Tachycardia-induced cardiomyopathy after functional closure of the foramen ovale in a fetus.

Although fetal tachyarrhythmias are relatively rare, they are an important causes of fetal morbidity and mortality. We report a 30-week pregnant woman with fetal tachycardia, fetal hydrops and ascites. Fetal heart rate was 230 bpm. Fetal heart rate was 230 bpm. M-mode echocardiography revealed a tachycardia with a 1:1 relationship between atrial and ventricular conduction and a short time interval between ventricular and atrial contraction. These findings suggested a diagnosis of atrioventricular re-entrant tachycardia. On the third day digoxin treatment, the fetal heart rate was still 225 bpm with a 1:1 relationship between atrial and ventricular conduction. At this time, no flow across the foramen ovale was detected. Functional closure of the foramen ovale was suspected.