Left ventricular rotational dyssynchrony before cardiac resynchronization therapy: a step forward into ventricular mechanics

AimsHeart failure patients show impaired left ventricular rotation and twist. In patients undergoing cardiac resynchronization therapy (CRT) significance of preimplant left ventricular rotational timing between different ventricular regions is unknown. We thoroughly evaluated, in patients eligible for CRT, baseline left ventricular rotational mechanics, also assessing segmental rotational timing, and investigated whether the presence of rotational dyssynchrony may be associated with echocardiographic response.MethodsBy two-dimensional speckle-tracking echocardiography, baseline peak apical and basal rotation, peak twist, and time-related parameters, such as delays between opposite segments at base and apex, were assessed in 55 CRT patients and 11 healthy participants.ResultsAt 6 months, 30 (54%) patients were echocardiographic responders. Left ventricular rotation and twist had no association with response. All time-related parameters were significantly altered in CRT patients. Maximum basal and apical segments delay, and anteroseptal-posterior delays at base and apex, were longer in responders than in nonresponders (P<0.05 for all), regardless of the presence of left bundle branch block (LBBB) and QRS duration. At multivariable analysis, apical anteroseptal-posterior delay resulted as independently associated with response [odds ratio (OR): 1.022 (1.007-1.038); P=0.004]. A cut-off value of 97.5ms for apical anteroseptal-posterior delay predicted response with 96% specificity and 57% sensitivity (AUC=0.83). Magnitude of left ventricular reverse remodeling was significantly related to apical anteroseptal-posterior delay (P=0.001).ConclusionIn heart failure patients eligible for CRT, left ventricular rotational timing is altered. Dyssynchrony in rotational mechanics shows a specific pattern in responders regardless of the presence of LBBB. Apical anteroseptal-posterior rotational delay is independently associated with left ventricular reverse remodeling.