Orthostatic Test Research Articles

Blood flow changes in the rabbit cranial and caudal venae cavae during postural loads after propranolol, bisoprolol and methyldopa pretreatment

To treat the hyperadrenergic form of postural orthostatic tachycardia syndrome, the β1,2-adrenergic receptor blocker propranolol, the β1-blocker bisoprolol and the central agonist of inhibitory presynaptic α2-adrenergic receptors, methyldopa, are used in clinical practice. There is no data in the literature concerning the effects of these drugs on venae cavae flows during postural tests. In acute experiments on anesthetized rabbits, we studied changes of cranial and caudal venae cavae flows during orthostatic (head up tilt by 25°) and antiorthostatic (head down tilt by −25°) tests for 20 s after preliminary pretreatment with propranolol, bisoprolol and methyldopa. Before administration of these drugs, in response to orthostasis at 4 and 20 s, a decrease of the cranial and caudal venae cavae flows was noted. During antiorthostasis, caudal venae cavae flow increased for 4 s, and by 20 s it decreased to the initial value; cranial venae cavae flow decreased by 4 s, and by 20 s it was greater than the initial one. After propranolol pretreatment, caudal venae cavae flow decreased to a greater extent compared with intravenous administration of bisoprolol and methyldopa. After methyldopa administration during orthostasis, by 20 s, the cranial venae cavae flow decreased more pronouncedly than in the caudal venae, while after propranolol and bisoprolol pretreatment under conditions of orthostasis, both cranial and caudal venae cavae flows decreased approximately to the same extent. During antiorthostasis by 20 s after pretreatment with propranolol caudal venae cavae flow increased more than cranial venae cavae flow. In case of pretreatment with bisoprolol and methyldopa, in response to antiorthostasis, cranial venae cavae flow increased not only to a greater extent than caudal venae cavae flow, but also more pronouncedly compared with its increase in rabbits initially. Thus, we concluded, that in case of postural loads after pretreatment with indicated above drugs, there are differences in the mechanisms of blood flows redistribution in the basins of the cranial and caudal venae cavae.

Morning versus Nocturnal Heart Rate and Heart Rate Variability Responses to Intensified Training in Recreational Runners

BackgroundResting heart rate (HR) and HR variability (HRV) are widely used parameters to assess cardiac autonomic nervous system function noninvasively. While resting assessments can be performed during sleep or after awakening, it would be relevant to know how interchangeable the results of these measurements are. This study aimed at examining the alignment between nocturnal and morning assessments during regular endurance training and in response to intensive training. A total of 24 recreational runners performed a 3-week baseline period (BL) and a 2-week overload (OL) period (Lucia’s training impulse + 80%). Their running performance was assessed with a 3000-m running test after the BL and OL. The participants recorded daily their nocturnal HR and HRV (the natural logarithm of the root mean square of successive differences; LnRMSSD) with a photoplethysmography-based wrist device and performed an orthostatic test (2-min supine, 2-min standing) every morning with a chest-strap HR sensor. The HR and LnRMSSD segments that were analyzed from the nocturnal recordings included start value (SleepStart), end value (SleepEnd), first 4-h segment 30 min after detected sleep onset (Sleep4h), and full sleep time (SleepFull). The morning segments consisted of the last-minute average in both body positions. All segments were compared at BL and in response to the 3000-m test and OL.ResultsAll nocturnal HR and LnRMSSD segments correlated with supine and standing segments at BL (r = 0.42 to 0.91, p < 0.05). After the 3000-m test, the HR increased and LnRMSSD decreased only in the SleepStart, Sleep4h, and SleepFull segments (p < 0.05). In response to the OL, the standing HR decreased (p < 0.01), while the LnRMSSD increased (p < 0.05) in all segments except for SleepStart. The Pearson correlations between relative changes in nocturnal and morning segments were − 0.11 to 0.72 (3000-m) and − 0.25 to 0.79 (OL). The OL response in Sleep4h HR and LnRMSSD correlated with the relative change in 3000-m time (r = 0.63, p = 0.001 and r=-0.50, p = 0.013, respectively).ConclusionsNocturnal and morning HR and LnRMSSD correlated moderately or highly in the majority of cases during the BL, but their responses to intensive training were not similarly aligned, especially in LnRMSSD. The nocturnal segments seemed to be sensitive to physical loading, and their responses were associated with the performance-related training responses.

