[The effectiveness of radiofrequency ablation and repeated cardioversion in combination with antiarrhythmic drug therapy in maintaining stable sinus rhythm in patients with atrial fibrillation and heart failure].

Aim To compare the efficacy of radiofrequency ablation (RFA) and antiarrhythmic therapy (AAT) in patients with atrial fibrillation (AF) and chronic heart failure (CHF) during 12-month observation.Materials and methods This prospective, nonrandomized comparative observational study included 130 patients with AF (men, 65 %; mean age, 62.8±11.8 years) and CHF with left ventricular ejection fraction (LV EF) <50 %. Paroxysmal AF was observed in 60 (46 %) patients and persistent AF was observed in 70 (54 %) patients. According to results of transthoracic echocardiography (EchoCG) 107 (82 %) patients had intermediate LV EF (40-49 %) and 23 (18 %) patients had reduced LV EF (<40 %). RFA of AF was performed for 65 patients whereas 65 patients received an optimal AAT. The 24-h electrocardiogram monitoring, EchoCG, and assessment of the quality of life (QoL) with the SF-36 questionnaire were performed for all patients on admission and at 12 months of observation. Stability of sinus rhythm, EchoCG, QoL, and exercise tolerance were evaluated at 12 months of observation.Results 49 (75%) of patients in the RFA group and 26 (40%) of patients in the AAT group had stable sinus rhythm (SR) at 12 months. Repeated RFA for relapse of AF was performed for 6 (12 %) of 49 patients; repeated cardioversion was performed for 16 (61.5 %) of 26 patients. In the AAT group, there were more interventions for maintaining SR than in the RFA group (p<0.001). In patients with SR of the RFA group at 12 months of observation, LV EF was increased (р<0.001), left ventricular dimension (р<0.001) and volume (р<0.001) were decreased, and mental (р<0.001) and physical (p<0.001) components of health were improved according to the SF-36 questionnaire. In patients with SR of the AAT group, only improvement of mental (р<0.001) and physical (р<0.001) components of health was observed according to the SF-36 questionnaire.Conclusion RFA provided a considerable decrease in the frequency of AF relapse and improvement of LV EF in patients with CHF. The effectiveness of RFA did not depend on the type of arrhythmia. For 12 months of observation, the number of hospitalizations for decompensated CHF and interventions to maintain SR decreased in the RFA group compared to the AAT group.

[Dilated cardiomyopathy caused by p.E446K mutation in SCN5A gene].

Dilated cardiomyopathy (DCM) is myocardial disorder characterized by progressive heart chambers enlargement and impairment of myocardial contractility. This disorder is the most common cause of advanced heart failure requiring the heart transplantation. The prevalence of the disease is 36.5 per 100 000 in population. About 20-30% of cases are familial. Disease is genetically heterogenous, there more than 100 genes when mutated can give rise a DCM. In 2004, the role of SCN5A gene mutations was shown in origin of DCM with cardiac conduction defects and arrhythmias. In this work we present a clinical case of dilated cardiomyopathy with cardiac arrhythmias and p.E446K mutation in SCN5A gene. We have observed DCM with mild left ventricular hypertrophy, progressive AV block, atrial fibrillation and congenital heart defect (atrium septal defect) in two generations. The congenital heart defect did not co-segregate with SCN5A mutation and DCM.

[Cardiac resynchronization therapy in patients with narrow QRS].

Conduction delay affecting 30-50% of patients with NYHA class III-IV heart failure (HF) mainly results from left bundle branch block and leads to deterioration of cardiac contractility through intra- and interventricular dyssynchrony. Cardiac resynchronization therapy (CRT) has class I recommendation for the treatment of patients with severe systolic HF who have left ventricular ejection fraction less or equal to 35%, QRS duration greater than or equal to 120 ms. Nevertheless some studies have shown that systolic asynchrony is present in 27-43% of HF patients with narrow QRS complexes (defined as <120 ms). We present here results of CRT in 20 patients (13 male, 7 female). Main indication for CRT was ventricular dyssynchrony during basic cardiac rhythm or cardiac pacing independently of QRS width. In 4 patients width of QRS complex was less than 120 ms, in 3 QRS varied from 120 to 149 ms pts and in 13 it was equal to or exceeded 150 ms. CRT in patients with narrow QRS resulted in clinical improvement associated with increase of cardiac contractility and decrease of left ventricular end systolic volume. This allows to conclude that CRT can be beneficial for HF patients with narrow QRS and ventricular dyssynchrony.

[Nibentan in arresting acute atrial fibrillation: risk or benefit?].

AIM: To study efficacy and safety of using a domestic anti-arrhythmic drug nibentan for arresting acute atrial fibrillation. MATERIAL AND METHODS: A total of 210 patients received nibentan in a dose 0.125 mg/kg dissolved in 20.0 ml of 0.9% sodium chloride solution by intravenous slow jet 3-min injection. In no response, the injection was repeated 20 min later. Nibentan injection was accompanied with continuous ECG monitoring, measurements of QT interval, arterial pressure. The criterion of efficacy was atrial fibrillation conversion into the sinus rhythm within 24 hours after injection of a total nibentan dose. RESULTS: Nibentan in a dose 0.125 mg/kg demonstrated high efficacy (91.9%) and sufficient safety (incidence of polymorphic ventricular tachycardia 2.4%) including patients taking other antiarrhythmic drugs. A basic marker of an electrophysiological effect of nibentan on the myocardium is a dynamic change in the interval QT which may serve a predictor of sinus rhythm reestablishment (in QT > or =480 ms) and of a risk to develop proarrhythmogenic complications (in QT > or =640 ms).