Left ventricular systolic function between left bundle branch pacing and right ventricular septum pacing in patients...

To compare the left ventricular systolic function between the 1eft bundle branch pacing (LBBP) and right ventricular septum pacing (RVSP) in patients with pacemaker dependence by three-dimensional speckle tracking imaging (3D-STI).

A total of 65 patients with atrioventricular block (AVB) (Mobitz type II second-degree AVB, high-degree AVB, or third-degree AVB), who underwent permanent cardiac pacing implantation including 32 patients receiving LBBP (LBBP group) and 33 patients receiving RVSP (RVSP group) from June 2018 to June 2019,were enrolled in this study. These patients met the following inclusion criterion: pre-operative left ventricular ejection fraction (LVEF)>50% and ventricular pacing rate>40% at 6-month programming follow-up; and the patients underwent echocardiography at pre-operation and 6 months after operation. The 3D-STI was used to obtain global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), and global area strain (GAS).

All the patients in the LBBP group and the RVSP group had normal LVEF, there was no significant difference between the 2 group (P>0.05). The LVEF was slightly decreased at 6-month follow-up in the RVSP group, but there was no significant change compared with pre-operation (P>0.05). There were no significant difference in LVEF, GLS, GCS, GRS and GAS at pre-operation and 6-month after operation between the LBBP group and the RVSP group (all P>0.05). Compared with pre-operation, the GLS and GCS were significantly decreased in the LBBP group; while the GLS, GCS, GRS and GAS in the RVSP group were also significantly decreased at 6-month follow-up (all P<0.05).

For patients with pacemaker dependence and normal LVEF at pre-operation, the cardiac function in the LBBP group is not significantly better than that in the RVSP group in short term follow-up. But in terms of physiologic pacing and long-term cardiac function protection, the 1eft bundle branch pacing is an optimal pacing mode.