Long-term Outcome of Pacemaker Therapy in Extracardiac Fontan Patients

Background: Single ventricle patients undergoing Fontan palliation occasionally acquire bradycardia due to sinus node dysfunction or atrioventricular (AV) block and may need pacemaker (PM) stimulation. The risk for adverse events in extracardiac Fontan patients with PM are discordantly described in the literature and long-term data are rare. Therefore, our aim was to evaluate our Fontan cohort regarding the indication for PM implantation and their risk for long-term complications as heart transplantation (HTX) or death.

Methods: This retrospective single center study includes all patients born between January 1994 and August 2013 (>10 years of age) who underwent a Fontan procedure at our center. We reviewed medical charts, clinical follow up visits, ECG’s and Holter monitoring until August 2023. The primary outcome measure was HTX-free survival at most recent follow up (FU) and statistical analysis was performed applying an univariate binary logistic regression analysis to predict if PM requirement is a risk factor for HTX or death.

Results: Of 321 Fontan patients with a median age of 13.9 years (IQR:6.9) at their last FU, 18 patients (=5.6%) had a PM implanted. 4/18 patients (=22.2%) required PM insertion before the Fontan procedure and 14/18 (=77.8%) received a PM at a median time of 2.8 years (IQR:5.1) after the Fontan. Two patients had heterotaxy syndrome; three patients acquired protein losing enteropathy (PLE) and one plastic bronchitis (PB) during FU. HTX free survival in patients with PM was 72.2% vs. 94.7% in those without PM (OR:6.9, 95% CI: 2.2–21.7; p < 0.001). Cause of HTX/death was non-PM related ventricular failure in four and failing Fontan due to PLE in one patient at median of 8.4 years after PM implantation.

Diagnosis, n (%) n = 18

HLHS Tricuspid atresia Single ventricle DORV, hypopl. LV Unbalanced CAVC Mitral atresia, TGA

8 (44.4) 4 (22.2) 2 (11.1) 2 (11.1) 1 (5.6) 1 (5.6)

Indication, n (%) n = 18

Sinus node dysfunction AV block III AV block II Junctional rhythm Resynchronization

6 (33.3) 5 (27.8) 4 (22.2) 2 (11.1) 1 (5.6)

Conclusion: Extracardiac Fontan patients have a low incidence of bradycardia requiring PM stimulation at our center. Although not directly related to PM insertion and stimulation, these patients are at increased risk for heart failure or death. Therefore these patients need thorough monitoring of concomitant Fontan related long-term complications such as PB and PLE.

Publication History

Article published online:
13 February 2024