Introduction. Thromboembolic syndrome is a dangerous complication of atrial fibrillation (AF). Left atrial appendage (LAA) is the most frequent location of the thrombus formation in AF. Enlargement of the LAA, special anatomical forms of the appendage are accepted as a risk factors of the LAA thrombosis.

Aim: to assess the revealing macro-/microthrombosis LAA in dependence of the morphological form of the appendage in autopsy.

Methods. 85 cadaveric hearts were investigated. LAA was measured in three dimensions, the anatomical form of the LAA were estimated by Wang et al. classification. Histological investigation of the LAA slices was made in Hematoxylin Eosin colouring.

Results. Macrothrombosis was revealed in 4 LAA. Microthrombus in the LAA were revealed in 46 (54,1%) specimens. We did not find statistical significance between frequency micro thrombosis of the LAA and morphology of the appendage (p = 0,3) with the trend to revealing more microthrombus in anatomic form of the LAA «chicken wing» (65% of this morphological type). Analysis of the diseases died patients showed absence AF in 54,3% cases of the LAA microthrombosis group. AF was diagnosed only in 16 (45,7%) cases in stroke group with revealed micro thrombosis in the LAA.

Conclusion. The investigation did not show statistical significance between the anatomical form of LAA and revealing of appendage microthrombosis. Possibly, there is a common pathomorphological process of the LAA thrombosis independence of the AF presence. Further trials are needed to confirm this consumption.

Purpose: to compare epicardial and endocardial surface area of local abnormal ventricular activity (LAVA) and low voltage zone (LVZ) and effectiveness of endocardial versus combined endo-epicardial ablation of ventricular arrhythmias in ARVC patients.

Methods: a prospective observational “case-control” study comprised 20 patients with ARVC and ventricular arrhythmias referred to catheter ablation. The study group with epicardial approach (EPI group) comprised 10 patients with sustained VT, who signed informed consent for the epicardial access. The control group (ENDO group) comprised 10 patients with sustained VT or frequent symptomatic premature ventricular contractions (PVC). Electroanatomical voltage mapping and LAVA ablation was performed.

Results: the patient mean age was 41.4±13.8 years, 70% males; 90% patients in the EPI group had sustained VT, 50% - in the ENDO group. In the EPI group the endocardial unipolar low voltage zone area (LVZ) significantly prevailed over the bipolar endocardial LVZ area: 75.4 cm² [IQR: 23.2; 211.9] vs 6.7 cm² [IQR: 4.4; 35.5] (Р=0.009). In the ENDO group the LVZ area on unipolar map had a trend toward the prevalence over the bipolar area, but was not statistically different: 12.7 cm² (IQR: 0; 46.3) vs 3.65 cm² (IQR: 0; 46.3) (Р>0.05). The epicardial bipolar LVZ area prevailed over unipolar epicardial LVZ area: 65.3 cm² [IQR: 55.6; 91.3] vs 6.7 cm² [IQR: 4.4; 35.3] (Р=0.005). Non-inducibility of any ventricular arrhythmia was achieved in 90% of EPI patients and in 80% of ENDO cases. The median follow-up period was 22.3±10.5 months. During a mean follow-up period freedom of ventricular arrhythmia recurrence was 70% in the EPI group and 100% in the control group (Р>0.05).

Conclusion: Although there was a significant difference in bipolar LVZ areas between endo- and epicardial maps, our series showed that endocardial only ablation is an effective strategy in ventricular arrhythmia management in ARVC patients.

Purpose: to design mathematical model, that can predict positive response to cardiac resynchronization therapy (CRT) in patients with congestive heart failure (CHF) and sinus rhythm, according to complex analysis of neurohumoral and immune activation biomarkers, fibrosis, renal dysfunction, echocardiography.

Material and methods: parameters of echocardiography, plasma levels of NT-proBNP, interleukins-1β, 6, 10, tumor necrosis factor α, С-reactive protein (СRP), matrix metalloproteinase-9 (ММР-9), tissue inhibitors of metalloproteinase 1 and 4, cystatin С (CYSTATIN) were studied in 40 CHF patients with sinus rhythm (65% coronary artery disease patients, 75% males, mean age 54.8±10.6 years old) during the period of maximum decrease of left ventricular end-systolic volume (LVESV) (mean duration 27.5 [11.1; 46.3] months). Responders (decrease in LVESV ≥15%) and non-responders (decrease in LVESV ˂15%) were identified.

