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Biomedical subjects

Iu N Belenkov

Publications and source records attributed to Iu N Belenkov.

At least 19 recordsLinked to original sources
PubMed1992

[Effects of digoxin on ventricular arrhythmia in patients with heart failure: relations with the state of the sympathetic-adrenal system].

Ventricular arrhythmias were analysed in 38 patients with Stages I-IIB heart failure from 24-hour Holter monitoring data obtained before and after digoxin therapy by comparing with the concentrations of catecholamines. There was a direct relationship between the plasma levels of epinephrine and norepinephrine and the severity of ventricular arrhythmias, as well as between the changes in cumulative catecholamine levels and ventricular arrhythmias during digoxin therapy. Virtually in all cases, the antiarrhythmic effect of the drug was accompanied by lower plasma catecholamine concentrations whereas the levels of norepinephrine and epinephrine remained nearly unchanged or increased with the tentatively arrhythmogenic action. The findings may suggest that hypercatecholaminemias are essential in the genesis of ventricular arrhythmias in heart failure. Cardiac glycosides can heterogeneously affect ventricular arrhythmias by modifying the activity of the sympathoadrenal system.

Adolescent↗
PubMed1992

[Cellular mechanisms of impaired cardiac energetics in patients with dilated cardiomyopathy: decrease in mitochondrial respiration and creatine kinase expression].

The mitochondrial functional characteristics were assessed in the biopsy specimens from patients with various Functional Classes dilated cardiomyopathy (DCMP). The assessment was made by using endomyocardial biopsy specimens weighing 2-4 mg which had been taken from 39 patients aged 19-64 years during coronary ventriculography and cardiac transplantation. The status of mitochondria and the efficiency of mitochondrial creatine kinase functioning were evaluated by recording the respiration of saponin-skinned muscular fibers. The maximum mitochondrial respiration rate calculated on a dry weight basis was not substantially different in all functional classes of DCMP, while the acceptor control index (Vmax/V0) and the level of creatine-activated respiration decreased with an increase in the functional class of DCMP. The findings show a good positive correlation between ejection fraction and creatine-stimulated respiration values and a linear negative correlation between this parameter and end-diastolic pressures. Thus, the respiratory parameters of mitochondria in the endomyocardial biopsy specimens may be used to assess the severity of cardias lesions.

Adult↗
PubMed1992

[Anaerobic threshold in patients with chronic circulatory insufficiency].

To evaluate the severity of chronic circulatory insufficiency (CCI), 12 healthy subjects and 69 patients with cardiovascular diseases underwent exercise testing. Parameters such as anaerobic threshold (AT) and peak oxygen consumption (peak VO2) were measured by respiratory gas analysis to assess the circulatory insufficiency. AT decreased with an increase in New York Heart Association functional class and amounted to 18.9 +/- 4.3, 14.5 +/- 3.5, 11.6 +/- 2.9, and 7.5 +/- 2.0 ml/min/kg in Classes 1, 2, 3, 4, respectively. The peak VO2 decreased as hCCI progressed. The findings suggest that the parameters of external respiration and gas exchange are closely associated with CCI pathophysiology. The parameters may be used as objective and valid criteria for the severity of CCI and its dynamics in the course of treatment.

Adult↗
PubMed1992

[The serum neopterin level in acute rheumatic fever].

Acute rheumatic fever (ARF) is a systemic inflammatory disease etiologically related to infection with group A streptococcus characterized by a broad spectrum of disorders of cellular and humoral immunity. To estimate the activity of the immunopathological process and to forecast myocardial derangement in ARF patients, measurements were made of neopterin in the serum of ARF patients. Nine men with ARF serving in the armed forces were examined. The control group comprised 24 donors. The reference group included 13 patients with dilated cardiomyopathy and 14 with chronic myocarditis. The mean level of neopterin in ARF patients was equal to 14.5 +/- 12.2 nM/l and was significantly higher than in the donors (5.0 +/- 2.0 nM/l). In patients with dilated cardiomyopathy and chronic myocarditis, it was 9 +/- 6 and 16 +/- 11 nM/l, respectively. On more careful clinical analysis the highest level of neopterin was recorded in 3 patients with impairment of the valvular apparatus of the heart. That level was observable during the whole period of the follow-up of the patients. In other patients, no impairment of the valves was detected, whereas the concentration of neopterin fell to normal. Therefore, the rise of the level of neopterin was described for the first time in patients with ARF. Besides, a relationship was found between the high level of neopterin and impairment of the valvular apparatus of the heart.

