Aim. The results presented, of subanalysis of the catheter ablation (CA) registry in atrial fibrillation (AF) with the patients properties, specifics of CA and treatment results, in Russia comparing to European countries. Material and methods. During 2012 to 2015, totally 3742 patients included to the registry, of those 477 in Russia. In 467 Russian patients (males 56,5%; mean age 58,5 y. o.) CA AF was done. During one year 392 patients were followed up. Minimum requirements to follow-up: routine ECG registration and non less than one contact after 12 months passed. Results. In Russian patients there were more common obesity (46,1% and 29,2%, pu003c0,001), hypertension heart disease (40,2% and 22,8%, pu003c0,0001), coronary heart disease (31,7% and 16,2%, pu003c0,0001), chronic heart failure (67,3% and 13,0%, pu003c0,0001). In Russia the patients more commonly underwent primary CA (83,5% in Russia and 77,6% in European countries, pu003c0,05), more rare in Russia the cryoballoon ablation was done (3% and 18%, pu003c0,05). Generally adverse events were reported more rare in Russia (10,5% and 16,6%, p=0,0007), including cardiovascular adverse events (2,6% and 5,2%, pu003c0,05). Tachiarrhythmias recurs were diagnosed more rare in Russia, including by the subsutaneous ECG monitors (17% and 1,6% in other countries, рu003c0,001). Within the year of follow-up, full absence of tachiarrhythmias recurs in Russia was found in 65,8% of patients, in other countries — in 74,7% (р=0,0003). Conclusion. In real clinical setting, high efficacy of CA AF was shown, resistant to antiarrhythmic therapy. In most of Russian patients there were cardiovascular comorbidities. There was lower rate of reported adverse events in Russian centers of interventional treatments.

To study the contribution of elimination of concealed conduction from pulmonary veins revealed with the aid of bolus administration of adenosine triphosphate to the effectiveness of radiofrequency catheter ablation (RFCA), 134 patients with paroxysmal and persistent atrial fibrillation (AF) and indications to RFCA were examined after the procedure. The patients were randomly distributed into two following groups: Group I (control group) where the concealed conduction was recorded but not subsequently eliminated (n=69) and Group II (n=65) where the concealed conduction was both registered and eliminated. No statistically significant difference in the clinical characteristics of the study group subjects was found. Most patients were men; three fourths of the study subjects had paroxysmal AF; in one fourth of the study subjects, typical atrial flutter was documented in addition to AF. The ablation catheter and circular 10 polar catheter were introduced into the left atrium via a transseptal access. Radiofrequency applications were made around the pulmonary vein antra in an irrigated regime until signs of the pulmonary vein isolation appear and the circular line closes. Later on, the patients were monitored for 30 minutes. In case of acute recurrence, additional radiofrequency applications were made in the “breach” area. After the period of monitoring, adenosine triphosphate tests were performed in all study subjects. If the concealed conduction in pulmonary veins was found, additional radiofrequency applications were made in transient “breach” areas in Group II until the negative test was reached, whereas in Group I the concealed conduction was left intact. The scheduled ECG Holter monitoring was performed in 3 and 6 months, as well as every 6 months thereafter. In all 134 cases, 268 ipsilateral pairs of pulmonary veins were isolated. The procedure duration was significantly longer in Group II (116±18 min and 130±16 min, respectively; p<0.0001). Nevertheless, the fluoroscopy time as well as the duration of radiofrequency applications did not significantly differ. The adenosine triphosphate test revealed concealed conduction in at least one ipsilateral pair of pulmonary veins in 31 of 134 subjects (23%). In total, the concealed conduction was found in 33 of 268 pairs (12%) of ipsilateral pulmonary veins. Within a three-year follow-up period, at least one sustained episode of AF or post-ablation tachycardia took place in 33 patients of Group I (48.8%) and 32 patients of Group II (49.2%), the difference was insignificant (log-rank test =0.084; p=0.77). Among 31 patients with the concealed treatment documented during the secondary adenosine triphosphate test, post-operation recurrence of arrhythmia occurred in 19 subjects (61%). At least one episode of AF or post-ablation tachycardia was found in 11 of 17 patients with concealed conduction in Group I (65%) and 8 of 14 patients with concealed conduction in Group II (57%). The difference in freedom of arrhythmia in patients with the concealed conduction in Group I and Group II did not reach the statistical significance (log-rank test =0.75; p=0.39). Thus, the elimination of concealed conduction revealed using the adenosine triphosphate test does not improve the late RFCA outcome.

A clinical case is given of assessment and treatment of a 62 year old female patient with paroxysmal atrialfibrillation, in whom, after the pulmonary vein isolation, activation mapping of localized re-entry triggering the atrial fibrillation activity was made; radiofrequency applications in this area terminated the arrhythmia.

