Premium
Lead one ratio in left bundle branch block predicts poor cardiac resynchronization therapy response
Author(s) -
Loring Zak,
Friedman Daniel J.,
Emerek Kasper,
Graff Claus,
Sørensen Peter L.,
Hansen Steen M.,
Wieslander Bjorn,
Ugander Martin,
Søgaard Peter,
Atwater Brett D.
Publication year - 2020
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/pace.13916
Subject(s) - medicine , cardiac resynchronization therapy , cardiology , left bundle branch block , ejection fraction , hazard ratio , qrs complex , heart failure , bundle branch block , electrocardiography , confidence interval
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 cardiac resynchronization therapy (CRT) outcomes is unknown. We compared clinical outcomes and echocardiographic changes after CRT implantation by LOR. Methods Consecutive CRT‐defibrillator recipients with LBBB implanted between 2006 and 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 vs ≥12 using Cox‐proportional hazard models. Changes in LVEF and LV volumes after CRT were compared by LOR. Results Baseline ECG LOR <12 was associated with an adjusted hazard ratio (HR) of 1.69 (95% CI: 1.12‐2.40, P = .01) for heart transplant, LVAD, or death. Patients with LOR <12 had less reduction of LV end diastolic volume (ΔLVEDV −4 ± 21 vs −13 ± 23%, P = .04) and LV end systolic volume (ΔLVESV −9 ± 27 vs −22 ± 26%, P = .03) after CRT. In patients with QRS duration (QRSd) ≥150 ms, LOR <12 was associated with an adjusted HR of 2.01 (95% CI 1.21‐3.35, P = .008) for heart transplant, LVAD, or death, compared with LOR ≥12. Conclusions Baseline ECG LOR <12 portends worse outcomes after CRT implantation in patients with LBBB, specifically among those with QRSd ≥150 ms. This ECG ratio may identify patients with a class I indication for CRT implantation at high risk for poor postimplantation outcomes.