[Peripheral perfusion in CAD patients with various-stage chronic heart failure undergoing coronary artery bypass grafting]. / Perifericheskaia perfuziia u bol'nykh IBS s razlichnoi stadiei khronicheskoi serdechnoi nedostatochnosti pri koronarnom shuntirovanii.

Using the orthostatic test, we examined peripheral perfusion by means of laser Doppler flowmetry (LDF) and transcutaneous oximetry in a total of 104 patients presenting with coronary artery disease and functional class II-IV chronic heart failure (CHF) prior to coronary artery bypass grafting (CABG) and in the remote terms thereafter. Volumetric velocity of the microcirculatory blood flow (MCB) of the lower limbs was measured by means of LDF in perfusion units; partial oxygen pressure (TcPO2, mmHg) was registered by means of transcutaneous oximetry. The patients with CAD were subdivided into two groups as follows: Group One comprised patients with FC II CHF and Group Two included those with FC III-IV CHF. Prior to CABG according to the findings of LDF, the lowest level of MCB of the lower limbs was revealed in Group Two, being by 57.9% (42.5-61.3) less as compared with Group One (p=0.008). In Group Two patients as compared with Group One there was a larger proportion of patients with impaired reactivity of the peripheral microcirculatory bed during the orthostatic test in the form of: 1) a paradoxical reaction of the MCB both before CABG (60.6 versus 13.9%, p=0.00001) and in the remote terms after the operation (64.3 versus 16.2%, p=0.00001); 2) lack of the reaction of the MCB prior to the operation (19.7 versus 4.7%, p=0.02) and in the remote period after CABG (16.7 versus 2.7%, p=0.04). Group Two patients both before and after CABG were found to have a decrease (compared with the norm) in the TcPO2 parameters at rest, as well as lower reactivity of tissue metabolism of peripheral tissues during the orthostatic test. An initial decrease in the left ventricular output fraction of < 42% increases the chances of preserving the post-CABG decreased values of TcPO2 of less than 24 mm Hg (OR=3.1; 95% CI 1.1-6.8; p=0.003). Lack of the reaction of the MCB during the orthostatic test prior to CABG increases the chances for the development of surgically significant atherosclerotic lesions of lower-limb arteries after myocardial revascularization (OR=4.2; 95% CI 1.3-2.3; p=0.01). Hence, the most pronounced impairments of the mechanisms of adaptation of the MCB in the orthostatic test prior to and in the remote terms after CABG were detected in CAD patients with FC III-IV CHF. A decrease in the microvascular tonicity during the test and, consequently, inhibition of the nutritive component in this cohort of patients were accompanied by low metabolic reactivity of peripheral tissues.

[Efficacy and safety of temporary bypass grafting in carotid endarterectomy]. / Éffektivnost' i bezopasnost' vremennogo shuntirovaniia pri karotidnoi éndarteréktomii.

The authors analysed interrelationship between the use of temporary bypass grafting during operations of carotid endarterectomy and the frequency of the development of ischaemic complications (stroke and transitory ischaemic attacks in the early postoperative period). It was shown that in the group wherein a temporary bypass graft was established only by the criterion of decreasing retrograde pressure ischaemic complications were encountered in ten (4.4%) patients and in the group wherein temporary shunts were established by the criterion of a simultaneous decrease in cerebral oxygenation and retrograde pressure - in two (0.9%) patients (OR 5.28; 95% CI 1.22-24.38; p=0.03). It was demonstrated that using temporary bypass grafting in cases of isolated assessment of the parameters of cerebral oxygenation and retrograde pressure increased the frequency of the development of shunt-related ischaemic complications as compared with the patients in whom shunts were not used due to lack of a synchronous decrease in these parameters (13.5 vs 1.5%, respectively; OR 10.0; 95% CI 1.1-82.2; p=0.039). The findings of the carried out retrospective analysis suggested that the main predictor of the development of the outcome 'stroke + transitory ischaemic attack' was the use of a temporary internal shunt during the main stage of the operation (p<0.00001).

Risk of development of neurological complications in prosthetic repair of the aortic ascending portion and arch. / Risk razvitiia nevrologicheskikh oslozhnenii pri protezirovanii voskhodiashchego otdela i dugi aorty.

