Fetal Supraventricular Tachyarrhythmias: Pharmacokinetics, Modes of Action, and Results of Anti-Arrhythmic Drug Therapy

Supraventricular tachycardia (SVT) belongs to the common cardiac causes of fetal heart failure and perinatal death [1]. With the arrival of ultrasound imaging to non-invasively detect cardiac anomalies before birth, the fetus has increasingly become the target of intended prenatal treatment. This includes the off-label administration of pharmaceutical agents via the maternal circulation or directly into the fetus to treat SVT. As anti-arrhythmic drugs act on one or several ion channels, the autonomous system, or both, we will start with an overview of the normal and abnormal electro-mechanical activation of the heart before discussing indications, modes of action, and effects of anti-arrhythmic therapy for fetal SVT.