biostudies-literatureUnknownSoares Brandao SC<h4>Aims</h4>Left bundle branch block (LBBB) is associated with mechanical dyssynchrony, heterogeneous perfusion, and adverse left ventricular (LV) remodeling. However, not all patients with LBBB develop cardiomyopathy, and dyssynchrony can occur without conduction defects. The role of microvascular dysfunction remains uncertain. We aimed to assess how mechanical dyssynchrony and perfusion heterogeneity relate to LV remodeling and function in patients with and without LBBB.<h4>Methods and results</h4>We retrospectively analyzed 233 patients with isolated LBBB and 932 matched controls who underwent PET myocardial perfusion imaging, assessing mechanical dyssynchrony (phase entropy), myocardial blood flow (MBF), coronary vascular resistance (CVR), myocardial flow reserve (MFR), septal-to-latemedRxiv : the preprint server for health sciences2026.01.09.26343726https://www.ebi.ac.uk/biostudies/studies/S-EPMC12870548biostudies-literatureMechanical Dyssynchrony and Perfusion Heterogeneity Predict Adverse LV Remodeling in Patients with and without LBBB.PMC12870548Di Carli MFSoares Brandao SCBlankstein RLemley MVan Kriekinge SDKnight SBerman DSKavanagh PDorbala SLiang JCarre SLopez DBuiloff VDivakaran SSlomka PJMason SRosamond TLRamirez GWopperer SHainer JWeber BJoseph LBrown JMDey DChareonthaitawee PLe VTHuck DMfalseMechanical Dyssynchrony and Perfusion Heterogeneity Predict Adverse LV Remodeling in Patients with and without LBBB.<h4>Aims</h4>Left bundle branch block (LBBB) is associated with mechanical dyssynchrony, heterogeneous perfusion, and adverse left ventricular (LV) remodeling. However, not all patients with LBBB develop cardiomyopathy, and dyssynchrony can occur without conduction defects. The role of microvascular dysfunction remains uncertain. We aimed to assess how mechanical dyssynchrony and perfusion heterogeneity relate to LV remodeling and function in patients with and without LBBB.<h4>Methods and results</h4>We retrospectively analyzed 233 patients with isolated LBBB and 932 matched controls who underwent PET myocardial perfusion imaging, assessing mechanical dyssynchrony (phase entropy), myocardial blood flow (MBF), coronary vascular resistance (CVR), myocardial flow reserve (MFR), septal-to-late2026-01-01T00:00:00Z2026 Jan2026-07-09T11:19:56.366Z2026-07-09T10:46:14.454ZS-EPMC128705484164682710.64898/2026.01.09.26343726