Results: the number of responders was 26 (65%). Initial set of variables included: age, left ventricular ejection fraction (EF), systolic pressure in the pulmonary artery, right ventricle size and NT-proBNP, СRP, ММР-9, CYSTATIN. According to logistic regression analysis, a model was created: F=3.231 + 0.344 х EF - 3.479 x CYSTATIN - 0.039 х ММР-9 - 0.638 х CRР. Prediction of response to CRT (P) was carried out using the equation: Р=1/(1+е(^-F)); a less than 0.696 p-value was associated with membership of non-responders group; p-value greater than or equaled to 0.696 was associated with group of responders. The specificity of the model was 92.9%, sensitivity - 83.3%, AUC=0.952 (р˂0.001).

Conclusions: the proposed model, based on assessment of left ventricular EF and laboratory data, that reflect key mechanisms of development and progression of CHF - immune inflammation, fibrosis, renal dysfunction, suggests a possible response to CRT.

Objective. To improve the results of treatment for the patients with non-paroxysmal atrial fibrillation (AF) in combination with isthmus-dependent (typical) atrial flutter (AFL) by determining the optimal surgical tactics.

Material and methods. The research based on the study of treatment results for 37 patients who are consequentially underwent thoracoscopic radiofrequency fragmentation (TRF) of the left atrium (LA) in the period from April 2017 to December 2019. All of the patients suffered from a combination of 2 types of arrhythmias: non-paroxysmal AF and AFL. Depending on history of catheter ablation (CA) of cavotricuspid isthmus (CTI) before TRF, all patients divided into 2 groups: group 1 - there was anamnesis of CA of CTI before TRF (N = 16; 43%); group 2 - there was no CA of CTI before TRF of the LA (N = 21; 57%). In the postoperative period, all patients underwent examination and interviewed regarding cardiac arrhythmias. At the time of April 1, 2020, information about heart rhythm and its disorders during follow-up period was received from 100% of patients. The duration of the follow-up period after TRF was 17 (3; 35) months.

Results. There was no supraventricular tachyarrhythmias (SVT) during all follow-up period after TRF among the patients of group 1. There was 8 patients (38%) of group 2 with AFL, which is developed in the period from 1 to 6 months after TRF. All these patients underwent a CA of CTI after the end of a “blanking” period. There was 2 of 8 patients with developing of SVT after CA of CTI. The source of new rhythm disorder was the ablation line formed during TRF on the roof of the LA.

Conclusion. In order to achieve long-term freedom from SVT requiring surgical intervention in patients suffering from a non-paroxysmal AF in combination with a typical AFL it is reasonable to perform catheter radiofrequency ablation of CTI at the first stage before TFR of the LA.

Purpose. To analyze the possibility of using high-sensitivity cardiac troponin I (hsTnI), N-terminal pro-B type natriuretic peptide (NT-proBNP), tissue hemodynamics parameters, echocardiographic data and the quality of life for selection of the individual regimen for ventricular rate (VR) control drug therapy in patients with permanent atrial fibrillation (AF). Methods. The study included 120 patients aged >60 years old with the diagnosis of permanent AF, who gave the informed consent. Patients were randomized into 2 groups according to the target range of VR at rest: 60-79 bpm (first group, n=60) and 80-100 bpm (second group, n=60). Patients in both groups were prescribed a selective beta1 -adrenoceptors blocker bisoprolol for VR control. The following parameters were determined before randomization and after 6 months of VR control in the target ranges: atrial and ventricular remodeling with transthoracic echocardiography; biochemical markers hsTnI and NT-proBNP; the tissue hemodynamics by the mean flow velocity (Vm) and the value of the pulsatility index (PI) using high-frequency ultrasound Doppler flowmetry; the patients’ quality of life with the “Atrial Fibrillation Effect on QualiTy-of-life (AFEQT) Questionnaire” and the “EQ-5D-5L” system with a scale EQ-VAS.

