Prediction of Response to Cardiac Resynchronization Therapy by New Echocardiographic Methods

The Cardiac Resynchronization Therapy (CRT) reduces mortality of patients with heart failure and reduced LV ejection fraction. The clinical benefit of CRT is mediated by LV reverse remodelling (decrease in LV end-systolic volume over time). However, 30 to 50 % of these patients will not experience LV reverse remodelling following CRT.

Classical parameters of dyssynchrony obtained by conventional methods of echocardiography (including doppler tissue imaging) have a limited value in predicting CRT response. Meanwhile, patients with a Left Bundle Branch Block (LBBB) on the electrocardiogram experience more frequently LV reverse remodelling than those without a LBBB.

LBBB is responsible for specific LV contractile abnormalities that can be identified by speckle tracking strain echocardiography (early septal contraction, stretching of late contraction of the postero-lateral wall). The predictive value of these abnormalities remains to be studied.

Thus, it has been hypothesised that these LBBB-related contractile abnormalities may be independent predictors of LV reverse remodelling and outcome following CRT.

The present observational prospective study aims at identifying echocardiographic parameters (based on the LBBB-like contraction of the LV ascertained using new methods of echocardiography including speckle tracking strain) that are linked to CRT response and a better outcome following CRT.