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.