Prenatal diagnosis of junctional ectopic tachycardia

The congenital form of junctional ectopic tachycardia has never been report ed during the prenatal period. We describe a case in which the diagnosis co uld be ascertained in utero with the superior vena cava/ascending aorta Dop pler approach. The diagnosis was based on the evidence of ventricular tachy cardia with atrioventricular (AV) dissociation and the simultaneous occurre nce of atrial and ventricular contractions during an episode of tachycardia with 1:1 AV relationship.