RESUMEN
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⯱â¯3 months and weighing 4⯱â¯2â¯kg were included in the study. Indications for pacemaker implantation were: acquired AV-block (nâ¯=â¯44), congenital AV block (nâ¯=â¯22), sick sinus syndrome (nâ¯=â¯4) and AV block type Mobitz II (nâ¯=â¯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⯱â¯0.71⯵J to 0.45⯱â¯0.35⯵J; Pâ¯<â¯0.001) but was stable for ventricular leads (0.57⯵J [0.05; 39.47] to 0.64⯵J [0.13; 9.45], Pâ¯=â¯0.97). Atrial lead impedance increased significantly (569⯱â¯137 Ω to 603⯱â¯134 Ω, Pâ¯<â¯0.001), whereas ventricular lead impedance decreased (603⯱â¯202 Ω to 490⯱â¯150 Ω, Pâ¯<â¯0.001) after 5 years. Repeat operations were required for generator change (nâ¯=â¯55), lead exchange (nâ¯=â¯17) and infection (nâ¯=â¯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 (Pâ¯=â¯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.