儿童左束支区域起搏六例临床观察

目的探讨儿童左束支区域起搏(LBBAP)的安全性及有效性.方法回顾性分析2019年1月至6月于北京安贞医院小儿心脏科住院采用LBBAP方式行永久心脏起搏器植入术的6例患儿(男1例、女5例)的临床资料、起搏心电图及参数并进行随访.组间比较采用t检验.结果6例患儿年龄9~14岁,体重26~48 kg;三度房室传导阻滞5例,右室心尖起搏术后伴心功能下降1例;1例患儿心功能降低,余5例心功能均正常;QRS波时限(95±13)ms;左心室舒张末径(LVEDD)Z值为1.85±0.65.起搏心电图V1呈右束支传导阻滞样,QRS波时限(111±20)ms,与术前相比,差异无统计学意义(t=-1.610,P>0.05).起搏阈值为(0.85±0.26)V,感知(15.0±4.3)mV,阻抗(717±72)Ω.3例可记录到P电位.起搏钉至左心室激动时间为(56±5)ms,不同输出电压下数值恒定.术后超声提示电极均位于室间隔左心室心内膜下.随访无心肌穿孔、电极脱位等并发症发生,患儿术后3个月阈值、感知及阻抗分别为(0.60±0.09)V、(16.1±3.9)mV、(662±78)Ω.左心室射血分数(LVEF)降低者LBBAP术后3d恢复正常(45%比57%).术后3个月LVEDD Z值降至(1.1±0.3),较术前明显减小(t=2.383,P<0.05).结论LBBAP可实现窄QRS波起搏,接近生理性起搏,起搏参数稳定,可快速、有效地纠正长期心动过缓所致的左心扩大及长期右室心尖起搏所致的心功能低下及心脏扩大.较大年龄儿童行LBBAP近期安全性、有效性好,远期潜在风险有待进一步观察研究.

Clinical observation on six children of left bundle branch area pacing

Objective To explore the safety and effectiveness of left bundle branch area pacing(LBBAP)in children.Methods Clinical data,pacing electrocardiogram and parameters of 6 patients(5 females and 1 male)who underwent permanent pacemaker implantation and LBBAP from January to June 2019 in the Department of Pediatric Cardiology of Anzhen Hospital were retrospectively analyzed.Results The weight of the 6 patients aged between 9 and 14 years ranged from 26 to 48 kg.Five patients were diagnosed with third degree atrioventricular block,and 1 patient was diagnosed with cardiac dysfunction after right ventricular apical pacing.Cardiac function decreased in one patient and remained normal in the other five patients.Left ventricular end diastolic diameter(LVEDD)Z score was 1.85±0.65.V1 lead showed changes like right bundle branch block in pacing electrocardiogram.No significant difference was found regarding QRS wave duration((95±13)ms vs.(111±20)ms,t=-1.610,P>0.05)between preoperation and postoperation.Pacing threshold was(0.85±0.26)V.The sensing threshold was(15.0±4.3)mV and the impedance was(717±72)Ω.P potential was recorded in 3 cases.The earliest left ventricular local activation time was(56±5)ms and remained stable at different output voltages.Postoperative echocardiography revealed that the electrodes were located near the endocardium of the left ventricular septum.No complications such as myocardial perforation and electrode dislocation occurred during follow-up.The pacing threshold,sensing threshold and impedance were(0.60±0.09)V,(16.1±3.9)mV,(662±78)Ωrespectively at 3 months after operation.The patient with low left ventricular ejection fraction(LVEF)recovered to normal on the 3 rd day after LBBAP(45%vs.57%).The LVEDD Z score decreased to(1.1±0.3)at 3 months after operation and was significantly lower than that before operation(t=2.38,P<0.05).Conclusions LBBAP in children can achieve narrow QRS pacing andphysiological pacing with stablepacing parameters.It can improve left ventricular enlargement caused by long-term bradycardia,and cardiac dysfunction and cardiac enlargement caused by long-term right ventricular apical pacing quickly and effectively.LBBAP is safe and feasible for older children in the near future.However,the long term potential risks of LBBAP need further observation and study.