Summary of patient characteristics and measurements at baseline (LBBB) and outcomes (>6 months CRT).

Patient characteristics include age (years), NYHA classification, forward ejection fraction (fEF) (%), QRS duration (QRSd) (ms), mitral valve regurgitant volume (MRV) (mL), heart rate (HR) (beats per minute), and anatomical location of myocardial infarct. Clinical and echocardiographic responses were determined by the change in the NYHA class and the reduction in LV end-systolic volume (%), respectively. Responders are denoted with a “R” and non-responders are denoted with “NR”.