Fetal bradyarrhythmias: Etiopathogenesis, diagnosis and treatment: Between literature review and experience of a tertiary center

Abstract

Fetal arrhythmias reach up around 10% of the total third-level perinatal cardiology references. Sustained brady-cardia is defined as a baseline fetal heart rate (FHR) of less than 110 bpm sustained for at least 10 min. The overall incidence of malignant fetal bradyarrhythmias, such as complete atrioventricular block (AVB) and channellopa-thies, is relatively rare, 1:5000 pregnancies, but represents a serious emergency for the gynecologist, neonatolo-gists, and pediatric cardiologists. Fetal complete AVB is strongly associated with maternal connective tissue disease, but it can be also associated with congenital heart disease and usually with a poorer prognosis with high risk of fetal hydrops and abortion. Currently, the treatment of severe fetal bradyarrhythmias is principally phar-macological and aims to increase the FHR, besides an early resolution of underlying causes, when possible, and a promptly management of fetal heart failure. Intrauterine electrostimulation nowadays is an experimental pioneering method, reserved for limited selected cases.