Adolescent↗
PubMed1992

[The radionuclide diagnosis of dilated cardiomyopathy: a new approach to assessing myocardial perfusion function by 201Tl scintigraphic data at rest and during the performance of the dipyridamole test].

A method for quantitative determination of the percentage of left ventricular myocardial 201Tl isotope uptake at rest and during dipyridamole test was first used in patients with dilated cardiomyopathy and coronary heart disease complicated by circulatory insufficiency or chronic myocarditis. This method makes it possible to judge the level of myocardial blood flow and perfusion reserve in these diseases. The most common differences were found between patients with coronary heart disease and those with chronic myocarditis. The patients with chronic myocarditis exhibited the greatest sizes of perfusion defects, highest values of 201Tl uptake at rest and a lower myocardial perfusion reserve during dipyridamole test. In response to exercise, most patients with chronic myocarditis had diminished perfusion defects, whereas those with coronary heart disease displayed increased defects. The myocardial perfusion was varied in patients with dilated cardiomyopathy. Some patients had a scintigraphic pattern close to that in patients with chronic myocarditis and others had a pattern identical to that in patients with coronary heart disease.

Adolescent↗
PubMed1992

[Use of functional classes to assess the status of patients with severe heart failure].

The possibilities of the classification developed by Lang, Strazhesko, Vasilenko and that of heart failure functional classes, which has been adopted by the New York Heart Association (NYHA), to evaluate the status of patients with severe heart failure are compared in this communication. A total of 1619 patients with Stages IIB-III heart failure of various origin (coronary heart disease, dilated cardiomyopathy, rheumatic heart disease, myocarditis, primary pulmonary hypertension) were studied. To assess the patients' status the attending physicians used 7 grades: (1) satisfactory; (2) close to moderate; (3) moderate; (4) close to severe; (5) severe; (6) close to critical; (7) critical. Each patient was independently evaluated for grade and functional class by experts by using a specially developed schedule. An analysis of the distribution of the patients by grade and functional class demonstrated that the 4-graded functional class classification has advantages over the 7-graded one due to more settled, reproducible, recurrent and less scattered opinions (in case of the common source of information), the functional class, unlike the grade, was found to be unassociated with the nature of the disease. A simple grade summing-up (regrouping the patients from 7 to 4 grades) unenables one to adequately go over to the NYHA functional class. It is concluded that the tested NYHA classification should be used to evaluate the status of patients with severe heart failure.

Cardiac Output, Low↗
PubMed1991

[The clinical importance of the dynamic determination of the serum neopterin level in patients with dilated cardiomyopathy].

Serum neopterin was measured over time (from 3 to 24 months) by RIA in 15 patients with dilated cardiomyopathy. Comparison with the clinical data revealed that the initially normal concentration of neopterin (less than 9 nM/l) was associated with a stable disease course on a long-term observation (group I). The second group with an initially high neopterin concentration showed an objective improvement of the health status together with normalization of the neopterin level. The third group of patients were characterized by an increase of the neopterin level measured over time, coupled with a disease progress. It should be noted that 5 out of 8 patients died. In addition to neopterin measurements, the patients with dilated cardiomyopathy were examined for serum beta-2-microglobulin (beta-2M). Analysis of the data obtained has demonstrated a similar relationship between the level of neopterin and beta-2M and the clinical course of dilated cardiomyopathy. Still, neopterin is a more sensitive marker. Therefore, the data obtained attest to a possibility of the use of serum neopterin as a prognostic marker in patients suffering from dilated cardiomyopathy.

Adolescent↗
PubMed1991

[Permanent forms of tachyarrhythmia as the possible cause of the development of the dilated cardiomyopathy syndrome].

To specify a possible role played by rhythm disorders in the development of dilated cardiomyopathy (DCM), 9 patients showing permanent sinus and/or supraventricular tachycardia (since birth or within the first 5 years of life) coupled with ventricular rhythm disorders and 11 patients with an assumed infectious disease onset were examined. It has been established that in supraventricular tachycardia, sinus tachycardia included, patients of the child and juvenile age may develop dysfunction of the left ventricle followed by its dilatation which manifests clinically by DCM. The use of antiarrhythmic (cordarone) in such cases may lead to diminution and even to normalization of the heart size and to amelioration of the hemodynamic parameters.

Adolescent↗
PubMed1991

[Serum type III procollagen in dilated cardiomyopathy].

