Introduction . The problem of neurogenic bradycardia among young adults is socially significant, as it is associated with the need for surgical treatment, the only option for which has long been pacemaker implantation. Cardioneuroablation is a new method that has demonstrated its efficacy and safety in the treatment of neurogenic bradycardia. Brief description . This article presents a case of successful treatment of neurogenic binodal disease in a young patient after pacemaker extraction due to an infectious complication. Cardioneuroablation improved sinoatrial and atrioventricular node automaticity and eliminated clinical symptoms associated with bradycardia. Follow-up demonstrated a sustained effect lasting up to 3 months, with improved quality of life and no need for pacemaker reimplantation. Discussion . The potential to eliminate vagotonic effects on the cardiac conduction system through destruction of the parasympathetic atrial ganglionic plexuses underlies the cardioneuroablation method. According to several studies, the achieved improvement in the functional state of the sinoatrial and atrioventricular nodes is sustainable during long-term follow-up. The alternative of eliminating bradycardia without pacemaker implantation allows for the avoidance of unnecessary infectious complications while improving the patient’s quality of life and clinical status. Conclusion . This case clearly demonstrates the importance of diagnosing the autonomic causes of cardiac conduction system dysfunction in young patients and the potential for their elimination using cardioneuroablation, which makes it possible to avoid pacemaker implantation and the risk of related complications.

Aim . To study the characteristics of the atrial fibrillation (AF) cryoballoon ablation (CBA) procedure and features of patient’s management in real clinical practice in Russia. Methods . “Prospective Atrial Fibrillation Cryoablation Registry” is an observational prospective national multicenter study. It was conducted from 01.2017 to 12.2019 in centers of Russian Federation. The registry included patients over the age of 18 who were agreed to participate this study and had indications for CBA of AF. The study protocol did not provide for significant restrictions on inclusion criteria, procedure technique and postoperative follow-up. The data was collected prior to the CBA of AF, during hospitalization for CBA and on the 12-month follow-up. Results . Participating centers enroll 980 patients according to inclusion criteria. CBA of AF was performed in 976 (99.6%) (mean age 59.7±9.2 years, 545 (55.8%) men) primary procedure - 840 (86.1%), re-ablation - 136 (13.9%). Parox- ysmal AF occurred in 828 (84.8%) patients and persistent AF (mean time of persistence 4.4±3.7 months) - in 145 (15.1%) patients. The average procedure time was 108.1±33.3 minutes and mean fluoroscopy time was 24.9±13.6 min. Most of the procedures were performed under general anesthesia. Complications after AF CBA occurred in 53 (5.4%) patients. The most common complication was paresis of the phrenic nerve - 20 (37.7%) cases which were associated with lower temperatures of CBA application of the right pulmonary veins (τ=0.08; p<0.05). The features of antiarrhythmic and anticoagulant therapy were evaluated. A group of patients without adequate anticoagulant therapy in the postoperative period was identified. Due to COVID-19 restrictions only 374 (38.3%) patients completed 12-month follow-up. The recurrence of arrhythmia was occurred in 85 (22.7%) patients. Multivariate regression analysis revealed the following predictors of arrhythmia recurrence: the first procedure (OR 3.96; p=0.023), male sex (OR 1.77; p=0.014), duration of the procedure (min) (OR 1.01; p=0.007). Conclusion . CBA is an effective and relatively safe procedure for the treatment of paroxysmal and persistent AF. Data from real clinical practice show a low proportion of serious complications of AF CBA. Data on the dynamics of drug therapy, including anticoagulant and antiarrhythmic therapy, were obtained. The attention of specialists performing AF catheter ablation and patient monitoring is required, since errors in patient management have been identified.

