[Oxygen supply to the brain in chronic disturbances of cerebral circulation in patients with pathology of brachiocephalic arteries].

We assessed objective parameters of cerebral oxygen supply in 469 patients with multifocal atherosclerosis, hemodynamically significant lesions in brachiocephalic arteries in dependence on degree of severity of vascular cerebral insufficiency according to A.V. Pokrovsky classification of chronic disturbances of cerebral circulation. Comparison of clinical classification with parameters of cerebral oximetry and level of cerebral tolerance to hypoxia allowed to characterize pathophysiological mechanisms of cerebral oxygen metabolism, what was important for determination of risk of surgical treatment and postoperative prognosis.

[Cardiorespiratory abnormalities and cerebral oxygen supply in chronic thromboembolic pulmonary hypertension].

Aim of the study was assessment of severity of cardiorespiratory abnormalities and cerebral oxygen supply in patients with chronic thromboembolic pulmonary hypertension (CTEPH). We examined 56 patients with diagnosis of chronic pulmonary thromboembolism and duration of the disease 3 (1.5-4.1) years. According to data of pulmonary angiography pulmonary artery pressure was 78 (58-92) mm Hg, pulmonary vascular resistance - 618 (450-935) dyne/sec/cm-5, Miller index - 25 (22-27). Further investigation revealed changes of anatomo-functional parameters of the heart and parameters of pulmonary ventilation. These changes were associated with insufficient oxygen supply to the brain and lowering of tolerance to hypoxia. Results of this study should be taken into consideration when brain protective measures are provided during surgical treatment of CTEPH.

[Oxygen status of the brain and quality of life in remote terms after carotid endarterectomy].

The authors assessed efficacy of eversion carotid endarterectomy and its effect on dynamics of the oxygen status of the brain and quality of life of 122 patients at terms from 6 months to 4 years after surgical treatment. It was shown that positive effect from the operation is preserved in 94% of cases, lethality in the remote terms amounted to less than 1%, acute impairment of cerebral circulation on the side of revascularization was registered in 2.5% of cases, haemodynamically significant restenoses in the zone of vascular reconstruction in 2.5%. Revascularization results in increased efficacy of the oxygen supply of the brain and the level of quality of life, including in patients with a history of ischaemic stroke.

[Gender peculiarities of development of atherosclerosis and impairment of brain oxygen supply in excessive body weight].

Aim of the given study was to elucidate special characteristics of mechanisms of development of atherosclerosis and supply of oxygen to the brain in overweight men and women. We included into this study 80 patients with multifocal atherosclerosis without history of myocardial infarction. We analyzed parameters of blood lipid composition, data of cerebral oxymetry, echocardiography, and central hemodynamics. We found gender linked differences in structural-functional parameters of myocardium and in mechanisms of progression of atherosclerosis which increased with increase of excess body weight. This was associated with differences in oxygen brain supply between men and women.

[Brain oxygen supply in the residual period of ischemic stroke].

Brain oxygen supply in the residual period of ischemic stroke was studied in 25 patients with systemic atherosclerosis who had ischemic stroke in the basin of the right- or the left middle cerebral artery 1-13 years ago. The diagnosis was verified by multispiral computed tomography. All patients underwent duplex scanning of brachiocephal arteries with the measurement of vessel diameter and blood flow velocity. The venous component of the brain blood flow was evaluated by the data of bifrontal cerebral oxymetry. The greater volume velocity of arterial blood flow and reduced cerebral oxygenation were characteristic of the damaged hemisphere compared to the intact one. The analysis of cerebral vessel reactivity revealed that the index of vasomotor reactivity with the domination of vascular dilatation reserve was higher by 17-18% in the stroke hemisphere. Therefore, the indices of hemodynamics of arteries in the damaged hemisphere were compensatory higher compared to the intact hemisphere but the venous blood flow along the damaged hemisphere was lower due to the vascular dilatation. The asymmetry of vascular tone may be explained by the disturbance of mechanisms of autoregulation of cerebral blood circulation with the hyperfunction of the damaged hemisphere.

[Oxygen provision of the brain during carotid endarterectomy in the settings of general and local anaesthesia].

Based on the indices of cerebral oximetry, analysed herein is efficiency of oxygen support of the brain in various types of anaesthesiological provision (total and general anaesthesia) in patients presenting with atherosclerosis of the brachiocephalic arteries during carotid endarterectomy. It was shown that at the expense of preserving the mechanism of autoregulation, the use of local anaesthesia provides higher efficiency of cerebral perfusion than general anaesthesia which is evidenced by the values of cerebral oximetry exceeding 60% at all stages of the operation. Dynamics of cerebral oxygenation during occlusion of the carotid arteries in the setting of local anaesthesia suggests high reactivity of the cerebral vessels in this cohort of patients and hence preservation of the cerebrovascular reserve in them.

