Cardiac resynchronization therapy determined clinical and functional benefit that was similar in patients with wide or "narrow" QRS. Cardiac resynchronization therapy may be helpful in patients with echocardiographic evidence of interventricular and intraventricular asynchrony and incomplete left bundle branch block.

Our results confirm the limited value of QRS duration in the selection of patients for CRT. A less-advanced stage of disease and echocardiographic evidence of interventricular dyssynchrony demonstrated to predict response to CRT, while intraventricular dyssynchrony did not predict response.

Pacing with constant adaptation of ventricular output in dual-chamber devices has the potential to increase generator longevity and to reduce sizeably pacing-related costs compared with standard programming.

CRT induced a gender specific LV remodeling response.

No abstract