Aim. To analyze the significance of contrast-enhanced cardiac magnetic resonance imaging (MRI) and endomyocardial biopsy (EMB) in the diagnosis of myocarditis in patients with atrial fibrillation (AF) of unknown origin. Material and methods. The study included 57 patients with AF of unknown origin aged 45,5 [38,8;53,3] years (men, 77,2%). Paroxysmal AF was observed in 56,1% of patients, while persistent AF — in 22,8%, and long-standing persistent AF — in 21,1%. Thirty-five patients underwent contrast-enhanced cardiac MRI and Lake-Louise criteria assessment. Simultaneously with AF ablation, all patients underwent EMB from the interventricular septum, outflow tract, and right ventricular apex with histological diagnosis of myocarditis based on the Dallas criteria modified by the World Heart Federation. Results. According to contrast-enhanced cardiac MRI, delayed contrast accumulation was diagnosed in 91,4%. In 17,1% of cases, signs of edema were detected on T2-weighted images, while the average left ventricular (LV) edema level was 1,6±0,3 (reference <2,0). In 25,7% of patients, signs of hyperemia were detected with average LV hyperemia index of 3,4 [2,2;4,0] (reference <4,0). Myocarditis was diagnosed in 12 patients (34,3%) with 3 criteria detected in 2 patients, 2 in 10 patients (6 with hyperemia + fibrosis, 4 with edema + fibrosis), and 1 (fibrosis) in 22 patients. Histological criteria of lymphocytic myocarditis were detected in 28 out of 57 patients (49,1%): focal in 19 (67,9%), diffuse in 6 (21,4%), and diffuse-focal in 3 (10,7%). Edema signs on MRI was the factor most strongly associated with the total number of detected T-lymphocytes in myocardial fragments, assessed using ROC analysis (AUC 0,782 (95% confidence interval 0,61-0,93) p=0,032). The combined use of MRI and EMB allowed to increase the accuracy of myocarditis diagnosis from 34,3 to 62,9%. Conclusion. Myocarditis was diagnosed in 34,3% of patients according to MRI and in 49,1% according to EMB. Edema according to MRI data was the only sign that had predictive value for the severity of inflammatory cell infiltration in myocardial fragments. Histological analysis in combination with MRI increased the accuracy of myocarditis diagnosis in patients with AF of unknown origin from 34,3 to 62,9%.

Aim. Search for predictors of early recurrence of atrial tachyarrhythmias after radiofrequency ablation (RFA) of atrial fibrillation (AF).Methods. The study included 57 subjects with persistent (n = 17; 30%) and paroxysmal (n = 40; 70%) forms of AF, admitted for the RFA. All patients underwent transthoracic echocardiography, assessment of deformation of both atria using 2D Strain, computed tomography (CT) with 3D reconstruction of the left atrium (LA). Intraoperatively, high-density voltage mapping of LA was performed before RF pulmonary vein isolation. All patients underwent follow-up after 3 months.Results. Recurrence of atrial tachyarrhythmia after 3 months was recorded in 17.5% of patients. High prevalence of low-amplitude activity zones in the LA and persistent AF were the strongest predictors. The LA reservoir function below 21.7%, the conduction function below 15.7%, the LA stiffness index above 0.314 relative units, the LA volume with the appendage above 121.7 ml, and the LA vertical size according to CT data above 65.5 mm statistically significantly predicted early recurrences of atrial tachyarrhythmias with high sensitivity and specificity.Conclusion. The decreased LA deformation in the reservoir and conductor phase, increased LA stiffness index, the prevalence of low-amplitude activity zones, vertical size and volume of the LA with an auricle according to CT data and persistent AF are significant predictors of early relapses after interventional treatment of AF.

