Abstract Background: Subcutaneous implantable cardioverter defibrillators (S-ICDs) avoid complications secondary to transvenous leads, but inappropriate shocks (ISs) are frequent. Furthermore, IS data from patients with Brugada syndrome (BrS) with an S-ICD are scarce. Objective: We aimed to establish the incidence, mechanisms, and predictors of S-ICD in this population. Methods: We analyzed the clinical and electrocardiographic characteristics, automated screening test data, device programming, and IS occurrence in adult patients with BrS with an S-ICD. Results: Thirty-nine patients were enrolled (69% male, mean age at diagnosis 46±13 years, mean age at implantation 48±13 years). During a mean follow-up of 26±21 months, 18% patients experienced IS. Patients with IS were younger at the time of diagnosis (36±8 versus 48±13 years, p=0.018) and S-ICD implantation (38±9 versus 50±23 years, p=0.019) and presented with spontaneous type 1 Brugada ECG pattern more frequently at diagnosis or during follow-up (71% versus 25%, p=0.018). During automated screening tests, patients with IS showed lower QRS voltage in the primary vector in the supine position (0.58±0.26 versus 1.10±0.35 mV, p=0.011) and lower defibrillator automated screening score (DASS) in the primary vector in the supine (123±165 versus 554±390 mV, p=0.005) and standing (162±179 versus 486±388 mV, p=0.038) positions. Age at diagnosis was the only independent predictor of IS (hazard ratio=0.873, 95% confidence interval: 0.767-0.992, p=0.037). Conclusion: IS was a frequent complication in patients with BrS with an S-ICD. Younger age was independently associated with IS. A more thorough screening process might help prevent IS in this population.

Introduction: We sought to investigate the net effect of wide area circumferential radiofrequency catheter ablation (WACA) on the atrial (LA) geometry. Methods and results: Seventy-one patients, who underwent a second PVI procedure, after index procedure of point-by-point WACA, for recurrent paroxysmal (n=31) or persistent (n=40) atrial fibrillation (AF) in our center were included. A three-dimension rotational angiography of the left atrium (3D-RA) under rapid ventricular pacing was performed immediately before ablation, at index and repeat ablation in all patients. LA geometry in terms of volume, sphericity and surface were assessed in all patients between first and second PVI. There was a statistical significant reduction of the LA volume (65,6 ± 14 ml/m2 vs 62,2 ± 15 ml/m2, p<0,001) and of the surface of the LA (74,4 ± 11,2 vs 70,4 ± 11,2 cm2/m2, p<0,001), whereas the sphericity of the LA increased significantly (82 ± 2% vs. 83 ± 2%, p=0,004) in all 71 patients. Patients with paroxysmal AF showed significant decrease of the LA volume (121,8 ± 25,7 vs 116 ± 32 ml, p=0,008) and increase of the LA sphericity (82,3 ± 2,1 vs 83,1 ± 2%, p=0,009). Patients with persistent AF showed significant decrease of the LA volume (133,5 ± 32 vs 126 ± 32 ml, p=0,005), but only a trend towards increased sphericity (82,4 ± 2,8 vs 83 ± 2,4%, p=ns). Conlusions: WACA results into significant reduction of the LA volume, LA surface area and into significant increase of the LA sphericity in treated patients with recurrent AF.