Brady-arrhythmias requiring permanent pacemaker implantation during and after staged Fontan palliation

Background: Brady-arrhythmia requiring pacemaker implantation remains one of the Fontan-specific complications before and after total cavopulmonary connection. Methods: A retrospective analysis of 620 patients who underwent total cavopulmonary connection between 1994 and 2021 was performed to evaluate the incidence of brady-arrhythmia and the outcomes after pacemaker implantation. Factors associated with the onset of brady-arrhythmia were identified. Results: A total of 52 patients presented with brady-arrhythmia and required pacemaker implantation. Diagnosis included 16 sinus node dysfunctions, 29 atrioventricular blocks, and 7 junctional escape rhythms. Pacemaker implantation was performed before total cavopulmonary connection (n = 16), concomitant with total cavopulmonary connection (n = 8), or after total cavopulmonary connection (n = 28, median 1.8 years post-operatively). Freedom from pacemaker implantation following total cavopulmonary connection at 10 years was 92%. Twelve patients needed revision of electrodes due to lead dysfunction (n = 9), infections (n = 2), or dislocation (n = 1). Lead energy thresholds were stable, and freedom from pacemaker lead revision at 10 years after total cavopulmonary connection was 78%. Congenitally corrected transposition of the great arteries (odds ratio: 6.6, confidence interval: 2.0–21.5, p = 0.002) was identified as a factor associated with pacemaker implantation before total cavopulmonary connection. Pacemaker rhythms for Fontan circulation were not a risk factor for survival (p = 0.226), protein-losing enteropathy/plastic bronchitis (p = 0.973), or thromboembolic complications (p = 0.424). Conclusions: In our cohort of patients following total cavopulmonary connection, freedom from pacemaker implantation at 10 years was 92% and stable atrial and ventricular lead energy thresholds were observed. Congenitally corrected transposition of the great arteries was at increased risk for pacemaker implantation before total cavopulmonary connection. Having a pacemaker in the Fontan circulation had no adverse effect on survival, protein-losing enteropathy/plastic bronchitis, or thromboembolic complications.