左束支双极起搏对心脏电学和机械同步性的影响

Effects of bipolar left bundle branch pacing on cardiac electrical and mechanical synchrony

目的评估左束支单、双极起搏对心脏电学和机械同步性的影响。方法本文为回顾性研究。选取2018年1月至2019年8月于南京医科大学第一附属医院心血管内科行左束支起搏(LBBP)的患者,分别在心房起搏伴房室结自身下传(SR组)、单极低电压起搏(ULBBP组,输出电压:1.0 V/0.5 ms)和双极高电压起搏(BLBBP组,输出电压:7.5 V/0.5 ms)3种不同起搏模式下进行心脏电学和机械同步性的评估。同时选取2018年6月至2020年10月10例完全性右束支传导阻滞(CRBBB组)的心脏结构和功能正常的患者作为对照组,比较LBBP组与CRBBB组患者的心脏电学和机械同步性的差异。结果15例LBBP患者中位年龄64.8岁,年龄范围44~83岁,其中男5例(33.3%,5/15)。LBBP组患者起搏时QRS时限(QRSd)和左右心室间机械延迟时间(IVMD)均明显短于CRBBB组患者[QRSd:(135.0±16.2)ms对(157.1±16.4)ms,P=0.003;IVMD:(19.7±19.0)ms对(52.5±15.5)ms,P<0.001]。LBBP时,BLBBP的QRSd明显短于ULBBP[(120.3±14.2)ms对(135.0±16.2)ms,P<0.001]。BLBBP与ULBBP相比,IVMD、左心室12节段收缩峰值速度的标准差(Tmsv12-SD)及长轴应变(GLS)差异均无统计学意义[IVMD:(14.0±13.1)ms对(19.7±19.0)ms,P=0.221;Tmsv12-SD:(37.3±17.4)ms对(39.9±14.2)ms,P=0.492;GLS:(-16.6±3.1)%对(-15.6±3.5)%,P=0.116]。结论LBBP时,与ULBBP相比,BLBBP可纠正RBBB形态并改善心脏电学同步性,但并不能显著改善心脏机械同步性。

ObjectiveTo evaluate the effects of unipolar and bipolar left bundle branch pacing(LBBP)on cardiac electrical and mechanical synchrony.MethodsA retrospective study of patients undergoing LBBP from January 2018 to August 2019 in Department of Cardiology,The First Affiliated Hospital of Nanjing Medical University,cardiac electrical and mechanical synchrony were evaluated in three different pacing modes:atrial pacing with atrioventricular node(SR Group),unipolar left bundle branch pacing(ULBBP group)at 1.0 V/0.5 ms and bipolar left bundle branch pacing(BLBBP group)at 7.5 V/0.5 ms,respectively.From June 2018 to October 2020,10 normal patients with complete right bundle branch block(CRBBB)with normal cardiac structure and function were selected as the control group.The cardiac electrical and mechanical synchrony were also compared between LBBP and CRBBB patients.ResultsThe median age of the patients was 64.8 years old,age ranging from 44 to 83 years,and 5 patients were male(5/15,33.3%).There was no significant difference in baseline characteristics between LBBP group and CRBBB group.The QRS duration(QRSd)during pacing and the interventricular mechanical delay(IVMD)in LBBP group were significantly shorter than those in CRBBB group[QRSd:(135.0±16.2)ms vs.(157.1±16.4)ms,P=0.003;IVMD:(19.7±19.0)ms vs.(52.5±15.5)ms,P<0.001].During LBBP,the QRSd of BLBBP was significantly shorter than that of ULBBP[(120.3±14.2)ms vs.(135.0±16.2)ms,P<0.001].However,there was no significant difference in IVMD,standard deviation of time-to-peak contraction velocity in the 12 segments of left ventricle(Tmsv12-SD)and global longitudinal strain(GLS)between BLBBP and ULBBP groups[IVMD:(14.0±13.1)ms vs.(19.7±19.0)ms,P=0.221;Tmsv12-SD:(37.3±17.4)ms vs.(39.9±14.2)ms,P=0.492;GLS:(-16.6±3.1)%vs.(-15.6±3.5)%,P=0.116].ConclusionDuring LBBP,compared with ULBBP,BLBBP corrected right bundle branch block(RBBB)morphology and improved cardiac electrical synchrony,but didn’t significantly improved cardiac mechanical synchrony.