The objective of our study was to identify blood pressure (BP) and pulse wave velocity (PWV) changes during orthostatic loading, using a new the head-up tilt test (HUTT), which incorporates the usage of a standardized hydrostatic column height. Methods: 40 healthy subjects 20–32 years performed HUTT, which was standardized to a height of the hydrostatic column at 133 cm. Exposure time was 10 min in each of 3 positions: horizontal supine 1, HUTT, and horizontal supine 2. The individual tilt up angle made it possible to set the standard value of the hydrostatic column. Hemodynamic parameters were recorded beat to beat using “Task Force Monitor 3040 i”, pulse-wave velocity (PWV) was measured with a sphygmograph–sphygmomanometer VaSera VS1500N. Results: Orthostatic loading caused a significant increase in heart rate (HR) and a decrease in stroke volume (SV) (p < 0.05) but no significant reductions in cardiac output, changes in total vascular resistance (TVR), or BP. An analysis of personalized data on systolic blood pressure (SBP) changes in tilt up position as compared to horizontal position (ΔSBP) revealed non-significant changes in this index in 48% of subjects (orthostatic normotension group), in 32% there was a significant decrease in it (orthostatic hypotension group) and in 20% there was a significant increase in it (orthostatic hypertension group). These orthostatic changes were not accompanied by any clinical symptoms and/or syncope. During HUTT, all subjects had in the PWV a significant increase of approximately 27% (p < 0.001). Conclusion: The new test protocol involving HUTT standardized to a height of hydrostatic column at 133 cm causes typical hemodynamics responses during orthostatic loading. Individual analysis of the subjects revealed subclinical orthostatic disorders (OSD) in up to 52% of the test persons. During HUTT, all test subjects showed a significant increase in PWV. The new innovative HUTT protocol can be applied in multi-center studies in healthy subjects to detect preclinical forms of orthostatic disorders under standard gravity load conditions.

Arterial hypertension (AH) remains one of the most common diseases and a leading risk factor for cardiovascular diseases (CVD) in the 21st century. It determines the importance of a search for new factors provoking an increase in blood pressure. This review focuses on studies of preclinical predictors of hypertension. Orthostatic circulatory disorders with clinical signs of cardiovascular deconditioning are risk factors for the development of hypertension and CVD, accompanied by a more rapid increase in vascular stiff ness. Such abnormalities, even minor ones without clinical manifestations, increase the risk of hypertension development in the young population. The review deals with orthostatic changes in hemodynamics and features of neurohormonal change. It has been shown that adaptive processes counteracting an increase in hydrostatic pressure contribute to a significant transient increase in vascular stiff ness. The evolution of orthostatic hemodynamic disorders from preclinical to clinical forms accelerates the process of vascular wall remodeling, leading to a spontaneous increase in its rigidity — one of the significant risk factors for hypertension and CVD. To identify preclinical predictors, a new protocol of passive orthostatic test (POT) was developed. It was standardized not by the tilt angle, but by the height of the hydrostatic column. Further research is needed to evaluate the prognostic capabilities of predictors, to reveal the pathogenetic connection of orthostatic disorders with the development of hypertension, and to remodeling the vascular wall, which causes an increase in its rigidity. It is also required to search for ways to correct preclinical orthostatic disorders in healthy young population for early prevention of hypertension.

The purpose of the study: to study hemodynamic parameters and the degree of its orthostatic stability during verticalization in patients with long-term impairment of consciousness in post-comatose period of brain damage.Materials and methods. This study included 30 patients with long-term impairment of consciousness caused by severe brain damage (Group 1), 10 of whom were in a vegetative state (VS) and 20 patients had a minimally conscious state (MCS). A severe traumatic brain injury was the most frequent cause of long-term disorders of consciousness (53.3%), other causes were associated with severe disorders of cerebral circulation (13.4%) and following consequences: rupture of cerebral aneurysms (10%), or post-hypoxic brain damage (10%), or removal of brain tumors (13.3%). The second group was comprised of 24 patients with local neurological symptoms after cerebral circulation disorders. The third group included 40 healthy volunteers. Systemic hemodynamic parameters were monitored using a multifunctional monitor TFM 3040i (CNSystem Austria) . Blood pressure (BP), heart rate (HR), stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR) were measured in real time. The statistical analysis was carried out using the Statistica-10 software package.Results. 26 patients of the first group (86%) demonstrated satisfactory hemodynamic stability in the tilt test at 30° and 60°; 3 patients of this group presented signs of orthostatic hypotension and 1 patient developed postural orthostatic tachycardia syndrome (SPOT) when tilted by 30°. A comparative analysis of hemodynamic parameters in patients of the first and second groups did not demonstrate significant differences, except for significantly higher HR values and lower SV values in the first group. Parameters of systemic hemodynamics in the horizontal position were significantly different in healthy volunteers, and were characterized by higher SV and CO values and lower BP, HR and TPR values as compared to patients of groups 1 and 2.Conclusion. This study demonstrated a hypokinetic type of blood circulation in all patients with brain lesions; it was more severe in patients with long-term impaired consciousness after severe brain damage. The majority of patients in this group presented satisfactory orthostatic hemodynamic stability; different types of orthostatic disorders were found in 14% of cases. A passive orthostatic test (0—30—60°) applied in this study allowed to diagnose orthostatic disorders at a slight tilt up to the onset of clinical symptoms of brain hypoperfusion. This indicates the need for hemodynamic monitoring in the early stages of patients' verticalization.

