The aim of the study was to analyze clinical and anamnestic data, the nature of anticoagulant therapy and the incidence of adverse events based on the data of the registry of atrial fibrillation (AF) patients at the outpatient stage (20192020).
Methods. The study involved 638 people (56.7% of them women) included in the registry of patients with AF, 68.2±4.5 of age. Inclusion criteria: patients over the age of 18 who applied for a consultation with a cardiologist at a cardiodispensary polyclinic and signed an informed consent.
Results. The analysis of clinical and anamnestic data of patients with tachyarrhythmia was carried out. Paroxysmal AF was registered in 311 (48.8%) patients, persistent in 138 (21.6%), long-term persistent in 44 (6.9%) and permanent in 142 (22.7%) patients. The average score on the CHA2DS2-VASc was 4.8±1.8 points, on the HAS-BLED score 2.8±1.6 points, on the 2MACE score 1.3±0.8 points. Compliance to treatment corresponded to 2.5±1.5 points. When analyzing the registry of AF patients, the characteristics of anticoagulant therapy are presented. In fact, 172 (27%) patients took rivaroxaban, 166 (25%) apixaban, 84 (13%) dabigatran and 210 (33%) patients took warfarin. Among those examined, the main cause of death in 30 (4.7%) patients was coronary artery disease, of which two had myocardial infarction.
Conclusion. Based on clinical and anamnestic data, a ‘portrait’ of a patient with AF at the outpatient stage is presented, which is characterized by a predominance of the risk of thrombotic complications over the risk of hemorrhagic and coronary events, with low adherence to treatment and implementation of doctor’s recommendations. When analyzing the register of patients with AF, the characteristics of anticoagulant therapy and the causes of adverse outcomes are presented.

Aim. To evaluate the factors and degree of progression of tricuspid regurgitation (TR) depending on the type of implanted electrode in patients after primary implantation of a cardiac implantable electronic device (CIED) in the late postoperative period.
Methods. Case histories of 674 patients who underwent primary implantation of an implantable cardioverterdefibrillator (ICD) for the secondary prevention of sudden cardiac death for the period from 2009 to 2019 were analyzed and 75 case histories were selected. Using similar criteria, a comparison group was selected, who were implanted with a permanent pacemaker (PM) for sinus node dysfunction. For maximum comparability of the main and reference groups, pseudo-randomization was used using the nearest neighbor search method; 68 pairs were formed, comparable in terms of the main factors. Multiple logistic regression was used to analyze the predictors of progression of TR in the postoperative period.
Results. In the preoperative period in the ICD group, 34 patients (50%) had a mild degree of TR, moderate and severe TR occurred in an equal number of cases 2 patients (2.9%) each. In the PM group, mild TR was detected in 24 cases (35.3%), moderate in 2.9% (n=2) of cases, respectively. In the postoperative period, predominantly mild TR was determined in both groups (in the ICD group in 67.6% (n=46), in the PM group in 48 patients (70.6%)).
In the analysis of the general group of patients with implanted CIEDs (n=136), in the late postoperative period, an increase in the volume of both atria and the degree of TR was revealed. Left ventricular ejection fraction and end-diastolic volume didn’t have significant dynamics. All echocardiographic data obtained in the postoperative period were within the normal range.
According to the results of multiple logistic regression, a history of coronary heart disease (CHD) has the greatest predictive power (hazard ratio 4.170; 95% confidence interval 1.751-9.933, p=0.001).
Conclusion. TR in patients after primary implantation of a CIED in the late postoperative period progresses slightly, regardless of the type of right ventricular electrode. A long history of CHD is associated with the greatest risk of progression to tricuspid valve insufficiency.

Aim. To analyze the success rate and other intraprocedural parameters of implantation His bundle pacing lead using different approaches.
Methods. Since 2018 to 2022 we have tried His bundle lead implantation in 32 pts. During implantation 4 different approaches were used: on-stylet in 6 pts (19%), on-stylet over the delivery tool in 9 pts (28%), over the C304 SelectSite (Medtronic, USA) delivery tool in 10 pts (31%), over the modified C304 SelectSite delivery tool in 12 pts (37%).
Results. Four studied implantation approaches did not differ by means of procedure duration as well as lead parameters. The success rate of implantation using modified C304 SelectSite delivery tool was higher than using other 3 techniques (91,7% vs 44%, p-0,006).
Conclusion. His bundle lead implantation success depends significantly on chosen implantation technique.

