Left Septal Pacing or Left Bundle Branch Pacing to Avoid Left Ventricle Systolic Dysfunction

Right ventricular apical pacing (RVAP) can produce left ventricular dysfunction (LVD). Conduction system pacing (CSP) has been used successfully to reverse LVD in patients with left bundle branch block. A recent randomized controlled trial (RCT) has demonstrated that CSP, mostly performed with left bundle branch area pacing (LBBAP), can preserve normal ventricular function and heart failure admissions compared to RVAP in the setting of a high burden of ventricular pacing11 (Stay Trial). Criteria to assess the LBBAP distinguishes those cases in which the LBB is captured (LBBP) from those in which only the muscular septum surrounding the LBB is captured (LVSP). To date, data regarding LVSP to preserve left ventricle ejection fraction (LVEF) is scarce and limited to non-randomized studies.