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Biomedical subjects

S L Dzemeshkevich

Publications and source records attributed to S L Dzemeshkevich.

At least 19 recordsLinked to original sources
PubMed2005

[Heart rate variability in patients with paroxysmal atrial fibrillation of various etiologies].

Heart rate variability (HRV) was assessed on 24 hour Holter ECG recordings from 32 healthy persons and 54 patients with paroxysmal atrial fibrillation (AF) of different etiology (hypertension, ischemic heart disease, rheumatic mitral valve disease, idiopathic AF) aged 45-73 years. Nocturnal, diurnal and 24 hour HRV was measured. Time and frequency domain HRV measures were lower in patients with AF and underlying heart disease compared with healthy persons and for most of the parameters with patients with idiopathic AF (p<0,05). Patients with idiopathic AF compared with healthy persons had higher values of high frequency power during nighttime (p<0.05), what reflected activation of parasympathetic nervous system in this category of patients.

Aged↗
PubMed2002

[Prolonged pulmonary artery pressure monitoring in patients with pulmonary hypertension].

Pulmonary artery pressure (PAP) was monitored for 24-48 hours in 10 and 8 patients with primary and secondary pulmonary hypertension, respectively. The data obtained were compared with results of prolonged PAP monitoring in 2 healthy volunteers. Variability of mean PAP was 7.43-/+3.1, 5.78-/+1.64, and 3.4-/+0.63 mm Hg, coefficient of variability - 10.39-/+3.68, 13.04-/+6.01 and 22.73-/+8.03% in patients with primary and secondary pulmonary hypertension and healthy subjects, respectively. After surgery in patients with secondary pulmonary hypertension coefficient of variability rose from 13.04-/+6.01 to 16.7-/+12.8%, while variability decreased from 5.78-/+1.64 to 4.3-/+1.65 mm Hg. Level of spontaneous fluctuations of PAP was the highest in healthy subjects (71.4%) and the lowest - in patients with primary pulmonary hypertension (34.9%). Thus PAP variability is a widespread phenomenon which should be taken into consideration during right heart catheterization and acute pharmacological tests.

Adolescent↗
PubMed2002

[Prevalence of detection of autoantibodies to beta-1 adrenoreceptors in patients with myocarditides and cardiomyopathies].

BACKGROUND: Autoantibodies to the second extracellular loop of a cardiac beta1-adrenoreceptors has been detected in some patients with cardiomyopathies and myocarditides. In animal experiments these autoantibodies have been shown to cause reduction of myocardial contractility. AIM: To estimate prevalence of detection of autoantibodies to beta1-adrenoreceptors in patients with myocarditides and cardiomyopathies. MATERIAL: Forty three patients including 18 with dilated cardiomyopathy (DCM), 14 with ischemic heart disease (IHD), 3 with myocarditides, 1 with alcoholic cardiomyopathy and 7 after cardiac transplantation. METHOD: Autoantibodies to beta1-adrenoreceptor were determined in patient's blood serum by direct immunoassay. Synthetic fragment containing 26 amino acids of the beta1-adrenoreceptor second loop was used as antigen. RESULTS: Ten patients had obviously elevated content of autoantibodies. Three of these patients had IHD, 3 - DCM, 1 was studied 6 moths after myocarditis and 3 - 6-9 years after cardiac transplantation. Tests were repeated with intervals from 6 months to 1 year and levels of autoantibodies remained elevated in all these patients. Detection of antibodies did not depend on the etiology of systolic cardiac failure (IHD, DCM), severity of hemodynamic impairment, presence of disorders of cardiac rhythm or conduction.

Autoantibodies↗
PubMed1998

[Anatomic orthotopic heart transplantation: the surgical characteristics and the advantages of the method].

Standard technique of establishment of interatrial anastomoses allows to carry out orthotopic transplantation of the heart quickly and reliably. However the accumulation of collective experience evidences about a number of unavoidable shortcomings of such operation: rhythm disturbances, worsening of hemodynamics in discordant atrial contractions of recipient and donor, atrio-ventricular valve insufficiency, thromboembolism, coronary fistulas. Since 1990 in RRCS 25 operations were carried out with the use of standard technique and we also met with the risk of developing the above complications. In experiment on 30 mongrel dogs the technique of anatomical, truly orthotopic transplantation of the heart with six anastomoses was developed: left pulmonary veins with a common cuff, separate anastomoses of the superior and inferior caval veins, anastomoses of aorta and pulmonary artery. Particular attention was paid to developing of original surgical modes for prophylaxis of stenoses in the area of anastomoses of pulmonary and caval veins. In 1997 the anatomical technique of heart transplantation was successfully introduced by us into clinical practice. Clinical electrophysiological, echocardiographic and functional examinations have confirmed the results of the experiments and have evidenced for substantial advantages of the anatomical technique of orthotopic transplantation of the heart. By reliability the new operation is not inferior to standard method of N. Shumway.

Anastomosis, Surgical↗
PubMed1997

Simultaneous separate assessment of the cardiac and LVAD output.