A radioimmunoassay study of procollagen type III end protein (PEP) was conducted in the serum of 11 patients with confirmed dilated cardiomyopathy (DCMP) and 9 patients with coronary heart disease. For DCMP patients PEP levels averaged 8.8 +/- 7.9 micrograms/l, for coronary patients 4.4 +/- 1.6 micrograms/l, in donors 1.7 +/- 1.4 micrograms/l. Thus, the difference between DCMP and coronary patients, donors appeared significant (p less than 0.05). PEP concentrations over 4.5 micrograms/l occurred in 54% of DCMP patients. Growing of PEP turned out most substantial in severe disease (circulatory failure stage IIB-III, pulmonary thromboembolism). Determination of PEP is thought valid for laboratory diagnosis of myocardial inflammation and fibrosis. The discussion covers possible causes and mechanisms underlying high production of PEP from the view point of impaired collagen production.

Adolescent↗
PubMed1991

[Minimal pulmonary regurgitation (pulsed Doppler echocardiography findings) in the absence of pulmonary valve defect].

A diastolic turbulent flow of pulmonary regurgitation with the maximum velocity of no more than 1.5 m/sec and prevalence in the exit portion of the right ventricle up to 17 mm was detected in 36 patients with cardiac and pulmonary diseases and apparently healthy individuals without organic pulmonary valve lesion and diastolic localization at the respective site, by using pulsed Doppler echocardiography. The highest diastolic transpulmonary pressure gradient estimated by a modified Bernulli's equation was no more than 9 mm Hg (within the range of normal values for diastolic pulmonary artery-right ventricle pressure gradient). Asymptomatic subclinical pulmonary regurgitation of physiological and functional nature without substantial hemodynamic significance which has been detected in these patients cannot be regarded as a manifestation of pulmonary valve defect.

Adult↗
PubMed1991

[Evaluation of the hemodynamic effects of the long-acting peripheral vasodilator flosequinan in patients with chronic heart failure].

The hemodynamic effects of the peripheral vasodilator flosequinan, 100 mg/day, were evaluated in 20 patients with Stage IIA-IIB (the Lang-Strazhesko-Vasilenko classification) heart failure. The doses of digoxin and diuretics were found to be stable. The right cardiac cavities and pulmonary artery were catheterized by Swan-Ganz balloon catheters. The agent was demonstrated to produced profound effects showing decreased pre- and afterload when given both in a single dose or in course therapy.

Adult↗
PubMed1991

[Atrial natriuretic factor in chronic heart failure].

Seventy-six patients with chronic heart failure, stages I-III, that developed after different heart diseases were examined. Catheterization of the right heart was carried out in 51 patients. The concentration of immunoreactive atrial natriuretic factor (ANF) in peripheral blood plasma and in the blood from the right atrium was increased in patients and rose as heart failure progressed. No correlation was discovered between the character of heart disease and the concentration of immunoreactive ANF in the plasma. The latter one was directly dependent on the wedging pressure in the pulmonary artery and on the pressure in the right atrium. The level of immunoreactive ANF in the atrium was higher than in the periphery. However, that was not of statistical power.

Adult↗
PubMed1991

[MR-tomography of the heart in cardiomegaly caused by dilated cardiomyopathy and ischemic heart disease].

The paper deals with the results of magnetic resonance cardiac tomography in 19 patients with dilated cardiomyopathy and 10 patients with coronary heart disease who had severe cardiomegaly and congestive heart failure symptoms. Magnetic resonance tomography showed that the patients with dilated cardiomyopathy exhibited profound dilatation of all the 4 cardiac cavities and a chaotic pattern of impaired segmental left ventricular contractility, whereas those with coronary heart disease had predominant dilatation of the left cavity and local myocardial dysfunctions. Magnetic resonance may be one of the non-invasive tools which make the genesis of cardiomegaly clear in patients with heart failure.

Adult↗
PubMed1991

[Magnetic resonance tomography of the heart in dilated cardiomyopathy].

NMR-tomography using a spin-echo technique, ECG synchronization in exposure to 0.23 T magnetic field was performed in 13 patients with dilated cardiomyopathy (DCMP). The results were correlated with echocardiography findings. NMR-tomography provided a good image of cardiac chambers dilatation, their size being in agreement with that shown by echocardiography. No significant differences in myocardial relaxation time T2 was recorded in DCMP patients compared to normal subjects. NMR-tomography can be successfully employed in cardiac investigations in case of complicated echocardiography.

Adult↗