Seeking the sweet spot for left bundle branch pacing

In this issue of the journal, Su et al describe in detail the electrical findings during implantation of left bundle branch pacing (LBBP) in patients with a QRS < 120milliseconds, and correlate them with pacing parameters at short‐term follow‐up. The authors can be congratulated for this article, which is a valuable contribution to a field which is rapidly gaining interest. LBBP was first described by the senior author of the article —Dr Weijan Huang—in 2017. The technique consists of first locating the His bundle, and then positioning a catheter‐delivered lead (model 3830 and C315 delivery sheath; Medtronic, Minneapolis, MN) at about 1 to 1.5 cm toward the apex from this position in a 30° right anterior oblique view. The site is identified by pacemapping (showing a characteristic “W” QRS pattern in lead V1) and the lead is advanced by manual rotations. The lead is screwed‐in perpendicular to the ventricular septum by rotating its body (due to the fixed helix) while carefully monitoring the paced electrocardiogram (ECG) morphology and impedance (decreasing values). If a left bundle branch (LBB) potential is recorded with a paced right bundle branch pattern, the lead is not advanced any further. The main findings were: