Left bundle branch block-induced cardiomyopathy: a diagnostic proposal for a poorly explored pathological entity

Int J Cardiol. 2020 Jan 15:299:199-205. doi: 10.1016/j.ijcard.2019.06.008. Epub 2019 Jun 4.

Abstract

Despite being increasingly recognized as a specific disease, at the present time left bundle branch block (LBBB)-induced cardiomyopathy is neither formally included among unclassified cardiomyopathies nor among the acquired/non-genetic forms of dilated cardiomyopathy (DCM). Currently, a post-hoc diagnosis of LBBB-induced cardiomyopathy is possible when evaluating patients' response to cardiac resynchronization therapy (CRT). However, an early detection of a LBBB-induced cardiomyopathy could have significant clinical and therapeutic implications. Patients with the aforementioned form of dyssynchronopathy may benefit from early CRT and overall prognosis might be better as compared to patients with a primary muscle cell disorder (i.e. "true" DCM). The real underlying mechanisms, the possible genetic background as well as the early identification of this specific form of DCM remain largely unknown. In this review the complex relationship between LBBB and left ventricular non-ischaemic dysfunction is described. Furthermore, a multiparametric approach based on clinical, electrocardiographic and imaging red flags, is provided in order to allow an early detection of the LBBB-induced cardiomyopathy.

Keywords: Cardiac resynchronization therapy (CRT); Dilated cardiomyopathy (DCM); Dyssynchronopathy; Left bundle-branch block (LBBB); Left bundle-branch block-induced cardiomyopathy.

Publication types

  • Review

MeSH terms

  • Bundle-Branch Block / complications*
  • Bundle-Branch Block / diagnostic imaging*
  • Bundle-Branch Block / physiopathology
  • Cardiac Resynchronization Therapy / methods
  • Cardiomyopathies / diagnostic imaging*
  • Cardiomyopathies / etiology*
  • Cardiomyopathies / physiopathology
  • Echocardiography / methods
  • Electrocardiography / methods
  • Humans
  • Ventricular Dysfunction, Left / diagnostic imaging
  • Ventricular Dysfunction, Left / etiology
  • Ventricular Dysfunction, Left / physiopathology