Aim. To assess the incidence of chronic myocarditis in patients with atrial fibrillation.Material and methods. The study included 145 patients. The majority of patients were male — 118 (81.4%). The median age was 45 (38; 50) years. Most had paroxysmal AF — 60 (41.4%), slightly fewer had persistent AF — 55 (37.9%), 30 (20.7%) patients had long-term persistent AF. All patients underwent radiofrequency ablation of AF and endomyocardial biopsy (EMB) with subsequent histological and immunohistochemical studies (IHC). Morphological verification of myocarditis was performed in accordance with the Dallas criteria modified by the World Heart Federation.Results. Signs of chronic myocarditis were identified in 64 patients (44.1%). The median age of patients with myocarditis was 44 (36.5;49) years, without myocarditis — 46 (38;51) years. In men, myocarditis was detected in 50 cases (42%), in women — in 14 (51.9%). In paroxysmal AF, myocarditis was detected in 25 patients (41.7%), in persistent AF — in 23 (41.8%), and in long-term persistent AF — in 16 (53.3%). The groups with and without chronic myocarditis were comparable when compared based on the main echocardiographic parameters. Regression analysis did not show a significant influence of these factors on the probability of detecting chronic myocarditis in patients with AF. In patients under 30 years of age, there were no signs of inflammation without the presence of myocardial fibrosis, while the maximum stage of fibrosis occurred in patients from 31 to 40 years of age. The stage of fibrosis did not depend on gender. More often than others, a combination of enterovirus and herpes virus type 6 was detected in biopsy specimens. In patients over 51 years of age, biopsies generally did not express any virus on immunohistochemical studies.Conclusion. Chronic myocarditis in patients with AF was significantly more often detected in younger patients (up to 50 years inclusive), and was more common in women, as well as in the presence of a long-term persistent form of AF, regardless of gender. Detection of myocardial fibrosis signs is more typical for young patients with the maximum stage at the age of 31 to 40 years.

Aim . To assess the dynamics of left (LA) and right atrium (RA) strain after antral pulmonary vein isolation in patients with paroxysmal and persistent atrial fibrillation. Methods . The study included 57 subjects (31 men and 26 women) aged of 55.4±9.8 years. Patients were divided into 2 groups: group 1 with paroxysmal atrial fibrillation (n=40; 70%) and group 2 with persistent atrial fibrillation (n=17; 30%). All patients were treated (were undergone) with antral isolation of the pulmonary veins. Speckle-tracking echocardiography at sinus rhythm was performed before interventional treatment, after 3 days, 3 months and one year. The reservoir, conduit and contractile LA function and peak longitudinal RA strain were analyzed. Results . In both groups, reservoir (p<0.001), conductive (p<0.001) and contractile LA functions (p<0.001 and p=0.001) decreased significantly in the early postoperative period. LA mechanics recovered after 3 months in all patients and were comparable to the level before and one year after radiofrequency ablation. RA strain was significantly increased in the early postoperative period. RA strain was significantly higher at one year follow-up period compared with baseline. Conclusion . Catheter ablation has a damaging effect on the LA - inhibition of reservoir, conductive and contractile functions in the early postoperative period, while the RA strain is intensified. LA strain is recovered in 3 months after radiofrequency ablation and remains comparable with the baseline level at one year follow-up. Reservoir and conduction function of LA and longitudinal deformation of RA are better in the patients with a stable sinus rhythm for a year after ablation compared with patiens who had a tachyarrhythmia recurrence.

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 evaluate the effect of catheter ablation on left (LA) and right atria (RA) function in patients with atrial fibrillation.Material and methods. The study included 28 patients (14 men and 14 women) aged 33 to 72 years (mean age, 57,7±9,9 years) with paroxysmal (n=23) and persistent AF (n=5). All patients underwent radiofrequency ablation (RFA) with pulmonary vein antrum isolation. Before ablation and 3 days after, transthoracic twodimensional echocardiography was performed in sinus rhythm with an assessment of LA reservoir, conduit and booster pump function and RA peak longitudinal strain.Results. In the studied patients, a significant decrease in the reservoir, conduit and booster pump function of the LA was revealed after RFA, while there was no significant change in RA peak longitudinal strain after catheter ablation. LA reservoir, conduit and booster pump function decreased by 6,45% (p<0,001), 3,59% (p<0,001), 2,85% (p<0,001), respectively, while RA peak longitudinal strain increased by 0,73% (p=0,43).Conclusion. Catheter ablation has a significant damaging effect on the LA tissue, inhibiting the reservoir, pumping and pipeline functions. At the same time, the contractility of the PP in the early postoperative period improves, but not significantly.

