Subjects
The study included 64 consecutive patients who underwent Micra-TPS (Medtronic, Dublin, Ireland) implantation using the transfemoral vein approach at our hospital between October 2017 and April 2020. The inclusion criteria were successful placement of the TPS, no clear dislodgement of the device, and patient consent to use their data. The exclusion criterion was missing data owing to patient loss to follow-up. Micra-TPS implantation was performed by two cardiologists; one conducted 35 implantation procedures and the other 29 procedures. The pull-and-hold method was used for all subjects during implantation to confirm that the device was hooked onto the myocardium, followed by extension of at least two of the four tines on the TPS. Pacemaker impedance, threshold, and sensitivity were measured at the time of discharge from the hospital and postoperative follow-up examinations at 1, 3, 6, 12, and 24 months. Additionally, chest radiography (CXR) was also performed during each follow-up examination to assess whether the position of the Micra-TPS device had changed from that at implantation. The Micra-TPS output pacing threshold setting was initially set to +1.5 V during implantation and for 1 month postoperatively. Thereafter, the output setting was set by the Micra-TPS Capture Management system (Medtronic). This study was approved by the Mito Saiseikai General Hospital ethics committee.