Cardiac Impulse Propagation in Left Bundle Branch Block

Recently, left bundle branch block (LBBB) diagnose has gained interest due to its association with cardiac resynchronization therapy (CRT) outcome. This work analyzes differences in the conduction velocity of the cardiac electrical impulse in the Healthy, LBBB, and strict LBBB (sLBBB) groups. Two databases were employed: the first contained healthy electrocardiographic (ECG) records obtained from the Chapman University, Shaoxing People’s Hospital, and Ningbo First Hospital databases, and the second was derived from the MADIT-CRT study, including ECG records from subjects with heart failure. The results show a significant decrease in propagation velocity in the LBBB and sLBBB groups. Vectorcardiographic loops were obtained, clearly demonstrating differences in duration and shape between the groups, indicating slower depolarization in subjects with LBBB and sLBBB. These results suggest that the study of cardiac electrical impulse propagation velocity could potentially be useful for timely detection of LBBB.