Atwater BD, Emerek K, Samad Z, et al. - Since it is difficult to predict which patients with left bundle branch block (LBBB) and normal left ventricular (LV) ejection fraction (EF) will experience reduced LVEF, therefore, to resolve this issue, researchers herein analyzed retrospectively identified 50 patients with LBBB and normal LVEF. They compared patients who encountered reduced LVEF and those who did not, focusing on clinical, electrocardiographic, and echocardiographic variables. In this study, a relative risk of developing reduced LVEF of 7.0 (95% confidence interval 3.0 to 16.0) was observed in patients in whom diastolic filling time (DFT) accounted for < 38% of the cardiac cycle vs those with DFT accounting for ≥ 38% of the cardiac cycle.