[Approximation of mathematical scanning simulation data and clinical results f radiofrequency ablation of perimitral atrial flutter. Condition of existence of perimitral atrial flutter].

AIM: 1) to create Perimitral Atrial Flutter (PMAFL) model and estimate theoretical probability of elimination of perimital reetntry using left atrial geometry two-dimensional mathematical modeling and ablative formatting; 2) to compare clinical results of PMAFL ablation by means of mitral vs inferioseptal isthmus ablation and mathematical modeling data. MATERIAL AND METHODS: Clinical phase. Study was conducted on 24 pts (6 women, 57.1 ± 9.3 years) with PMAFL. Initially RF-lesions delivered in LA in the MI (endocardial approach to MI). Distal CS roof ablation (epicardial approach to MI) was a second step. As a third step linear RF-lessions of the inferioseptal isthmus (ISI)- from right pulmonary vein ostium to mitral annulus was performed (endocardial approach to ISI). As a fourth step RF-applications applied inside the proximal CS roof (epicardial approach to ISI). Mathematical phase. As the first step numeric reconstruction of the autowave process in excitable tissues of the left atrium was performed. Fitzhugh-Nagumo equation was used for simulation to enabled us to take into account the electrical inhomogeneity of the atria (pulmonary vein ostia). A special scanning method was used for calculating characteristics of autowave processes in a two-dimensional mathematical model of the atrium. As the second step simulation of linear ablation formatting which linked PV ostia and active medium boundaries (corresponding to mitral and inferioseptal isthmus ablation lines) was performed. RESULTS: Clinical phase. Left MI endocardial RFA terminated PMAFL in 6 cases, increased CL without changes of atrial hierarchy activation in 2 cases, and transformed PMAFL to AFib in 2 cases. Distal CS ablation terminated PMAFL in 2 pts. Endocardial ISI ablation of associated with SR restoration in 2 cases and increasing of PMAFL CL in 5 cases. Proximal CS-roof ablation terminated PMAFL in 12 pts. Follow up was 26.7 ± 12.4 mos. Endocardial and epicardial MI approach terminated PMAFL in 8 pts (36%). RFA of endocardial 39nd epicardial aspects of the ISI restored SR in 12 pts (64%) (p< 0.05). MATHEMATICAL PHASE: There are three definite conditions of PMAFL existing: 1) Initial autowave spreading between superior PV and boundary of medium (corresponding to patent conduction between superior PV ostia and mitral annulus); 2) Non-active medium existing between four PV ostia (corresponding to PV isolation after index ablation); 3) Refractory characteristics of medium (corresponding to posterior wall of LA) and medium between PV ostia and boundaries (corresponding to isthmus zones) have to differ each other. The linear ablation patterns (from PV ostia to boundary of medium) suppress PAMFL in two-dimensional mathematical modeling of the left atrium. CONCLUSION: There are definite conditions of PAMFL simulation by means autowave processing in a 2-D active medium using scanning algorithm. Those conditions may consistent with certain EP characteristics of LA after index ablation clinical results of PAMFL ablation.

[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.

[Comparison of effectiveness of radiofrequency catheter ablation of left arterial isthmuses for treatment of postablational perimitral atrial flutter].

AIM: To compare results of radiofrequency (RF) ablation (A) of mitral and inferior septal isthmuses in the left atrium for the treatment of perimitral atrial flutter (AF) in patients with atrial fibrillation previously subjected to RF isolation of pulmonary veins and modification of the left atrial anatomical arrhythmia substrate. MATERIAL AND METHODS: We treated 20 patients (3 women, mean age 57.1+/-9.3 years) with recurrent postablational perimitral AF verified by 3-dimensional reconstruction of left and right atrial activation by nonfluoroscopic mapping and pacing techniques of entrainment into tachycardia cycle. At first stage RFA was carried out in the region of mitral isthmus (its endocardial parts). At second stage RFA was performed in the region of coronary sinus (CS) roof (epicardial portions of the mitral isthmus). At the third stage RFA influences were applied in the region of inferior septal isthmus (endocardial portions of the inferioseptal isthmus). At the fourth stage RFA was applied in the region of roof of proximal CS (epicardial portions of inferioseptal isthmus). RESULTS: Application of RF influences to endocardial parts of the mitral isthmus resulted in sinus rhythm (SR) restoration in 6 cases. Change of length of the tachycardia cycle was noted in 5cases. SR restoration was observed after RFA in the region of the roof of distal CS in 3 cases and change of length of the tachycardia cycle was noted in 2 more cases. RFA of epicardial parts of the inferioseptal isthmus resulted in SR restoration in 3 cases and in increase of atypical AF cycle length in 6 cases. In 12 cases SR was restored during RFA application in the region of the roof of proximal CS parts. RF influences in the region of endocardial (stage 1) and epicardial (stage 2) parts of the mitral isthmus resulted in SR restoration in 9 cases while continuation of RFA in the region of endocardial (stage 3) and epicardial (stage 4) parts of the inferioseptal isthmus led to SR restoration in the remaining 15 cases (p<0.05). CONCLUSION: RFA of endocardial and epicardial parts of the inferioseptal isthmus significantly more often led to termination of perimitral atypical AF in patients previously operated because of atrial fibrillation.

