Doppler echocardiography for managing fetal cardiac arrhythmia.

The successful management of fetal arrhythmias is contingent on an accurate diagnosis of arrhythmia and its effects on fetal well-being. Regardless of the rate (tachycardia or bradycardia) or rhythm (regular or irregular), the diagnosis of arrhythmia by Doppler echocardiography is based on the atrioventricular relationship and the atrial and ventricular rates. Fetal well-being at the time of diagnosis and during treatment can be assessed by Doppler flow patterns in the fetal systemic veins and atrioventricular valves. Information from Doppler echocardiography will distinguish those fetuses that can be conservatively managed from those that would benefit from in-utero pharmacotherapy.