To assess correlation between the portion (percentage) of the scar tissue in the left ventricle (LV) and the risk of ventricular arrhythmias in patients with coronary artery disease and implanted cardioverter-defibrillator (ICD), 49 patients (46 men and 3 women) aged 63±12 years were examined. Only patients with ischemic cardiomyopathy were included into the study (LV ejection fraction less than 45%). Prior to the ICD implantation, 48 patients underwent aorto-coronary bypass grafting or percutaneous coronary intervention. In all patients, prior to the ICD implantation performed were echocardiography and ECG analysis using the computational tables (method by R.H. Selvester et al. for assessment of the scar tissue area). The patients were distributed into two following groups: Group I included patients without the ICD activity (n=25) and Group II, patients with the episodes of ICD activation (n=24). The percentage of scar tissue was 17.3±8.8 ΰ /ο in Group I and 25.5±13.4 ΰ /ο in Group II (p=0.014). The QRS complex width did not statistically significantly differ in both groups (127.6±35.6 ms in Group I and 121.9±34.6 ms in Group II; p=0.58). It could be related to fact that the QRS widening in the patients with ischemic cardiomyopathy can be considered a predictor of death due to heart failure deterioration. A statistically significantly lower LV ejection fraction in the patients without episodes of ICD activity (Group I) is possible related to a greater number of patients with ICDs implanted for the primary sudden death prevention. Principal limitations of the current study were a small sample and the retrospective nature of the study. Thus, ECG assessment using the technique by R.H. Selvester et al. can be used for the risk stratification of ICD activity due to ventricular arrhythmias.

To assess acute recurrence and concealed conduction in the pulmonary vein (PV) antrum, 134 patients aged 56±8.6 years with paroxysmal and persistent atrial fibrillation (AF) with documented indications to radiofrequency ablation (RFA) were examined. During the operation, the anatomic map of the left atrium (LA) was constructed; radiofrequency applications were made on the perimeter of the PV antrums. Ipsilateral PVs were isolated as a single whole (en bloc). Upon isolating pulmonary veins, the “point of final isolation” (PFI) was marked. In case of development of acute recurrence in PVs, during the observational period (30 min), additional radiofrequency applications were made in the “break” area. After the observational period, the ATP test was carried out. In the case of recording of concealed conduction in PV, additional radiofrequency applications were made in the area of transitory “break”. The duration of the procedure was 123±18 min, of the X-ray exposure (fluoroscopy), 23±6.7 min. In all 134 cases, all PVs were isolated (268 ipsilateral couples). In the left antrum, PFI were located in the left atrium crest in more than in 50% of cases. In the right antrum, PFI were located on the posterior wall and were adjacent to the left atrium “roof’ in more than 60% of cases. In the observational period, acute recurrence was noted in 84 of 134 patients (63%), in total in 94 of 238 couples (35%) of ipsilateral PVs. During the ATP test, in 31 of 134 patients (23%), the concealed conduction into at least one ipsilateral vein was revealed, in total in 33 of 268 couples (12%). Thus, acute recurrence takes place in a considerable number of patients who receive RFA of AF. The location of acute recurrence and concealed conduction is inhomogeneous and is related to the peculiar features of RFA.

The article describes the data of efficiency of catheter ablation of substrate of ventricular arrhythmias, performed in patients with ischemic heart disease and implanted cardioverter- defibrillator (ICD) in order to decrease the number of ICD therapy. An assessment of the follow-up study of 32 patients was made, the catheter ablations were performed in 10 of them. The statistically reliable number of ICD therapy and at the same time both "shock" and antitachycardia pacing decreased in the group of catheter ablation.

A case report is given of a female patient with combination of arrhythmogenic cardiomyopathy of the right ventricle and the long QT interval syndrome, in whom development of live-threatening arrhythmias was related to phase of menstrual cycle.

A case report is given of an altered inter-ventricular conduction at the site of the electrode implantation as well as corresponding peculiar features ofprogramming of a dual chamber pacemaker in a patient with persistent left superior vena cava are presented.

The results of examination and treatment are given for a 58 year old patient with persistent atrial fibrillation, in whom the successful re-operation because of early recurrence of therapy-resistant arrhythmia was performed 5 weeks after the initial procedure.

The case report data are provided regarding examination and treatment including the radiofrequency catheter ablation and the cardiac pacemaker implantation in a female patient with paroxysmal ventricular tachycardia caused by re-entry in the His bundle branches.

A case report is provided of the high frequency catheter destruction of the typical atrial flutter persisting for a long period time in a male patient with the ischemic cardiomyopathy, complete left bundle branch block, and severe chronic heart failure; the analysis of potential treatment strategies was made.

Three case reports are considered of revelation of an accessory left superior vena cava in the course of permanent endocardial pacing and catheter procedures with catheterization of the coronary sinus through the left subclavian vein.

A case report is presented of change in the sequence of the left atrium retrograde activation during orthodromic atrioventricular tachycardia with participation of the left accessory atrioventricular pathway during radiofrequency ablation of the accessory atrioventricular pathway due to a partial and subsequently complete block in “mitral isthmus.

A case report is given of the successful radiofrequency catheter modification of atrioventricular junction due to typical paroxysmal re-entry atrioventricular nodal tachycardia in a female patient with congenital malformation of veins: occlusion of inferior vena cava.