Funding Acknowledgements Type of funding sources: None. Introduction Implantable cardioverter defibrillator (ICD) is gold standard therapy for primary and secondary prevention of sudden cardiac death (SCD) and ventricular tachyarrhythmias. While reducing arrhythmic mortality in patients with left ventricular dysfunction of various causes, inherited primary arrhythmia syndromes and after aborted SCD, these devices can have serious adverse effects including inappropriate shocks and device-related infection. Purpose The aim of this study was to create an institutional ICD registry and to examine the major complications after ICD implantation. Methods We analysed the data concerning all newly implanted ICDs in our institution from 2011 to 2017. All patients received periprocedural antibiotic prophylaxis according to relevant guidelines. Follow-up data was collected from hospital electronic medical records. Results Total number of implanted ICDs was 507 (85.4% male, 57.6 ± 14.0 years-old) and mean follow-up was 34.3 ± 23.8 months. Major complications (infection, large haematoma/hemorrhage, lead displacement/dysfunction) occurred in 18 (3.6%) patients. In 9 (1.8%) cases patients were diagnosed with ICD infection (8 surgical wound/pocket infections and 1 confirmed endocarditis of the lead). Device was explanted in 5 cases (1.0%) while the rest were treated only with antibiotic therapy (empirically or according to swab/blood culture results). All of the infections were successfully resolved and no relapses were noted. Eventually, 3 of 5 devices were reimplanted. One death was recorded 5 month after the explanation. Second most common complication was lead displacement/dysfunction which occurred in 5 (1.0%) patients and was successfully repaired in all cases. Large haematoma and/or hemorrhage at the implantation site were present in 5 (0.8%) patients (2 required surgical revision and transfusion while 2 were managed by needle aspiration). Pneumothorax (2 cases, 0.4%) had to be drained in one patient. There was one case of subclavian vein thrombosis which was treated by anticoagulation. Conclusion Despite appropriate antibiotic prophylaxis, the rate of ICD infections in our institution was relatively higher than the one reported in similar registries. The prevalence of other major complications, including lead dysfunction was quite low. Institutional registries could help monitor and plan actions to resolve ICD-related complications to improve patient outcomes.

Funding Acknowledgements Type of funding sources: None. Background His bundle pacing (HBP) physiologically activates the ventricles by a direct stimulation of the His-Purkinje cardiac conduction system. It was first described in the 1970s, and the initial feasibility studies were reported in the early 2000s. Later on, technological advances led to its widespread adoption and growing evidence base.  Purpose This retrospective study aimed to assess implant success rate, feasibility and safety of the His-bundle lead implantation program in our centre. Methods All patients who underwent His-bundle lead implantation in our centre from the start of the HBP program in November 2018 until November 2020 were analyzed. Data were collected from existing hospital electronic medical records. Results A total of 125 patients (64.8 % male, 65.1 ± 13.9 years) were included in the study. Nearly half of patients (47.2 %) had chronic heart failure and 39.2 % had atrial fibrillation. Indications for pacing included antibradycardia pacing (68.8 %) and cardiac resynchronization therapy (31.2 %). His-bundle lead was successfully implanted in 114 patients (91.2 % acute success), while the rest of the procedures were converted into right ventricle lead placement. 32.8 % of all patients had native narrow QRS complexes. Among patients who received HBP for cardiac resynchronization therapy, QRS duration was reduced from 177.5 ± 26.4 at baseline to 145.8 ± 23.9 after HBP (p < 0.001). However, QRS duration slightly prolonged in the antibradycardia group from 118.8 ± 31.9 at baseline to 130.4 ± 25.3 after HBP (p = 0.011). Seven (8.6 %) patients in the antibradycardia group had late lead disfunction/dislodgement and therefore underwent reoperation with the conventional right ventricle lead placement. Two patients (4.7 %) from the resynchronization group had inappropriate resynchronization response and underwent the conventional coronary sinus lead implantation. Only one patient (0.8 %) had a device-associated infection.  Conclusion Our data suggest that HBP is a feasible strategy of physiological pacing and resynchronization with an acceptable success and low complication rates. Our His-bundle implantation program results are similar to data available in the current literature.