Myocardial Contractile Function in the Region of the Left Ventricular Pacing Lead Predicts the Response to Cardiac Resynchronization Therapy Assessed by Two-Dimensional Speckle Tracking Echocardiography

Background The aim of this study was to test the impact of posterolateral myocardial systolic function on response to cardiac resynchronization therapy (CRT). Methods Forty patients were studied before and 4 ± 2 months after CRT. Dyssynchrony was defined as anteroseptal wall–to–posterior wall delay (≥130 ms) caused by speckle-tracking radial strain. The average longitudinal strain in 4 posterior and lateral segments (ϵ-pl) in which the left ventricular pacing lead was positioned was calculated by automated functional imaging. Response to CRT was defined as a ≥15% decrease in end-systolic volume. Results The negative value of ϵ-pl in responders was significantly higher than that in nonresponders at baseline (−7.8 ± 6.9% vs −2.1 ± 4.9%, P < .01). Combining dyssynchrony with ϵ-pl < −7.8% was more effective for predicting response to CRT than dyssynchrony parameters alone (92% vs 75%). Conclusion The addition of posterolateral myocardial systolic function to the measurement of dyssynchrony appears to be of value for predicting response to CRT.