Aim. To compare the effectiveness and safety of endovascular occlusion and thoracoscopic amputation of the left atrial appendage (LAA) in patients with atrial fibrillation (AF).

Methods. We present a retrospective single-center study with a prospective component including 25 patients with AF who underwent thoracoscopic amputation of the LAA and 31 patients on prospective part who underwent endovascular occlusion of the LAA. All patients signed voluntary informed consent for medical intervention and participation in the study. The criteria for selecting patients for thoracoscopic amputation of the LAA were the impossibility of performing an endovascular technique, features of its anatomy and increased trabecularity.

Results. In the group of patients with thoracoscopic amputation of the LAA, 2 cases of embologenic stump of the LAA with a depth of 1.6 cm (8%) were identified; these patients were recommended to continue taking anticoagulant therapy. Among patients who underwent thoracoscopic amputation, no complications were identified in the first 30 days after surgery, including mortality, bleeding, phrenic nerve paresis, acute cerebrovascular accident, pleurisy, pneumothorax, hemothorax. In 3 patients who underwent endovascular occlusion of the LAA, hematomas were detected at the site of puncture of the great vessels (9.7%), in 2 patients thrombus were detected on the occlusion device according to the results of transesophageal echocardiography (6.5%), which required the prescription of warfarin in these patients. Also, in 2 patients (6.5%) during implantation of the occluder into the LAA, as a result of the incorrect diameter of the disk of the occluding device, a residual cavity with a depth of 0.7 cm was formed between the ridge and the occluder. No significant differences in the frequency of non-severe complications were found in the groups, p =0.139. During the year of postoperative observation, thromboembolic complications were absent in the operated patients of both groups.

Conclusion. When comparing two methods of LAA isolation, no severe complications were identified, either in the perioperative or in the early or late postoperative period. There were no significant differences in the incidence of non-severe complications in the early postoperative period. Thus, the effectiveness and safety of thoracoscopic amputation and endovascular occlusion of the left atrial appendage are comparable.

Aim. Evaluation of the clinical efficacy and safety of a high-power short-duration (HPSD) strategy for ablation index (AI) guided pulmonary vein isolation (PVI) using different power settings.

Methods. 185 patients were scheduled for AI guided ablation. Patients were randomized into 2 groups and every group was divided into two subgroups. First group (n=95) PVI was performed with 50W. Second group (n=90) with 45 W. In Ia and IIa AI was 400-450 au (arbitrary unit) in posterior wall and 500-550 au. in the anterior wall. In Ib and IIb AI was 400-450 au in posterior wall and 450-500 au in the anterior wall.

Results. Efficacy of the PVI was 100% in all patients. Within 6 months, atrial fibrillation recurred in Ia, Ib, IIa and IIb subgroups were 5/55 (9.0%), 4/40 (10%), 6/50 (12%) и 5/40 (12.5%) p>0,05. First-pass PVI in Ia, Ib, IIa and IIb subgroups were 53/55 (96.36%), 37/40 (92.5%), 46/50 (92%), 36/40 (90.5%) (p>0,05). There was no significant intra operative complications. The total procedure time was 55±10 min, 50±8 min, 60±10 min, 56±9 min (p>0.05).

Conclusions. HPSD ablation in patients with atrial fibrillation significantly reduces the procedure time, does not increase the incidence of intraoperative complications and is effective in the short term results.

Aim. To study the change in the position of the esophagus during radiofrequency ablation of the pulmonary veins (RFA PV) using esophagography

Methods. The period of the study is from August 2022 to January 2023 inclusive. The study is a single-center observational non-randomized study. The study included 191 patients. RFA PV were performed under conscious sedation with dexmedetomidine and fentanyl. The patients were available for verbal contact throughout the operation. After performing a transeptal puncture, esophagography was performed in the LAO 30° projection using 10 ml of Omnipac water-soluble contrast agent (GE Healthcare Ireland). At the end of the operation, esophagography was performed repeatedly. The position of the esophagus was determined relative to the shadow of the spine. Measurements were carried out at three levels: the upper one at the intersection of the esophagus and the roof of the left atrium, the lower one at the intersection with the ring of the mitral valve; the middle level at the middle of the distance between the upper and lower measurements. The width of the contrasted lumen of the esophagus was measured at the same levels. Lateral displacement of the esophagus was defined as the difference in the values of measurements of the position of the lateral and medial boundaries of the esophageal shadow on esophagograms obtained at the beginning and end of the operation.

Results. The average lateral displacement of the esophagus was 2.0 ±1.9 mm at the upper level, 3.4±1.6 mm at the middle level and 1.4±1.2 mm at the lower level of the left atrium. There was no significant statistically difference in the change in the position of the esophagus at the beginning and end of the operation (p=0.251, p=0.558, p=0.824, respectively, for the upper, middle and lower measurement levels). The most significant displacement of the esophageal shadow was 5.3 mm. The maximum change in the width of the contrasted lumen of the esophagus was 5.5 mm.

Conclusions. According to esophagography with water-soluble contrast, the position of the esophagus during RFA PV does not experience clinically significant changes.

Aim. To present our clinic’s experience of His bundle pacing in pediatric patients.

Methods. Six patients underwent endocardial pacemaker implantation with a ventricular lead in the Hisian position. A standard diagnostic examination was carried out, including routine general clinical and laboratory examinations, an ECG with an assessment of QRS width, Holter monitoring, echocardiography (Echo) with an assessment of the sizes, volumes of the heart chambers, left ventricle (LV) contractile function and Speckle-tracking Echo with an assessment of LV global longitudinal strain (LV GLS). To assess dynamic control ECG, Holter monitoring, Echo and Speckle-tracking Echo were performed.