The electroimpedance indicators' dilution (EIID) technique was used to study the possibility of a simultaneous separate assessment of the biological heart and LVAD performance in the position of LVB. The experimental part of the research was performed on 5 dogs; an artificial ventricle of the pulsing type (USA) with cusps was used as a pump. The clinical part of the work was conducted on 5 patients after open-heart surgery who had the clinical picture of postcardiotomy cardiogenic shock; a centrifugal pump "Biopump" (Medtronic, USA) was used. The authors have shown a principally important possibility of applying the EIID, technique for studying the performance curves which are the integral derivatives of the work of a specific hybrid system--"the biological heart-assist device". From the practical viewpoint the EIID technique permits in the read time mode to control continuously the part of the pumping function which is assumed by the patient's own heart. This information can serve as the basis for making the prognosis and determining the further tactics of treatment; the restoration of the heart performance or its replacement by transplantation.

Animals↗
PubMed1997

"Temporary prosthesis" of the fibrotic ring for relative insufficiency of the tricuspid valve.

BACKGROUND: De Vega type suturing dosage plasty is the intervention most widely used for relative insufficiency of the tricuspid valve (TV). In fact, this operation may be considered as an equivalent of prosthetic reconstruction of the fibrotic ring, shaping a fixed orifice for passage. Intrapulmonary pressure normalized as early as during the first months after surgery in patients with the mitral-tricuspid cardiac valvular disease. Under such conditions a rigid suture (prosthesis of the anulus) at the interface of the right atrium and ventricle is not physiological. METHODS: We used Maxon CV 2-0 (D+G) suture absorbable for 6 months. Xenopericardial pads were fixed at the edge of the suture. The pads were prepared by enzymatic and chemical processing. RESULTS: Operations were performed in 7 patients, the results were followed for up to 28 months. The size of the TV fibrotic ring was measured by transesophageal ultrasonography (Hewlett-Packard SONOS 1500; OMNIPLANE) on the operating table and for 2 years postoperation. No signs af tricuspid insufficiency were detected.

Heart Valve Prosthesis Implantation↗
PubMed1997

[Immediate and long-term outcomes of aortic valvuloplasty in acquired heart diseases].

Plastic operations were made in 214 patients with rheumatic aortic valvular diseases. In addition to correction of aortic valvular disease, that of mitral valvular disease was performed in 177 patients, 26 underwent interventions into 3 valves. Hospital mortality was 6.5%. Intraoperative hemodynamic measurements indicated good correction of aortic valvular disease in most patients. A hundred and forty three patients were followed up for 1 to 11 years. Five-year survival was 81.0%. At year 5, 93.8% of patients needed no resurgery.

Aortic Valve↗
PubMed1994

The use of high doses of aprotinin to decrease blood loss in aortocoronary by-pass surgery.

There were examined 100 patients who had been operated in extracorporeal circulation for ischemic heart disease. In the 1st group (50 patients), each patient intraoperatively received 6,000,000 KIE of aprotinin; in the 2nd group (50 patients) placebo. Both groups were similar as for the age, duration of extracorporeal circulation, and myocardium anoxia. The total intraoperative blood loss was higher in 2nd group, 638 +/- 5 ml and 952.4 +/- 15.5 ml p < 0.05 correspondingly. The rate of cases without the intraoperative use of donor blood was 42% in group 1 and 18% in group 2. The postoperative blood loss was significantly lower with the use of aprotinin, 392 +/- 6.6 ml and 689.7 +/- 9.6 ml, p < 0.05 correspondingly; and in that the Hb concentration in the drainage blood was higher in group 2: 31.3 +/- 0.5 g and 73.1 +/- 2.2 g, p < 0.05. In group 1 22% of the patients received donor blood in the early postoperative period, and group 2 twice as many -56%. Thus prolonged intraoperative use of large aprotinin dosages in aortocoronary by-pass surgery is an effective means for stabilization of homeostasis, and it allows to reduce intra- and postoperative blood loss and diminishes the requirements in donor blood.

Aprotinin↗
PubMed1994

Long-term results of plastic reconstructions in acquired aortic valvular disease.

Plastic surgery in acquired aortic valvular disease was performed in 164 patients. Among them, 9 had the isolated aortic valvular injury; 130 mitral-aortic defects; and 25 three-valve injuries. The restoration of the injured valve function was achieved, as a rule, using a combination of surgical methods: commissurotomy or wedge resection of the fibrous tissue in the commissurial area; parietal resection; the aortic root frame plasty; perforation hole plasty; the allogenic valvuloaortic complex sector transplantation; and wedge resection or isometric cusp plication in the commissurial area. Calcinosis was not a contraindication to surgery, if it could be removed completely without the cusp closing function disturbances. The hospital mortality rate was 8%. After hospital treatment all the patients were followed-up: 108 for over 1 year, and the maximum term of the follow-up was 7 years. From 1 to 4 years postoperatively, 4 patients were reoperated due to the appearance of aortic insufficiency. The causes of relapse were: infectious endocarditis (3 patients); active rheumatic process (1 patient); and progressive dilatation of the fibrous ring (1 patient). During the follow-up 8 patients died: 6 of infectious endocarditis with mitral prosthetic injury; and in 2 the cause of death was not clear. The study of immediate and long-term aortic valvuloplasty results based on the clinical experience of 164 operations allows to recommend the elaborated principles of the aortic valve surgical reconstruction for a wide application in cardiac surgery.

