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Biomedical subjects

S F Sokolov

Publications and source records attributed to S F Sokolov.

At least 19 recordsLinked to original sources
PubMed1992

Pharmacology and clinical use of a new group of antiarrhythmic drugs: derivatives of tricyclic nitrogen-containing systems.

This paper is concerned with a new group of antiarrhythmic drugs: derivatives of phenothiazine and dibenzazepine which belong to tricyclic nitrogen-containing systems. It has been discovered that the transition from omega-aminoalkyl to omega-aminoacyl phenothiazine derivatives results in a decrease in psychotropic activity and an increase in cardiovascular, particularly antiarrhythmic, action. Based on structural and antiarrhythmic activity studies, the new and effective drugs ethmozine, ethacizine and bonnecor have been selected and extensively studied. Data on spectra and mechanisms of their action, obtained in different arrhythmia models, have been confirmed by clinical studies. Correlation between pharmacological properties and electrophysiological mechanisms, and differences in action of the drugs studied on brain and heart plasma membrane receptors may serve as a starting point for the further directed search for new antiarrhythmic drugs among tricyclic nitrogen-containing structures.

Animals↗
PubMed1992

[Anti-arrhythmic therapy of patients with recurrent ventricular tachycardias after prior myocardial infarction].

An examination of 30 patients with paroxysmal ventricular tachycardias following prior myocardial infarction showed that drug tests by using invasive and noninvasive monitoring of the action of antiarrhythmic agents allowed beneficial pharmacotherapy to be chosen for their long-term use in 20% of this category of patients. The remaining 80% were resistant to antiarrhythmic drug therapy, which was associated with the highly unfavourable prognosis confirmed by 50% mortality on a 2-year follow-up. Open heart surgeries were performed in 3 cases refractory to antiarrhythmic therapy. The operations aimed at liquidating the source of tachycardia produced a full antiarrhythmic effect. The application of this method for treating patients with postinfarction cardiosclerosis is limited by severe organic heart lesion that determines the high risk of operative mortality. This makes it necessary to intensively develop other methods of non-drug therapy providing less surgical intervention and to introduce them into practice.

Adult↗
PubMed1991

[Etatsizin efficacy in patients with ventricular tachycardias. The results of intracardiac electrophysiological research].

As many as 30 patients with different pathologies of the cardiovascular system and paroxysms of ventricular tachycardias were examined. According to the ultrasonography data, an ejection fraction was not lower than 35% in all the patients. It has been shown by electrophysiological studies that intravenous injection of ethacizine in a dose of 0.6 +/- 0.1 mg/kg prevented induction of ventricular tachycardia in 66.7% of patients. In 16.7% of patients, the drug exerted an arrhythmogenic effect that showed up by a decrease of the cycle of tachycardia. Oral administration of ethacizine in the daily dose 100 or 150 mg prevented tachycardia induction by endocardial stimulation in 20.8% of patients. The arrhythmogenic effect of the drug was recorded in 12.5% of patients. The action of ethacizine when administered by both routes was accompanied by a significant elongation of the P--Q interval, QRS complex and of the cycle of ventricular tachycardia. Continuous administration of ethacizine in the daily dose 150 mg to patients with a positive antiarrhythmic drug action (according to the electrophysiological data) prevented paroxysms of ventricular tachycardia, with the observation period being 2 to 6.5 years.

Adolescent↗
PubMed1991

[The diagnosis and possibilities for the anti-arrhythmia treatment of malignant ventricular disorders of the heart rhythm].

Altogether 130 patients with malignant ventricular disorders of cardiac rhythm were examined to demonstrate a possibility of obtaining the diagnostically significant data with the aid of Holter's monitoring of the ECG in 89.2%, with the aid of bicycle ergometry exercise tests in 72.3%, and by means of an electrophysiological examination of the heart in 82.5% of the above-indicated group of patients. The drug testing with the use of invasive and noninvasive techniques of monitoring the action of antiarrhythmic drugs given per os makes it possible to choose effective therapy on an individual basis. The long-term use of such therapy may prevent ventricular tachycardia relapses and noticeably enhance the patients' survival. Severe organic pathology of the heart associated with a decrease of its pump function seen in the majority of patients with malignant ventricular disorders of cardiac rhythm refractory to pharmacotherapy restricts, in a considerable number of cases, the potentialities of drastic surgical treatment because of the risk of operative death. To improve the disease prognosis of these patients, it is necessary that other methods of nonmedicamentous treatment may be used, requiring a less scope of surgical intervention, such as implantation of a cardioverter-defibrillator.

Adolescent↗
PubMed1991

[Electrophysiological mechanisms of the effect of allapinin in patients with paroxysmal supraventricular tachycardia].