Results. VR at rest after 6 months was 70±3 and 88±4 bpm (p₁, p₂˂0.001) in the first and second groups, respectively (p₁ - comparing the initial and achieved values, p₂ - values of the first and second groups). The level of hsTnI significantly decreased in both groups, but it was more pronounced in the 60-79 bpm range group (p˂0.001). Spearman’s correlation coefficients between the degree of decrease in VR and decrease in the level of hsTnI were 0.45 (p˂0.001) and 0.44 (p˂0.001) in the first and second groups, respectively. AFEQT and EQ VAS scores of quality of life improved after 6 months in both groups: the increase in the total AFEQT score in the first group -56.2±17.0% (M±SD), in the second - 42.6±15.3% (p˂0.001); EQ VAS values also increased, but differences between groups were not significant (p=0.078). In both the first and second groups, a strong positive correlation was found between the degree of decrease in VR and increase in the total score of the AFEQT questionnaire. The tendency toward an increase in Vm and a decrease in PI observed in both groups was more pronounced in the group with VR of 80-100 bpm, where Vm increased by more than 10% (p₁, p₂˂0.001). Changes in NT-proBNP under the influence of therapy for the reported observation period did not reach statistical significance in both groups (p₁ =0.092, p₂ =0.063). There was no significant dynamics of echocardiographic parameters of myocardial remodeling.

Conclusion. The degree of chronic myocardial damage caused by arrhythmia (estimated by hsTnI), as well as the tissue hemodynamic parameters Vm and PI, can be the basis for individualized selection of the target VR range. This approach will allow to find a balance between cardioprotection and improvement of tissue blood flow. In creating the algorithm of selecting the target VR for patients older than 60 years with permanent AF, it is advisable to use such parameter as the degree of the initial VR change and quality of life data from the “AFEQT Questionnaire”.

Aim: to assess morpho-functional properties of left ventricle (LV) in patients with superresponse (SR) to CRT using the helical ventriсular band concept (HVB).

Materials and methods: 56 patients were examined (mean age 54.0±9.9 years) at baseline and during follow-up visit: 48.8±25.6 months. Patients were divided into groups: I group (n=34) with decrease of LV end-systolic volume (ESV) ≥30% (superresponders) and II group (n=22) - decrease of LV ESV ˂30% (nonsuperresponders).

Results: apical loop descendens segment (DS) and ascendens segment (AS) of HVB were evaluated according to the concept of F. Torrent-Guasp et al. According to the logistic regression mechanical interventricular delay (MID) (OR 1.072, 95% CI 1.017-1.131; p=0.01) and systolic thickening fraction (STF) of interventricular septum (IVS) DS (OR 0.944, 95% CI 0.895 - 0.995; p = 0.033) had an independent relationship with CRT SR. According to the ROC analysis the sensitivity and specificity of this model were 72.7% and 66.7% (AUC=0.769; р=0.001). AS STF of IVS was higher in SR (22.5 [0.0;40.0]% и 0.0 [0.0;25.0]%; р=0.005). The survival rate in group I was 85.1%, in group II was 63.6% (Log-Rank test p=0.019).

Conclusion: SR is associated with a higher AS STF of IVS, higher MID, also with a higher survival rate.

Aim. To identify predictors of ventricular tachyarrhythmias (VTA) in patients with ischemic cardiomyopathy.

Materials and methods. The study included 40 patients (males - 36, mean age - 63,4 ± 7,8 years) with coronary artery disease (CAD), II-III functional class of chronic heart failure, left ventricle ejection fraction 35% or less, without sustained VTA and cardioverter-defibrillator (CD) implantation indications (primary prevention of the sudden cardiac death). Patients before CD implantation underwent 6-minute walk test, echocardiography, heart rate variability (HRV) analysis and cardiac single-photon emission computed tomography with 123I-meta-iodobenzylguanidine (¹²³I-MIBG). All patients after CD implantation were followed-up during two years and divided into two groups. The 1-st group consisted of patients with VTA events, the 2-nd group - without VTA events.

