Cardiac physiologic pacing in Pediatrics: the new alternative of cardiac stimulation

Abstract Introduction Conduction physiological pacing (CPP), stimulating the bundle of His or the left bundle branch (LBBP), allows physiological activation of both ventricles. Studies in adults have shown improvement in electrical and mechanical dyssynchrony, ejection fraction and reversal of pacemaker-induced cardiomyopathy. Studies in pediatric patients are scarce compared to adults. Objectives To describe the characteristics of patients who have undergone CPP and compare them with those with traditional RV stimulation. Methods ambispective study, in a single center. Patients who underwent transvenous PM implantation with an age less than or equal to 18 years were included. Generator replacements without implantation of new leads were excluded. Results From 2019 to 2024, 36 transvenous PM implants were included, 13 of which were CPP (2 His and 11 LBBP). The youngest age in CPP was 2 years old. Compared to the non-CPP group, in the CPP cases a longer fluoroscopy time was required (18 min 44 sec vs 12 min 14 sec, p=0.03), QRS shortening was observed (QRS differential -10.2 ms vs 30 ms, p <0.01) as well as a narrower stimulated QRS (110.9 ms vs 137.2 ms, p < 0.01). There were no differences in complications during or after the procedure between groups. Conclusions CPP in Pediatrics allows obtaining narrower paced QRS, without longer duration of the procedure or complications compared to traditional RV stimulation, but with longer fluoroscopy time.