The study comprised a total of 68 patients (presenting) with chronic dissection of the aortic ascending portion and arch, undergoing surgery and subjected to measuring at various stages of the operation the level of cerebral oxygenation (rSO2) of the right and left hemispheres by means of bilateral transcranial spectroscopy. The aim of the study was to examine the risk for the development of neurological complications in patients with chronic dissection of the aortic ascending portion and arch in various methods of cerebral protection during aortic prosthetic reconstruction. Group One consisted of thirty-one 40-to-61-year-old (mean age 51 years) patients who during circulatory arrest (CA) were as cerebral protection subjected to antegrade cerebral perfusion (ACP) on the background of moderate hypothermia (23-24°C). Group Two included thirty-seven 40-to-58-year-old (mean age 48 years) patients who during CA were subjected to cerebral protection consisting in craniocerebral hypothermia on the background of total deep hypothermia (18°C). Prior to surgery and in the immediate period thereafter, all patients underwent clinical and instrumental examination of the neurological status. During CA while aortic arch repair in Group One patients at the expense of maintaining cerebral perfusion a decrease in rSO2 registered in the right and left hemispheres amounted to only 11.8 and 8.7%, respectively, compared with the baseline values. In Group Two patients during CA a decrease in rSO2 along the right and left hemispheres amounted to 29.6 and 30.9% compared with the initial values, which was statistically significantly more than in Group One (p=0.002 and p=0.003). Thus, in Group Two patients during CA cerebral hypoperfusion resulted in a considerable decrease in oxygen supply of the brain, in spite of systemic deep hypothermia and craniocerebral hypothermia, promoting reduction of cerebral metabolism. Using ACP during CA in Group One patients maintained the oxygen status of the brain at an optimal level. In Group One patients, in the early postoperative period neurological complications were registered in 12.9% of cases. In Group Two, neurological complications were noted in 35.1% of cases. The univariate logistic regression analysis demonstrated that the risk for the development of any neurological complications depended on the degree of a decrease in rSO2 during CA while prosthetic repair of the aortic arch relative to the previous values - OR 1.25; 95% CI 1.11-1.65; p=0.02. Hence, deep hypothermia and craniocerebral hypothermia used as cerebral protection during CA turned out to be less effective compared with ACP, because despite reduction of metabolic requirements of the brain, cerebral hypoperfusion substantially of neurological status impairments in the early postoperative period.

Oxygen provision of the brain at various stages of operation in patients with chronic pulmonary artery thromboembolism.

The authors studied cerebral oxygen supply by means of cerebral oximetry in patients presenting with chronic pulmonary artery thromboembolism (PATE) at various stages of operation. The study was aimed at assessing cerebral oxygen supply while carrying out surgical treatment in patients with chronic PATE on the background of various methods of perfusion. Thromboendarterectomy (TEA) from the pulmonary artery with the use of circulatory arrest and craniocerebral hypothermia is accompanied by more pronounced impairment of oxygen supply of the brain with a decrease in the cerebral oxygenation indices by more than 30% from the baseline values. These alterations promote increased risk for the development of neurological complications in the early postoperative period. Using the technique of antegrade cerebral perfusion ensures a minimum decrease of cerebral oxygenation during TEA and contributes to a reduction of the risk for the development of neurological complications.

[Peripheral microcirculation in patients with lower-limb atherosclerosis on the background of metabolic syndrome].

The authors studied the peripheral microcirculatory blood flow (MCBF) by means of laser Doppler flowmetry in a total of 112 patients presenting with stage IIB-IV lower limb chronic ischaemia (LLCI) on the background of metabolic syndrome (MS). The study was aimed at assessing the state of the peripheral MCBF in LLCI patients on the background of MS. Atherosclerotic lesion of lower-limb vessels on the background of MS is characterised by more pronounced impairments of the functional state of microcirculation in the form of a decrease in the reserve of capillary blood flow during the occlusion test both before and in the early period after revascularization. Patients with LLCI combined with MS were found to have more pronounced alterations in sympathetic regulation and reactivity of the microcirculatory bed in the form of the paradoxical reaction of the blood flow during the breath-holding test.

[Cerebral oxygen supply in patients with chronic pulmonary artery embolism].

Aim of this study was to assess brain oxygen supply in patients with chronic pulmonary embolism (CPE) for elucidation of factors of risk of neurological complications in early postoperative period. We examined 34 patients with diagnosis of CPE. Mean duration of the disease was 3 (1.4-4.2) years. Data on baseline cerebral oxygenation, monitoring of brain oxygen during various stages of surgery, and level of cerebral oxygen supply in immediate postoperative period are presented. More than 40% lowering from initial values of parameters of cerebral oxygenation during circulatory arrest substantially increases risk of development of neurological complications in early postoperative period.

[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.

[Microcirculation blood flow of the upper extremities in patients with coronary artery disease combined with non-insulin dependent diabetes mellitus].

The work was aimed at assessing the possibilities of the microcirculatory blood flow (MBF) of the upper extremities in patients suffering from coronary artery disease (CAD), as well as in patients with CAD accompanied by type 2 diabetes mellitus (NIDDM) by means of laser Doppler flowmetry (LDF) using functional tests. The obtained findings of the study demonstrated that that the lowest reserve capabilities of the MBF were observed in the group of patients with CAD and NIDDM, and this group considerably more often versus patients with CAD without NIDDM showed decreased collateral reserve and low compensatory capabilities of the microcirculatory bed of the upper limbs.

[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.

[The study of microcirculation in walls of chambers of the heart in patients with aortic stenosis in dependence on heart failure stage].

We studied microcirculatory blood flow (MBF) by laser Doppler flowmetry (LDF) in 52 patients with stage III-IV aortic stenosis (AS) and class II-IV chronic heart failure (CHF). MBF was assessed in walls of right and left cardiac chambers before and after correction of the defect. Aim of this study was to assess functional state of MBF in walls of different chambers of the heart before and after defect correction in patients with AS at various stages of CHF. We distinguished 2 groups of patients: group 1 with class II CHF, group 2 with class III-IV CHF. In group 2 compared with group 1 before and after AS correction of AS we found the lowest level of MBF in walls of left cardiac chambers and right atrium and highest parameters of the left ventricular and atrial function according to echocardiography data. Progression of anatomic-functional changes of left ventricle at the background of AS and development of CHF is characterized by lowering of MBF volume velocity in walls of left cardiac chambers.

[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.