[Recommendations of the Eurasian Arrhythmology Association (EURA) for the diagnosis and treatment of patients with arrhythmias and conduction disorders during the COVID-19 pandemic].

The beginning of 2020 was characterized by the development of a new coronavirus pandemic (COVID-19). Information about the epidemiology, etiology, pathogenesis, clinical and laboratory diagnostics, as well as prevention and therapy for this disease is constantly being expanded and reviewed. The COVID-19 pandemic creates the need for the emergence of new conditions of specialized care for patients with heart rhythm and conduction disorders [1]. These recommendations are intended for general practitioners, internists, cardiologists, electrophysiologists/arrhythmologists, cardiovascular surgeons, functional diagnostics doctors, anesthesiologists-resuscitators, laboratory diagnostics specialists, health care organizers in the system of organizations and healthcare institutions that provide specialized care to patients with heart rhythm and conduction disorders.

Serum interleukin-6: Association with circulating cytokine serum levels in patients with sinus arrhythmia and patients with coronary artery disease.

In this study, we were focused on the differences between certain circulating cytokine levels in patients with or without sinus arrhythmia, according to the median IL-6 level. All patients were stable with regards to symptoms and therapy for at least one month prior to the measurements conducted within this study.Exclusion criteria were: patients with sleep apnea, asthma, respiratory insufficiency of any genesis, active infection, allergy, inflammatory diseases, cancer, diabetes of any type and treatment with anti-inflammatory drugs. The study was approved by the Institutional Review Board. All recruited patients gave their verbal and written consent for participation in the study. The study group consisted of 74 patients divided into two groups: with (38) and without sinus arrhythmia but with diagnosed coronary artery disease (36). Sinus arrhythmia was confirmed by 24h Holter monitoring. From all test parameters only cytokines IL-2, IL-8, IL-10, IL-17 and IL-18, showed statistically significant increasing in patients with statistically higher IL-6 levels. It is possible that IL-6 may not be a marker for the selection of patients with sinus arrhythmia or coronary artery disease. The findings indicate that IL-6 represents a reliable indicator for increased expression of IL-2, IL-8, IL-10, IL-17 and IL-18 in patients with sinus arrhythmia or coronary artery disease. Further studies in a large number of patients would be necessary to confirm our observations.

[Successful restoration by radiofrequency ablation and maintenance of sinus rhythm in a patient with longstanding (for 21 years) persistent atrial fibrillation].

Clinical observation of a patient with atrial fibrillation persisting throughout 21 years is presented with discussion of results of radiofrequency catheter ablation.

[Long-term results of radiofrequency catheter ablation of long-lasting persistent atrial fibrillation: five years of follow-up].

AIM: To evaluate long-term results of radiofrequency catheter ablation (RFA) vs. rate-control strategy in patients with long-lasting persistent atrial fibrillation (AF) METHODS: We assessed 5-years results in 66 patients (53.3+/-12.3 years old, 8 women) with long-lasting persistent AF who underwent RFA (ablation group), as well as in age-gender-AF duration-matched patients who were treated with rate-control strategy (rate-control group).The ablation strategy consisted of wide-area circumferential lines around pulmonary veins, roof lines and extensive RFA of the left atrial substrate modification using a three-dimensional mapping system. Incidence of sinus rhythm (SR) maintenance, death, stroke, myocardial infarction (MI), worsening of heart failure (NYHA) were evaluated after 5 years of follow-up. RESULTS: After 5 years of follow up SR was present in 38 (56%) of 42 who were under follow up patients of ablation group and all patients had AF in rate-control group (95% CI 0.02247-0.3598; p=0.0001). Seventeen (27%) patients of ablation group continued to take atniarrhythmic drugs. 29 (44%) patients of ablation group vs. 48 (73%) patients of rate-control group received warfarin (95% CI 0.442-1.1; p=0.046) at five years of follow up. After five years of follow up the incidence of MI, stroke, worsening of heart failure functional class, and death in the ablation/rate-control groups were 0%/7.5% (95% CI 0.05247-0.30898; p=0,006), 0%/9% (95% CI 0.08903-0.32561; p=0.001), 6%/25% (95% CI 0.147-0.894; p=0.006), and 0.02%/0%, respectively. CONCLUSIONS: In patients with long-lasting persistent AF ablation strategy results in stable SR in the majority of patients, and decreased incidence of cardiovascular events compared with rate-control strategy during up to 5 years of follow-up.

