Prenatal echocardiographic diagnosis and outcomes of fetal sustained supraventricular tachycardia: a ten-year single-center experience

Fetal echocardiography plays a pivotal role in the diagnosis and management of fetal arrhythmias, allowing evaluation of the electrophysiological mechanism and guiding appropriate medical therapy. Herein, we describe our ten-year experience as a tertiary referral center in Southern Italy in the diagnosis and management of fetal sustained supraventricular tachycardia. Thirty-two consecutive fetuses were included: 16 fetuses with atrioventricular reentrant tachycardia, 7 fetuses with ectopic atrial tachycardia, 8 fetuses with atrial flutter, and 1 fetus with permanent junctional reciprocating tachycardia. Transplacental therapy guided by echocardiographic diagnosis was highly effective in achieving complete rhythm control (74%) or partial rhythm control (24%), even in presence of heart failure or hydrops fetalis. Postnatal antiarrhythmic therapy was not required in over one third of cases due to spontaneous resolution. Earlier gestational age at diagnosis was associated with arrhythmia resolution at birth. The presence of fetal heart failure or hydrops did not predict postnatal persistence of arrhythmia.