Aim To evaluate efficacy and safety of the anticoagulant therapy in patients with atrial fibrillation (AF) during a 36-month follow-up after an interventional treatment. Material and methods This study included 302 patients aged 29 to 81 years with various forms of AF. Catheter ablation (CA) of AF foci was performed for all patients. The patients were divided into 3 groups: group 1 with paroxysmal AF, group 2 with persistent AF, and group 3 with longstanding persistent AF. Two subgroups were isolated in each group, with effective and ineffective CA. Results of the follow-up were analyzed at 12, 24, and 36 months after discharge from the hospital. The follow-up interview recorded complaints of palpitation attacks, effectiveness of administered CA, compliance with the treatment, adverse clinical outcomes, including thromboembolic complications (TEC), bleeding, and hospitalizations. Results Efficacy of the interventional treatment for 36 months was 65.3 % in patients with paroxysmal AF, 59.7 % in patients with persistent AF, and 57.1% in patients with longstanding persistent AF. Patients with paroxysmal AF and effective CA had no adverse events throughout the same period during the antithrombotic treatment (ATT). In contrast, the group with ineffective ablation had both TEC and hemorrhagic complications during the ATT. In the group with persistent AF and effective CA throughout the follow-up period, TECs were less frequent than in the group of ineffective ablations during the ATT treatment. Patients with longstanding persistent AF and effective CA throughout the follow-up period, had no TECs in contrast to patients with ineffective ablation during the ATT treatment. There were no fatal outcomes in patients with effective procedure. Conclusion A successful CA procedure for AF provides a significant decrease in the risk of ischemic stroke. Furthermore, the invasive strategy does not increase the risk of major and minor bleedings.

The article describes clinical cases demonstrating the advantages of non-invasive long-term electrocardiogram (ECG) monitoring allowing to detect asymptomatic atrial fibrillation (AF) and transient atrioventricular (AV) and sinoatrial (SA) blocks.

There is a group of patients with so-called idiopathic atrial fibrillation (AF) without the causes of arrhythmia established by a standard examination.Aim. To study the effect of histological changes in the myocardium in patients with idiopathic AF on the effectiveness of ablation.Material and methods. The study included 101 patients with idiopathic AF All patients underwent ablation, during which a myocardial biopsy was performed. Depending on the results of intervention, 3 groups were formed: 1 — no AF within 12 months, 2 — recurrent arrhythmia within first 3 months of follow-up, 3 — recurrent arrhythmia after first 3 months of follow-up. To assess inflammatory changes and the severity of fibrosis, histological and immunohistochemical tests of myocardial biopsies were performed.Results. Histological criteria for lymphocytic myocarditis in group 1 observed in 47,5% of patients, in groups 2 and 3 in 27,3% and 25%, respectively. Infiltration of less than 7 cells per 1 mm2 by CD3+ lymphocytes prevailed in group 3. The activity of inflammation in the studied groups did not significantly differ. The minimum severity of fibrosis was significantly less frequently recorded in group 1 than in group 2 and 3. Nonexpression of viral antigens in the first group was significantly less common than in the second and third groups. Moreover, the combination of expression of enterovirus VP1 and human herpesvirus 6 antigens was significantly more often recorded in the first group. Positive correlation was found between the expression of viral antigens and markers of endo- and myocardial fibrosis.Conclusion. The primary risk factor for recurrent arrhythmia was the initial stage of fibrosis, while inflammatory changes and viral infection were not risk factors. The presence of viral antigens in the myocardium had an indirect effect on the clinical outcome.

