The association of fetal arrhythmias with congenital heart disease

ALAN BOLNICK, JAMES EGAN, ELIZABETH MILEWSKI, CAROLYN ZELOP, ELISA GIANFERRARI, MARY BETH JANICKI, ADAM BORGIDA, University of Connecticut, Obstetrics and Gynecology, Farmington, Connecticut, Saint Francis Hospital & Medical Center, Obstetrics & Gynecology, Hartford, Connecticut, Hartford Hospital, Obstetrics and Gynecology, Hartford, Connecticut OBJECTIVE: Congenital heart disease occurs in 8 per 1000 live births. Allen et al (Ultrasound Obstet Gynecol, 2001) have shown that cardiac arrhythmias in fetuses have been observed in 2% of pregnancies. We sought to determine the association of fetal rhythm abnormalities with structural cardiac abnormalities. STUDY DESIGN: We performed a retrospective analysis by searching our ultrasound database from 1999-2004 to identify all patients referred for fetal arrhythmias. Fetal cardiac arrhythmias were evaluated by fetal echocardiography (which normally lasted 45-50 minutes), M-mode and Doppler ultrasound. Data were analyzed with descriptive statistics. RESULTS: Cardiac or rhythm abnormalities were documented on 1045 of the fetal echocardiograms we performed during the study period. Of these, 82 (7.8%)were identified as abnormal cardiac rhythms. Premature atrial contractions were found in 66 (87%) of the 69 fetuses with extrasystoles. There were two fetuses with atrial flutter (2.1%) and one with bradycardia (1.4%). These patients required monitoring and/or pharmaceutical rate control. One patient (1.4%) referred for AMA was found to have a hypoplastic left heart that was associated with an arrhythmia. Eleven (13%) of the fetuses had a normal cardiac rhythm during the examination. CONCLUSION: Patients referred for fetal arrhythmias had a very low risk of structural heart disease which was only slightly greater than the background risk of CHD. Our study showed that 5% of the patients required intensive surveillance, 3 for cardiac rate irregularity and one for a structural abnormality.