[Echocardiographic parameters in patients with Wolf-Parkinson-White syndrome before and during one year after radiofrequency catheter ablation of accessory atrioventricular junction].

We present in this paper results of assessment of morphofunctional state of myocardium in patients with the Wolf-Parkinson-White syndrome before and during one year after radiofrequency catheter ablation (RFA) of accessory atrioventricular junction (AAVJ) and comparison of them with analogous parameters of the group of healthy volunteers as well as in dependence on electrophysiological properties of AAVJ and its localization. One hundred sixty patients took part in the conducted study: main group comprised 160 patients (80.7%) with WPW syndrome (114 men [81.4%], 26 women [18.6%], mean age 39.5+/-15.3 years), comparison group comprised 20 practically healthy persons (15 men [75.0%], 5 women [25%], mean age 41.9+/-5.3 years). All main group patients were subjected to endocardial electrophysiological investigation and RFA of AAVJ. Transthoracic echocardiography (EchoCG) was carried out in patients of main group before and in 2, 6, and 12 months after operation of RFA of AAVJ, and once in control group. Analysis of parameters of central hemodynamics according to data of transthoracic EchoCG in patients with WPW syndrome before RFA of AAVJ demonstrated that before conduct of operative intervention no significant differences were revealed in the studied parameters compared with analogous characteristics of the clinical comparison group. During whole period of dynamic observation (2, 6, and 12 months after fulfilled RFA of AAVJ) in patients with WPW syndrome the studied parameters of central hemodynamics did not undergo substantial changes compared with initial characteristics. We failed to establish significant differences of EchoCG parameters in patients with WPW syndrome in dependence on electrophysiological properties of AAVJ (concealed, manifest) and on AAVJ localization (right, left, septal). According to EchoCG data in patients with WPW syndrome so called "minor" anomalies of development of connective tissue of the heart were diagnosed in 69 (49.3%) patients while in control group - in 2 (10%) patients.

[Parameters of central hemodynamics in patients with typical atrial flutter before and after radiofrequency catheter ablation].

We present here results of dynamic assessment of morphofunctional state of the myocardium by the method of transthoracic echocardiography (EchoCG) in patients with paroxysmal and chronic forms of typical atrial flutter (AF) before and during one year after radiofrequency catheter ablation (RFA) of cavo-tricuspid isthmus, and comparison of them with analogous parameters in a group of healthy volunteers. Eighty six patients participated in the study. Group 1 comprised 48 patients suffering from paroxysmal form of typical AF including 42 (87.5%) men, 6 (12.5%) women (mean age 50.9+/-18.1 years). Group 2 consisted of 18 patients with permanent form of typical AF including 16 (88.9%) men and 2 (11.1%) women (mean age 53.6+/-9.4 years). The group of clinical comparison comprised 20 practically healthy persons (mean age 41.9+/-5.3 years) without structural pathology from the side of cardiovascular system including 15 (75.0%) men and 5 (25.0%) women. All group 1 and 2 patients were subjected to RFA of typical AF. In patients of groups 1 and 2 EchoCG was carried out before and in 2, 6, and 12 months after operation of RFA, in control group--once. Analysis of parameters of central hemodynamicas in patients with typical AF detected significantly lowered values of characteristics of myocardial contractile function compared with the group of practically healthy subjects. But these parameters did not differ significantly between patients with different variants of clinical course of arrhythmia. It was established that in patients with typical AF in 2 months after conduct of procedure significant improvement of myocardial inotropic function and diminishment of dimensions of cardiac chambers was noted. In 6 months after fulfilled RFA values of investigated parameters approximated analogous parameters in the group of clinical comparison.

[Simulation of the distribution of spinocerebellar ataxia type 1 in Yakut populations: model parameters and results of simulation].

Demographic and clinical genetic parameters used for simulation modeling of the prevalence of spinocerebellar ataxia type 1 (SCA1) in Yakut populations are described. Demographic parameters of simulated populations and the clinical genetic characteristics of carriers of the SCA1 mutant allele in them have been compared with actual data on Abyisky and Ust-Aldansky uluses of the Republic of Sakha (Yakutia). The results of a series of simulation experiments (without migration or spontaneous mutagenesis) agree with the conclusion that the high prevalence of rate of spinocerebellar ataxia type 1 in Yakut populations may be maintained because of their specific demographic structure. Prediction of the disease prevalence has shown that it will take about 1290 years for natural selection to eliminate the mutation from the population. If medical genetic counseling (MGC) is offered to 1% of the carriers of the mutation, this period will be reduced to 200 years.

