Association of Shunt Type With Arrhythmias After Norwood Procedure.

Background: Transplant-free survival for single right ventricle (RV) lesions remains less than 70% at 3 years. Arrhythmia burden, influence of shunt type at Norwood procedure (RV-to-pulmonary artery shunt [RVPAS] versus Blalock-Taussig shunt [BTS]), and implications for mortality risk are not well defined.

Methods: The authors performed a single-center retrospective analysis of patients with single RV lesions enrolled in a prospective study of arrhythmias after congenital heart surgery.

Results: Fifty-eight patients received a RVPAS and 62 received a BTS, with a median follow-up of 773 days. Overall arrhythmia incidence was 78%, two-thirds of which prompted intervention. Among all types of arrhythmias, only ventricular arrhythmias (VAs) differed by shunt type, which were more common in patients receiving an RVPAS (29% RVPAS versus 14% BTS; p = 0.049). The majority of VAs were transient (69% less than 1 minute), and typically occurred early post-Norwood procedure (median 12 days). No additional variables were associated with development of VAs. Shunt type did not influence transplant-free survival. Within the entire cohort, there was a trend toward increased mortality with prior history of VA (odds ratio, 2.90; 95% confidence interval, 0.99 to 8.90; p = 0.052). For interstage survivors to Glenn palliation, any VA associated with a 14-fold increased risk of death or transplant (hazard ratio, 14.00; 95% confidence interval, 3.66 to 53.40; p < .001). No other tachyarrhythmia or bradyarrhythmia was associated with mortality.

Conclusions: In this cohort with single RV lesions and prospective rhythm surveillance, patients receiving an RVPAS at Norwood surgery had an increased incidence of VAs compared with patients with a BTS. VAs correlated with late mortality in patients who survived the interstage period.