Unraveling autonomic cardiovascular control complexity during orthostatic stress: Insights from a mathematical model

Understanding cardiovascular control mediated by the autonomic system remains challenging due to its inherent complexity. Consequently, syndromes such as orthostatic intolerance continue to evoke debates regarding the underlying pathophysiological mechanisms. This study develops a comprehensive mathematical model simulating the control of the sympathetic branch of the cardiovascular system in individuals with normal and abnormal responses to the head-up-tilt test. We recruited four young women: one control, one with vasovagal syncope, one with orthostatic hypertension, and one with orthostatic hypotension, exposing them to an orthostatic head-up tilt test (HUTT) employing non-invasive methods to measure electrocardiography and continuous blood pressure.Our work encompasses a compartmental model formulated using a system of ordinary differential equations. Using heart rate as input, we predict blood pressure, flow, and volume in compartments representing the veins, arteries, heart, and the sympathetic branch of the baroreflex control system. The latter is modulated by high- and low-pressure baroreceptor afferents activated by changes in blood pressure induced by the HUTT. Sensitivity analysis, parameter subset selection, and optimization are employed to estimate patient-specific parameters associated with autonomic performance. The model has seven sensitive and identifiable parameters with significant physiological relevance that can serve as biomarkers for patient classification.Results show that the model can reproduce a spectrum of blood pressure responses successfully, fitting the trajectory displayed by the experimental data. The controller exhibits behavior that emulates the operation of the sympathetic system. These encouraging findings underscore the potential of computational methods in evaluating pathologies associated with autonomic nervous system control, warranting further exploration and novel approaches.

Cardiovascular autonomic function in middle-aged people with long-term cervical and upper thoracic spinal cord injuries

Objectives To examine cardiovascular autonomic function in middle-aged people with long-term cervical and upper thoracic spinal cord injury (SCI) compared with the general population, and explore if the neurological level of injury (NLI) is related to cardiovascular autonomic function. Design Population-based cross-sectional study with matched controls. Setting Outpatient SCI unit in Southern Sweden. Participants Twenty-five individuals (20% women, mean age 58 years and mean time since injury 28 years, NLI C2-T6, American Spinal Injury Association Impairment Scale A-C) from the Swedish SPinal Cord Injury Study on Cardiopulmonary and Autonomic Impairment (SPICA). Matched controls were obtained from the population-based Swedish CArdioPulmonary bioImage Study (SCAPIS) at a ratio of 5:1. Interventions Not applicable. Outcome measures 24 h electrocardiography and deep breathing tests. 24 h ambulatory blood pressure (BP) monitoring and orthostatic BP tests. Results In individuals with SCI compared with controls, heart rate variability (24h mean SD of the normal-to-normal interval 112 ms vs 145 ms, P < 0.001) and diastolic orthostatic BP increase (2.0 and 9.4 mmHg, P < 0.001), were significantly lower, whereas BP variability was significantly higher (24h mean systolic SDBP 17.8 mmHg vs 15.7 mmHg, P = 0.029). Circadian patterns of heart rate variability and BP (lack of nocturnal dip) were significantly different among the individuals with SCI than controls. Higher NLI was significantly (P < 0.05) correlated with impairments to various cardiovascular autonomic function variables. Conclusions This exploratory study indicates that cardiovascular autonomic function is impaired in middle-aged people with long-term cervical and upper thoracic SCI compared with the general non-SCI population, and more pronounced with a higher NLI. Future research is needed to understand the pathophysiological mechanisms underlying these impairments, and the prognostic significance for individuals with SCI. Trial registration ClinicalTrials.gov identifier: NCT03515122.

Orthostatic testing for heart rate and heart rate variability monitoring in exercise science and practice.

