Perspective:

For a few decades, (more) physiological pacing has been the holy grail of cardiac rhythm management. Direct pacing of the proximal left bundle branch pacing has been recently proposed as a more reliable method than previously advocated His-bundle pacing. LBBAP is an umbrella term which includes left bundle branch pacing, left ventricular septal pacing, and left bundle fascicular pacing. The current study shows the heterogeneity of the results with several capture types. Left bundle fascicular capture was the most common. Unfortunately, implantation failures were more likely to occur in patients who need the procedure the most—those with heart failure, enlarged left ventricle, and broad baseline QRS duration. Complications related specifically to LBBAP occurred in 8% of patients, but they were almost always septal perforations without sequelae. Based on our understanding of physiology, QRS characteristics, and a trend for lower complication rates, it seems that distal fascicular capture may be preferable. Long-term outcomes for the various types of left bundle capture are unknown and this will assuredly remain an area of intense inquiry.