To assess the effectiveness of cardioresynchronizing treatment and incidence of ventricular arrhythmias in patients with heart failure refractory to medical treatment (functional classes III IV according to NYHA classification) and ventricular dyssynchronism, 35 patients (11 females and 24 males) aged 42 68 years (mean 58.3±14.4 years) with coronary artery disease and dilated cardiomyopathy were followed up.

To study in detail the histological structure of the postero superior part of interatrial septum (IAS) including of the oval fossa valve as well as peculiar features of local conduction in this area, examined were 10 patients aged 46 59 years (mean 53.1±3.3 years) with paroxysmal atrial fibrillation and 5 subjects with accessory left side atrio ventricular pathways without history of atrial fibrillation aged 17 36 years (mean 31.2±6.3 years); in addition, 45 hearts of patients deceased in the age of 23 81 years were studied.

To assess the antiarrythmic effect of pre infarction angina and its interrelations with the technique of myocardial reperfusion, Holter monitoring was performed in 75 patients aged 57.9±1.5 years (50 males, 25 females) within the first day of myocardial infarction.

To assess the patterns of cardiac arrhythmias in patients with mitral insufficiency before and after its surgical correction with use of different techniques, the analysis of outcomes of surgical treatment was made in 83 patients with primary and secondary mitral valve prolapse, in whom valvuloplasty or mitral valve replacement were performed.

To study the effectiveness of therapeutic training of patients with atrial fibrillation, training sessions consisting of 3 lessons of duration of no more than 60 minutes were delivered to 40 patients with atrial fibrillation aged 62.1±10.2 years (25 females, 15 males) with chronic (22 patients), persistent and paroxysmal atrial fibrillation (18 patients).

To assess the potentiality of use of cardioversion for treatment of permanent forms of supraventricular tachycardias, 12 pediatric patients aged from 2 days to 3 years including 7 neonates were examined. Atrial tachycardia was found in 6 ones of them, atrial flutter, in 5 patients, and one patient had atrioventricular nodal re entry tachycardia.

To stratify the risk of cardiovascular death in patients with permanent atrial fibrillation, 225 patients aged 69.5±0.6 years predominantly with coronary artery disease (191 patients, 90.1%) and not receiving anticoagulants were studied.

To improve the diagnostic value of tilt test of differential diagnosis of neurogenic and orthostatic syncope with the aid of the rhythmogram evaluation by the methods of nonlinear dynamics, 56 subjects with syncope including 23 ones with neurogenic syncope aged 31±11 years (5 males, 18 females), 15 patients with orthostatic hypotension aged 56±18 years (5 males, 10 females), and 18 healthy subjects aged 40±15 years (6 males, 12 females) were studied.

To assess the symptoms, the data of electrophysiological study, echocardiography, as well as functional tests in pediatric patients with I degree atrioventricular block, 103 patients aged 1.6 17.3 years (mean 12.6±3.7 years; 41 males and 62 females) were studied and subsequently followed up for 4.4±2.5 years.

To compare the effectiveness and mechanisms of action of the lipophilic β adrenoblocker Propranolol and the hydrophilic β adrenoblocker Sotalol in the case of ventricular arrhythmias and ventricular fibrillation caused by occlusion of the left descending coronary artery, the experiment was performed on urethan anesthetized mongrel rats of body mass of 150 250 g under artificial pulmonary ventilation.

The peculiar features are considered of acquired long QT interval syndrome developed at the background of psychopharmacological medical treatment.

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".