Aim. To evaluate the influence of epicardial adipose tissue (EAT) volume and density, based on computed tomography (CT) data, on the severity of myocardial injury assessed using cardiac biomarkers. Material and methods. The study included patients with newly diagnosed acute myocardial infarction (MI). All patients underwent invasive coronary angiography. Two following groups were formed: 1) MI with obstructive coronary artery disease (MICAD) (stenosis ≥50%); 2) MI with non-obstructive coronary arteries (MINOCA) (stenosis <50%). Cardiac biomarker levels (cardiac troponin I (cTnI), cardiac creatine phosphokinase (CPK-MB)) were determined at admission, 24 hours later, and on days 4 and 7. CT coronary angiography was performed on day 7 hospitalization. EAT volume and density were calculated using CT data. Results . The study included 31 patients as follows: 21 with MICAD (age 62 (56; 68) years) and 10 with MINOCA (age 68 (57; 79) years). MICAD patients had higher levels of cardiac biomarkers. Significant differences in EAT volume were found between MICAD and MINOCA patients (p<0,05). The median EAT volume in MICAD patients was greater than in MINOCA patients: 125 (69,4; 169) cm3 and 70,9 (62,4; 140) cm3, respectively. EAT density did not differ significantly as follows: MICAD -76,3 (-80; -71,6) HU, MINOCA -77,6 (-82,7; -73) HU. In the total sample, a significant nonparametric correlation was found between EAT volume and left ventricular end-diastolic mass (ρ=0,41; p=0,032), body surface area (ρ=0,55; p=0,002), and body mass index (ρ=0,54; p=0,003). EAT density negatively correlated with left ventricular enddiastolic mass (ρ=-0,39; p=0,041), body surface area (ρ=-0,54; p=0,003), and body mass index (ρ=-0,57; p=0,002). In the MINOCA group, negative correlations were obtained between biomarker levels and EAT volume, as well as significant positive correlations between CPK-MB at 24 h and cTnI on the 7th day with EAT density. EAT density was positively associated with elevated cTnI levels on day 7 (odds ratio (OR) 2,0, 95% confidence interval (CI) 1-3,5, p<0,05), CPK-MB at 24 h (OR 1,3, 95% CI 1-2,0, p<0,05), and CK-MB on day 4 (OR 2,0, 95% CI 1-3,5, p<0,05). Conclusion. In the acute period after acute MI, in patients with MINOCA, the EAT phenotype, characterized by a smaller volume and higher density, is associated with greater myocardial damage according to biomarker assessment, while in MICAD, the relationship between EAT properties and cardiac biomarkers is predominantly absent.

Acute cerebrovascular accidents and other thromboembolic events pose a serious challenge in the treatment of patients with atrial fibrillation (AF). Arrhythmias are known to be an independent predictor of an increased risk of stroke and other systemic complications compared to the general population. At the same time, AF is associated with a significantly increased risk of systemic thromboembolism, regardless of clinical form and symptom severity. Effective stroke prevention requires a comprehensive approach, including timely diagnosis, treatment, and risk factor management, as well as the development of novel interventional methods aimed at reducing the risk of thromboembolic events in various AF forms.

Interventional treatment of atrial fibrillation, one of the most common arrhythmias, involves various ablation techniques. Their potential has expanded in recent years due to the availability of electromagnetic fields (electroporation) in addition to thermal myocardial procedures (radiofrequency or cryoablation). Surgical treatment of any type is associated with a certain risk of various complications, some of which are more common with traditional techniques, while others are more common with newer ones. The range of possible complications and the extensive research on this topic require further study to better understand the problem and treat patients in clinical practice. This review presents the main types of potential complications associated with atrial fibrillation ablation and analyzes data from recent large studies.

The ligament of Marshall as a vestigial structure plays a key role in arrhythmogenesis due to the combination of preserved muscle fibers with abnormal automaticity and dense autonomic innervation. Its elimination leads to an increase in the effectiveness of interventional treatment of persistent atrial fibrillation and also prevents postoperative atrial fibrillation and ventricular arrhythmias.

The leading risk factors for atrial fibrillation (AF) include advanced age, structural heart disease, high blood pressure, and excessive alcohol use. In other cases, predictors of AF cannot be identified, reflecting the genetic basis of AF. Genetic predisposition increases the risk of AF at a young age by 40%. AF is not strictly hereditary but rather a multifactorial disorder. To date, more than 160 AF-associated genetic loci have been identified based on several studies, including Genome-Wide Association Studies (GWAS). These studies have revealed that AF has a complex genetic architecture. Studying the genetic basis of AF may identify new molecular mechanisms of AF and, as a result, may improve the quality of existing treatments and develop novel therapeutic approaches for isolated AF. This can ensure a more personalized approach and reducing healthcare costs. The aim of this literature review is to present the latest advances and discoveries in the field of AF genetic polymorphism.

