Patients
A total of 108 consecutive patients who met Class I or IIa indications for pacemaker therapy and intended to receive MicraTMleadless pacemaker implantation in the RV mid-septum were prospectively enrolled from December 18, 2019 to June 17, 2021. All patients were randomized to the radiography group (N =81) or the non-radiography group (N =27) in a 3:1 format. The 3:1 randomization was used for allowing more patients to receive mid-septal pacing. The exclusion criteria were as follows: (1) presence of thrombosis or cancer embolus in the inferior vena cava (IVC) or portal vein; (2) presence of bilateral femoral vein stenosis or tortuosity that could cause failure to accommodate the MicraTM pacemaker delivery system; (3) inability to tolerate heparinization or allergy to heparin; (4) presence of implanted devices that interfered with the MicraTM pacemaker delivery system, such as IVC filters or tricuspid mechanical valve replacement; (5) presence of severe renal insufficiency (glomerular filtration rate <30 mL/min) or iodine allergy; (6) acute phase of myocardial infarction, and (7) contraindications for CT scan or contrast agents. All patients signed an informed consent form prior to the surgical procedure. This study was approved by the Ethics Committee of the First Affiliated Hospital of Xinjiang Medical University (ethical approval number: K201912-10) and registered in China Clinical Trial Registry (ChiCTR2100051374). Th data that support the findings of this study are available from the corresponding author on reasonable request