Left Ventricular Systolic Motion Pattern Differs Among Patients with Left Bundle Branch Block Patterns

Abstract

Background: The electrical activation patterns in pacemaker rhythm, type B Wolff-Parkinson-White syndrome, and premature ventricular complexes originating from the right ventricular outflow tract are similar to those of the complete left bundle branch block and can be considered as LBBB patterns. Methods: Two-dimensional speckle tracking was used to evaluate peak value and time to peak value of the LV twist, LV apex rotation, and LV base rotation in patients with PM, B-WPW, RVOT-PVC, CLBBB, and in age-matched control subjects. The apical-basal rotation delay was calculated as the index of LV dyssynchrony. Results: The LV motion patterns were altered in all patients compared to the control groups. Patients with PM and CLBBB had a similar LV motion pattern with a reduced peak value of LV apex rotation and LV twist. Patients with B-WPW demonstrated the opposite trend in the reduction of LV rotation peak value, which was more dominant in the basal layer. The most impairment in the LV twist/rotation peak value was identified in patients with RVOT-PVC. Compared to the control group, the apical-basal rotation delay was prolonged in patients with CLBBB, followed by those with B-WPW, RVAP, and RVOT-PVC. Conclusions: The LV motion patterns were different among patients with different patterns of LBBB. CLBBB and PM demonstrated a reduction in LV twist/rotation that was pronounced in the apical layer, B-WPW showed a reduction in the basal layer, and RVOT-PVC in both layers. CLBBB had the most pronounced LV apical-basal rotation dyssynchrony.