Abstract
A 3-year-old girl with Ebstein's anomaly lapsed into sinus node dysfunction and junctional rhythm after the Fontan-type procedure. Following temporary atrial pacing for 4 weeks then cilostazol and theophylline to promote improvement of sinus node function, her cardiac rhythm showed sinus while awake and junctional during sleep and she had edema and coldness of extremities early in the morning. Pulsed-Doppler echocardiography revealed the absence of A-wave on transmitral flow, decreased systolic fraction in area and increased PVA-wave peak velocity on pulmonary venous flow. Loss of atrioventricular (AV) synchrony seemed to deteriorate both booster pump function and reservoir function of the atrium. Cardiac catheterization was performed to compare hemodynamic measurements during junctional rhythm with during transesophageal atrial pacing which mimics sinus rhythm. Mean central venous pressure was similar in both, however, spike pressure waveforms were present in the superior vena cava and the inferior vena cava during junctional rhythm. Cardiac index and arterial pressure were decreased during junctional rhythm, compared to transesophageal atrial pacing. After undergoing permanent pacemaker implantation, she was relieved from congestive heart failure. This case shows the importance of AV synchrony, that is, the maintenance of appropriate cardiac rhythm for a higher quality Fontan physiology.
