Neonatal Tuberous Sclerosis and Multiple Cardiac Arrhythmias
An infant female was born at term with a presumptive diagnosis of tuberous sclerosis. Fetal echocardiograms had demonstrated multiple cardiac masses suggestive of rhabdomyomas (Figures 1 and 2⇓), and a fetal magnetic resonance image suggested the presence of brain lesions. An urgent Cesarean section was performed at term due to an irregular tachycardia. Postnatal echocardiograms demonstrated multiple cardiac masses, with large lesions along the lateral wall of the right atrium, the right ventricular apex and at the atrioventricular septum (Figure 3). Intracavitary obstruction was not apparent, but a smaller rhabdomyoma seen under the pulmonary valve caused mild right ventricular outflow tract obstruction. A cranial ultrasound demonstrated multiple echogenic foci, confirming the diagnosis of tuberous sclerosis, and a subsequent computed tomography scan of the brain delineated these lesions more clearly (Figure 4).
The infant was born with ectopic atrial tachycardia with variable atrioventricular conduction (Figure 5). During tachycardia, the P-wave morphology suggested a right lateral atrial focus that correlated with the large right atrial rhabdomyoma. Following termination of the tachycardia with intravenous procainamide, intermittent ventricular preexcitation was present, and the patient was diagnosed with Wolff-Parkinson-White Syndrome (Figure 6). Evaluation of the delta wave morphology suggested a septal accessory pathway, which corresponded to the location of the large septal rhabdomyoma. Over the next several days, progressive impairment of atrioventricular nodal conduction was observed although all antiarrhythmic medications were stopped. On the infant’s 8th day of life, a decision was made to proceed with pacemaker placement due to the development of advanced heart block (Figure 7), which was also likely related to the septal rhabdomyoma. Complete elimination of the atrial tachycardia was subsequently achieved with a combination of oral flecainide and propranolol. Over the next few months of follow-up, the preexcitation was no longer seen, and the underlying rhythm remained sinus with only intermittent Mobitz I 2nd degree block (Wenckebach block). The cardiac lesions did not significantly change in size, but normal cardiac growth accounted for a relative diminution of the lesions. By 4 months of age, the patient had not had recurrences of tachycardia but did develop a seizure disorder.
Tuberous sclerosis is associated with cardiac rhabdomyomas that can result in both hemodynamic compromise and rhythm disturbances. While severe obstruction of intracardiac inflow or outflow can necessitate urgent surgical resection, cardiac rhabdomyomas most often regress with time. As demonstrated in this patient, a large number of rhythm abnormalities may also occur, including ectopic atrial tachycardia, atrioventricular node dysfunction, and ventricular preexcitation. This case illustrates that tumors at specific anatomic locations may result in, and possibly predict, diverse cardiac arrhythmias.
We are grateful to Dr Ashok Panigrahy in the Department of Radiology at Childrens Hospital Los Angeles for his assistance with the interpretation and description of the neurological images.
The online-only Data Supplement, which contains Movies I through III, can be found at http://circ.ahajournals.org/cgi/content/full/115/7/e395/DC1.