Orthostatic testing, involving the transition from different body positions (e.g., from lying or sitting position to an upright or standing position), offers valuable insights into the autonomic nervous system (ANS) functioning and cardiovascular regulation reflected through complex adjustments in, e.g., measures of heart rate (HR) and heart rate variability (HRV). This narrative review explores the intricate physiological mechanisms underlying orthostatic stress responses and evaluates its significance for exercise science and sports practice. Into this matter, active orthostatic testing (e.g., active standing up) challenges the cardiovascular autonomic function in a different way than a passive tilt test. It is well documented that there is a transient reduction in blood pressure while standing up, leading to a reflex increase in HR and peripheral vasoconstriction. After that acute response systolic and diastolic blood pressures are usually slightly increased compared to supine lying body position. The ANS response to standing is initiated by instantaneous cardiac vagal withdrawal, followed by sympathetic activation and vagal reactivation over the first 25-30 heartbeats. Thus, HR increases immediately upon standing, peaking after 15-20 beats, and is less marked during passive tilting due to the lack of muscular activity. Standing also decreases vagally related HRV indices compared to the supine position. In overtrained endurance athletes, both parasympathetic and sympathetic activity are attenuated in supine and standing positions. Their response to standing is lower than in non-overtrained athletes, with a tendency for further decreased HRV as a sign of pronounced vagal withdrawal and, in some cases, decreased sympathetic excitability, indicating a potential overtraining state. However, as a significant main characteristic, it could be noted that additional pathophysiological conditions consist in a reduced responsiveness or counter-regulation of neural drive in ANS according to an excitatory stimulus, such as an orthostatic challenge. Hence, especially active orthostatic testing could provide additional information about HR(V) reactivity and recovery giving valuable insights into athletes' training status, fatigue levels, and adaptability to workload. Measuring while standing might also counteract the issue of parasympathetic saturation as a common phenomenon especially in well-trained endurance athletes. Data interpretation should be made within intra-individual data history in trend analysis accounting for inter-individual variations in acute responses during testing due to life and physical training stressors. Therefore, additional measures (e.g., psychometrical scales) are required to provide context for HR and HRV analysis interpretation. However, incidence of orthostatic intolerance should be evaluated on an individual level and must be taken into account when considering to implement orthostatic testing in specific subpopulations. Recommendations for standardized testing procedures and interpretation guidelines are developed with the overall aim of enhancing training and recovery strategies. Despite promising study findings in the above-mentioned applied fields, further research, thorough method comparison studies, and systematic reviews are needed to assess the overall perspective of orthostatic testing for training monitoring and fine-tuning of different populations in exercise science and training.

An Evaluation of the Autonomic Nervous Activity and Psychomotor Vigilance Level for Smells in the Work Booth

In this study, we investigated the effects of the smell environment in the work booth on autonomic nervous activity (ANS) and psychomotor vigilance levels (PVLs) using linalool (LNL) and trans-2-nonenal (T2N). The subjects were six healthy males (31 ± 6 years old) and six healthy females (24 ± 5 years old). They sat in the work booth filled with the smells of LNL and T2N for 10 min, and their electrocardiograms (ECGs), skin conductance levels, pulse wave variabilities, skin temperatures, and seat pressure distributions were measured. In addition, the orthostatic load test (OLT) and psychomotor vigilance test (PVT) were performed before and after entering the work booth, and a subjective evaluation of the smell was also performed after the experiment. This paper focused on ECG and PVT data and analyzed changes in heart rate variability indices and PVT scores. Males felt slightly comfortable with the LNL smell and showed promoted sympathetic nerve activity in the OLT after the smell presentation. Females felt slightly uncomfortable with the T2N smell and showed promoted sympathetic nerve activity and a decrease in PVT scores in the OLT after the smell presentation. Gender differences were observed in ANS and PVLs, and it is possible that the comfort of LNL increased sympathetic nervous activity in males, while the uncomfortableness of T2N may have reduced work performance in females.

Особенности вегетативной регуляции ритма сердца у пациентов с гипертонической болезнью после ишемического инсульта

INTRODUCTION. A decrease in heart rate variability indicates a violation of the autonomic control of cardiac activity, which is one of the reasons for the poor prognosis in this category of patients. Until now, the problem of the effectiveness and safety of correction of high blood pressure during the acute period of ischemic stroke remains a subject of debate. AIM. To determine clinical, autonomic and hemodynamic changes at rest and during an active orthostatic test to assess the functional state and adaptive capabilities of the cardiovascular system and identify risk factors for the unfavorable course of arterial hypertension in patients with hypertension in the acute period of ischemic stroke. MATERIAL AND METHODS. 78 patients with hypertension who were treated in a therapeutic hospital were examined. The first group consisted of 40 people with hypertension complicated by ischemic stroke, the second group included 38 people with uncomplicated hypertension. The patient's condition was assessed using the NIHSS scale and the Rankin scale. data from electrocardiography, duplex scanning of blood vessels, computed tomography of the brain, transthoracic ECHO-CG, portable monitor VNS-Micro and Poly-Spectrum SM from Neurosoft. The study of heart rate variability was carried out in patients with stroke upon admission, on days 5-10 and before discharge from the hospital (days 15-21). With the Revermead mobility index, more than 7 patients underwent an active orthostatic test with parallel ECG recording, measurement of blood pressure and heart rate at rest and when moving to a vertical position. RESULTS AND DISCUSSION. Patients with insufficient recovery of neurological functions on days 5-7 of stroke demonstrate the development of hypotension during an orthostatic test. An active orthostatic test on days 15-21 of stroke is successfully performed by patients with increased tone of the sympathetic nervous system. Patients with good recovery of neurological functions at discharge have normal autonomic reactivity and an adequate response of the sympathetic division of the autonomic nervous system to standing. CONCLUSION. Young men with hypertension should be closely monitored by physicians and receive primary stroke prevention. To increase tolerance to physical activity in patients who did not complete an active orthotest on days 5-7 of a stroke, daily passive verticalization is necessary. KEYWORDS: ischemic stroke, active orthotest, heart rate variability, hypertension, verticalization

