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Updated: Jun 14, 2026

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
Contractile reserve assessed using dobutamine echocardiography predicts left ventricular reverse remodeling after
Mario Sénéchal1, Patrizio Lancellotti, Julien Magne
1Institut Universitaire de Cardiologie et de Pneumologie de Québec, Department of Cardiology, Quebec, Quebec, Canada. mario.senechal@criucpq.ulaval.ca
Background:
The presence of viable myocardium may predict response to cardiac resynchronization therapy (CRT). The aim of this study is to evaluate in patients with left ventricular (LV) dyssynchrony whether response to CRT is related to myocardial viability in the region of the pacing lead.
Methods:
Forty-nine consecutive patients with advanced heart failure, LV ejection fraction < 35%, QRS duration > 120 ms and intraventricular asynchronism > or = 50 ms were included. Dobutamine stress echocardiography was performed within the week before CRT implantation. Resting echocardiography was performed 6 months after CRT implantation. Viability in the region of LV pacing lead was defined as the presence of viability in two contiguous segments. Response to CRT was defined by evidence of reverse LV remodeling (> or =15% reduction in LV end-systolic volume).
Results:
Thirty-one patients (63%) were identified as responders at follow-up. The average of viable segments was 5.9 +/- 2 in responders and 3.2 +/- 3 in nonresponders (P = 0.0003). Viability in the region of the pacing lead had a sensitivity of 94%, a specificity of 67%, a positive predictive value of 83%, and a negative predictive value of 86% for the prediction of response to CRT.
Conclusions:
In patients with LV dyssynchrony, reverse remodeling after CRT requires viability in the region of the pacing lead. This simple method using echocardiography dobutamine for the evaluation of local viability (i.e., viability in two contiguous segments) may be useful to the clinician in choosing the best LV lead positioning.

