Background: Atrial arrhythmias are frequently seen in the early and late postoperative periods after the Fontan operation. Bidirectional Glenn shunt (BDG) and hemi-Fontan procedure (HFP) are intermediate-stage palliative procedures on the pathway to Fontan completion. Since each surgical intervention exposes sinus node region to risk of injury, staged approach may increase the risk of atrial arrhythmias.

Methods: Sixty patients underwent HFP and 21 patients BDG operation between August 1989 and October 1997. Thirty-four patients in HFP group (56%) and 14 patient (66%) in the BDG group had Fontan completion. Rhythm was assessed immediately before stage 1, prior to hospital discharge after stage 1, immediately before Fontan completion, prior to hospital discharge after Fontan and at most recent follow-up. The outcome variables assessed were sinus nod dysfunction (SDD) supraventricular tachycardia (SVT) and permanent pacemaker requirement.

Results: Post stage 1 seven patients (12%) in the HFP group and one patient (5%) in the BDG group developed SDD, while two patients (3.3%) in the HFP group and one patient (5%) in the BDG group had SVT. Pre-Fontan; five patients (9%) in the HFP group none of patients in the BDG group were in non-sinus rhythm. Post-Fontan seven patients (22%) in the HFP group and seven patients (36%) in the BDG group had SDD, while four patients (12%) in the HFP group and none of patients in the BDG group developed SVT. Two patients (6%) in the HFP group and two patients (14%) in the BDG group required permanent pacemaker. SDD, in both protocols, is transient in the majority of patients. There was no statistical difference for the development of SDD or SVT or requirement of the permanent pacemaker between two groups at any time point.

Conclusion: Functional and anatomical considerations may be more important than arrhythmias in choosing between these two Fontan protocols.

Keywords : Stayed fontan, bi-directional glenn shut, hemi-Fontan procedure, atrial arrythmia