Assessment of epicardial left ventricular pacing in children

Introduction. The relevance of this work is due to the high incidence of pacemaker-induced cardiomyopathy (PICM) associated with chronic right ventricular pacing, reaching up to 30% in the pediatric population. Current evidence suggests the benefits of left ventricular (LV) pacing in preserving contractile function and intraventricular synchrony. This study presents the immediate and longterm results of epicardial LV pacemaker lead implantation in children. Aim: To retrospectively assess epicardial LV pacing in children with atrioventricular blocks (AVB). Material and methods. This single-center retrospective study included patients with clinically significant atrioventricular (AV) block who underwent implantation of an epicardial pacing system with the ventricular lead localized in the LV apex. In the early and late postoperative periods, all patients underwent a comprehensive examination, including: 12-channel electrocardiography (ECG) with assessment of the QRS complex width, pacemaker function control, 24-hour Holter monitoring, echocardiography (EchoCG) according to a standard protocol with determination of LV contractile function parameters, chest X-ray in the frontal and lateral views. To minimize the influence of anthropometric variability in childhood, such EchoCG parameters as LV end-diastolic volume, as well as the sizes of the left and right atria were expressed as a percentage of the expected values, taking into account weight and height characteristics. Additionally, intraventricular dyssynchrony (IVD) was assessed using tissue Doppler ultrasonography and global longitudinal strain (GLS) of the LV using Speckle-tracking echocardiography. Results. From 2013 to 2024, 36 patients underwent primary implantation of an epicardial pacemaker system with the ventricular lead localized at the apex of the LV (33 dual-chamber systems in DDD mode, 3 single-chamber systems in VVI mode). The age of patients at the time of surgery was 4 [1;7] years, from 14 days to 14 years. There were no clinical signs of heart failure and echocardiographic markers of PICMP in the entire group in the early postoperative period and during long-term follow-up (up to 9 years). During longterm follow-up (up to 9 years), all patients had no clinical signs of heart failure and echocardiographic markers of PICMP, including IVD and increased LV GLS. Conclusion. Epicardial LV pacing in children with AVB demonstrates favorable long-term results, including preservation of systolic function, intraventricular synchrony, and absence of signs of PICMP. The data obtained confirm the advisability of choosing the LV apex as the optimal implantation point in this category of patients.