[Typical atrial flutter: classification, clinical manifestations, diagnosis, and treatment].

Main etiological factors, mechanisms of arrhythmogenesis and classification of atrial flutter (AFl) are presented. Clinical electrocardiographical and electrophysiological features of typical AFl are described. Main diagnostic measures are delineated and principles of tactical approach to management of patients with typical AFl presented. Indications to radiofrequency catheter ablation, and physical characteristics of radiofrequency interventions in lower isthmus of the right atrium are discussed. Data of analysis of comparative efficacy of pharmacological and interventional approaches to management of patients with typical AFl as well as spectrum of possible complications associated with surgery are also presented.

[Simulation of the distribution of spinocerebellar ataxia type I in Yakut populations: description of the model].

A simulation model has been developed for predicting the distribution of trinucleotide repeat expansion diseases in human populations. The interface of the software used to run this model presents the options for simulating natural reproduction of a population, with the population demographic parameters taken into account, and for simulating the appearance of a dynamic mutation in populations, transmission of the mutant gene from parents to offspring, and the effect of the phenotypic expression of the disease (the patients' life expectancy and birthrate) on the transmission of the mutant allele in the patients' families and its accumulation in the population.

[Quality of life of patients with Wolff-Parkinson-White syndrome before and during one year after radiofrequency catheter ablation of accessory pathways].

The paper contains presentation of complex analysis of quality of life (QL) of 140 patients with Wolff-Parkinson-White (WPW) syndrome before and during one year after radiofrequency catheter ablation (RFCA) of accessory pathways (AP) . Assessment of QL was based on the use of nonspecific and specific questionnaires. Parameters of QL were analyzed in dependence on localization of AP and its electrophysiological properties (concealed, manifested). It was shown that before intervention parameters of QL in patients with WPW syndrome were significantly lower than in the group of clinical comparison (practically healthy persons). Complex study of criteria of QL allows to assert that just after 2 months after RFCA there occurs considerable improvement of the general condition of patients with WPW syndrome. 6 and 12 months after operation complete restoration of both physical and mental working capacity was noted. This is confirmed by absence of significant differences between QL criteria in patients with WPW syndrome and in the group of healthy volunteers.

[Radiofrequency ablation of chronic atrial fibrillation by combined isolation of pulmonary veins and anatomical modification of arrhythmia substrate].

Primary procedure of radiofrequency ablation (RFA) of chronic atrial fibrillation (AF) using nonfluoroscopic mapping system was carried out in 49 patients (mean age 52.2 +/- 11.3 years, 6 women). Etiology of AF was coronary artery disease, cardiosclerosis after myocarditis, dilated cardiomyopathy in 32, 11 and 2 patients, respectively. AF was idiopathic in 4 patients. History of chronic AF varied from 6 months to 17 years (mean 1.8 years). During follow-up for 14 +/- 5 months total efficacy of RFA was 86%. Redo procedures of endocardial electrophysiological study EPS and RFA were performed in 3 cases because of atypical atrial flutter in 2, 3, and 6 months after initial intervention, and in 1 case because of focal left atrial tachycardia (2 months after initial procedure of EPS and RFA for AF). After repetitive sessions because of atypical atrial flutter and focal left atrial tachycardia efficacy was 98%. There were no complications related to the operations.

[First experience of the use of rotational coronary atherectomy in patients surviving myocardial infarction].

An experience of the use of rotational atherectomy during interventions on calcified stenoses of coronary arteries in survivors of myocardial infarction is presented. The article contains consideration of potential advantages of the use of rotablation, indications to its application and possible complications, as well as discussion of results of clinical studies of assessment of efficacy and safety of this procedure in patients with ischemic heart disease.

[The experience of the use of intracardiac echocardiography during puncture of atrial septum].

We analyzed results of 175 intracardiac ultrasound studies (ICUS) in 113 men (mean age 54,6 +/- 11,0 years) and 62 women (mean age 49,7 +/- 8,9 years) with atrial fibrillation (n=146) and WPW syndrome (n=29). ICUS was used for guidance of catheters or electrodes from right to left atrium through atrial septum in 160 procedures of radiofrequency ablations for atrial fibrillation (n=146) or WPW syndrome (n=14). Complications of transseptal puncture developed in 4 patients (2,7%) with atrial fibrillation. There were no procedure related deaths. In all cases ICUS allowed to visualize interatrial septum and its thinnest part. Thus ICUS facilitates transseptal approach to the left atrium, provides lowering of risk of dangerous complications, and allows real time monitoring of possible intraprocedural complications.