[Heart failure and imbalance of chemical elements in myocardium of patients with ishemic heart disease].

Tissue content of chemical elements indirectly characterizes some metabolic processes. We have analyzed content of chemical elements in left and right ventricular myocardium of patients with ischemic heart disease with progressing heart failure and have shown that during development and progression of heart failure metabolic processes have unidirectional character in myocardium of both ventricles. Derangement of left ventricular contractile capacity is associated with lowering of content of microelements involved in antioxidant processes and energy metabolism in tissues (Cu, Mn, Cr) and elevated concentration of elements characterizing progressive of myocardial stiffness (Ca, Fe).

[Assessment of brain protection by means of cerebral oximetry incarotid endarterectomy].

Presented herein are the results of cerebral oximetry in the assessment of the indication for brain protection during operations of carotid endarterectomy in a total of forty-eight patients presenting with carotid artery stenoses. It was determined that cerebral oximetry gives an insight into the degree of efficacy of the collateral blood flow along both hemispheres, and by virtue of its integral approach to the assessment of cerebral blood flow is an important criterion in determining the indications for brain protection during carotid endarterectomy.

[Comparative characteristics of quality of life and physical status of patients with ischemic heart disease and aortic valve disease].

For comparison of physical status and quality of life of patients we analyzed 2 clinical groups: patients with ischemic heart disease (IHD) and aortic valve disease. Using original methodology of bringing results of questionnaire " Nottingham Health Profile " to functional classification we had a possibility to compare quality of life of patients with functional classes of physical working capacity and NYHA classification. Subjective component inserted into NYHA classification and quality of life questionnaire leads to substantial discrepancy with objective data on physical working capacity. In most cases patients of both clinical groups subjectively overestimate functional capacity of their organism. In patients with IHD most significant limitations manifest in psychic sphere of life, while in patients with aortic valve disease - in physical sphere of life, what demonstrates great effect of psychosomatic factor in development of IHD.

[Distribution of chemical elements in various parts of the heart of patients with acute heart failure].

By the method of autopsy in patients with ischemic heart disease (IHD) who died of acute heart failure we took samples of myocardium from 6 parts of the heart: left and right atrium, left and right ventricle, region of myocardial infarction, and scar of the left ventricle. Simultaneously we conducted histological study of these parts of myocardium. For the control we investigated content of chemical elements in myocardium of healthy victims of traffic accidents. By the method of roentgen fluorescent analysis with the use of synchrotron emission we detected content of 17 chemical elements: 4 macroelements (S, Cl, K, Ca) and 13 microelements (Cr, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb, Sr, As, Mo, Hg). It was established that in patients with IHD who had died of acute heart failure content of Ca was elevated 4-8 fold in all parts of the heart. In infarction zone compared with other regions of the heart maximal quantity of Sr, Cr, Hg was contained. These elements can be looked upon as markers of infarction. In myocardium of patients with IHD especially in the zone of infarction elevation of activity of processes of lipid peroxidaton has been noted (calculated activity of malone aldehyde as example).

Role of chemical elements in formation of an aortic aneurysm.

The method of X-ray fluorescence employing synchronous radiation was used to study the content of chemical elements (CE) in the aortic wall in patients suffering from CAD (Group I), patients diagnosed with an ascending aortic aneurysm (Group II), and those presenting with aortic dissection (Group III). The obtained findings revealed a pronounced CE disbalance in the aortic wall in Group II and III patients as compared with Group I patients, suggesting an important role of trace and macroelements in metabolic processes related to formation of artic aneurysms. Based on the degree of the ascending aorta dilatation, we determined the coefficient of the ratio of the ascending aorta maximal diameter to the fibrous ring aortic valve diameter, equalling 1.88 +/- 0.04, above which metabolic processes in the aortic wall change over to a qualitatively another level. This point was arbitrarily termed the metabolic process reversibility point.

[Stages of compensation of circulation in acquired aortic valve disease according to data of physical working capacity].

We examined 194 men (mean age 40 +/- 1.4 years) with acquired aortic valve disease. Basing on the data of estimation of physical working capacity and reserve of cardiorespiratory system we assessed staging of development of compensatory mechanisms of circulation in patients with acquired aortic stenosis and aortic insufficiency. According to working capacity all patients were divided into 4 groups with different hemodynamic response of the organism to physical work. Staged development of mechanisms of compensation of the circulation was found to be related to pronounced left ventricular remodeling: concentric myocardial hypertrophy developed in aortic stenosis while aortic insufficiency was associated with eccentric hypertrophy of the myocardium. These differences in geometry were observed already at stage II. Parameters of systemic hemodynamics and energy expenditures of the heart during exercise practically did not differ between aortic stenosis and insufficiency of aortic valve and were characterized by progressive lowering of efficacy of circulation from stage II to stage IV despite pronounced tension of myocardial reserve. As a result significant lowering of tolerance to physical effort took place in patients of the given group.