Orthostatic hypotension in elderly patients (case report)

Introduction. Orthostatic hypotension (OH) is a common problem in elderly people, characterized by a pathological decrease in blood pressure (BP) upon moving to an upright position and leading to weakness, dizziness, and syncope.Aim. To present a clinical case of OH in an elderly patient and discuss the features of diagnosis and treatment of OH in his patient category.Materials and methods. A clinical case of a 76-year-old patient with a history of cancer who was diagnosed with OH is described. A comprehensive examination was performed, including a passive orthostatic test (tilt table test).Results. During the orthostatic test, a decrease in systolic BP by 18 mmHg upon verticalization and impaired baroreflex sensitivity were revealed. Based on the discussion of the clinical case and a literature review, the features of management of elderly patients with OH were considered, including the need for an individual approach taking into account comorbidity, functional status, and the risk of adverse effects of therapy. Recommendations for non-pharmacological methods of OH correction and careful selection of medications when drug treatment is necessary are given. The importance of educating patients and their relatives about measures to prevent OH and associated complications is emphasized.Conclusion. Timely diagnosis and correction of OH in elderly patients are essential for preventing falls, injuries, and improving quality of life. Management of patients with OH requires a comprehensive approach, taking into account individual characteristics, and should include both non-pharmacological methods and rational pharmacotherapy.

Hindfoot Alignment in Flexible Cavovarus Deformity Under Orthostatic and Coleman Block Test Positions: A Weightbearing Computed Tomography Study.

Flexible cavovarus deformity is prevalent and the Coleman block test is frequently used to assess the first ray plantarflexion malpositioning in the overall deformity as well as the flexibility of the hindfoot. The objective was to assess and compare the weightbearing computed tomography (WBCT) 3-dimensional (3D) changes in clinical and bone alignment in flexible cavovarus deformity patients when performing the Coleman block test when compared to normal standing position and to controls. Twenty patients (40 feet) with flexible cavovarus deformity and 20 volunteer controls (40 feet) with normal foot alignment underwent WBCT imaging of the foot and ankle. Cavovarus patients were assessed in normal orthostatic and Coleman block test positions. Foot and ankle offset (FAO), hindfoot alignment angle (HAA), talocalcaneal angle (TCA), subtalar vertical angle (SVA) and talonavicular coverage angle (TNCA) and a CT-simulated soft tissue envelope image, WBCT clinical hindfoot alignment angle (WBCT-CHAA), were evaluated by 2 readers. Measurements were compared between cavovarus nonstressed and stressed positions and to controls. P values of .05 or less were considered significant. The intra- and interobserver intraclass correlation coefficient were good or excellent for all WBCT measurements. Cavovarus patients demonstrated significant correction of WBCT-CHAA (9.7 ± 0.4 degrees), FAO (2.6 ± 0.4%), and TNCA (8.8 ± 1.8 degrees) when performing the Coleman block test (all P values <.0001). However, WBCT-CHAA and FAO measurements were still residually deformed and significantly different from controls (P values of .001 and <.0001, respectively). TNCA values corrected to values similar to healthy controls (P = .29). No differences were observed in cavovarus patients during Coleman block test for the coronal measures: HAA, TCA, and SVA measurements. In this study, we observed improvement in the overall 3D WBCT alignment (FAO), axial plane adduction deformity (TNCA), as well as CT simulated clinical hindfoot alignment (WBCT-CHAA) in flexible cavovarus deformity patients when performing a Coleman block test. However, we did not find improvement in measures of coronal alignment of the hindfoot, indicating continued varus positioning of the hindfoot in these patients.