An intracardiac electrophysiological study was undertaken to examine 15 patients with paroxysmal supraventricular tachycardias. Allapinin intravenously given in a dose of 0.4 mg/kg, was tested for effects. The agent was demonstrated to cause a substantial inhibition of rapid retrograde pathway function in atrioventricular nodal tachycardia and abnormal antero- and retrograde pathway function. This is the major aspect of the drug's action that prevents the development of episodes of paroxysmal supraventricular tachycardias. The agent fails to virtually affect the function of the atrioventricular node in the anterograde direction in the two types of the tachycardia. Thus, allapinin has the mechanism of action that is typical of quinidine-like drugs used in supraventricular tachycardias.

Aconitine↗
PubMed1990

[Comparative study of the effects of verapamil, ethmozin and ethacizine on provoked attacks of atrioventricular nodal reciprocal tachycardia].

27 patients underwent serial electrophysiological studies by using transesophageal atrial stimulation. A-V nodal reciprocal tachycardia was documented by intracardiac electrophysiological examinations. Sustained tachycardia was induced in all the patients before drug administration. On day 4 after oral verapamil, 320 mg/day, ethmosine, 800 mg/day, and ethacizine, 150 mg/day, the patients were subjected to transesophageal atrial stimulation. An antiarrhythmic effect was regarded to be reached if the authors failed to induced sustained tachycardias again. Verapamil, ethmosine, and ethacizine were found to be beneficial in 21 (78%), 13 (48%) and 21 (78%) patients, respectively. A comparative analysis demonstrated that ethacisine was not inferior to verapamil, but ethmosine produced less effects than verapamil and ethacizine. The crossover and individual efficacy shown by each drug suggests that it is necessary to use the technique of serial testing and to choose beneficial drugs from a possibly wide range of medicaments for each patient.

Adult↗
PubMed1990

[Effect of a new anti-arrhythmia drug allapinin on hemodynamics in patients with a persistent form of atrial fibrillation before and after restoration of sinus rhythm].

Echocardiographic study was performed in 24 patients with persistent atrial fibrillation (PAF) without clinical signs of circulatory failure. When treated with allapinin , all the patients with PAF showed a significant increase in heart rate (HR) and cardiac output (CO) and a decrease in total peripheral vascular resistance (TPVR). No substantial changes in the major hemodynamic parameters were found in patients with higher left ventricular dimensions; however, a significant rise in end systolic volume (ESV) was noted. There was significantly lower HR, diminished ESV, higher stroke volume and increased CO, elevated ejection fraction and TPVR with sinus rhythm. In PAF patients without apparent signs of circulatory failure, hemodynamic effects of allapinin may be accounted for by its direct vasodilatory action on the arterial bed and by its ability to affect cardiac autonomic innervation. A moderate cardiodepressive effect of the agent may be reflected by deteriorated latent signs of myocardial incompetence which are levelled off following sinus rhythm recovery.

Aconitine↗
PubMed1990

[Changes in systemic and intracardiac hemodynamics during bicycle ergometry in patients with fibrillation arrhythmia treated with allapinin before and after sinus rhythm recovery].

In atrial fibrillation, allapinine was shown to enhance rhythm by 7% and to increase cardiac output (p less than 0.05), as well as to slightly lower mean blood pressure and peripheral vascular resistance at rest. With exercise, both in atrial fibrillation, and sinus rhythm, there was a decrease in end-diastolic and end-systolic volumes of the left ventricle (p less than 0.05), a slight drop in ventricular ejection, that was statistically significant only with sinus rhythm (p less than 0.05). Physical exercise was not followed by an apparent additional aggravation of myocardial contractility, which makes allapinine preferable for long-term application to preserve sinus rhythm in patients without evident signs of heart failure.

Aconitine↗
PubMed1990

[The effect of allapinine on external respiratory function in patients with diseases of the cardiovascular system].

The cardiorespiratory system was studied comprehensively in 27 patients with permanent atrial fibrillation (PAF) without the clinically marked signs of circulatory failure. After allapinine treatment 15 patients with bronchial obstruction manifestations demonstrated, in the presence of lasting PAF, a significant increase of the forced expiration capacity per s and of the maximum volumetric expiration rates. The data obtained may attest to the fact that the drug has beta-stimulating properties, confirming the reported evidence.

Aconitine↗
PubMed1990

[Use of phase images in radionuclide ventriculography for topical diagnosis of Wolff-Parkinson-White syndrome and sources of pathologic rhythm of the heart ventricles].

The paper presents the results of the mapping of various types of the Wolff-Parkinson-White syndrome and ventricular arrhythmias by using phase images of radionuclide ventriculograms as compared to 12 leads and electrophysiological studies. Phase images are a highly informative method that supplements an electrophysiological study in the topical diagnosis of abnormal tracts and ventricular arrhythmias.

Adolescent↗
PubMed1989

[Thyroid function in patients with ventricular arrhythmia].

