A U-shaped type II contraction pattern in patients with strict left bundle branch block predicts super-response to cardiac resynchronization therapy

TY - JOUR

T1 - A U-shaped type II contraction pattern in patients with strict left bundle branch block predicts super-response to cardiac resynchronization therapy

AU - Jackson, Tom

AU - Sohal, Manav

AU - Chen, Zhong

AU - Child, Nicholas

AU - Sammut, Eva

AU - Behar, Jonathan

AU - Claridge, Simon

AU - Carr-White, Gerald

AU - Razavi, Reza

AU - Rinaldi, Christopher Aldo

PY - 2014/10

Y1 - 2014/10

N2 - Background: New criteria to define strict left bundle branch block (LBBB) on the basis of pathophysiological principles predict response to cardiac resynchronization therapy (CRT). Heterogeneous activation and contraction patterns have been identified in patients with classical LBBB. Cardiac magnetic resonance (CMR) imaging has demonstrated that a U-shaped (type II) contraction predicts reverse remodeling post-CRT. A homogeneous spread of (type I) contraction is less predictive. Objectives: The purpose of this study was to investigate contraction patterns among patients with strict LBBB and to test whether a type II contraction pattern better predicts CRT response and super-response. Methods: Thirty-seven patients with strict LBBB (QRS duration ≥140 ms for men and ≥130 ms for women with mid-QRS notching or slurring in ≥2 contiguous leads) underwent cine CMR imaging pre-CRT with an analysis of their contraction patterns by using endocardial contour tracking software. Patients were evaluated for reverse remodeling 6 months postimplantation. Results: Nineteen patients (51%) had a type II contraction pattern. A total of 25 patients (68%) of the cohort reverse remodeled. In the type II contraction group, all 19 patients (100%) reverse remodeled as compared with 6 patients (33%) in the type I contraction group ( P < .01). Super-response was achieved in 21 patients (57%) of the total cohort: 5 patients with a type I contraction pattern (28%) and 16 patients with a type II contraction pattern (84%) ( P < .01). Conclusion: Patients with strict LBBB who are guideline indicated for CRT have heterogeneous contraction patterns derived from cine CMR. A type II contraction pattern is strongly predictive for reverse remodeling and super-response. This questions whether strict LBBB criteria alone are sufficient to reliably predict a positive response to CRT.

AB - Background: New criteria to define strict left bundle branch block (LBBB) on the basis of pathophysiological principles predict response to cardiac resynchronization therapy (CRT). Heterogeneous activation and contraction patterns have been identified in patients with classical LBBB. Cardiac magnetic resonance (CMR) imaging has demonstrated that a U-shaped (type II) contraction predicts reverse remodeling post-CRT. A homogeneous spread of (type I) contraction is less predictive. Objectives: The purpose of this study was to investigate contraction patterns among patients with strict LBBB and to test whether a type II contraction pattern better predicts CRT response and super-response. Methods: Thirty-seven patients with strict LBBB (QRS duration ≥140 ms for men and ≥130 ms for women with mid-QRS notching or slurring in ≥2 contiguous leads) underwent cine CMR imaging pre-CRT with an analysis of their contraction patterns by using endocardial contour tracking software. Patients were evaluated for reverse remodeling 6 months postimplantation. Results: Nineteen patients (51%) had a type II contraction pattern. A total of 25 patients (68%) of the cohort reverse remodeled. In the type II contraction group, all 19 patients (100%) reverse remodeled as compared with 6 patients (33%) in the type I contraction group ( P < .01). Super-response was achieved in 21 patients (57%) of the total cohort: 5 patients with a type I contraction pattern (28%) and 16 patients with a type II contraction pattern (84%) ( P < .01). Conclusion: Patients with strict LBBB who are guideline indicated for CRT have heterogeneous contraction patterns derived from cine CMR. A type II contraction pattern is strongly predictive for reverse remodeling and super-response. This questions whether strict LBBB criteria alone are sufficient to reliably predict a positive response to CRT.

KW - Cardiac magnetic resonance

KW - Heart failure

KW - Imaging

KW - Left bundle branch block

KW - Pacing

KW - Resynchronization

U2 - 10.1016/j.hrthm.2014.06.005

DO - 10.1016/j.hrthm.2014.06.005

M3 - Article

SN - 1547-5271

VL - 11

SP - 1790

EP - 1797

JO - Heart Rhythm

JF - Heart Rhythm

IS - 10

ER -