Results. Selective His bundle pacing (isolated capture of the His-Purkinje system) was achieved in only one patient; non-selective His bundle pacing was performed in the remaining 5 patients. With His bundle selective and non-selective pacing, a significant normalization of the LV electromechanical dyssynchrony index (GLS) was noted from -17 [-15; -19] to -21.4 [-21;-22] (p = 0.013). The most significant normalization of LV longitudinal strain was recorded in a patient with previous epicardial stimulation of the right ventricle (RV).

Conclusion. Physiological His bundle pacing favours ventricular synchronization, providing the most physiological myocardium pacing, both during primary pacemaker implantation and in patients with previous long-term RV pacing, accompanied by ventricular dyssynchrony.

Aim. To evaluate the safety of subcutaneous cardioverter-defibrillator (SCD) systems.

Methods. Fifty-six patients underwent implantation of a SCD. The follow-up period for patients was 18 months. The number of early and late complications, as well as the number of episodes of shock therapy, were assessed.

Results. During observation, complications were recorded in 5 patients, which amounted to 0.9% of the total number of surgical interventions performed. Three complications occurred in the early postoperative period. In the late postoperative period, complications occurred in 2 (3.5%) patients. The number of inappropriate shocks in the total sample of patients was 6 episodes (10.7%).

Conclusion. SCD systems are effective for primary and secondary prevention of sudden cardiac death. Implantation of these systems is associated with a low number of perioperative complications, as well as a low percentage of inappropriate shock therapy.

Aim. To identify factors associated with the effectiveness of radiofrequency catheter ablation (RFA) of focal atrial tachycardia (AT) in school-aged patients in the long-term period.

Methods. The study group consisted of 57 children aged 11 to 17 years 11 months (Me 15.83, IQR 14.63-17.0), who underwent catheter ablation, including repeated, for focal AT in the Almazov National Medical Research Centre from December 2009 until April 2023. We analyzed clinical and demographic data, laboratory data, parameters of tachyarrhythmia, electrophysiological study and RFA. Structural heart diseases were present in 13 children, and idiopathic arrhythmia was present in 44 patients. The criterion for intraoperative effectiveness were the absence of arrhythmia at the end of the waiting period in the X-ray operating room, delayed within 12 months after the procedure.

Results. Intraoperative effectiveness of RFA was achieved in 51 patients (89.5%), long-term in 32 patients (56.1%). Based on the data obtained, a prognostic model of the delayed effectiveness of RFA of focal AT in school-age children was developed (p<0.001). Predictors included in the model: percentage of arrhythmia during the day (odds ratio (OR): 0.981; 95% confidence interval (CI) 0.962-0.999; p=0.043), presyncope (OR: 0.177; 95% CI 0.035-0.903; p=0.037), number of ectopic foci (OR: 0.289; 95% CI 0.128-0.649; p=0.003), right atrium localization (OR: 0.097; 95% 0.013-0.699; p=0.021). The area under the ROC curve corresponding to the association of the absence of arrhythmia after ablation and the values of the logistic regression function was 0.843±0.54 with 95% CI: 0.738-0.938. The sensitivity was 81.3%, specificity 76.0%. No significant association with effectiveness of RFA was found between the method of arrhythmia induction and the use of drug sedation.

Conclusion. It was established that factors such as percentage of arrhythmia during the day, the presence of presyncope, the number of ectopic foci and the presence of an ectopic foci in the right atrium had an inverse relationship with the effective outcome of RFA.

Genetic causes are increasingly found to be responsible for the development of sudden death in young people. Since 2009, pathogenic mutations in RBM20 gene were recognized as an important cause of dilated cardiomyopathy (DCM) and sudden cardiac death (SCD). The high risk of malignant ventricular arrhythmias in RBM20-cardiomyopathy has made these patients potential candidates for the implantable cardioverter-defibrillator for primary prevention of SCD. The presented clinical case of malignant pathogenic mutation in the RBM20 gene demonstrates different phenotypes, including DCM, SCD and asymptomatic forms in one family. Moreover, for the first time we described the presence of prolonged QT interval due to the fusion with U wave on ECG in carries of this malignant familial mutation. The prolonged QT interval may contribute to the development of ventricular arrhythmias and the increased risk of SCD in patients with this rare genetic pathology.

We present a case of asymptomatic coronary-atrial fistula formation after zero fluoro catheter ablation for incessant right atrial tachycardia using ABLATION INDEX module.

The article focuses on the role of left atrial (LA) fibrosis as the basis of the electroanatomic substrate in atrial fibrillation (AF), which determines not only the stability of AF but also the success of catheter ablation (CA). In the article the molecular and cellular aspects of LA fibrosis formation and possible mechanisms of arrhythmogenic effects of fibrotic tissue are considered in details, the methods of estimation of LA fibrosis size determining the effectiveness of CA in patients with AF are demonstrated. Current data on the possibilities of using circulating fibrosis biomarkers as predictors of fibrosis severity and recurrence of AF after CA are presented.

Flecainide is a IC antiarrhythmic drug with a history of more than 30 years, nowadays it is widely used for the management of acute episodes of atrial fibrillation and sinus rhythm maintenance, however, firstly was approved for the treatment of ventricular arrhythmia and later due to the results of the Cardiac Arrhythmia Suppression Trial was contraindicated in patients with ischemic structural heart disease. Of note, flecainide use is feasible in different clinical situations, such as catecholaminergic polymorphic ventricular tachycardia, for unmasking Brugada syndrome, and for patients with long QT syndrome. In our country, flecainide is new for clinical use; therefore, the clinical experience with flecainide is limited. In this review article, we aim to describe the use of flecainide and its role in the management of cardiac arrhythmias.