Hyperthyroidism was diagnosed in 4.8% of 21 patients with persistent ventricular arrhythmias (grades 2 to 5 by the Lown-Wolf classification), and latent hypothyroidism was diagnosed in 38.1% of those, using up-to-date radioimmune assays of thyroid hormones and the thyroliberin (TRH) test. It was those conditions that made arrhythmias resistant to antiarrhythmic treatment in most cases. Latent thyroid dysfunction was particularly common in elderly patients with ventricular arrhythmias and aggravated thyroid history or abnormal thyroid scintigraphic findings. Substitution therapy for hypothyroidism was conducive to the disappearance of paroxysms of ventricular tachycardia and the decrease in total number and grades of ventricular extra-systoles in patients with ventricular arrhythmias; moreover, sensitivity to antiarrhythmic agents developed to replace an earlier resistance.

Adult↗
PubMed1989

[Effect of a single oral dose of allapinin in patients with chronic ventricular extrasystole].

Effect of a new antiarrhythmic drug allapinin was studied in 21 patients with chronic ventricular extrasystoles by an acute drug test with single oral dose of the drug controlled by 12-hour Holter monitoring. In 9 cases the dose was 50 mg. Maximal total reduction of ventricular ectopic complexes (VEC) per hour was 67 +/- 28% (mean value); in 5 cases (55%) it exceeded 90% of basal level. At peak of action, PQ interval increased by 15%, QRS--by 14%, QT was not significantly changed. In 14 cases the dose was 75 micrograms. Maximal VEC number reduction per hour was on the average 89 +/- 18% and in 12 cases (88%) exceeded 90%. PQ increased by 22%, QRS--by 23% and QT by 9% though JT was not changed (average peak values). It is thus concluded that single oral dose of allapinin has pronounced antiarrhythmic effect in patients with VEC and influences ECG intervals in the way characteristic for class IC antiarrhythmic drugs. The degree of the effect depends on the dose.

Aconitine↗
PubMed1989

[Effect of anti-arrhythmia drugs on the beta2 receptor-dependent adenyl cyclase system of lymphocytes in patients with cardiac rhythm disorders].

The authors analyzed the density of beta 2-adrenoreceptors, their affinity for catecholamines and activity of peripheral lymphocyte adenylate cyclase in healthy donors and patients with frequent ventricular premature contraction (VPC) in their pretreatment state and during short-term ethmosine or allapinine therapy. The density of beta 2-adrenoreceptors was increased by 43%, whereas guanylimidodiphosphate- or forskolin-induced stimulation of adenylate cyclase was decreased in the lymphocytes of VPC patients as compared to those of healthy donors. Ethmosine therapy failed to produce any changes in the density and affinity of the receptors for catecholamines. Allapinine caused a 47% reduction in beta 2-adrenoreceptor density and a 10(2)-10(3)-fold decrease in receptor affinity for 1-isoproterenol. After discontinuation of allapinine, the changes in beta 2-adrenoreceptor density and affinity for catecholamines remained on days 3 and 7, respectively. The clinical effect of both ethmosine and allapinine was accompanied by an increase in lymphocyte adenylate cyclase activity.

Aconitine↗
PubMed1989

[A comparison of the results of endocardial and transesophageal electrostimulation of the heart in assessing sinus node function and atrioventricular conduction].

Forty five patients with cardiac arrhythmias were included in this study (20 had paroxysmal atrial fibrillation, 19, supraventricular tachycardias; 11 had sick sinus syndrome). In all patients endocardial electrophysiological study and transesophageal atrial pacing were performed in order to study sinus node function and atrioventricular conduction. The results of two methods of investigation have a high correlation. Quantitative criteria were developed for defining normal parameters of sinus node function and atrioventricular conduction during transesophageal atrial pacing.

Adolescent↗
PubMed1989

[Our initial experience in using allapinin in patients with paroxysmal supraventricular tachycardias].

Twenty one patients with various forms of paroxysmal supraventricular tachycardias (SVT) were treated with allapinine, a new antiarrhythmic drug. Intravenous infusion of allapinine (0.43 mg/kg) arrested the episodes of SVT in none of 7 patients. Oral administration of the drug for short-term treatment (150 mg/day) prevented the artificial induction or spontaneous occurrence of paroxysms in 10 of 16 patients. Thus, the first experience with allapinine shows its potential efficacy in the prophylactic treatment of paroxysmal SVT.

Aconitine↗
PubMed1989

[Study of thyroid function in patients with paroxysmal supraventricular tachycardia].

Twenty-nine patients with paroxysmal supraventricular tachycardias of different origins and clinical pattern were investigated to detect latent thyroid disorders; hyperthyroidism was diagnosed in 2 of those, and hypothyroidism, in 4. Functional thyroid disorders were more common in patients with mitral prolapse and supraventricular tachycardias due to additional conductive pathways (the Wolff-Parkinson-White syndrome) and paroxysmal nodal reciprocal tachycardia, particularly if they were resistant to antiarrhythmic treatment and/or had aggravated thyroid history. It is suggested that thyroid dysfunction is just a triggering factor of arrhythmia since thyrostatic and replacement therapy eliminate paroxysms of tachycardia, while organic pathology of the heart and its conductive network remains unaffected.

Adolescent↗