Diagnosis, treatment and follow up of fetal cardiac arrhythmia

INTRODUCTION: The importance of managing fetal arrhythmia has increased with the advance of fetal echocardiography. We aimed to describe incidence, type, clinical characteristics, treatment, and follow-up of fetal arrhythmia diagnosed patients in our center.
METHODS: Fetal echocardiographic examinations performed in our units between January 2016 and September 2019 were retrospectively evaluated. Fetal arrhythmias and their subtypes were identified using M-mode and Doppler echocardiography in all patients. Maternal age, gestational age, history of maternal or gestational pathology, diagnoses, and medications were recorded. Fetal arrhythmias were categorized in three main groups: 1) Irregular heart rhythm (ectopic beats, 2) Bradyarrhythmias: ventricular rate less than 110 bpm; and 3) Tachyarrhythmias: ventricular rate exceeding 180 bpm.
RESULTS: A total of 60 patients were diagnosed with fetal arrhythmia, corresponding to an overall incidence of 0.5%. Mean maternal and gestational age of patients with fetal arrhythmia were 28.35 ± 4.88 years and 31.03 ± 5.94 weeks. One patient had maternal systemic disease, and four had concurrent congenital cardiac disease. Fetal tachycardia, bradycardia, and irregular heart rhythm were detected in 10 (16.6%), 8 (13.3%), and 42 (70%) patients, respectively.
DISCUSSION AND CONCLUSION: Fetal echocardiography represents the main diagnostic tool for prenatal evaluation of fetal arrhythmias, which have a variable prognosis depending on the type of arrhythmia. The most common fetal arrhythmia, the irregular heart rhythm, generally does not necessitate any treatment and resolves spontaneously. The treatment plan in patients should be based on etiology and fetal conditions.