LP implantation
All the LP implantations were performed by experienced electrophysiologists under conscious sedation and pain control with opioid agents. The device was delivered into the right ventricle by a deflectable catheter through a percutaneous femoral approach. In cases without temporary pacemaker using an active-fixation pacing lead, temporary pacemaker was inserted into the right ventricular apex from the femoral vein aiming for a backup pacing and as an anatomical landmark. Once the catheter was positioned in the right ventricle, a suitable site of attachment in a septal position was identified according to the standard anatomical landmarks, and the location was then confirmed by injecting contrast medium into the right ventricle and filming in two complementary radiological projections. In case of the previous use of an active-fixation lead for temporary pacing after the TLE, we looked for an anchoring site for the LP that was not too close to the transvenous lead tip. The device fixation was considered adequate when the movement of at least 2 of 4 tines was confirmed. Following the device placement in the right ventricle, electrical measurements such as the pacing thresholds, pacing impedance, and R-wave amplitude were checked. If an adequate deployment was confirmed, the device was released from the tether, otherwise repositioning to another site of the right ventricle was attempted. A figure of eight stitch was used to guarantee correct hemostasis at the femoral cannulation site and was removed on the next day. The device data including pacing capture threshold, pacing impedance and R-wave amplitude were collected prospectively and electrocardiography and chest radiography were undergone for excluding the procedural adverse events before hospital discharge.
Patients were followed in the setting of regular care visits at our centers at 1 month and 6 months after LP implantation. Besides, they underwent clinical follow-up including laboratory tests for signs of ongoing infection at the satellite local doctors.