Dual-Site Ventricular Pacing in Patients With Fontan Physiology and Heart Block: Does it Mitigate the Detrimental Effects of Single-Site Ventricular Pacing?

JACC Clin Electrophysiol. 2018 Oct;4(10):1289-1297. doi: 10.1016/j.jacep.2018.07.004. Epub 2018 Aug 29.


Objectives: This study sought to determine the long-term effect of dual-site ventricular pacing (i.e., cardiac resynchronization therapy [CRT]) versus single-site pacing in patients with Fontan physiology and high-grade atrioventricular block (AVB).

Background: Chronic single-site ventricular pacing in Fontan patients is associated with significant morbidity and mortality.

Methods: The study conducted a retrospective review of all Fontan patients with high-grade AVB who received pacemakers at a single institution between 1990 and 2016 with follow-up of 12 months or greater. The primary study outcome was a composite of death or heart transplantation.

Results: Nineteen patients received CRT devices and 43 patients received single-site ventricular pacemakers (SVPMs), with a median follow-up of 4.9 years (range 1.1 to 11.3 years) and 10.4 years (range 1.1 to 26.8 years), respectively. One (5.3%) CRT patient and 11 (25.6%) SVPM patients reached the composite endpoint of death or transplant (odds ratio: 0.16; 95% confidence interval: 0.02 to 1.36; p = 0.09). Kaplan-Meier analysis showed similar rates of freedom from death or transplant between the 2 study groups over a 5-year follow-up period (p = 0.08). The proportion of SVPM patients with abnormal ventricular systolic function before device implantation (9.5%) and at follow-up (33.3%) significantly increased (p=0.009). The CRT cohort had less change in their ventricular function (42.1% before device implant, 36.8% at follow-up; p = 1.00); however, a Kaplan-Meier analysis over a 5-year follow-up period found no difference in the presence of abnormal ventricular systolic function between groups (p = 0.27).

Conclusions: There was no significant difference in long-term outcomes between Fontan patients who were single- or dual-site paced for high-grade AVB.

Keywords: Fontan procedure; heart block; resynchronization.

MeSH terms

  • Adolescent
  • Adult
  • Cardiac Resynchronization Therapy* / adverse effects
  • Cardiac Resynchronization Therapy* / methods
  • Cardiac Resynchronization Therapy* / mortality
  • Child
  • Child, Preschool
  • Female
  • Fontan Procedure* / adverse effects
  • Fontan Procedure* / methods
  • Fontan Procedure* / mortality
  • Heart Block / physiopathology
  • Heart Block / surgery
  • Heart Defects, Congenital / surgery
  • Heart Ventricles / physiopathology
  • Heart Ventricles / surgery
  • Humans
  • Infant
  • Male
  • Retrospective Studies
  • Young Adult