Validation of the Chinese orthostatic discriminant and Severity Scale (ODSS) for detection of orthostatic intolerance syndrome

BackgroundOrthostatic intolerance (OI) is the inability to tolerate orthostatic stress during any postural change. The etiology of OI varies, and methods to obtain a specific diagnosis and plan appropriate treatment are important. The tools available within the Chinese context to swiftly identify orthostatic intolerance syndrome (OIS) are currently limited. MethodsPatients with OI symptoms were included in this study and categorized into two groups based on the results of the supine-to-stand test. Those with abnormal test results were assigned to the OIS group, while those with normal test results were placed in the non-OIS group. We evaluated the internal consistency and predictive value of the Chinese Orthostatic Discriminant and Severity Scale (ODSS) by comparing patients’ scores with their physiological measurements collected during orthostatic stress tests and the results of other available questionnaires, including the orthostatic Symptom Questionnaire and Orthostatic Grading Scale (OGS). ResultsPatients with OIS scored significantly higher on all three questionnaires and showed significant differences in autonomic responses during orthostatic stress tests compared with non-OIS patients. Receiver operating characteristic curve analysis showed that the orthostatic score from the ODSS had moderate predictive value for the supine test (area under the curve [AUC] = 0.754). Further subgroup analysis revealed that the orthostatic score from the ODSS had uniquely high specificity and sensitivity for identifying patients with orthostatic hypotension with abnormal cerebral blood flow (OH–U, AUC = 0.919). ConclusionsWe conclude that the Chinese version of the ODSS has sufficient reliability and validity to distinguish patients with OIS and could possibly be used as a diagnostic tool for OH–U patients. Thus, the Chinese ODSS offers a beneficial screening tool for quickly assessing whether patients have OIS that requires further clinical assessment.

EFFECTS OF SHORT-TERM PRACTICE OF FAST DEEP BREATHING EXERCISE ON PARASYMPATHETIC FUNCTIONS IN TRANS-FEMORAL AND TRANS-TIBIAL-AMPUTATION PATIENTS

Background of the Study: After lower limb amputation, the functioning parasympathetic system is compromised so the regular practice of breathing techniques improves cardiorespiratory functions. To determine the effects of short-term fast-breathing exercises on parasympathetic functions in amputees. Methodology: The study was conducted at the Armed Forces Institute of Rehabilitation Medicine Rawalpindi, on 61 stable transfemoral and transtibial amputation patients within the duration of six months (January to June 2017), performed fast deep breathing exercises Parasympathetic functions were observed through different variables. Data was analyzed using IBM® SPSS® v 21. Results: Breathing exercises showed significant effects on HR with a p-value of (0.000), the Valsalva ratio had a p-value of (0.000), and oxygen saturation was improved in both control and experimental groups with p-values of (0.000) and (0.000). Valsalva’s BP systolic and diastolic p values were (0.001) (0.012), breathing exercise BP systolic and diastolic values were (0.16) and (0.000), and orthostatic testing BP systolic and diastolic p values were (0.134) and (0.389). Post Borg scale readings showed a significant decrease in exertion level Conclusion: The study concludes that short-term fast deep breathing exercise improves cardiovagal functioning.

The change in Baroreflex Regulation of Heart Rhythm after “Dry” Immersion Appears during Orthostasis, but not Lower Body Negative Pressure Test

The ratio of low-frequency (LF, ~0.1 Hz) waves of RR interval duration (RRI) and systolic blood pressure (SAP) reflects the cardiac baroreflex sensitivity (BRS). Gravitational unloading (GU) may alter BRS during the passive orthostatic test (HUT) and lower body negative pressure (LBNP) test. Both effects cause blood redistribution to the lower body, but HUT is accompanied by greater unloading of sinocarotid baroreceptors than LBNP and activation of the vestibulosympathetic reflex but GU effects on BRS in these tests have not been directly compared previously. In this study we tested the hypothesis that the effect of “dry” immersion (DI, on-ground model of GU) on BRS in the same subjects will be more pronounced during HUT than during LBNP, which causes a comparable decrease in stroke volume. Nine healthy men participated in two test sessions (before and after 7-day DI) consisting of five 3-min HUT (65°) and five 3-min LBNP (–35 mmHg) with averaging the parameters in each test. Wavelet analysis was used to determine the amplitude of the RRI and SAP waves in the range of 0.05–0.13 Hz. The amplitude of LF waves of SAP increased in both tests, after DI - more significantly in HUT. The amplitude of LF RRI waves decreased in the two tests; the degree of decrease did not differ between tests and did not change under the influence of DI. The α-coefficient (the ratio of the amplitudes of RRI and SAP LF waves) decreased equally in the two tests before DI, but after DI, the degree of α-coefficient reduction increased in HUT test but did not change in LBNP test. Thus, the effect of DI on BRS is evident in HUT, but not in LBNP, which may be explained by the more pronounced influence of HUT on the mechanisms of neural control of heart rhythm.