Purpose of the study: to examine sensibility of baroreceptors and the autonomic nervous in the passive orthostatic test in patients with chronic impairment of consciousness due to severe brain damage and determine their role in the rehabilitation process.Materials and methods. The study included 30 patients with long-term impairment of consciousness due to severe brain damage (group 1), 10 of them being in the vegetative state (VS) and 20 being in the minimally conscious state (MCS). Craniocerebral trauma was the main cause of severe damage in that group (53% of patients). The comparison group included 24 patients with focal neurological symptoms caused predominantly — 79.2% of cases — by cerebrovascular disorders (group 2). The control group (group 3) consisted of 22 healthy volunteers of a comparable age. All measurements were done with the help of a Task Force Monitor 1030i (CNSystem, Austria) in the course of passive orthostatic test at 0°–30°–60°–0°. Changes in the power of low-frequency (LFS) and highfrequency spectrum (HFS) of heart rate variability and baroreceptors sensibility (BRS) were analyzed. Statistical analysis was carried out using Statistica-10 software. Significance of inter-group differences on unrelated samples was determined by the Mann–Whitney U-test. Differences between groups were considered significant at P 0.05.Results. Maximal background values of BRS were found in the control group. In group 1 and 2 patients, considerable decrease of that index was noted, which was proportional to the brain damage severity. Similar dynamics was observed for the indices of autonomic nervous system sensibility (LFS and HFS). The main trend of orthostatic changes of BRS, LFS, and HFS was characterized by progressive decrease of the indices with increase of the patients’ angle of tilting and their return to the baseline level after the patients were put back into the horizontal position. 4 patients of group 1 (14%) displayed signs of orthostatic disorders upon tilting to 30°: in 3 cases, orthostatic hypotension was observed, and in one case the postural orthostatic tachycardia syndrome (POTS) was diagnosed. Those patients differed by lower BRS and higher sympathetic system activity (LFS) vs. the same indices of other patients in that group.Conclusion. Patients with chronic impairment of consciousness during the post-comatose period after a severe brain damage display a significant decrease of baroreceptors sensibility and autonomic nervous system disorders manifesting in significantly lower activity of the sympathetic and parasympathetic systems. The prominence of such disorders is associated with brain damage severity. Their risk of developing orthostatic hypotension during tilting towards a vertical position is higher in patients who have lower baroreceptors sensibility, and this should be taken into account beginning the process of their verticalization.

Aim: to study orthostatic hemodynamic changes in patients with chronic disorders of consciousness after critical brain damage.Materials and methods. We studied 30 patients (10 women and 20 men) with chronic disorders of consciousness after severe brain damage aged 45±7 years, 10 of which were in the vegetative state (VS) and 20 had the minimally conscious state (MCS). The main causes of brain damage were traumatic brain injury (53% of patients) and cerebrovascular accidents (CVA) (23.3%). The rest of the patients had posthypoxic encephalopathy or were after brain tumor removal surgery. Passive orthostatic test (POT) 0° to 60° to 0° was performed using an electrically driven tilt table (Vario Line). Hemodynamic monitoring during the verticalization was done using a non-invasive oscillometric recording of blood pressure on the brachial artery, stroke volume (SV) and cardiac minute output (CMO) were measured by impedance cardiography with the multifunctional «Task Force Monitor 3010i» (CNSystem, Austria). Data were statistically analyzed using the Statistica 10 software package.Results. Orthostatic hemodynamic stability was found in 26 out of 30 patients with chronic disorders of consciousness after critical brain damage. It was manifested by stable systolic blood pressure (SBP) in tilted orthostatic and horizontal position (120.7±2.2 and 121.1±3.6 mmHg, respectively, P>0.05). Orthostatic hypotension was observed in 3 patients and postural tachycardia syndrome (PTS) in one patient. We compared orthostatic hemodynamic changes in the studied cohort versus published data on orthostatic hemodynamic changes uncluding POT revealed in patients with severe brain damage examined before and after brain death.Conclusion. Orthostatic stability of blood circulation can be maintained for a short period of time in patients surviving after critical diffuse brain damage associated with chronic disorders of consciousness. Critical brain damage resulting in brain death associates with a significant reduction of all hemodynamic parameters and severe orthostatic hypotension with restoration of initial blood pressure values when the patient is returned to the horizontal position.