Background: Catheter ablation (CA) is a well-known treatment option for patients with symptomatic

Background: Radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) can be curative. There are conflicting data on whether AF associated atrial and ventricular structural remodeling reverses after ablation. The aim of this study was to evaluate the hemodynamic effect of AF ablation in patients with preserved left ventricular ejection fraction (LVEF). Methods: Forty three AF patients were studied (aged 56 ± 11 years; 29 male, 23% persistent AF, LVEF ≥ 50%) in whom RFCA was performed. Echocardiographic evaluation of atrial and ventricular diameters, volumes and strain imaging by two-dimensional speckle tracking were performed before and at least 6 months after RFCA. Nine patients had AF during baseline examination. Results: A significant decrease in the left (LA) and right (RA) atrial volume and an increase in the LA strain were observed 15 ± 7 months after RFCA. In the subgroup with baseline sinus rhythm, the increment in LA strain was only borderline significant. An increase in RA, right ventricular (RV) and Biatrial strain was noticed (p < 0.05). LVEF and global longitudinal strain of the left ventricle (LV), however, did not improve substantially. Conclusions: Radiofrequency catheter ablation of AF in patients with preserved LV systolic function results in significant improvement in RA and RV function with a substantial reduction in LA and RA size. No deleterious impact of AF ablation on LA function was revealed.

periods: in years 1995periods: in years -2001periods: in years (period I) and 2007periods: in years -2010, in order to compare the results of tests and solutions to all the problems with ICD systems revealed by means of PDT. (Cardiol J 2016; 23, 5: 532-538) Results: During period I, 193 tests were performed, among which the ICD system malfunction was observed in 16 cases. Those included: sensing issues, specifically R-wave undersensing during ventricular fibrillation (VF) (7 patients) and T-wave oversensing (4 patients), as well as high defibrillation threshold (DFT) (2 patients) and ICD-pacemaker interaction (3 patients). During period II, among 561 tests, system malfunction was observed in 15 cases

471the study was to evaluate the predictive value of LA and RA size and function on AF recurrence after RFCA. To minimize the impact of the left ventricle (LV) on atrial deformation, only patients with LV ejection fraction (LVEF) of 50% or more were included in the analysis.Methods This single-center prospective study included 41 patients with paroxysmal or persistent nonvalvular AF who underwent initial RFCA between January 2014 and December 2017. Only patients in sinus rhythm and with LVEF of 50% or more were eligible for enrollment. Follow-up visits with 12-lead electrocardiogram (ECG) and 24-hour Holter recording were scheduled at 3 and at least 6 months after RFCA at an outpatient arrhythmia clinic. Each outpatient who developed symptoms suggestive of AF was advised to undergo immediate ECG recording. The RFCA procedure was considered successful if during the follow-up, after a blanking period of 3 months, there was no recurrence of AF lasting more than 30 seconds, as detected on serial ECG or 24-hour Holter monitoring.A detailed description of the RFCA procedure and echocardiographic study with strain measurements can be found in the supplementary material.Statistical analysis Variables were compared with the t test for independent values, Mann-Whitney test, χ 2 test with Yates correction, or

IntroductionAmong the recipients of implantable cardioverter-defibrillators (ICDs), there is a group of patients in whom the defibrillation threshold (DFT) is too high to enable a sufficient safety margin between the DFT and the maximal available output of the device. The aim of the study was to investigate the ability of an additionally implanted single-coil subcutaneous array electrode to reduce the DFT in such patients.Material and methodsMedtronic 6996SQ electrode was implanted in 15 patients selected from our follow-up group of 741 ICD patients: 10 of them had insufficient post-implant DFT safety margin, and 5 had ineffective first maximal energy shock as recorded by the device. In 6 cases the patients had CRT-D devices, in 5 cases – dual-chamber ICDs, and in 4 cases – single-chamber ICDs. In all patients but one the defibrillating electrode was single-coil. In one patient it was dual-coil. The underlying disease was coronary artery disease in 10 patients, dilated cardiomyopathy in 4 patients and hypertrophic cardiomyopathy in 1 patient.ResultsThe subcutaneous electrode was successfully implanted in all the patients qualified for the procedure. No technical issues or perioperative complications were observed. Mean DFT was reduced from 33.3 ±4.1 J before the procedure to 25.3 ±4.4 J after the implantation procedure (p < 0.01).ConclusionsOur results show that the use of a single-coil subcutaneous electrode to reduce the DFT is a safe and effective procedure. Further studies are necessary to confirm these results.