07/01/2026
Left Bundle Branch Pacing (LBBP)/ Left Bundle Branch Area Pacing (LBBAP)
Left Bundle Branch Pacing (LBBP) is a more physiological conduction system pacing method compared with conventional pacing (right ventricular pacing [RVP]). It aims to mimic the heart’s natural electrical activation, resulting in a shorter QRS duration, reduced ventricular dyssynchrony, improved cardiac function, and better clinical outcomes, including heart failure. Although RVP remains an established technique, LBBP offers superior electrical synchrony and performance and may become the preferred pacing method for many patients.
LBBP targets the actual left bundle branch (LBB) or its fascicles to achieve precise physiological activation. In contrast, Left Bundle Branch Area Pacing (LBBAP) is a broader concept that includes both LBBP and Left Ventricular Septal Pacing (LVSP). LVSP captures the septal myocardium without direct engagement of the LBB but still seeks to achieve physiological pacing. LBBP generally results in a narrower QRS complex and better ventricular synchronization than LVSP. In essence, LBBP is a specific and highly physiological technique within the broader LBBAP strategy. While LVSP is technically easier to perform, LBBP is generally preferred due to superior left ventricular activation and better clinical outcomes.
In our patient, pacing is consistent with selective LBBP rather than LVSP, as evidenced by a left ventricular activation time (LVAT) or V6 R-wave peak time (V6RWPT) of 66 ms (yellow line) at both 3 V and 2 V output. LVAT was measured from the pacing spike to the peak of the R wave in lead V6. Additionally, there is a QRS transition from 3 V to 2 V output with an increase in R′ amplitude in lead V1 (yellow arrow), further supporting selective LBB capture.