Lead one ratio in left bundle branch block predicts poor cardiac resynchronization therapy response

BACKGROUND: A low electrocardiogram (ECG) Lead One Ratio (LOR) of the maximum positive/negative QRS amplitudes is associated with lower left ventricular ejection fraction (LVEF) and worse outcomes in left bundle branch block (LBBB); however, the impact of LOR on CRT outcomes is unknown. We compared clinical outcomes and echocardiographic changes after cardiac resynchronization therapy (CRT) implantation by LOR. METHODS: Consecutive CRT-defibrillator recipients with LBBB implanted between 2006-2015 at Duke University Medical Center were included (N = 496). Time to heart transplant, left ventricular assist device (LVAD) implantation or death was compared among patients with LOR /=12 using Cox-proportional hazard models. Changes in LVEF and LV volumes after CRT were compared by LOR. RESULTS: Baseline ECG LOR /=150 ms, LOR /=12. CONCLUSIONS: Baseline ECG LOR /=150 ms. This ECG ratio may identify patients with a class I indication for CRT implantation at high risk for poor post-implantation outcomes. This article is protected by copyright. All rights reserved.