Neonates and infants requiring life-long cardiac pacing: How reliable are epicardial leads through childhood?

Background: In the literature, data is lacking on mid-term results of epicardial pacemaker implantation in neonates and infants. Our aim was to evaluate the mid-term results of epicardial pacemakers implanted in infants under 1 year of age. Methods and results: We conducted a retrospective review of patients who underwent pacemaker implantation between 2000 and 2017. Pacemaker and lead parameters were reviewed at discharge, 2, 4 and more than 5 years after implantation. A total of 71 patients aged 4 ± 3 months and weighing 4 ± 2 kg were included in the study. Indications for pacemaker implantation were: acquired AV-block (n = 44), congenital AV block (n = 22), sick sinus syndrome (n = 4) and AV block type Mobitz II (n = 1). Median follow-up time was 5 years (range: 1 month–17 years). At 5 years of follow-up, atrial lead energy threshold for pacing decreased significantly (0.72 ± 0.71 μJ to 0.45 ± 0.35 μJ; P < 0.001) but was stable for ventricular leads (0.57 μJ [0.05; 39.47] to 0.64 μJ [0.13; 9.45], P = 0.97). Atrial lead impedance increased significantly (569 ± 137 Ω to 603 ± 134 Ω, P < 0.001), whereas ventricular lead impedance decreased (603 ± 202 Ω to 490 ± 150 Ω, P < 0.001) after 5 years. Repeat operations were required for generator change (n = 55), lead exchange (n = 17) and infection (n = 1). At 2, 5 and 10 years, atrial lead survival was 96%, 91% and 76% and ventricular lead survival was 94%, 82% and 75%, respectively (P = 0.45). Conclusion: Stable pacing thresholds after 5 years indicated that epicardial pacemakers are safe for infants under 1 year of age until at least school enrolment age. However, due to stimulation at higher heart rates in infancy, battery depletion is a frequent occurrence.