal isolated arrhythmia, especially without any preexcitation syndrome. Further studies are necessary for a better understanding of the meaning and mechanism of such an association.