Assessment of Left Ventricular Mechanical Dyssynchrony in Left Bundle Branch Block Patients with and Without Heart Failure by Tissue Doppler Imaging

Introduction: Large number of patients with heart failure (HF) have left bundle branch block (LBBB). Most precise method for identification of intraventricular dyssynchrony is tissue Doppler imaging (TDI). Purpose of this research was to compare left ventricular (LV) mechanical dyssynchrony in LBBB patients with and without HF and to compare various methods of LV systolic dyssynchrony assessment by TDI. Materials and Methods: One hundred and sixteen patients with a diagnosis of LBBB were included in the study. All patients underwent conventional two-dimensional echocardiography for global LV function assessment. LV systolic dyssynchrony was measured by opposing wall delay, maximum delay, and Yu index. LBBB patients were grouped into four classes according to their LV function and the presence or absence of HF, normal LV function without HF (Group A), normal LV function with HF (Group B), LV dysfunction with HF (Group C), and LV dysfunction without HF (Group D). Results: LV systolic dyssynchrony was significantly higher ( P <0.001) in Group C and D as compared to Group A and B. LV systolic dyssynchrony was significant higher in Group C and D as compared to Group A and B by using opposing wall delay ( P <0.001), Yu index ( P <0.001), and maximum delay ( P <0.001) imaging criteria. Mean Yu index ( P <0.001) and mean maximum delay ( P <0.001) were significantly higher in Group C and D as compared to Group A and B. Conclusions: LV systolic dyssynchrony was more common in LBBB patients with LV dysfunction than those with normal LV function, irrespective of the presence or absence of HF.