Heated environment increases blood pressure drop and postural sway during initial orthostasis in healthy subjects.

We tested the hypothesis that heat stress influences the closed-loop cardio-postural control by an increased blood pressure (BP) drop and postural sway. Fourteen healthy individuals (eight women) performed two orthostatic tests under thermal reference (TC; ~ 24ºC) and HOT (~ 38ºC) conditions. The center-of-pressure (COP) displacements and the electromyography (EMG) activity of the calf muscles (medial gastrocnemius and tibialis anterior) were recorded during the initial orthostasis (ORT onset) after the supine-to-stand challenge. At the same period, BP (beat-to-beat) was continuously monitored, and supine-to-stand variations (∆%) were calculated. Sublingual temperature (Tsl) was measured as a surrogate of internal temperature. Tsl increased in HOT compared to TC (TC 36.5 ± 0.3 vs. HOT 36.7 ± 0.3ºC; p < 0.01). COP distance was greater in HOT compared to TC condition (TC 596.6 ± 242.4 vs. HOT 680.2 ± 249.1mm; p < 0.01). EMG activity of the gastrocnemius decreased in HOT compared to TC condition (TC 95.5 ± 19.8 vs. HOT 78.4 ± 22.8%mV; p = 0.02). EMG of tibialis did not change between TC and HOT (TC 83.5 ± 42.9 vs. HOT 66.1 ± 31.9%mV; p = 0.29). BP showed a greater fall in HOT compared to TC condition (∆%TC -24.5 ± 13.2 vs. ∆%HOT -33.2 ± 20.2%; p = 0.01). Heat stress causes a greater fall in blood pressure and a reduction in musculoskeletal pump activity during orthostatic onset. These effects could be potential mechanisms that underlie augmented postural instability under a heated environment.

Cardiohemodynamic responses and heart rate variability following an active orthostatic test among male residents of the North with different NOS3 (rs2070744) genotypes

AIM: This study explored associations between the -786TC (rs2070744) genetic polymorphism of the NOS3 gene and the main indices of systemic hemodynamics and heart rate variability following an active orthostatic test in men living in the North. MATERIAL AND METHODS: Eighty-three healthy men aged 33.5±1.5 yеаrs on average, who were permanent residents of the Magadan Region, comprised the sample. The participants underwent both resting and active orthostatic testing modes. Cardiovascular system variables were recorded using an automatic tonometer. Hemodynamic indices were then calculated. Short-term heart rate variability in frequency and spectral areas was simultaneously measured using the Varikard hardsoft complex unit. Genotyping was conducted using polymerase chain reaction. The sample was then divided into two groups: Group 1 consisted of homozygotes with the TT genotype (n=34), while Group 2 comprised carriers of the NOS3*C allele variant (genotypes TC+CC) associated with reduced nitric oxide production (n=49). RESULTS: By examining the complex vasomotor, chrono- and inotropic reactions of hemodynamic and heart rate variables during the active orthostatic test, we were able to discern unique patterns in the response of the two groups under study. Men in Group 1 demonstrated an elevated cardiac output response during orthostatic changes, while maintaining consistent vascular resistance values. This was accompanied by a shift towards sympathetic autonomic activity and an increase in the very low-frequency component of heart rate variability. In Group 2, individuals with sympathetic insufficiency and increased vascular resistance during the orthostatic test showed a 35% increase in the low-frequency component of the cardiac rhythm reflecting the importance of this indicator as a stimulator of blood pressure rhythm fluctuations mediated by baroreflex mechanisms. CONCLUSION: Our findings suggest that men lacking the NOS3*С allele variant in their genotype demonstrate more favorable responses to the active orthostatic test. This may reflect higher level of cardiovascular functional reserves. The 786TC (rs2070744) polymorphism of the NOS3 gene can be considered as a marker of cardiohemodynamic status and autonomic regulations during functional exercise, such as an active orthostatic test.

