The characteristics of the electrocardiogram and the intracardiac electrogram in left bundle branch pacing.

The ECG and EGM characteristics of LBBP can be summarized as: 1) RBBB pattern; 2) usually with the LBB potential; 3) SLBBP with specific ECG changes and a discrete component in EGM; and 4) with a constant and shortest stimulus to LVAT at different pacing outputs. Further studies are necessary to confirm these observations.