Aortic Valve↗
PubMed1994

The mitral valve replacement by the new-type bioprostheses (features of design and long-term results).

The BAKS bioprostheses were created in our centre and they have the following features: (1) to reduce immunogenicity they underwent a combined fermentochemical treatment which resulted in the native xenovalve consisting of collagen and elastic fibres only; (2) in cutting out the valve the natural aortic sinuses were preserved; and (3) the xenovalve was fixed on a functional frame of an original design. From 1979, BAKS have been implanted in 243 patients with the isolated mitral valve reumatic injury. The patients age varied from 11 to 59 years; 91 patients (37.5%) were under 35 years. The 12-year survival rate (without hospital lethality) was 65.5 +/- 5.3%. The most serious longterm complications were: infectious endocarditis (3.14 patients/years); spontaneous degeneration of bioprosthetic cusps (2.24% patients/years); thromboembolism (0.6% patients/years). The morphological examination of bioprostheses removed in reoperations from 10 days to 10 years after implantation was performed in 51 cases. Most often, collagen degeneration occurred in patients under 35. The pathologic structural changes originated because of the localized saturation of bioprosthetic cusps with the recipient plasma proteins, gradual disintegration of collagen fibres, and further calcification of that area. The indications to the mitral valve replacement by BAKS were: the left atrium thrombosis, thromboembolytic syndrome, contraindications to anticoagulation therapy, and the age over 35 years.

Adolescent↗
PubMed1993

[Aortic valvuloplasty in acquired valvular disease].

On the basis of the results of studying the morphology, biomechanics, and physiology of the aortic root and the cusps of the aortic valve the authors suggest a substantiated set of surgical manipulations which allow the patient's natural valve to be preserved. Coarse calcinosis of the cusps and fibrous ring of the aortic root is the only absolute contraindication for valvuloplasty. The authors' clinical experience consists of the first 100 operations. Hospital mortality--8.0%. With intraoperative appraisal of hemodynamics, good correction of the abnormality was achieved practically in all patients. The maximal follow-up period by April, 1991 was 5.5 years. During that period four patients were again subjected to operation because aortic insufficiency recurred. The authors recommend their experience with plastic operations on the aortic valve for wide clinical application.

Adolescent↗
PubMed1992

[Intraoperative transesophageal echocardiography in diagnosing left atrial thrombosis in patients with mitral valve disease].

Intraoperative transesophageal echocardiography was conducted in 63 patients with various cardiosurgical pathology (mitral stenosis--43, combined mitral valvular disease--3, mitral incompetence--10, combined mitral-aortal valvular disease--8). Thrombosis of the left atrium was diagnosed in 13 patients. Transesophageal echocardiography in 38 patients revealed spontaneous echo-contrasting of blood currents in the cavity of the left atrium. Statistical analysis showed this sign to be characteristic of mitral stenosis complicated by thrombosis of the left atrium (p < 0.001). Transesophageal echocardiography allows visualization of thrombi of small diameter (1.0-1.5 cm). Specificity of the method is 100%, sensitivity 87%.

Adult↗
PubMed1991

Extracorporeal mechanical pulsatile pump and its significance for myocardial function recovery and circulatory support.

The authors performed 12 acute (on dogs) and 12 chronic (on calves) assisted circulation experiments with the use of the total extracorporeal mechanical pump (TEMP) artificial ventricles. The functional morphological research of the myocardium suggests that in addition to the possibility of the biological heart function full replacement, the artificial ventricle also helps recover damages in both the myocardial infarction and distal zones. The critical time period up to the onset of artificial circulation is not more than 2 h, and after that myocardial changes are irreversible.

Animals↗
PubMed1991

Total artificial heart without valves: principles of design and implantation technique.

A total artificial heart (TAH) without valves is a TAH of a new design. The entry and exit are combined in one opening. The excision of the biologic ventricles is below the atrioventricular groove, while the outlet and position of the right and left ventricles are preserved. The aortic and pulmonary valves have been left intact. Bioprostheses BAKS are implanted into the mitral and tricuspidal positions. Initial experiments hold much promise: the absence of artificial valves decreases the risk of thromboemboly; the natural heart basis remains intact, which facilitates the subsequent donor heart transplantation; and the work of the new TAH is practically noiseless.

Bioprosthesis↗
PubMed1991

[Heart transplantation conducted at the All-Union Research Center of Surgery (the first clinical experience)].

The authors analyse experience in the first eight operations for orthotopic transplantation of the heart. Six patients were discharged from the clinic with good immediate results. Comparison of their own data with summarized results gained in other countries allowed the authors to define some specific problems which are of practical interest for clinics embarking on the clinical realization of the problem of heart transplantation.

Adult↗