Background: The optimal pacemaker (PM) strategy for infants with isolated congenital complete heart block (CCHB) is unknown. Dual-chamber pacing (DDD) provides AV synchrony and normal heart rate variability. Compared to single chamber ventricular pacing (VVI), DDD has more extensive surgery and increases ventricular pacing burden on a myocardium inherently susceptible to left ventricular (LV) dysfunction.
Objective: To compare clinical outcomes of VVI vs DDD PM in infants with CCHB.
Methods: A multi-center retrospective study was conducted to evaluate infants with PM implantation from 2006 to 2018. Inclusion criteria were age < 1 year at PM, single site ventricular pacing and absence of significant congenital heart disease. Outcome measures included LV dysfunction, assessed by a single cardiologist as change in LV end diastolic volume (LVEDV) and ejection fraction (LVEF), and device related complications.
Results: Sixty-one infants met inclusion criteria, 51 (84%) was autoimmune associated and 40 (61%) had VVI pacing. Mean follow-up was 5.4 (1-13) years. Baseline characteristics are shown in figure 1A. Right ventricular lead placement was more frequent in VVI group (p<0.05) with no difference in apical vs basal position. There was no difference in the complication rate and number of subsequent procedures between 2 groups (Fig 1A). Both groups had normalization in LVEDV post PM (p<0.05) with no difference in changes in LVEDV and LVEF over time between 2 groups (Fig 1B, 1C).
Conclusion: In infants with CCHB requiring pacing, there is no significant difference in LV function, PM related complications and number of subsequent procedures between DDD paced and VVI paced groups.