Currently, catheter-based methods are the leading approach to treating cardiac arrhythmias. A current trend in ablation is the use of navigation mapping, which offers high accuracy in localizing arrhythmias. The aim of this review is to present modern navigation systems and catheters, their characteristics, and potential. The results of studies on the use of high-density mapping for cardiac arrhythmias such as atrial fibrillation, ventricular tachycardia, and atrial tachyarrhythmias are presented, confirming the effectiveness of this approach in real-world practice.

Catheter-based pulmonary vein isolation is the treatment of choice for patients with symptomatic atrial fibrillation (AF). Despite technological advances, the treatment efficacy, according to various sources, does not exceed 60-80%. In the vast majority of cases, this is due to nonpulmonary sources of arrhythmia. One of the most underestimated structures for the initiation and maintenance of AF is the left atrial appendage (LAA). This literature review provides a current understanding of LAA isolation methods, their effectiveness, and potential complications. It also addresses the issue of potential thromboembolic events after LAA isolation, which is the most common and significant limitation to the widespread use of procedure.

Aim. Morphological search for an arrhythmogenic substrate of coronavirus disease 2019 (COVID-19) in atrial fibrillation (AF). Material and methods. The study included 312 patients with confirmed COVID-19 as follows: 274 who died during the acute phase and 38 post-acute patients who recovered from the disease and required endomyocardial biopsy to diagnose cardiovascular pathology. The morphological study included histological and immunohistochemical analysis with quantitative morphometry (CD3, CD68, HLADR, VEGF, MHC I, Ang1, C1q, SARS-CoV-2 spike, and enterovirus VP1) and statistical processing with logistic regression modeling and calculation of odds ratios for AF predictors. Results. In the acute COVID-19 phase, AF was associated with ischemic microthrombosis (odds ratio (OR)=3,89) and focal necrosis (OR=2,62) with prior cardiomyocyte hypertrophy (OR=4,17). Among clinical factors, the most significant were diabetes, heart failure, and lymphopenia. The created model demonstrated high accuracy (ROC-AUC=0,944). In the post-acute period, AF was associated predominantly with dilated cardiomyopathy (OR=2,16) and myocarditis with enterovirus VP1 expression in cardiomyocytes, the vascular wall, and the inflammatory infiltrate in all cases, as well as persistent SARS-CoV-2 spike expression in macrophages. Low vascular expression of Ang1 and VEGF, as well as moderate macrophage infiltration, were more common in patients without AF (ROC-AUC=0,942). Conclusion. The combination of infection with cardiac comorbidities and systemic inflammation with ischemic myocardial necrosis increases the AF risk in the acute period. In the post-acute period, AF pathogenesis is due to incomplete myocardial repair with macrophage infiltration and virus persistence.

Cryoballoon ablation (CBA), along with radiofrequency ablation and pulsedfield ablation, has proven to be a safe and equally effective method with a short learning curve and minimal time investment. The CBA technique for atrial fibrillation (AF) involves cryoballoon pulmonary vein occlusion, which is confirmed by the absence of contrast leakage from the target vein on fluoroscopy, followed by cryotherapy. Numerous studies have demonstrated the negative impact of fluoroscopy on the human body. This is especially relevant in centers performing a high volume of surgical procedures. This paper presents the immediate and long-term results of non-fluoroscopy CBA of AF and describes the methodology. This technique involves intravascular ultrasound-guided (IVUS) manipulations, eliminating the need for contrast agent or ionizing radiation. It also simultaneously monitors the position of tools within the heart cavities and the echo-free space. The technique is described step by step and illustrated with IVUS screenshots and explanations. Over eight years of clinical experience using non-fluoroscopy CBA of AF has demonstrated that its effectiveness and safety are comparable to the classical technique using fluoroscopy and venography. It eliminates the negative effects of ionizing radiation and radiocontrast agents, maintains the "one shot" principle, does not increase surgical time, and is reproducible.

Due to the high prevalence of atrial fibrillation (AF), including subclinical forms, the search for novel approaches to screening for this arrhythmia, monitoring symptoms, and effective methods for monitoring therapy adherence is becoming increasingly important. Along with implantable monitors, modern digital methods for personalized rhythm monitoring are being used to diagnose AF: wireless recorders, smart devices, mobile assistants, and other technologies. This paper provides a comparative analysis of the most common personal monitoring methods for AF, developed to assess disease progression, manage symptoms, and prevent complications. Modern technologies for improving medication adherence in various clinical patient groups are also discussed. The authors present results on the development of original mobile application for patients with AF.