[Comparison of the effectiveness of pulmonary veins isolation vs linear radiofrequency ablation in paroxysmal atrial fibrillation patients using either mathematical scanning or clinical approach].

AIM: to compare clinical results of linear ablation vs. PVI approach in patients with paroxysmal AF and to estimate theoretical probability of 4-waves re-entry to eliminate as a results of the both ablative techniques formatting by means left atrial geometry two-dimensional mathematical modeling. MATERIAL AND METHODS: Clinical phase. Study was conducted on 20 pts (6 women, 51,4±13,6 years of age) with paroxysmal AF underwent index RFA. All pts were divided into two age-sex-arrhythmia history duration-antiarrhythmic drugs (AAD)-matched groups. The first group consisted of 10 pts (3 women, mean age - 51,1±11,9, history of arrhythmia - 3,2±1,2 years) in whom ablation strategy consisted of PVI using LASSO technique. The second group concluded of 10 pts (3 women, mean age - 51,1±12,9, history of arrhythmia- 3,1±1,1 years) in whom ablation strategy consisted of wide-area circumferential lines application around pulmonary veins, combined to roof line and mitral isthmus RFA using three-dimensional mapping system. Mathematical phase. As the first step numeric reconstruction of the autowave process in excitable tissues of the left atrium and the simulation of AF was performed. Fitzhugh-Nagumo equation was used for simulation to enabled us to take into account the electrical inhomogeneity of the atria (pulmonary vein ostia). A special scanning method was used for calculating characteristics of autowave processes in a two-dimensional mathematical model of the atrium. As the second step simulation of circular (corresponding to LASSO approach) and linear ablation (corresponding to 3D approach) was performed. RESULTS: Clinical phase. There were no complications associated with RFA. 7 pts of the first group vs 4 pts of the second subgroup had early recurrences of arrhythmia. AAD free sinus rhythm incidence in the first/second groups was 80%/20% at 12 months respectively (p=0,003). Mathematical phase. While circular LASSO-like ablation pattern was used, there was no elimination of 4-waves re-entry turning around the pulmonary veins ostia and vortex waves caused by them in a distributed two-dimensional atrial medium after time period equal to the re-entry period. Thus, the circular ablation formatting does not affect peripulmonary veins re-entry and, therefore, does not suppress AF. In contrast, linear ablation patterns suppress arrhythmias caused by 4-waves re-entry in two-dimensional mathematical modeling of the left atrium. CONCLUSION: Mathematical approach using linear ablation to simulate suppressed 4-waves re-entry more effectively comparing to PVI only. Clinical results are consistent with ablation formatting data obtained by means of 4-waves re-entry simulation in a two-dimensional mathematical modeling of the left atrium.

[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.

[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.

[Antitachycardia pacing in patients with implanted cardioverter defibrillators].

Efficacy and safety of the use of antitachycardia pacing (ATP) function in 54 patients (age 18-54, mean age 62.2 +/- 11.5 years, 6 women) with cardioverter defibrillators implanted for prevention of sudden death. Duration of follow-up was 6-64 months (mean 27.3 +/- 8.6 months). Ischemic heart disease (IHD) was etiopathogenetic basis for development of ventricular rhythm disturbances in 38 (70.4%) patients. Arrhythmogenic right ventricular dysplasia (ARVD) was diagnosed in 8 (14.8%), hypertrophic cardiomyopathy--in 3, dilated cardiomyopathy--in 2, the Brugada syndrome--in 2 patients, and long QT syndrome--in 1 patient. Three regimens of ATP were studied--burst, ramp, ramp(+)--which were activated in 22 patients (17 with IHD and 5 with ARVD). We registered 776 episodes of ATP occurring because of ventricular tachycardia (VT) in 20 of 22 patients with activated ATP. Overall efficacy of burst ATP was 49.1%; VT was not terminated or was accelerated in 43.2 and 7.6% of cases, respectively. Ramp ATP was effective in 44.3, ineffective--in 33.9, and caused VT acceleration in 21.8% of cases, what called forth fulfillment as a next step of shock therapy (cardioversion or defibrillation). ATP led to successful termination of VT in 67.5% of patients with IHD and to acceleration of arrhythmia--in 6% of episodes. Most effective type was ramp ATP which effectively terminated VT in 76.3% of cases, while efficacy of burst ATP was 61.4% (p < 0.01). In patients with ARVD total efficacy of ATP was 25%, acceleration of VT during ATP was observed in 24% of cases; optimal was burst ATP, which efficacy was 33.9%--significantly higher than efficacy of ramp and ramp+ ATP (19.4 and 24.4%, respectively, p < 0.005).

