[Potential risk factors of atrial fibrillation recurrence after cryoballoon ablation].

Aim      To identify risk factors for recurrence of atrial fibrillation (AF) following cryoballoon ablation (CBA).Material and methods  This prospective study included patients with paroxysmal AF who had undergone CBA (141 patients, median age 60 years, 3% men). The evaluation prior to CBA included clinical instrumental parameters (electrocardiography (ECG), 24-h ECG monitoring, echocardiography, contrast-enhanced cardiac multispiral computed tomography). Also, possible intraoperative indexes that could affect the CBA effectivity, were evaluated. The postoperative follow-up duration was 12 months. Effectivity was assessed during in-person visits at 3, 6, and 12 months, when questioning of patients and 24-h ECG monitoring were performed. CBA was considered ineffective if the patient had recurrences of any atrial tachyarrhythmia longer than 30 sec after the end of the 3-month "blind" period.Results During the 12-month follow-up, recurrences of atrial tachyarrhythmia were observed in 46 (32.6 %) patients. Patients with ineffective CBA more frequently had AF during the first 3 months (71.7 % vs. 11.6 %; р<0.001). Such patients had a history of multiple ineffective treatments with antiarrhythmic drugs (AAD), common pulmonary venous (PV) collector (41.3 % vs. 20.0 %; р=0.008), and stroke/recurrent ischemic attacks (15.2 % vs. 5.2 %; р=0.047). Multifactorial regression analysis showed that the factors of AF recurrence included common PV collector (relative risk (RR) 2.35; 95 % confidence interval (CI) 1.29-4.25; р=0.005), multiple ineffective AADs (RR 1.42; 95 % CI 1.08-1.86; р=0.011), and early AF recurrence (RR 7.57; 95 % CI 3.84-14.90; р<0.001).Conclusion      Common PV collector and multiple ineffective AADs are risk factors of ineffective CBA. Early recurrences during the first 3 postoperative months are a significant risk factor of long-term AF recurrences.

[Comparative efficacy and safety of enoxaparin followed by warfarin and rivaroxaban monotherapy in the treatment of venous thrombosis in patients after intracardiac catheter interventions].

AIM: to compare two anticoagulant therapy (ACT) regimens in the treatment of venous thrombosis (VT) in patients after catheter interventions - electrophysiological studies (EFIs) and ablations: enoxaparin followed by warfarin, and rivaroxaban monotherapy. MATERIALS AND METHODS: The study included patients from 18 years and older with heart rhythm disorders and planned catheter ablation. When parietal venous thrombosis (VT) were detected at the femoral vein puncture site, all patients were randomly assigned to two treatment groups. In group I enoxaparin 1 mg/kg was prescribed every 12 hours with switching to warfarin after 7 days with maintenance of the target INR values (2.0-3.0). In group II rivaroxaban therapy was started at a dose of 15 mg twise/day for 21 days with a further transition to a dose of 20 mg/day. The total period of observation and treatment of patients was at least 3 months. RESULTS: 408 patients were observed, 42 (10.3%) patients with parietal VT were divided into two treatment groups. In group I (n=16) complete lysis of VT was noted by the 7th day of treatment in 7 (58.3%) patients, however this scheme was associated with a greater risk of complications (р=0.003) at the puncture site in the form of arteriovenous fistulae (n=1; 8.3%) and intermuscular hematomas (n=4; 25%). In group II (n=26), no complications were noted, the lysis time of VT was on average 21 days (n=18; 69.2%). Complete lysis of VT was noted in both groups at the time of the control observation point (3rd month). CONCLUSION: The efficiency of the two VT treatment regimens was comparable. Enoxaparin therapy is associated with a high risk of local complications, namely intermuscular hematomas (n=4; 25%) and arteriovenous fistulas (n=1; 8.3%). Rivaroxaban monotherapy is safer (p=0.003); in Group II none of the patients had any complications.

[Recent advances in diagnosis and management of atrial fibrillation].

Alterations of heart rhythm are a common clinical event. They can be caused by almost any kind of heart disorder. Atrial fibrillation (AF) is the most common type of abnormal heart rhythm. Prevalence of AF in the general population is 1-2%, and given that AF incidence rate continues to increase it can be predicted that the number of patients will be doubled within the next 50 years. This review provides the most recent diagnostic and treatment methods, including both unique domestic antiarrhythmic drugs and non - drug methods for AF treatment which were developed and implemented in clinical practice at NMRC of Cardiology of the Ministry of Health of the Russian Federation.

[Refralon (niferidil) is a new class III antiarrhythmic agent for pharmacological cardioversion for persistent atrial fibrillation and atrial flutter].

AIM: To evaluate the efficacy and safety of refralon (niferidil), a new class III antiarrhythmic agent whose activity is related to the block of delayed rectifying potassium current and to the prolongation of atrial and ventricular action potential and refractory periods, when it is used as an agent for pharmacological cardioversion for atrial fibrillation (AF) and atrial flutter (AFL). SUBJECTS AND METHODS: The efficacy of the drug as 3 intravenous boluses of 10 µg/kg was evaluated in 134 patients (90 men; 57.8 ± 11 years) with a mean AF duration of 3 (1.5; 6) months. Its effect was controlled by 24-hour Holter ECG monitoring. The criterion for its antiarrhythmic effect was 24-hour sinus rhythm (SR) recovery. RESULTS: Niferidil restored SR in 47.7% of the patients with AF after administration of bolus 1, in 62% after bolus 2, and in 84.6% after bolus 3. SR was restored in all 100% patients with AFL. With the AF duration of less than 3 months, the efficacy of niferidil was 91.8%. There was nonsustained polymorphic ventricular tachycardia (VT) (torsade de pointes) in 1 (0.7%) patient and nonsustained monomorphic VT was stated in 5 (3.7%) patients. CONCLUSION> Pharmacological cardioversion with niferidil for persistent AF and VT may be regarded as a possible alternative to electrical cardioversion.

[Effect of radio frequency catheter ablation on spectral parameters of heart rate variability in patients with paroxysmal supraventricular tachyarrhythmias]. / Vliianie radiochastotnoi kateternoi ablatsii na spektral'nye pokazateli variabel'nosti ritma serdtsa u bol'nykh s paroksizmal'nymi nadzheludochkovymi takhiaritmiiami.

AIM: To assess effect of radio frequency catheter ablation (RFCA) on heart rate variability (HRV) in patients with supraventricular tachyarrhythmias (SVT). METHODS: Spectral analysis of HRV on 5-minute ECG strips was carried out in 19 patients with SVT before and 2 days after RFCA. RESULTS: Both total and high frequency power significantly decreased (p<0,05) after RFCA in supine and orthostatic positions. Significant decrease of low frequency power occurred after RFCA in orthostatic position. CONCLUSION: In patients with SVT RFCA alters autonomic regulation of chronotropic function of the heart. Sympathetic and parasympathetic influences on the chronotropic function of the heart are attenuated in early period after the procedure.