目的 探讨小年龄、低体重的先天性心脏病（先心病）术后合并三度房室传导阻滞（AVB）患儿，经颈内静脉植入无导线起搏器的安全性和可行性。方法 回顾性分析1例先心病术后合并三度AVB患儿的临床资料，以及经颈内静脉植入无导线起搏器的情况。结果 患儿，女，6.5岁，体重15 kg，因先心病修补术后并发三度AVB导致晕厥，在评估血管直径和心脏大小后，成功经颈内静脉植入AVEIR无导线心脏起搏器，术后起搏参数良好，临床症状消除，无起搏器相关并发症发生。结论 对于小年龄、低体重的儿童，经充分的术前血管和心脏评估，颈内静脉途径植入无导线心脏起搏器是安全可行的治疗方案。

Objective To explore the safety and feasibility of implanting leadless pacemakers via the internal jugular vein in children with congenital heart disease (CHD) of small age and low weight who have developed third-degree atrioventricular block (AVB) after surgery. Methods A retrospective analysis was conducted on the clinical data of a child with grade three AVB after congenital heart disease surgery, as well as the implantation of leadless pacemaker through the internal jugular vein. Results A 6.5-year-old girl (weighing 15 kg) with syncope secondary to third-degree AVB following congenital heart defect repair underwent successful implantation of an AVEIR leadless cardiac pacemaker via the internal jugular vein after comprehensive evaluation of vascular diameter and cardiac dimensions. Postoperative pacing parameters were good, clinical symptoms were eliminated, and no pacemaker-related complications occurred. Conclusions In low-weight young children, after thorough preoperative vascular and cardiac function evaluations, the intracervical vein approach for leadless cardiac pacemaker implantation proves a safe and feasible choice.