[Parameters of central hemodynamics in patients with paroxysmal atrioventricular nodal reciprocal tachycardia before and after radiofrequency catheter ablation].

We present in this article results of assessment of morphofunctional state of the myocardium in patients with typical form of paroxysmal atrioventricular nodal reciprocal tachycardia (AVNRT) before and during one year after radiofrequency catheter ablation of slow part of atrioventricular junction and their comparison with analogous parameters of control group. Participants of this study (n=81) were divided into 2 groups: main (study group) and control group. Main group comprised 61 (75.3%) patients with AVNRT in variant of typical course, mean age 45.3+/-15.1 years. All patients of study group were subjected to endocardial electrophysiological investigation and radiofrequency ablation (RFA) - modification of slow part of atrioventricular junction. Control group comprised 20 practically healthy persons aged 41.9+/-5.3 years in whom no structural pathology of cardiovascular system was found. Transthoracic echocardiography (EchoCG) was carried out before and in 2, 6, and 12 months after operation in patients of main group and once in control group. Analysis of parameters of central hemodynamics studied with the Echo method in patients of main group before and in 2, 6, 12 months after RFA demonstrated that before conduct of surgical intervention there were no significant differences between the parameters studied and analogous characteristics of the control group. It was established in the course of dynamic observation of patients of the study group that in 2, 6 and 12 months after RFA the studied parameters of central hemodynamics did not undergo substantial changes compared with initial values. According to EchoCG data so called minor anomalies of development of cardiac connective tissue were diagnosed in 28 cases (45%) among patients of study group and in 2 cases (10%) in control group.

[Atrioventricular nodal reciprocal tachycardia: classification, clinical manifestations, diagnosis, and treatment].

Data on prevalence, mechanisms of arrhythmogenesis and classification of atrioventricular (AV) nodal reciprocal tachycardia are presented. Clinical-electrocardiographical and electrophysiological features of typical and atypical forms of AV nodal reciprocal tachycardia are described. Main diagnostic measures are delineated and principles of tactical approach to management of patients with AV nodal reciprocal tachycardia presented. Indications to radiofrequency catheter ablation, and physical characteristics of radiofrequency interventions in the region of registration of AV junction slow part fibers potentials of lower isthmus of the right atrium are discussed. Data of analysis of comparative efficacy of pharmacological and interventional approaches to management of patients with AV nodal reciprocal tachycardia as well as spectrum of possible complications associated with surgery are also presented.

[Remote clinical results of treatment of atrioventricular nodal reciprocated with the use of novel and traditional methods of radiofrequency catheter ablation of slow part pathway of atrioventricular junction].

Remote results of radiofrequency catheter ablation (RFCA) - modification of "slow" part pathway of atrioventricular junction (AVJ) in patients with typical form of atrioventricular nodal reciprocal reciprocated tachycardia (AVNRT), carried out on the basis bi and monopolar recording of electrical activity of fibers of slow" part pathway of AVJ. Study participants were 104 patients (44 women) aged 21-86 years with typical form of AVNRT who had been subjected to primary RFCA procedure - modification of slow part pathway of AVJ. In group 1 (n=51) RCA RFCA was conducted on the basis of simultaneous monoand bipolar endocardial registration recording of new potential of "slow" part pathway of AVJ. In group 2 (n=53) RCA RFCA was done on the basis of bipolar registration of traditional potentials of "slow" part pathway of AVJ. Total period of follow up of patients was 32+/-11 months. According to data of control visits 1, 3, 6, 12, and 24 months after RCA RFCA for AVNRT based on collection of anamnesis, physical examination, registration of electrocardiogram and Holter monitoring none of the patients had recurrences of AVNRT in indicated periods of follow up. Method of mapping of fibers of "slow" part pathway of AVJ based on redislocation of destructive electrode in the zone of novel potential located at significant distance from compact part of AVJ differs from common approach and allows to carry out catheter RCA RFCA with minimal risk of impairment of atrioventricular conduction. Long term results of radiofrequency modification of "slow" part pathway of AVJ performed on the basis of registration recording of novel potential are comparable with results of traditional RCA RFCA technique in patients with AVNRT.

