Fetal supraventricular tachycardia (SVT) and atrial flutter (AF) can be associated with significant morbidity and mortality. Digoxin is often used as first-line therapy but can be ineffective and is poorly transferred to the fetus in the presence of fetal hydrops. As an alternative to digoxin monotherapy, we have been using sotalol at presentation in fetuses with SVT or AF with, or at risk of, developing hydrops to attempt to achieve more rapid control of the arrhythmia. The present study was a retrospective review of the clinical, echocardiographic, and electrocardiographic data from all pregnancies with fetal tachycardia diagnosed and managed at a single center from 2004 to 2008. Of 29 affected pregnancies, 21 (16 SVT and 5 AF) were treated with sotalol at presentation, with or without concurrent administration of digoxin. Of the 21, 11 (6 SVT and 5 AF) had resolution of the tachycardia within 5 days (median 1). Six others showed some response (less frequent tachycardia, rate slowing, resolution of hydrops) without complete conversion. In 1 fetus with a slow response, the mother chose pregnancy termination. The 5 survivors with a slow response were all difficult to treat postnatally, including 1 requiring radiofrequency ablation as a neonate. One fetus developed blocked atrial extrasystoles after 1 dose of sotalol and was prematurely delivered for fetal bradycardia. Three grossly hydropic fetuses with SVT showed no response and died within 1 to 3 days of treatment. In conclusion, transplacental sotalol, alone or combined with digoxin, is effective for the treatment of fetal SVT and AF, with an 85% complete or partial response rate in our series.

Background Tetralogy of Fallot with absent pulmonary valve is associated with high mortality, but it remains difficult to predict outcomes prenatally. We aimed to identify risk factors for mortality in a large multicenter cohort. Methods and Results Fetal echocardiograms and clinical data from 19 centers over a 10-year period were collected. Primary outcome measures included fetal demise and overall mortality. Of 100 fetuses, pregnancy termination/postnatal nonintervention was elected in 22. Of 78 with intention to treat, 7 (9%) died in utero and 21 (27%) died postnatally. With median follow-up of 32.9 months, no deaths occurred after 13 months. Of 80 fetuses with genetic testing, 46% had chromosomal abnormalities, with 22q11.2 deletion in 35%. On last fetal echocardiogram, at a median of 34.6 weeks, left ventricular dysfunction independently predicted fetal demise (odds ratio [OR], 7.4; 95% CI 1.3, 43.0; P=0.026). Right ventricular dysfunction independently predicted overall mortality in multivariate analysis (OR, 7.9; 95% CI 2.1-30.0; P=0.002). Earlier gestational age at delivery, mediastinal shift, left ventricular/right ventricular dilation, left ventricular dysfunction, tricuspid regurgitation, and Doppler abnormalities were associated with fetal and postnatal mortality, although few tended to progress throughout gestation on serial evaluation. Pulmonary artery diameters did not correlate with outcomes. Conclusions Perinatal mortality in tetralogy of Fallot with absent pulmonary valve remains high, with overall survival of 64% in fetuses with intention to treat. Right ventricular dysfunction independently predicts overall mortality. Left ventricular dysfunction predicts fetal mortality and may influence prenatal management and delivery planning. Mediastinal shift may reflect secondary effects of airway obstruction and abnormal lung development and is associated with increased mortality.