Results. The 1-st group consisted of 36 (90,0%) patients, the 2-nd group - 4 (10,0%) patients. The univariate ROC-analysis showed that the low values of the HRV, reflecting a decrease of the parasympathetic effect on the heart, as well as an increase in indexed left ventricle volumetric and dimensional indicators (end-diastolic and end-systolic indices) and ¹²³I-MIBG accumulation defect on early and delayed scintigrams, reflecting an increase of the sympathetic effect on the heart leaded to frequent occurrences of the VTA (p=0,0001). The multivariate ROC-analysis demonstrated that only LF (p=0,0136), which associated with sympathoparasympathetic imbalance, leaded to frequent occurrences of the VTA. Also, increase of the VTA predictive ratio, calculated according to this predictive model, more than 0,8936 leaded to frequent occurrences of the VTA (p=0,0001).

Conclusion. In patients with ischemic cardiomyopathy, the predominance of sympathetic and a decrease of parasympathetic effects on the heart, assessed by the analysis of heart rate variability, is a predictor of the life-threatening ventricular arrhythmias.

Purpose. To compare the effect of the completed and incomplete ablation lines on the permanent isolation of the pulmonary veins (PV) during intracardiac electrophysiological (EP) examination 3 months after the operation, as well as to assess the frequency of recurrence of atrial fibrillation (AF) and its relationship with the reconnection in the PV.

Methods. From January to December 2016, 60 patients with paroxysmal AF selected and operated. Patients were randomized into two groups in a 1:1 ratio. In the first group, after achieving isolation of PV, radiofrequency (RF) exposure continued until an anatomically continuous line of ablation was created. In the second group, after receiving electrical isolation of all PV, RF ablation was interrupted regardless of the anatomical completeness of the ablation line. After 3 months in a planned manner (regardless of clinical status), an endocardial EP study was performed to check the consistency of the input and output block of excitation in each PV and, if necessary, repeated RF ablation of the reconnection sites.

Results. A total of 53 people completed the study. In the first group intracardiac EP examination was performed on 29 patients, in the second group - on 24 patients. In the first group 4 patients retained isolation of all PV (13.8%), and in the second group - 5 (20.8%). No significant difference between the groups was obtained (p = 0.267). Sinus rhythm 3 months after the first procedure was observed in 28 patients (52.8%), of which 78.5% had reconnection in at least one PV. The recurrence rate of AF between the groups did not differ (OR 0.488 95% CI 0.162-1.460 p = 0.563) In the first group after 15 months the sinus rhythm was observed in 19 of 29 patients (65.5%), in the second group in 18 of 24 patients (75%). Differences are not statistically significant (OR 0.633 95% CI 0.191-2.103 p = 0.612)

Conclusions: in our study, there was no significant difference in the frequency of reconnection and the clinical efficacy of RF isolation of PV in groups with complete and incomplete ablation lines.

Aim. The potential distribution of the cardioelectric field on the body surface during the initial atrial activity and the sequence of depolarization of the atrial subepicardium in rats with experimentally induced pulmonary hypertension were compared. This work is devoted to non-invasive detection of arrhythmogenic foci of atria by using the cardioelectric field on the body surface during experimental pulmonary hypertension.

Materials and methods. The method of cardioelectrochronotopography has been used to study the electric field of the heart on the body surface and the sequence of propagation of the excitation wave along the atrial epicardium in rats with experimentally induced pulmonary hypertension caused by a single injection of monocrotaline (60 mg / kg, four weeks after drug administration).

Results. Pulmonary hypertension causes the appearance of an additional focus of initial excitation in the area of the pulmonary vein lacunae, which leads to an increase in the heterogeneity of the propagation of the excitation wave along the atrial epicardium. The appearance of the additional excitation focus in the mouths of the pulmonary veins in the left atrium changes the picture of the sequence of depolarization of the atrial epicardium. The heterogeneity of the propagation of the excitation wave along the atrial epicardium is reflected in a different arrangement of zones of positive and negative cardioelectric potentials on the body surface before and during the P-wave in comparison with the initial state.

Conclusion. Induced pulmonary hypertension contributes to the appearance of an additional focus of initial excitation in the area of the sleeves of the pulmonary veins of the left atrium in rats. This leads to an increase in the heterogeneity of the propagation of the excitation wave along the atrial epicardium. This is also reflected in the change in the arrangement of the zones of positive and negative cardioelectric potentials on the body surface before and during the P-wave in comparison with the initial state.

A case report of non-invasive electrophysiological mapping and high-density mapping used for treatment of ventricular tachycardia originating in the left ventricle.