目的探究真性左束支传导阻滞(true left bundle branch block,t-LBBB)心电图特征与慢性稳定型心力衰竭治疗效果的相关性.方法选取该院2019年3月—2020年1月收治的92例慢性稳定型心力衰竭患者为研究对象,依据其心电图检查结果,分为对照组[35例,非t-LBBB(nt-LBBB)]、观察组(57例,t-LBBB),两组均接受心脏再同步化治疗,治疗后持续随访1年.比较两组患者治疗前及末次随访时的心功能指标[美国纽约心脏病学会(New York Heart Association,NYHA)心功能分级、左室舒张末期内径(left ventricular end diastolic diameter,LVEDd)、左室射血分数(left ventricular ejection fraction,LVEF)、QRS波宽]、末次随访术后应答情况,分析t-LBBB心电图特征与慢性稳定型心力衰竭手术应答之间相关性.结果两组患者治疗前的NYHA、LVEDd、LVEF、QRS波宽水平比较,差异无统计学意义(P>0.05);末次随访时,观察组的NYHA、LVEDd、QRS波宽水平均低于对照组,LVEF水平高于对照组,组间差异有统计学意义(P<0.05).观察组手术应答率为94.74%,高于对照组的74.29%,差异有统计学意义(P<0.05).经Spearman相关性分析,t-LBBB与患者心脏再同步化治疗呈正相关(r=0.758,P<0.05).结论存在t-LBBB心电图特征的慢性稳定性心力衰竭患者,心脏再同步化治疗的结局更为理想.
Background:Left bundle branch block(LBBB)-induced cardiomyopathy has been proposed,but the association between LBBB and cardiac resynchronization therapy(CRT)response remains unclear and practical criteria for selecting CRT candidates are needed.Methods:One hundred and seventeen consecutive heart failure patients were reviewed,24 of whom received CRT.Only two patients had a clear temporal relation between cardiomyopathy and LBBB.Results:Compared with the patient with“cardiomyopathy-induced LBBB,”the patient with“LBBB-induced cardiomyopathy”had higher left ventricular(LV)wall thickness,higher LV wall thickening rate,higher peak circumferential strain,and longer peak circumferential strain delay.The LV deformation patterns in the two patients were obviously distinct on cardiovascular magnetic resonance tissue tracking.During follow-up,the patient with LBBB-induced cardiomyopathy had a good response to CRT(LV ejection fraction 23 before CRT vs.30%at 6 months vs.29 at 12 months vs.32%at 18 months;LV end-diastolic diameter 77 mm before CRT vs.66 mm at 6 months vs.62 mm at 12 months vs.63 mm at 18 months),and the other patient had no response to CRT(LV ejection fraction 29 before CRT vs.29%at 6 months vs.26 at 12 months vs.22%at 24 months;LV end-diastolic diameter 85 mm before CRT vs.88 mm at 6 months vs.85 mm at 12 months vs.84 mm at 24 months).Conclusion:The temporal relation between cardiomyopathy and LBBB could be a determinant for CRT response.Cardiovascular magnetic resonance tissue tracking may be a useful tool to identify the chronological order and a principal consideration for selecting candidates for CRT.Larger prospective clinical trials are needed to study the prevalence of,time course of,and risk factors for LBBB-induced cardiomyopathy.