Background. Atrial fibrillation (AF) is combined with an inflammatory process that occurs in the myocardium. Diagnosis of histological changes, including inflammatory changes, in the myocardium is a complex task in the field of modern medicine. The only reliable way of determining the inflammatory changes in the myocardium is endomyocardial biopsy (EMB). As per our literature review, there are no data on the effect of histological changes in the myocardium on the efficacy of interventional treatment for AF. Moreover, assessing the dynamics of EMB results allows us to approach the treatment of patients in greater detail, thereby lowering the risk of the development and progression of serious cardiac pathologies, particularly AF.Aim. To study the effectiveness of catheter treatment for ‘idiopathic’ AF, depending on the dynamics of histological changes in the myocardium.Methods. We enrolled 48 patients with an ‘idiopathic’ form of AF; the median patient age was 39.0 y (33.5–48.0 y). Of these, 42 (87.5 %) were men and 6 (12.5 %) were women. The median duration of arrhythmic history was 4.0 y (2.0–7.0 y). All the patients underwent radiofrequency isolation of the pulmonary veins (Rcil) and EMB from the right ventricle. Histological tests, using the criteria of Cristina Basso, and immunohistochemical (IHC) tests were performed to determine the antigens of the following viruses: herpes simplex virus (HSV) types 1, 2 and 6, enterovirus (EV), Epstein-Barr, adenovirus and parvovirus (PV). After 6 mon, EMB, histological and IHC studies were repeated. Depending on the clinical form of AF, the patients are divided into the following three groups: group 1—paroxysmal form [21 (43.7 %) patients], group 2—persistent [13 (27.1 %) patients], group 3—long-term persistent [14 (29.2 %) patients]. Based on the results of the observation and evaluation of effectiveness, all the groups were divided into the following three subgroups: a—absence of AF during 12 mon of observation, b—early arrhythmia recurrences were registered during the first 3 mon of observation, c—presence of late arrhythmia recurrence after 3 mon of observation.Results. According to the histological criteria for active lymphocytic myocarditis identified in the subgroups, there were 5 patients (35.7 %) in 1a, 2 (50 %) in 1b, 6 (75 %) in 2a, 2 (66,7 %) in 2b, 7 (70 %) in 3a, 2 (66.7 %) in 3b, and 1 (100 %) in 3c. The rest of the patients showed signs of lymphocytic infiltration. After 6 mon, only in group 2a, there was a significant reduction in the number of patients with active lymphocytic myocarditis (p < 0.05). All the patients showed fibrotic changes and expression of HSV 6 and EV antigens of varying severity; this persisted till after 6 mon. The overall effectiveness of the surgical treatment was 66.7 % for paroxysmal, 61.5 % for persistent and 71.4 % for long-term persistent forms of AF during 12 mon of follow-up.Conclusion. Patients with ‘idiopathic’ AF show inflammatory changes in the myocardium, and 48.7 % met the criteria for myocarditis. All the patients showed the expression of viral antigens and the development of fibrosis that met the criteria for post-inflammatory changes. A repeat study that was conducted after 6 mon showed no significant dynamics of inflammatory and fibrotic changes. Despite the presence of inflammatory changes in the myocardium, the effectiveness of catheter treatment was 66.7 % for paroxysmal, 61.5 % for persistent and 71.4 % for long-term persistent forms of AF. Received 29 April 2020. Revised 1 June 2020. Accepted 3 June 2020. Funding: The study did not have sponsorship. Conflict of interest: Authors declare no conflict of interest. Author contributionsConception and design: A.E. Shelemekhov, R.E. BatalovData collection and analysis: A.E. Shelemekhov, Yu.V. Rogovskaya, S.Yu. Usenkov, E.A. Archakov, M.S. Rebenkova Drafting the article: A.E. ShelemekhovStatistical analysis: A.E. Shelemekhov, A.M. GusakovaCritical revision of the article: R.E. Batalov, Yu.V. Rogovskaya, A.M. GusakovaFinal approval of the version to be published: A.E. Shelemehov, R.E. Batalov, Yu.V. Rogovskaya, S.Yu. Usenkov, E.A. Archakov, A.M. Gusakova, M.S. Rebenkova

Treatment of persistent and long-persistent forms of atrial fibrillation remains a pressing issue. Using a personalized approach can help to more successfully eliminate arrhythmias and reduce the return probability. One of these approaches is the use of radiofrequency ablation in conjunction with modern high-tech research methods. The article describes a clinical case of successful catheter ablation of persistent atrial fibrillation in a patient with a mechanical mitral valve prosthesis, due to the use of non-invasive topical diagnostics prior to surgery.