Special aspects of the cardiovascular system regulation and cerebral blood flow under gravitational influences. Review (part 2)

This survey presents the material of neuroradiologic methods of investigation brain structures and function which changes during space flight. It’s taken to attention from inspection of cerebral blood circulation, reversibility of changes in the volumes of gray and white matter, features of neuroplasticity and the formation of new connectivity properties not previously discovered on Earth. The results of magnetic resonance imaging studies, changes in the balance of body fluids, indicators of the cardiovascular system under orthostatic testing, and features of the formation of blood circulation regulation during sleep, which is an integral component of adaptation to microgravity conditions, are presented.

#1821 Baroflex sensitivity and hemodynamic responses during physical and mental tests: a comparative study between HD and PD patients

Abstract Background and Aims Cardiac arrhythmias and sudden death are the leading causes of mortality in end-stage kidney disease (ESKD) and autonomic dysfunction is considered to play a predominant role. This is the first study to compare baroreflex sensitivity (BRS) and hemodynamic responses after mental- and physical-stimulation maneuvers between hemodialysis (HD) and peritoneal (PD) patients. Method 68 ESKD patients (34 HD and 34 PD patients matched for age, sex, and dialysis-vintage) were included. Continuous recordings from Finometer-PRO at rest and during mental-arithmetic, orthostatic, and handgrip-exercise tests were used for calculation of BRS and hemodynamic responses in each individual. Results The two groups were similar in terms of age, sex, dialysis vintage and major comorbidities. BRS during mental (HD 3.59 ± 2.62 vs PD 5.50 ± 9.40 ms/mmHg, p = 0.280) and physical stress tests (orthostatic: HD 3.23 ± 2.42 vs PD 2.07 ± 2.69 ms/mmHg, p = 0.777) was similar between HD and PD patients. During mental test, both groups presented increases in SBP/DBP levels compared to rest (SBP HD: 156.3 ± 27.7 vs 142.7 ± 20.0 mmHg, p &amp;lt; 0.05; PD: 158.0 ± 25.6 vs 143.1 ± 23.6 mmHg, p &amp;lt; 0.05, respectively), but without significant between-group differences (p = 0.853/p = 0.611 respectively for SBP/DBP). Similarly, no significant between-group differences were noted in stroke volume, cardiac output, and total peripheral resistance during the same testing period. The mean SBP levels during the orthostatic test were significantly decreased compared to rest in both groups (HD: 135.4 ± 26.8 vs 142.2 ± 20.1 mmHg; p &amp;lt; 0.05; PD 135.3 ± 21.9 vs 143.1 ± 23.6 mmHg; p &amp;lt; 0.05), but the overall response was not different between-groups (p = 0.937). Similarly, the responses to the other hemodynamic parameters were similar between HD and PD. Finally, the hemodynamic responses during handgrip exercise and recovery were not differed between HD and PD. Conclusion BRS and hemodynamic responses to mental and physical stress tests were similar between HD and PD patients, suggesting that ANS function in ESKD is not affected by dialysis modality.

Geriatric ophthalmologic co-management : A case report of interdisciplinary collaboration

This case report details the assessment and interdisciplinary collaboration in the management of an 81-year-old patient presenting with acute visual impairment, dizziness, general weakness, gait disturbances and fear of falling. A holistic geriatric evaluation revealed orthostatic dysregulation and an underlying multifactorial gait disorder exacerbated by visual impairment. Ophthalmological findings included left central retinal artery branch occlusion and cataracts. A comprehensive geriatric assessment showed frailty, impaired mobility and decreased functional abilities. Subsequent patient-centered interdisciplinary approaches included treatment for retinal ischemia, orthostatic testing, medication reconciliation, physiotherapy and occupational therapy. This case emphasizes how interdisciplinary collaboration between ophthalmology and geriatrics enables proactive assessment and intervention to reduce the risk of functional decline and loss of autonomy in visually impaired patients, which is of particular relevance considering the increasing prevalence of visual impairment in the ageing population.

