Treatment of Fetal Arrhythmias

Abstract

Fetal arrhythmias are mostly benign and transient. However, some of them are associated with structural defects or can cause heart failure, fetal hydrops, and can lead to intrauterine death. The analysis of fetal heart rhythm is based on ultrasound (M-mode and Doppler echocardiography). Irregular rhythm due to atrial ectopic beats is the most common type of fetal arrhythmia and is generally benign. Tachyarrhythmias are diagnosed when the fetal heart rate is persistently above 180 beats per minute (bpm). The most common fetal tachyarrhythmias are paroxysmal supraventricular tachycardia and atrial flutter. Most fetal tachycardias can be terminated or controlled by transplacental or direct administration of anti-arrhythmic drugs. Fetal bradycardia is diagnosed when the fetal heart rate is slower than 110 bpm. Persistent bradycardia outside labor or in the absence of placental pathology is mostly due to atrioventricular (AV) block. Approximately half of fetal heart blocks are in cases with structural heart defects, and AV block in cases with structurally normal heart is often caused by maternal anti-Ro/SSA antibodies. The efficacy of prenatal treatment for fetal AV block is limited. Our review aims to provide a practical guide for the diagnosis and management of common fetal arrythmias, from the joint perspective of the fetal medicine specialist and the cardiologist.

Efficacy and Safety of Various First-Line Therapeutic Strategies for Fetal Tachycardias: A Network Meta-Analysis and Systematic Review

“…We searched the PubMed, Web of Science, Medline, Embase, and Cochrane Library databases to identify studies comparing and evaluating the effects of various drug regimens used to regulate fetal tachycardias from database inception to July 2021, with no limits on the study design, country of origin, tachycardia type, administration route (placental, intravenous, intramuscular or other administration routes), or whether combination treatment was applied. Additional studies for inclusion were identified from among the references of relevant reviews ( Alsaied et al, 2017 ; Hill et al, 2017 ; Carvalho, 2019 ; Yuan, 2020 ; Veduta et al, 2021 ). The search strategy was established previously, and the terms included digoxin; flecainide; sotalol; amiodarone; tachycardia(s); fetus; supraventricular tachycardia or SVT; and atrial flutter or AF.…”

Atypical fetal junctional ectopic tachycardia: a case report and literature review

“…Most fetal arrhythmias are benign and transient, but persistent fetal arrhythmia can cause fetal deterioration. Among them, fetal supraventricular tachycardia often responds to fetal therapy [ 1 ].…”

“…Fetal supraventricular tachycardia can be controlled by transplacental administration of anti-arrhythmic drugs such as digoxin, flecainide, sotalol, and, more rarely, amiodarone. Fetal therapy is the recommended management to sufficiently decrease the ventricular rate in order to achieve a good cardiac output for fetuses with hydrops or at high risk of developing hydrops such as those with sustained tachycardia with ventricular rates > 200 bpm [ 1 ]. A recent meta-analysis on the transplacental treatment of fetal tachycardia showed that both flecainide and sotalol were more effective than digoxin for conversion of any fetal tachycardia to sinus rhythm, especially in cases of fetal hydrops [ 2 ].…”

Fetal Atrial Flutter Associated with Atrial Septal Aneurysm

“…This is also a valid option for fetuses with AF not associated with ASA, since postnatal treatment of tachyarrhythmia is usually effective. There is little reason to pursue transplacental drug therapy for the term fetus with tachyarrhythmia but no hydrops [ 33 ].…”