The Temporal Relation between Cardiomyopathy and LBBB and Response to Cardiac Resynchronization Therapy:Case Series and Literature Review

• 作者: Changsheng Ma Fei Guo Hui Wang Jianzeng Dong Junping Kang Qiang Lv Rong Bai Sanshuai Chang Xiaohui Liu Xin Du Yi He
• 来源期刊: Cardiovascular Innovations and Applications
• 学科: 医学
• 关键词: LEFT BUNDLE branch block CARDIOMYOPATHY heart failure CARDIOVASCULAR magnetic resonance cardiac RESYNCHRONIZATION therapy
• 年，卷（期）: 2020,（1）
• 页码范围: 163-172
• 页数: 10页
• 分类号: R54

摘要

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.