Aim. To develop a personalized risk assessment score for the development of drug-induced QT interval prolongation while taking class III antiarrhythmic drugs (AAD).
Methods. We studied data from 110 patients with coronary artery disease and/or hypertension, who had heart arrhythmias and were taking class III AAD (amiodarone or sotalol) in a cardiology department. All patients underwent clinical, laboratory and instrumental studies, including history taking, 12-lead electricardiography recording, biochemical blood test, determination of the levels of neuronal NO-synthase (NOS1) and adapter protein of neuronal NO-synthase (NOS1AP) in blood plasma by ELISA, as well as the determination of polymorphisms G84A of the NOS1 gene using polymerase chain reaction. In order to stratify the risk of drug-induced QT interval prolongation, the method of linear discriminant analysis with stepwise inclusion was applied. The training sample consisted of 70 patients (63.6%), the test sample of 40 patients (36.4%). The score was developed on a training sample, and the testing was performed on a test sample with the construction of an ROC curve, calculation of AUC, sensitivity, and specificity.
Results. The training and test samples were comparable in terms of the main clinical and anamnestic parameters and features of the pharmacological history. Patients with QT interval prolongation had significantly lower levels of magnesium (p=0.001), NOS1 (p=0.015) and NOS1AP (p=0.035). The discriminant analysis algorithm was stopped at the fourth step, as a result of which four statistically significant predictors were included in the model: thiazide or loop diuretic intake, blood serum magnesium level, plasma NOS1 and NOS1AP levels, each of which was assigned a certain number of points according to the received standardized coefficients. When conducting an ROC analysis on the initial sample, a threshold value of the scale of 6 points was obtained (AUC 0.848 (0.759 0.937, p=0.002), sensitivity 73.81%, specificity 85.71%). The use of the scale on the test sample showed sensitivity of 77.27%, specificity of 77.77% and AUC of 0.834 (0.721 0.965, p=0.001), which corresponds to the good quality of the prognostic model.
Conclusion. Patients with a total score of ≥6 points have a high risk of drug-induced QT interval prolongation while taking class III AAD.

Aim. To study changes in pulmonary vein ostia strain after radiofrequency (RFA) and cryoballoon ablation (CBA) in patients with paroxysmal atrial fibrillation (AF) by intracardiac echocardiography.
Methods. Patients with paroxysmal AF (n=41) aged 60.1±7.1 years and duration of the disease 7.7±4.8 years were included in the study. Pulmonary vein (PV) isolation was performed with RFA (n=23) and CBA (n=18). All patients underwent transthoracic and intraoperative intracardiac echocardiography. Longitudinal strain of PV ostia was assessed before and after isolation.
Results. Groups were comparable in main clinical parameters. Regress of PV ostia strain after RFA and CBA was achieved in all of PV, which corresponded to complete PV isolation. Remarked trend toward a more pronounced regression of PV ostia longitudinal strain after CBA compared with RFA for left superior (10±0.7% and 6.1±0.8% respectively, p<0.001) and right inferior PV (9.3±0.7% vs 7.3±0.6%, p<0.001) requires continued observation and analysis of data in a larger group. There were no complications.
Conclusion. PV isolation is accompanied by a significant change in their longitudinal strain using intracardiac echocardiography both after CBA and after RFA.

Aim. To investigate the association between comorbidity burden and long-term clinical outcomes of patients with reduced left ventricular ejection fraction (HFrEF) undergoing cardiac contractility modulation (CCM).

Methods. Our study included 59 patients with HFrEF, functional class II/III (NYHA), sinus rhythm, who underwent implantation of CCM system between September 2015 and December 2018 and were further followed by a multidisciplinary team. A mean follow-up period was 1916±102 days. All-cause mortality and heart transplantation were considered as primary composite endpoint. The secondary composite endpoint included all-cause mortality, heart transplantation, im- plantable cardioverter defibrillator shocks due to ventricular tachyarrhythmia and hospitalizations due to decompensated HF. Predicted survival rate were calculated using MAGGIC Risk Calculator and Seattle Heart Failure Model (SHFM). Initially, the Charlson comorbidity index (CCI) was calculated for all patients.