Cardiac Autonomic Neuropathy in Graves' Disease: Smoking and Age as Predictive Factors

ObjectivesHypermetabolic state in Graves' disease (GD) has a great impact on heart homeostasis, acting directly on the heart muscle and modulating the autonomic nervous system. To characterize cardiac autonomic neuropathy (CAN) as a possible complication in patients with GD. MethodsWe evaluated euthyroid GD patients and a control group of healthy euthyroid people. CAN was assessed using autonomic tests of cardiovascular reflex and heart rate variability: respiratory, Valsalva, orthostatic and orthostatic hypotension tests, high frequency, low frequency, and very low-frequency bands. Transthoracic echocardiography was performed in GD patients. ResultsSixty GD patients and 50 people in control group were assessed. CAN was diagnosed in 20% of GD and 14% in the control group. Among GD, 13.3% presented incipient, and 6.7% established CAN, while in the control group, it was verified incipient in 8% and established in 6% (P = .7479). All GD patients with CAN presented an alteration in the deep breathing test. Age and smoking were evidenced as factors associated with the presence of CAN, while higher TRAb values at diagnosis decreased the chance of CAN. ConclusionsThe prevalence of CAN in euthyroid GD patients was 20%. Changes in the cardiac autonomic nervous system were identified, pointing to the importance of evaluating this complication in these patients. Smoking was a predictive factor for CAN, increasing its relationship with conditions that aggravate GD.

The Analysis of The Functional Status of Female Soldiers In The Conditions of The Legal Regime of The Martial State

This article presents the results of a study on the cardiorespiratory system of 30 female soldiers during a period of legal regime of martial state. It is important to note that all investigated cardiovascular parameters, determined by median, were within age norms. Our findings from hypoxic tests demonstrated that the functional capacity of the respiratory system of female military personnel was within age norms as well. The results also confirm that this category has the ability to effectively operate in hypoxic conditions, which is a crucial aspect for professional performance. Analysis of orthostatic test results indicates a significant variability in the body’s reactions to body position changes, with a median value of 5.0 bpm, a minimum of 0.0 bpm, and a maximum of 56.0 bpm. This means that female soldiers have different levels of adaptation. However, it is worth noting the stability of the cardiovascular system’s response to orthostatic stress, with minimal changes in systolic and diastolic blood pressure at 5 mmHg, indicating cardiovascular stability during orthostatic activity. In the vast majority of female military personnel (60.0%), hemodynamic reactions to changes in body position indicate a high level of adaptive capacity of the cardiovascular system. The results of the study of the functional state of the cardiovascular and respiratory systems in female military personnel indicate compliance with the majority of physiological norms; however, isolated cases are observed where the detected values may indicate certain abnormalities, particularly arterial hypertension. The results of respiratory tests indicate a normal response of the female military personnel's bodies to hypoxia conditions, which is important for fulfilling their service duties.

BLOOD PRESSURE CONTROL AND CIRCADIAN RHYTHM AMONG PATIENTS WITH PROGRESSIVE GLAUCOMA – PRELIMINARY RESULTS

Objective: Blood pressure (BP) control, postural changes and daily variability in patients with progressive glaucoma. Design and method: The study included 55 patients with different duration of open-angle glaucoma who had disease progression during the visit qualifying for this observational study. During two separate visits with 7 to 14 days interval, an ophthalmological and the clinical examination (standardized questionnaire, three BP measurements, orthostatic test, 24hour ABPM) were performed. The criterion for hypertension (HT) control in treated patients aged 80 years and over was office BP &lt;150/90 mmHg. Postural hypotension was defined as a drop in systolic BP (SBP) of at least 20 mmHg and/or a drop in diastolic BP (DBP) of at least 10 mmHg within 1, 3, or 5 minutes after standing. The validated devices were used to obtain BP measurements. Results: The mean age of patients was 69 years, most subjects were over 60 years of age; 40% were men, 75% were treated for hypertension (HT). ∗Data from ABPM are currently available for 39 patients. Patients with glaucoma progression noted in the short course of the disease (&lt;5 years) were more likely to have uncontrolled HT in the office setting; in ABPM also had higher daytime SBP and greater daily SBP variability, although no statistical significance was observed. In turn, the oldest patients with long-term (&gt;10 years) progressive glaucoma had too low nighttime SBP and DBP values. Conclusions: Conclusions. The results indicate an unfavorable prognostic impact of insufficient HT control and daily BP variability in people with a few years of glaucoma history. In the oldest patients, too low BP levels throughout the 24-hour period may contribute to its progression. Since most our patients had ABPM performed for the first time, emphasis should be placed on more frequent monitoring of circadian BP profile in glaucoma patients, especially among the oldest.