2.2 LBBAP surgery
In this study, all the pacemaker implantations were performed through
the left subclavian vein or the left axillary vein. During surgery, a
C315 His sheath was inserted into the tricuspid ring using a J-wire. In
the right anterior oblique position (RAO), the pacemaker electrode
(Model 3830, 69 cm, Medtronic Inc., Minneapolis, MN) was pushed forward
through the sheath, with the distal screw located at the tip of the
catheter. First, the His potential was marked, and the tip of the pacing
lead was moved downward and forward in the ventricular direction for
approximately 1.5-2 cm. Subsequently, the optimal pacing site was
determined by the following criteria: a) the pacing QRS interval was
less than 145 ms in the V1 lead, or the QRS wave had a “W” incisura in
the V1 lead; b) the left anterior oblique position confirmed that the
tip of the pacing lead reached the left ventricular septum intima; c)
recording to the left bundle branch potential (from scratch and small to
large); d) the pacing pattern gradually changes from the LBBB to the
RBBB pattern[7]. Finally, the electrode was fixed
and connected to the pacemaker using the screws. In this study, we
detected the pacing threshold, recorded the left bundle branch
potential, monitored the pacing impedance, and conducted
12-lead concurrent electrocardiography during the surgeries.