Left Bundle Branch Block-Induced Cardiomyopathy

Left bundle branch block-induced cardiomyopathy is an increasingly recognized type of dilated cardiomyopathy identified in a minority but not negligible proportion of patients with newly diagnosed heart failure. However, it has not yet been included among the possible etiologies of dilated cardiomyopathies or among the unclassified cardiomyopathies. Although a few sets of diagnostic criteria have been proposed, currently there is a lack of universal consensus regarding diagnostic criteria. Some specific clinical features and electrocardiography, echocardiography, and cardiac magnetic resonance imaging findings are recommended to help physicians in the diagnosis of left bundle branch block-induced cardiomyopathy. In this review, prevalence, pathophysiological mechanisms, diagnostic criteria, diagnostic modalities, and specific features of left bundle branch block-induced cardiomyopathy have been addressed with attention to the differential diagnosis of other dilated cardiomyopathies.