To summarize the echocardiographic characteristics of pacing electrode in left bundle branch area pacing (LBBP), and to explore the feasibility of using the distance from the base of septal tricuspid leaflet to lead tip (D_TV-L) to quantify the pacing electrode location.

Forty-nine patients with LBBP were enrolled. The echocardiographic characteristics of pacing electrode were analyzed. According to the position of lead under fluoroscopy, all patients were divided into high-septum (n=14), mid-septum group (n=17), and low-septum groups (n=18). The differences of D_TV-L in echocardiography were compared between the three groups.

The position of the lead tip could be assessed by echocardiography in all patients. The average length of lead in the interventricular septum was (8.13±2.10) mm, and the average distance from the lead tip to the endocardium was (2.25±1.79) mm. There was no significant difference in the above measurements among the three groups. The D_TV-L assessed by echocardiography in the high-septum group was significantly less than that of the mid-septum group [(10.79±6.62) mm vs (17.59±5.23) mm, P<0.05], and D_TV-L in the mid-septum group was significantly less than that of the low-septum group [(17.59±5.23) mm vs (32.83±8.99) mm, P<0.001].

Echocardiography can be used to assess the position of pacing lead accurately after LBBP. D_TV-L can provide a quantitative parameter in lead position assessment, and provide more information in postoperative evaluation.