Fetal arrhythmias: diagnosis and treatment.

Fetal arrhythmias are common, and they may resolve spontaneously in majority of the cases. Sustained fetal arrhythmias associated with major structural heart disorders, hydrops fetalis, and fetal heart failure warrant intrauterine pharmaceutical conversion of heart rhythm or early pacemaker implant in order to avoid fetal demise. Fetal atrial flutter (AF) and supraventricular tachycardia (SVT) resemble in terms of the effects of intrauterine therapies. Digoxin is more suitable for rhythm conversion of fetal AF and SVT in fetuses free of hydrops fetalis, while sotalol shows better effects for those with hydrops fetalis. In fetal cases of atrioventricular blocks, an etiological treatment for the maternal antibody exposure by steroids could be an alternative remedy. In this article, the clinical diagnosis and treatment of fetal arrhythmias are presented, and advantages and disadvantages of antiarrhythmic agents for fetal arrhythmias are compared.