[Effectiveness investigation on left bundle branch area pacing in 10 infants and toddlers].

Objective: To explore the feasibility, safety and effectiveness of left bundle branch area pacing (LBBAP) in children aged ≤3 years. Methods: A total of 10 children aged ≤3 years who were diagnosed with brady arrhythmia in the First Hospital of Tsinghua University from September 2020 to September 2021 were retrospectively analyzed. All the children met the indication of permanent pacemaker implantation and underwent LBBAP successfully. The intraoperative data (pacing parameters, electrocardiogram and radiographic imaging), cardiac ultrasound data and clinical data during regular postoperative follow-up were recorded. The preoperative and postoperative data were compared using matched samples t test. Results: Ten children (aged (1.6±0.7) years with weight of (10.3±2.5) kg) underwent LBBAP successfully. The QRS wave duration on the postoperative electrocardiogram was (100±9) ms, and the percentage of ventricular pacing was (97±7)%. The postoperative follow-up period was 6 (6, 12) months. At 1 week after operation, the left ventricular end-diastolic diameter Z scores in these children reduced significantly compared with those before operation (1.3±0.6 vs. 3.6±1.1, t=9.37, P<0.001). During the follow-up period, cardiac function was normal and the last left ventricular ejection fraction was (66±4)% in all children. At the last follow-up, the pacing threshold of the 10 children was smaller than 1.0 V and was acceptable. Compared with the intraoperative baseline values, the pacing threshold was slightly higher ((0.8±0.1) vs. (0.5±0.1) V, t=-5.27, P=0.001). However, no significant difference was found regarding sensing threshold ((16±5) vs. (14±4) mV, t=-0.83, P=0.426) and impedance ((584±88) vs. (652±86) Ω, t=2.26, P=0.050). During follow-up, no electrode related complications were recorded. Conclusions: LBBAP is safe and effective for infants and toddlers. Narrow QRS pacing with stable pacing parameters and normal cardiac function could be achieved postoperatively.