The role of echocardiography in fetal tachyarrhythmia diagnosis. A burden for the pediatric cardiologist and a review of the literature.

Supraventricular tachyarrhythmia represents the most frequent fetal dysrhythmia. In the lack of diagnosis and treatment these fetuses may develop hydrops and even death. For the therapeutic approach it is important to establish the diagnosis of the type of supraventricular tachycardia. In this paper we report 29 cases with different types of supraventricular tachycardia in which the diagnosis was established using our own protocol, which allowed us to make the difference between the types of tachycardia (atrioventricular reentry tachycardia due to the accessory pathway, atrial ectopic tachycardia and permanent junctional reciprocal tachycardia). We acquired the data by a series of recordings in M mode and pulsed Doppler by simultaneous recording of an artery and a vein flow. First of all, we diagnosed the supraventricular tachycardia type, with short or long ventriculoarterial interval, and afterwards, we made the difference between atrial ectopic tachycardia and permanent junctional reciprocal tachycardia using methods to decrease the atrioventricular conduction.