The effect of complete left bundle branch block on left ventricular radial dyssynchrony and rotation and twist

Objective To investigate left ventricular (LV) radial dyssynchrony and LV rotational change of isolated complete left bundle branch block (CLBBB) and CLBBB with heart failure (HF).Methods Twenty-six isolated CLBBB patients,twenty-four CLBBB patients with HF and twenty healthy controls were studied.Two-dimensional speckle tracking imaging (2D-STI) was applied to short-axis views to calculate LV radial dyssynchrony and LV rotational and twist degree and time to peak rotational and twist degree.Results LV radial dyssynchrony and LV rotation and twist degree were intermediately damaged in isolated CLBBB patients and was significantly damaged in CLBBB patients with HF,compared with healthy controls.Conclusions For isolated CLBBB patients,even if LV ejection fraction was in the normal range,another parameters of cardiac mechanic had changed and 2DSTI could be used to evaluate these alterations. Key words: Echocardiography; Bundle-branch block; Ventricular function,left; Speckle tracking imaging