[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.

[Comparison of transthoracic, transesophageal, and intracardiac echocardiography sensitivity for guiding transseptal puncture during radiofrequency ablation in the left atrium].

The paper contains comparison of sensitivity and rates of false negative results of transthoracic (TT), transesophageal (TE), and intracardiac (IC) echocardiography (echoCG) during transseptal puncture in the run of the procedure of radiofrequency ablation of atrial fibrillation. In the work fulfilled we analyzed results of 208 echocardiographical intraprocedural investigations conducted with the aim of visualization of interatrial septum (IAS) during transseptal puncture. TT, TE and IC echoCG were carried out in 32, 26, and 150 cases, respectively. Phenomenon of IAS stretching was visualized by TT echoCG in 2 (6%) cases (sensitivity 6.7%). At TE tenting phenomenon was verified in 20 patients (20%) (sensitivity 86.9%). Puncture of IAS was carried out under IC echoCG control in 127 patients. Puncture was made in the center of thin portion of IAS (in the region of fossa ovalis), in its upper and lower portions in 65, 28, and 15.7% of cases, respectively. Sensitivity of IC echoCG was 98.4%. Rate of false positive results reached 92.8, 13.04 and 1.5% for TT, TE and IC echoCG, respectively. At present IC echoCG is most sensitive and safe ultrasound technique for verification of optimal positioning of the system for conduct of transseptal puncture in the region of IAS in comparison with TT and TE echoCG.

[Wolff--Parkinson--White syndrome: classification, clinical manifestations, diagnosis, and treatment].

Main etiological factors, mechanisms of arrhythmogenesis, and classification of Wolff-Parkinson-White (WPW) syndrome are presented and clinico-electrocardiographical and electrophysiological peculiarities of atrioventricular reciprocal tachycardia in this syndrome are described. Main diagnostic measures, principles of their correct interpretation are specified and principles of tactical approach to management of patients are presented. Indications to electrophysiological investigation and radiofrequency catheter ablation, physical characteristics of radiofrequency action in regions of optimal mapping of supplementary atrioventricular junction are discussed. Data of analysis of efficacy of pharmacological and interventional approaches to the treatment of patients with WPW syndrome are also presented.

[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.

[Echocardiographic evaluation in patients with idiopathic ventricular arrhythmias originating from right ventricular outflow tract before and one year after radiofrequency catheter ablation].

PURPOSE: To estimate echocardiographic measurements in patients with idiopathic ventricular arrhythmias originating from right ventricular outflow tract (RVOT) before and one year after radiofrequency ablation (RFA) comparing with healthy volunteers. MATERIALS AND METHODS: The study consisted of 30 patients (7 women, 34.9+/-15.2 years of age) with predominantly repetitive monomorphic ventricular ectopy and nonsustained ventricular tachycardias. Arrhythmia history was 4.6+/-3.5 years. The control group consisted of 20 healthy unselected subjects (5 women, 41.9+/-5.3 years of age) without left ventricular (LV) dysfunction. All consecutive patients with idiopathic ventricular arrhythmias underwent electrophysiology study and RFA. Transthoracic echocardiography was performed before, 2, 6 and 12 months after RFA. RESULTS: Significantly higher LV end diastolic volume and lower LV ejection fraction were observed in study group patients to compare with control group patients. LV function significantly improved in postablative patients during 1 year follow up. There were no found complications associated with RFA. CONCLUSIONS: Idiopathic ventricular arrhythmias originating from right ventricular outflow tract (RVOT) could be a cause of arrhythmogenic LV remodeling. Successful ablation of the focal source of right ventricular ectopy resulted in normalization of LV function during follow up period.

[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.

[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.

[Clinical efficacy of permanent cardiac pacing in patients with bradysystolic forms of disturbances of cardiac rhythm and conduction].

From 1996 to 2002 primary implantations of pacing systems because of bradysystolic disturbances of cardiac rhythm and conduction had been carried out in 311 patients. Indications were disturbances of atrioventricular conduction in 168 and sick sinus syndrome in 143 patients. According to type of permanent pacing patients were divided into 3 groups: with single-chamber ventricular on demand pacing (VVI, n=215), with single-chamber atrial pacing (AAI, n=39), and with dual-chamber pacing (DDD, n=57). As characteristics illustrating long term clinical results of permanent pacing we used development of the pacemaker syndrome; development of permanent atrial fibrillation; risk of thromboembolic complications and strokes; progression of heart failure; total, cardiovascular mortality and their structure; 7 year survival.