2.5 Criteria of successful LBB capture.
Successful LBB capture was considered in the presence of a narrow paced QRS (<120ms) or in the presence of a left bundle branch potential on the sensed electrogram. When absent, short and stable pLVAT at differential high and low pacing output was used to confirm LBB capture. This was defined as pLVAT <85ms (for narrow native QRS) or <100ms (for wide native QRS or a complete AV block at baseline).[8–10]