Left ventricular (LV) pacing in Newborns and infants: Echo assessment of LV systolic function and synchrony at 5-year follow-up.

BACKGROUND: Small retrospective studies reported that left ventricular (LV) pacing is likely to preserve LV function in children with isolated congenital complete atrioventricular block (CCAVB). The aim of this study was to prospectively evaluate LV contractility and synchrony in a cohort of neonates/infants at pacemaker implantation and follow-up. METHODS: Patients with CCAVB who underwent LV pacing were evaluated with ECG and echocardiogram in a single-centre, prospective study. Data were collected at implantation, at 1-month and every year of follow-up, up to 5 years. LV ventricular dimensions (diameters and volumes), systolic function (ejection fraction, EF, global longitudinal strain, GLS) and synchrony were evaluated. Data are reported as median (25(th) -75(th) centiles). RESULTS: Twenty consecutive patients with CCAVB underwent pacemaker implantation (12 VVIR, 8 DDD) with epicardial leads, 17 on the LV apex (LVA) and 3 on the free wall (LVFW). Age at implantation was 0.3 months (1 day-4.5 months). Patients showed good clinical status, normal LV dimensions, preserved systolic function and synchrony at 60 (30-60) months follow-up. Ejection fraction (EF) increased to normal values in patients with pre-implantation EF<50%. Presence of antibodies and pacing mode (DDD vs. VVIR) had no impact on the outcome. CONCLUSIONS: LV pacing preserved LV systolic function and synchrony in neonates and infants with CCAVB at 5-year follow-up. LV EF improved in patients with low pre-implantation EF. Pacing mode or the presence of autoantibodies did not demonstrated an impact on LV contractility and synchrony. This article is protected by copyright. All rights reserved.