Endocardial pacemaker implantation in infants weighing < or = 10 kilograms.

Epicardial pacemaker implantation is the most common approach for small children requiring pacemaker implantation, though it is not free from complications. This article reviews the experience with endocardial pacemaker implantation, as an alternative approach, in children < or =10 kg at two centers. Thirty-nine children, median age 3.8 months (2 days-35 months), weight 4.6 kg (2.3-10 kg) underwent endocardial permanent pacing (VVI/R in 38, DDDR in 1). Indications for pacing were complete heart block (CHB) in 34 (congenital in 21, postsurgical in 12, congenitally corrected transposition of the great arteries 1), long QT syndrome in 3, and sinus bradycardia in 2 children. Two children with postsurgical CHB died 7 days and 3 weeks after implantation, respectively, due to heart failure and septicemia, despite appropriate pacemaker therapy. Over a median follow-up of 4.3 years (9 months-15.3 years), 12 patients underwent 18 generator replacements. Five patients were upgraded to physiological pacing. Ten patients underwent 12 ventricular lead advancements. Ventricular lead extraction was attempted 11 times in nine patients and succeeded 10 times. Two patients were converted to epicardial dual chamber systems. Two prepectorally placed generators required resiting due to threatened skin necrosis. Infective endocarditis on the lead, 9 months postimplant required removal of the system in one patient. The subclavian vein was found to be asymptomatically thrombosed in four patients. Endocardial permanent pacing is feasible and effective in children < or = 10 kg and an acceptable alternative to epicardial pacing.