[Application of the system for rheolytic thrombectomy in patients with acute myocardial infarction].

The authors present first experience of application of the system for rheolytic therapy AngioJet in a group of patients with acute myocardial infarction. They describe principle of the work of rheolytic systems, possible procedure related complications. They also discuss results of clinical studies analyzing efficacy of antithrombotic therapy, efficacy and safety of rheolytic therapy in patients with acute coronary syndrome and complicated atherosclerotic plaques in coronary arteries.

[Excimer laser coronary angioplasty in combination interventional treatment of patients with acute coronary syndrome].

The authors present first experience of application of the system for rheolytic therapy AngioJet in a group of patients with acute myocardial infarction. They describe principle of the work of rheolytic systems, possible procedure related complications. They also discuss results of clinical studies analyzing efficacy of antithrombotic therapy, efficacy and safety of rheolytic therapy in patients with acute coronary syndrome and complicated atherosclerotic plaques in coronary arteries.

[Long-term results of low-speed irrigated radiofrequency catheter ablation of atrial flutter].

The authors studied long-term results of low-speed (10 ml/min) irrigated radiofrequency catheter ablation (RFA) of the lower isthmus (LI) in patients with typical atrial flutter (AF). This treatment was based upon combined use of local and indirect criteria of the block of isthmus conduction. The influence of RFA LI on quality of life (QL), echocardiographic parameters and cardiac rhythm variability (CRV) was studied. Low-speed irrigated RFA LI, based upon combined use of local and indirect criteria for verification of complete bidirectional blockade in this area, is an effective and safe method of treatment of patients with different variants of clinical course of typical AF which makes it possible to significantly improve QL characteristics and central hemodynamic parameters, and normalize CVR parameters as well. Self-organization of chaos, which realizes according to RR interval time rows, in patients with typical AF after RFA LI may be considered an additional criterion of the effectiveness of this operative intervention and a prognostic sign that predicts maintenance of sinus rhythm in this category of patients.

[Effect of cardiac resynchronization therapy on quality of life of patients with chronic heart failure].

AIM: To study quality of life of heart failure patients who underwent cardiac resynchronization therapy. MATERIAL AND METHODS: Cardiac resynchronization devices were implanted to 27 consecutive patients (69.7+/-11.9 years of age) with severe heart failure (NYHA class III-IV). Follow up period was 11.6+/-4.9 months. Changes of parameters of quality of life (measured by questionnaire SF-36), ECHO-characteristics (left ventricular ejection fraction, end-diastolic diameter, end-systolic diameter, pulmonary artery blood pressure, mitral and tricuspid regurgitation), six-minute walk distance were assessed at baseline and in 2, 6, and 12 months after implantation of resynchronization device. RESULTS: Cardiac resynchronization therapy improved quality of life according to physical and emotional scales. Changes of the following hemodynamic characteristics were positive: ejection fraction (from 30.6+/-4,2% at baseline to 43.4+/-5.1, 46.8+/-0.3, 45.7+/-3.4% in 2, 6, 12 months after implantation, respectively), end-diastolic diameter (from 82+/-2 mm at baseline to 76+/-3, 73+/-2, 75+/-4 mm in 2, 6, 12 months after implantation, respectively), end-systolic diameter (from 56+/-2 mm at baseline to 53+/-2, 51+/-1, 52+/-3 mm in 2, 6, 12 months after implantation, respectively), pulmonary artery blood pressure (from 44+/-4 mm Hg at baseline to 35+/-3, 30+/-5, 34+/-4 mm Hg in 2, 6, 12 months after implantation, respectively), mitral regurgitation degree (from 2.8+/-0.2 at baseline to 2.4+/-0.2, 2.3+/-0.1, 2.5+/-0.3 in 2, 6, 12 months after implantation, respectively) and tricuspid regurgitation degree (from 2.5+/-0.1 at baseline to 2.1+/-0.2, 2.1+/-0.1, 2.2+/-0.2 in 2, 6, 12 months after implantation, respectively). Moreover, six minutes walk distance significantly improved (from 212+/-18 m at baseline to 270+/-14, 286+/-17 and 278+/-13 m in 2, 6, and 12 months after cardiac resynchronization device implantation, respectively). CONCLUSION: Cardiac resynchronization therapy improves quality of life of patients with terminal stage heart failure.