Abstract

Fetal supraventricular tachycardia (SVT) may rapidly lead to heart failure and hydrops fetalis, particularly when associated with structural congenital heart disease. Ebstein anomaly represents a highly arrhythmogenic substrate. We report a case of severe, drug-resistant fetal SVT complicated by hydrops fetalis in the setting of Ebstein anomaly type B, successfully managed with stepwise escalation of transplacental and direct fetal antiarrhythmic therapy. Fortunately, hydrops was resolved in utero, and a full-term baby was born with 3000g birth weight. Immediately after birth, SVT recurred and was terminated with intravenous adenosine. Subsequent evaluations demonstrated stable sinus rhythm without cardiomyopathy.