Abstract:Left bundle branch block (LBBB) is an important cause of heart failure. When LBBB occurs, the excitation sequence of the left ventricle changes, leading to the change of cardiac systolic pattern, resulting in cardiac electromechanical asynchronism, and eventually heart failure. At present, there is no unified standard for the diagnosis of true LBBB, and the epidemiological characteristics are unclear. This paper will focus on a comprehensive discussion of LBBB's anatomic features, electrocardiographic manifestations, epidemiology, etiology, clinical significance and treatment.