Sixty-seven patients with standard CRT criteria were prospectively enrolled between early 2009 and late 2010. Echocardiography including regional strain analysis by 2-dimensional speckle tracking was performed 1 week before implantation, at day 1, and 6 months after. Response was defined as a decrease in left ventricular end-systolic volume ?5 % . The predictive ability of a classical pattern was compared with time-to-peak measurements from velocity and deformation analysis.
Forty-three patients (65 % ) were classified as responders. The presence of a classical pattern showed 91 % specificity and 95 % sensitivity for response and performed significantly better than time-to-peak parameters in prediction of response to CRT (P < .001, all). In responders, CRT acutely increased septal longitudinal peak systolic strain (?.7 % ¡À 3.6 % to ?1.1 % ¡À 3 % , P < .001) but not in nonresponders.
The classical pattern is highly predictive of response to CRT and superior to time-to-peak methods. Patients who obtain long-term reverse remodeling are characterized by short-term reversal of the classical strain pattern. These findings emphasize the value of recognizing potentially reversible strain patterns in selection of CRT candidates.