Aim. To estimate the efficacy of catheter ablation in patients with type 2 diabetes mellitus (T2D) present with atrial fibrillation and sick sinus syndrome (SSS) undergoing permanent pacemaker implantation.Methods. 56 patients (34 females) with persistent AF and SSS were enrolled in the study. The mean age of patients was 67.7±10.7 years. Dual chamber cardiac pacemaker with remote monitoring function were implanted in all patients. All the patients were assigned to two groups: Group 1 comprised 31 patients aged 67.3±9.6 years, and Group 2 comprised 25 patients aged 72.6±9.9 years, including 22 (39.2%) diabetic patients. 2-3 days after pacemaker implantation, group 1 patients underwent intracardiac electrophysiology study and RFA of the pulmonary vein ostia, mitral isthmus and the left atrial posterior wall. Group 2 patients received antiarrhythmic drug therapy. Results. 3 patients (9%) in Group 1 had recurrent AF within the 6-month follow-up. The efficacy of the RFA for AF was 55% (n = 17) 1 year after the indexed hospitalization. 8 patients had short paroxysmal attacks which gradually lessened and stopped after. 5 patients (21%) in Group 2 did not have any AF paroxysms within the 1-year follow-up (Х2 = 5.52, р = 0.02). All these patients received amiodarone as antiarrhythmic drug therapy, whereas the others had paroxysmal attacks. Frequent attacks in 10 patients (40%) led to a change in antiarrhythmic drug use. Hospital readmission rates for AF were 16% and 52%, respectively (Х2 = 4.15, р = 0.04). The impact of atrial and ventricular stimulation on the development of recurrent AF was statistically insignificant (atrial stimulation – X2 = 0.01, cc = 1, p = 0.90; ventricular stimulation – X2 = 0.15, cc = 1, p = 0.69). None paroxysmal attacks were recorded in 10 diabetic patients (45%) after the RFA within the 1-year follow-up.Conclusion. Catheter ablation for persistent AF and SSS treated with permanent pacemakers is highly effective and safe method. In addition, it is superior to pharmacological approach. The presence of T2D likely did not significantly affect the efficacy of RFA for persistent form of AF.

The article presents the results of the analysis of hemostasis parameters in atrial fibrillation patients with and without anticoagulation therapy with dabigatran etexilate in the perioperative period of the arrhythmia ablation. We evaluated the capabilities of using the conventional indicators of the blood coagulation in atrial fibrillation patients receiving dabigatran etexilate to assess the possible risk of bleeding in the perioperative period of radiofrequency ablation.

Aim. To evaluate the speckle-tracking echocardiography (STE) application in atrial fibrillation (AF) patients during catheter treatment, by the data from intracardiac echocardiography (ICE). Material and methods. Totally, 30 patients included, with persistent and paroxysmal AF. In 25 (84%) the main disease was arterial hypertension, of those 14 (46%) had hypertension together with coronary heart disease. In 16% cases (4 patients) AF was idiopathic. All patients had indications for catheter treatment of the arrhythmia. Results. Before the start of radiofrequency intervention (RFI), superior pulmonary vein (PV) deformation was 24,5±1,5%, after the intervention 17,5±1,1%, tissue deformation decreased by 7% (р<0,001); of the left inferior PV before RFI — 21,5±0,9%, after — 14,4±0,9%, tissue deformation decreased by 7,1% (р<0,001); right inferior PV before RFI — 21,2±1,3%, after — 14,9±1,1%, tissue deformation decreased by 6,2% (р<0,001); right inferior before RFI — 20,5±1,1%, after — 14,4±1,1%, deformation change 6,1% (р<0,001). Under the influence of RFI, velocity of upper PV deformation decreased by 8,1% (р<0,001), to -5,36±0,5%, after — 4,93±0,35%; in lower inferior PV decrease of velocity by 8,3% (р<0,001), before RFI -5,38±0,6%, after — 4,93±0,55%; right superior PV — decrease of PV deformation by 8,5% (р<0,001), before RFI -5,5±0,15%, after -5,0±0,33%; in right inferior 8,2% (р<0,001) before RFI -5,9±0,4%, after -5,4±0,4%. Conclusion. Decrease of deformation by more than 6% and velocity of deformation by 8% after radiofrequency intervention are relevant signs of pulmonary veins ostia isolation.

