Beat to Beat: Antenatal Fetal Arrhythmia to Newborn Ventricular Tachycardia Caused by Rhabdomyomas and a Subsequent Diagnosis of Tuberous Sclerosis

Background: The findings of an irregular fetal heart rate antenatally and subsequently rhabdomyomas in the fetus suggest a genetic disease of considerable importance. Multiple rhabdomyomas trigger suspicion of tuberous sclerosis complex (TSC) because it is present in more than 80% of cases of rhabdomyomas. Usually, rhabdomyomas regress without intervention, but the association with TSC is life changing for the family. Knowledge of the outcome of affected fetuses and the true incidence of TSC in fetal cardiac rhabdomyomas is critical for accurate prenatal counseling, planning of prenatal treatment, and infant care after delivery. Case: We will discuss a woman with an irregular fetal heart rate detected at 34 weeks gestation. Initial ultrasonography revealed a slightly irregular fetal heart and a somewhat thickened cardiac septum. Ultrasonography at a Level III perinatal center revealed probable rhabdomyomas of the heart and ruled out tuberous sclerosis (TS). The fetal echocardiogram demonstrated intracardial rhabdomyomas with compromised outflow. Consults with a geneticist and pediatric cardiologist occurred. Weekly nonstress testing along with ultrasonography for signs of cardiac failure was done. At 38+ weeks gestation, a left ventricular enlargement was identified. At 39 weeks 4 days gestation, fetal lung maturity was ascertained and labor was induced. The infant weighed 3,460 g and had an Apgar score of 8/9. The infant echocardiogram showed multiple intracardiac lesions, including a tumor obstructing aortic outflow near the aortic valve, one on the anterior leaflet of the mitral valve, a tumor in the left ventricle (2/3 of the ventricle size), and multiple nonobstructive lesions. The infant was admitted to the neonatal intensive care unit for monitoring. Family bonding with the infant was encouraged and facilitated by the nursing staff. At 26 hours of age, the infant developed supraventricular/ventricular tachycardia. Cardioversion was done and antiarrhythmic drugs were started. The parents were notified, and the options and the definitive diagnosis of TS were discussed. On day 11 of life, the infant had open heart surgery to remove the tumors and did well postoperatively. Conclusion: This family was not expecting a child with a significant health problem. Support from staff was crucial. Initially, they focused on the risks of cardiac surgery and not on the more significant diagnosis of TSC. However, the diagnosis and its implications were addressed by the multidisciplinary team. TSC is an autosomal dominant multisystem disorder and early diagnosis is critical; recent literature suggests that early rapamycin use may prevent the development of TSC manifestations. © 2014 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses