89 RHYTHM DISTURBANCES AFTER FONTAN PROCEDURE

Abstract

Persistance of sinus rhythm is common after Fontan type operation (op) and the reported arrhythmias are infrequent. We reviewed 18 patients (pt) who survived Fontan op with regard to the occurrence of rhythm disturbances detected by ECG, Holter monitoring and stress ECG. All underwent op between 1975 and 1984 at age 3-18 years (median 11 years). Anatomical lesions were tricuspid atresia 11, univentricular heart 4, pulmonary atresia 2, transposition and pulmonary stenosis 1. Duration of follow-up was 6 months-9 years (mean 3.2 years) and all had serial ECGs. Preop rhythm disturbances were present in 8 pt (2 had short P-R intervals, 3 had ectopic atrial pacemaker or junctional rhythm and 3 had 1° A-V block). Post-op transient atrial dysrhythmias were seen in 9. Late post-op 1° A-V block developed in 1, sinus bradycardia in 2, PVCs in 3. 24 hour Holter monitor recordings were done in 12: 8 had rare PACs,, wandering pacemaker or junctional beats, 1 had short runs of supraventricular tachycardia. 8 had PVS: 6 uniform, 2 multiform. Bradycardia with junctional escape were seen in 4. Stress tests were done in 10 pt; 2 had ventricular tachycardia, and 1 also had couplets. Conclusion: Transient atrial dysrhythmias were common in immediate post-op period but prolonged atrial tachycardia was not seen. Significant ventricular dysrhythmias occurred but were rare. Sinus bradycardia developed in some. Stress test and 24 hour Holter monitoring were helpful in evaluating and detecting rhythm disturbances in post-op Fontan patients.