Цель: определить влияние интервенционного вмешательства по поводу фибрилляции предсердий (ФП) на дина мику протеолиза внеклеточного матрикса. Материал и методы. В исследование вошли 50 пациентов с персисти рующей – 27 (18 мужчин), средний возраст 62,1±9,4 лет и длительно персистирующей – 23 (14 мужчин), средний возраст 64±11 лет формами ФП, с наличием показаний для проведения интервенционного лечения аритмии. Выполнена радиочастотная антральная изоляция легочных вен, задней стенки левого предсердия (ЛП), левого истмуса сердца с использованием системы CARTO (Biosense Webster, США). Определяли динамику показателей системы протеолиза внеклеточного матрикса и факторов роста в сыворотке крови – матриксных металлопроте иназ (ММП) 1, 3, 9, тканевого фактора роста β1 (TGF β1), тканевого ингибитора матриксных металлопротеи наз (ТИМП 1), фактора роста фибробластов (FGF), до процедуры “Лабиринт”, непосредственно после нее, через одни сутки, через 3 и 6 мес. Результаты. Концентрация всех матриксных металлопротеиназ непосредственно пос ле процедуры резко снижалась, что, скорее всего, связано со значительным и объемным термическим поражени ем ЛП. Через сутки концентрация ММП 1 имела тенденцию к восстановлению, в то время как ММП 3 сохранялась на предыдущем уровне, а ММП 9 резко возрастала до уровня, превышающего таковой до вмешательства. По исте чению 3 мес. наблюдения концентрация ММП 1 и 3 практически возвращалась к исходной, а ММП 9 резко сни жалась до уровня, имеющегося непосредственно после процедуры. Через полгода наблюдения концентрация ММП 1 имела тенденцию к снижению, и была ниже исходного уровня, уровень ММП 3 также не достиг исходно го, в то время как концентрация ММП 9 вернулась к исходной точке. Концентрация тканевого фактора роста β1 также резко снижалась непосредственно сразу после процедуры, с медленным восстановлением к 6 му мес. на блюдения, чего нельзя сказать о факторе роста фибробластов. Так, сразу после процедуры его концентрация снижалась, что можно объяснить массовой гибелью клеток в миокарде предсердий. Через сутки концентрация увеличивалась и достигала исходных значений. Через 3 и 6 мес. концентрация снижалась. Заключение. Снижение активности металлопротеиназ и факторов роста при отсутствии аритмии после РЧА – результат прекращения структурного ремоделирования и, возможно, его регресса. Ключевые слова: фибрилляция предсердий, радиочастотная аблация, фиброз, внеклеточный матрикс, структур ное ремоделирование предсердий.

Aim. To study clinical and hemodynamic parallels in preschool children with arrhythmias in different age groups.Material and methods. Totally 195 children studied with idiopathic arrhythmias at the age of 0 to 7 y. o. — 82 with WPW syndrome, 55 with atrial tachiarrhythmias, 7 with AVNRT, 13 — with ventricular tachis (VT), 38 with ventricular and supraventricular onsets (isolated, group and their combination). Age groups: 1 — children 1 y. o. (n=72; 37%); 2 — 1-3 y. o. (n=37; 19%); 3 — 3-7 y. o. (n=87; 44%). All patients underwent standart laboratory assessment, electrocardiography in 12 standard leads, Holter monitoring, echocardiography.Results. In analysis of tachicardias course variants there was prevalence of of paroxysmal tachicardia in children of 3 to 7 y. o. (p=0,001) and permanent tachicardia in children less than 1 y. o. (p<0,001). Frequency of episodes in paroxysmal tachicardias in 1 y. o. children was higher than in those from 1 to 3 y. o. (p=0,028) and 3-7 y. o. children (p<0,001). In assessment of echocardiography of arrhythmic children depended on age there was significant prevalence of ACMP in older children comparing to the younger (p=0,002). Signs of heart failure were more common in children of 1 y. o. comparing to those of 1-3 and 3-7 y. o. (F=44,117; p=<0,001).Conclusion. So the arrhythmogenic heart remodeling mostly common for the children of 3 to 7 y. o. In less 1 year infants with arrhythmias clinical signs of HF are followed by diastolic disorders that develop before ACMP development, that is traditionally regarded as systolic dysfunction. Into the factors that influence these hemodynamic relations we include high mean heartrate, tendency of tachicardias to recurrent and permanent course, high frequency of attacks in paroxysmal tachicardias in infants before 1 year old.