Early outcomes of left bundle branch area pacing upgrade in pediatric pacing-induced cardiomyopathy

Abstract Introduction Cardiac resynchronization therapy is an effective option to reverse systolic disfunction in adult patients with pacing-induced cardiomyopathy. CRT may improve clinical and structural outcomes, however, there is still lack of data about CRT upgrade in pediatric PICM. In the last few years conduction system pacing became very promising and effective alternative to conventional CRT in patients with heart failure and pacing-induced cardiomyopathy. Upgrade to conduction system pacing in pediatric PICM is the area of interest of pediatric cardiology with many pitfalls. We present observational study of 6 pediatric patients with PICM, who underwent upgrade of conventional pacemaker to left bundle branch area pacing. Methods 6 consecutive patients with high-degree AV block and pacing-induced cardiomyopathy underwent upgrade to conduction system pacing. LBBAP implant technique was performed according to EHRA clinical consensus statement for CSP. We assesed pre-procedural ECG, TTE, NT-proBNP level. Follow-up period - 6 months. Results Total 6 patients was observed. 5 boys and 1 girl with mean age 10,5±5,1 years. Mean weight 36,5±24,2 kg. 4 patients underwent open-heart correction of congenital heart disease before pacemaker implantation. 2 patients presented with isolated PICM after pacemaker implantation. According to previous medical history 1 patient had Ebstein anomaly correction, 2 patients experienced VSD, right coronary cusp and tricuspid valve plasty, 1 patient presented with aortic coarctation repair with pulmonary artery banding, systemic pulmonary shunt and VSD plasty. All patients was pacemaker-dependent. Mean LV EF 28,5±12,4%. Mean paced QRS duration was 168,6±14 ms. All patients underwent succesfull LBBAP upgrade. Mean LBBAP QRS duration 113,6±11,5 ms. LBBAP resulted in mean LVAT of 71,6±5,3 ms, V6-V1 interpeak 41,4±8,7 ms. In 2 patients we performed right-sided implantation due to persistent left-sided SVC and occlusion of subclavian vein. In 1 patient weused styled-driven lead and 5 lumenless leads utilized fo other patients. Mean follow-up was 6 months. 5 patients showed increasing in LV EF (mean LV EF 41,2±18,3), however 1 patient remains CSP upgrade non-responder. Conclusion Upgrade to LBBAP in pediatric patients is feasible and safe option in case of pacing-indced cardiomyopathy during early period of obsevation. Due to small cohort and short-term longetivity of evaluation further investigations required to confirm safety profile and efficacy of novel pacing modality.Clinical examples of patients with LBBAP Graphical abstract