Background: Despite advances in ablation strategies, a substantial proportion of patients with atrial fibrillation (AF) experience arrhythmia recurrence, highlighting the need for improved preprocedural risk stratification. One of the emerging factors associated with arrhythmogenic remodeling is epicardial adipose tissue (EAT), particularly in the proximity of the left atrium (LA), due to its metabolic and inflammatory activity. Methods: This study investigated whether preprocedural assessment of EAT parameters on computed tomography (CT), including volume, mean attenuation, and attenuation dispersion, could predict AF recurrence following ablation. Seventy patients with AF underwent either pulsed field or cryoballoon ablation and were followed for 18 months. Results: Recurrence of AF occurred in 26 (37.1%) patients. Both higher LA-EAT attenuation (OR 1.09; 95% CI: 1.02–1.17) and greater total-EAT volume (OR 2.41; 95% CI: 1.16–4.99) were independently associated with arrhythmia recurrence. Subgroup analysis revealed that LA-EAT volume was highly predictive of recurrence in patients with persistent AF (AUC = 0.91), whereas LA-EAT attenuation demonstrated greater prognostic value in those with paroxysmal AF (AUC = 0.80). Conclusions: These findings suggest that quantitative evaluation of EAT using routine cardiac CT may enhance risk stratification before ablation.

Background: Catheter ablation (CA) is a safe and efficient treatment in patients with an atrioventricular accessory pathway (AP). Electroanatomical mapping (EAM) systems are useful during CA of AP, especially for reducing fluoroscopy. There are limited data about the feasibility of CA procedures performed with the use of the EAM system entirely without fluoroscopy in adults with AP. The aim of the study is to assess the feasibility, efficacy and safety of CA with the use of EAM without fluoroscopy, compared to CA with EAM and fluoroscopy in patients with AP. Methods: The study included 83 consecutive patients (age 38.25 ± 15.8 years), who were subjected to CA for AP. In 40 patients CA was performed with the use of EAM without fluoroscopy (EAM group), and in 43 patients CA was performed with EAM and fluoroscopy (control group). Baseline characteristics, procedure parameters and complications were obtained from the medical records. Data on permanent success rate was obtained after the mean follow-up time of 1 year. Primary outcomes were acute procedural success rate, long term success rate at 1-year follow-up and complications. Secondary outcomes were the procedure time and number of applications. Results: There were no statistically significant differences in baseline characteristics between the groups, except for the AP locations. Right-sided AP was more common in the EAM group, while left-sided AP was more common in the control group (p = 0.007 and p = 0.004, respectively). Acute procedural success was achieved in 38 patients (95.0%) in the EAM group and in 39 patients (90.7%) in the control group (p = 0.449). Long term success rate was achieved in 36 patients (90.0%) in the EAM group and in 36 (83.7%) patients in the control group (p = 0.399). There was one minor complication in the form of RBBB in the EAM group (p = 0.138). The mean procedure time was shorter in the EAM group compared to the control group (93.0 ± 58.3 min vs. 127.6 ± 57.5 min; p = 0.009). Conclusions: CA of both right-sided and left-sided AP completely guided by EAM without the use of fluoroscopy is feasible, safe and effective.

Background: Atrial fibrillation (AF) in patients with Wolff-Parkinson-White (WPW) syndrome is potentially life-threatening as it may deteriorate into ventricular fibrillation. The aim of this study was to assess whether the emergency medical team members are able to diagnose AF with a rapid ventricular response due to the presence of atrioventricular bypass tract in WPW syndrome. Methods: The study group consisted of 316 participants attending a national congress of emergency medicine. A total of 196 questionnaires regarding recognition and management of cardiac arrhythmias were distributed. The assessed part presented a clinical scenario with a young hemodynamically stable man who had a 12-lead electrocardiogram performed in the past with signs of pre-excitation, and who presented to the emergency team with an irregular broad QRS-complex tachycardia. Results: A total of 71 questionnaires were filled in. Only one responder recognized AF due to WPW syndrome, while 5 other responders recognized WPW syndrome and paroxysmal supraventricular tachycardia or broad QRS-complex tachycardia. About 20% of participants did not select any diagnosis, pointing out a method of treatment only. The most common diagnosis found in the survey was ventricular tachycardia/broad QRS-complex tachycardia marked by approximately a half of the participants. Nearly 18% of participants recognized WPW syndrome, whereas AF was recognized by less than 10% of participants. Conclusions: Members of emergency medical teams have limited skills for recognizing WPW syndrome with rapid AF, and ventricular tachycardia is the most frequent incorrect diagnosis

This paper presents an application of Approximate Entropy (ApEn) and Sample Entropy (SampEn) in the analysis of heart rhythm, blood pressure and stroke volume for the diagnosis of vasovagal syndrome. The analyzed biosignals were recorded during positive passive tilt tests—HUTT(+). Signal changes and their entropy were compared in three main phases of the test: supine position, tilt, and pre-syncope, with special focus on the latter, which was analyzed in a sliding window of each signal. In some cases, ApEn and SampEn were equally useful for the assessment of signal complexity (p < 0.05 in corresponding calculations). The complexity of the signals was found to decrease in the pre-syncope phase (SampEn (RRI): 1.20–0.34, SampEn (sBP): 1.29–0.57, SampEn (dBP): 1.19–0.48, SampEn (SV): 1.62–0.91). The pattern of the SampEn (SV) decrease differs from the pattern of the SampEn (sBP), SampEn (dBP) and SampEn (RRI) decrease. For all signals, the lowest entropy values in the pre-syncope phase were observed at the moment when loss of consciousness occurred.

The paper presents possible applications of entropy measures in analysis of biosignals recorded during head up tilt testing (HUTT) in patients with suspected vasovagal syndrome. The study group comprised 80 patients who developed syncope during HUTT (57 in the passive phase of the test (HUTT(+) group) and 23 who had negative result of passive phase and developed syncope after provocation with nitroglycerine (HUTT(−) group)). The paper focuses on assessment of monitored signals’ complexity (heart rate expressed as R-R intervals (RRI), blood pressure (sBP, dBP) and stroke volume (SV)) using various types of entropy measures (Sample Entropy (SE), Fuzzy Entropy (FE), Shannon Entropy (Sh), Conditional Entropy (CE), Permutation Entropy (PE)). Assessment of the complexity of signals in supine position indicated presence of significant differences between HUTT(+) versus HUTT(−) patients only for Conditional Entropy (CE(RRI)). Values of CE(RRI) higher than 0.7 indicate likelihood of a positive result of HUTT already at the passive phase. During tilting, in the pre-syncope phase, significant differences were found for: (SE(sBP), SE(dBP), FE(RRI), FE(sBP), FE(dBP), FE(SV), Sh(sBP), Sh(SV), CE(sBP), CE(dBP)). HUTT(+) patients demonstrated significant changes in signals’ complexity more frequently than HUTT(−) patients. When comparing entropy measurements done in the supine position with those during tilting, SV assessed in HUTT(+) patients was the only parameter for which all tested measures of entropy (SE(SV), FE(SV), Sh(SV), CE(SV), PE(SV)) showed significant differences.