Results. Three- and five-year survival rates were 79,7% and 66,1%, respectively, which were significantly higher than predicted by MAGGIC (p=0.02) and SHFM (p=0.01). The median time to the primary endpoint was 1494 days and the annual mortality was 7%. Patients with HF NYHA class III, chronic kidney disease and CCI ≥7 points had worse prognosis (p1=0.002, p2=0.003, p3=0.04 (log-rank test). There was a significant decrease in number of hospitalized pa- tients due to HF decompensated during CCM (p˂0.001) compared with the six-month period before the system implantation. Patients with CCI value ≥ 7 points reached secondary composite endpoint faster (p=0.002 and p=0.004 for three-year and five-year follow-up periods, respectively (log-rank test)).

Conclusion. Long-term survival rates of patients with HFrEF II/III (NYHA) receiving CCM and managed on multidisciplinary team were significantly higher than predicted. The heavy comorbidity burden negatively impacts on the clinical course and outcomes of HF patients following CСM implantation. Applying the Charlson index can be useful in a comprehensive assessment of the prognosis and determining the target population for the expensive implantable devices, including CCM, in risk stratification and decision-making algorithms.

After 20 years of dubious notions of parity between sinus rhythm control and ventricular rate control strategies in patients with atrial fibrillation, there is evidence of the prognostic superiority of the former. The review article presents the results of randomized trials that support early rhythm control in patients with atrial fibrillation, possible pharmacological and non-pharmacological methods of such treatment in real clinical practice.

The pectinate muscles are located on the inner surface of the right and left atria, but their functional significance remains unknown. This review describes the development of pectinate muscles at the molecular-genetic level, the features of ion channels and intercellular connections that allow pectinate to provide rapid conduction of excitation for the coordinated work of the atria and examines the influence of pectinate muscles on the development of atrial fibrillation.

Catheter radiofrequency ablation of the atrial fibrillation substrate may be difficult in patients after open heart surgery. Difficulties may arise in the presence of a mitral valve prosthesis, atrial arrhythmias of several morphologies (more often left atrial atypical flutter), including incisional ones. These cases require a thorough and scrupulous approach to achieve complete isolation of all available arrhythmia substrates. A distinctive feature of this observation is the successful simultaneous pulmonary vein isolation and two atrial arrhythmias in a patient with a mechanical mitral prosthesis.

A clinical case of the development of bradycardia after heart transplantation is described. Electrocardiography data corresponded to atrioventricular (AV) block against the background of sinus bradycardia, which was the reason for the implantation of a pacemaker. Using intraprocedural electrophysiological study, the absence of data for AV dysfunction was revealed. The concept of AV block arose since the contracting part of the recipient’s atria was electrically isolated from the donor’s atria, there was no atrial activity in the donor heart, and the ventricles contracted due to AV node rhythm, which created the possibility for the presence of two dissociated rhythms.

Atrial fibrillation (AF) is the most frequent form of cardiac arrhythmia in COVID-19 infected patients. The occurrence of AF paroxysms is often associated with the acute period of infection in time. At the same time, the pathophysiological mechanisms of the occurrence of AF associated with COVID-19 remain insufficiently studied. The review considers the available literature data on the influence of factors such as reduced availability of angiotensin-converting enzyme 2 re- ceptors, interaction of the virus with the cluster of differentiation 147 and sialic acid, increased inflammatory signaling, “cytokine storm”, direct viral damage to the endothelium, electrolyte and acid-alkaline balance in the acute phase of severe illness and increased sympathetic activity.

Fragments of Holter monitoring of a 39-year-old patient with a combination of an electrocardiographic pattern of the ventricular preexcitation phenomenon and atrioventricular block are presented. The possibility of remote analysis of the patient’s monitoring electrocardiogram data in twelve leads is provided.