Decrease In Peripheral Resistance Research Articles

Impact of the COVID-19 pandemic on acute ischemic stroke medical care: a prospective study

INTRODUCTION: Acute ischemic stroke (AIS) is not uncommon in patients with novel coronavirus infection. During the COVID-19 pandemic, an increase of the frequency of adverse clinical and functional outcomes of AIS was noted.OBJECTIVE: The recent study was to evaluate the impact of the COVID-19 pandemic on the clinical and diagnostic characteristics of patients with AIS, as well as on the results of various types of treatment.MATERIALS AND METHODS: The prospective study included 460 patients with AIS after systemic or selective thrombolysis, thromboextraction and combination of thromboextraction with thrombolysis and stenting, hospitalized in 2019–2022: 55 patients in 2019, and in 2020–2022 — 405 patients. All patients were clinically evaluated using NIHSS and Rankin scales. Instrumental data included: assessment of computed tomography (CT) lesion size, extracranial and transcranial Duplex ultrasound (DUS) and computed angiography. Patients who received invasive treatment (thromboextraction, including in combination with thrombolysis or stenting) underwent cerebral angiography (CA). The characteristics of cerebral hemodynamics before and after the use of various types of treatment, clinical and functional outcomes were subject for comparison.Statistics: The statistical software Statistica 12.0, SPSS Statistics 17.0 were used. Normality of distribution was assessed using the Shapiro–Wilks test. Comparison of groups based on quantitative parameters was carried out using the Mann–Whitney U test. When testing statistical hypotheses, the acceptable level of error of the first type was considered to be a value not exceeding 0.05. To assess the correlation between parameters, the Spearman method was used.RESULTS: During the pandemic of COVID-19, patients with AIS were younger, had lower percentage of comorbidities and a higher NIHSS score. A significantly lower rate of favorable clinical and functional outcomes was obtained during the pandemic compared to the period before the pandemic, including after the use of invasive treatment methods: only 47% of patients had clinical improvement during the pandemic, while in 2019 the proportion of favorable outcomes was 64% (p=0.003). There was an increase in the share of pulmonary embolism and pneumonia in the structure of mortality from AIS during the pandemic (25% in the period before the pandemic vs 38% during the pandemic). Duplex ultrasound of cerebral arteries demonstrated high comparability with angiography data (correlation coefficient with invasive methods 0.84).DISCUSSION: According to the literature data, strokes are not uncommon in patients with COVID-19, especially in those with severe disease and risk factors. The authors consider thrombosis and/or thromboembolism of cerebral arteries to be possible ways of cerebral ischemia. According to Russian scientists, from the beginning of the pandemic, a significant increase in the incidence of ischemic stroke of varying severity was noted. The statistical pattern we identified confirms the data from literature sources that when infected with the SARS-CoV-2 virus, the brain and cerebral arteries are target organs. It is significant for clinical practice that we have evaluated the clinical and instrumental characteristics of these lesions in relatively homogeneous gender, age and clinical groups.CONCLUSION: The incidence of favorable clinical and functional outcomes during the pandemic was significantly lower compared to the pre-pandemic period. Complete and partial restoration of blood flow, as well as a decrease in the ischemic focus, were significantly more common before the pandemic. The effectiveness of invasive methods of cerebral revascularization during the pandemic were also lower. Duplex ultrasound serves as a reliable method not only for primary diagnosis, but also for dynamic monitoring. Initial changes in hemodynamics in patients with AIS before and during the pandemic did not differ significantly and were represented by hypoperfusion with a decrease in peripheral resistance. In 2020–2022 after treatment, hypoperfusion was observed significantly more often, which can be considered as one of the reasons for the less favorable clinical and functional outcomes obtained during the pandemic.

Lowering blood pressure by exercise: investigating the effect of sweating.

High blood pressure (hypertension), is a common medical condition, affecting millions of people and is associated with significant health risks. Exercise has been suggested to manage hypertension by inducing sweating and the corresponding loss of sodium and water from the body.Thus, a variety of epidemiological and clinical studies have been conducted to investigate the relationship between sweating and exercise-induced blood pressure reduction and its impacts on hypertension. The mechanisms underlying exercise-induced blood pressure reduction are complex and still not fully understood. However, several pathways have been suggested, including the loss of sodium and water through sweat, a decrease in peripheral resistance, and an improvement in endothelial function in the blood vessels. The decrease in sodium and water content in the body associated with sweating may result in a reduction in blood volume and thus a decrease in blood pressure. Moreover, the reduction in peripheral resistance is thought to be mediated by the activation of the nitric oxide synthase pathway and the release of vasodilators such as prostacyclin and bradykinin, which lead to vasodilation and, thus, a reduction in blood pressure. In conclusion, exercise-induced sweating and consequent sodium and water loss appear to be a reliable biological link to the blood pressure-reducing effects of exercise in hypertensive individuals. Additionally, the mechanisms underlying exercise-induced blood pressure reduction are complex and involve several biological pathways in the cardiovascular system. Therefore, understanding the role of sweat production in blood pressure management is important for developing effective exercise interventions to prevent and manage hypertension.

Modulating Effect of Extremely High-Frequency Low-Intensity Electromagnetic Radiation on Tissue Oxidative Metabolism and Skin Microhemodynamics

We set out to examine the indicators of microhemodynamics and tissue oxidative metabolism in rats after their tenfold exposure to extremely high-frequency low-intensity electromagnetic radiation (EHF EMR). The aim was to elucidate the specifics of skin microcirculation and tissue oxidative metabolism following exposure to tenfold electromagnetic radiation of extremely high frequency. The experiment was carried out on 40 mature male Wistar rats weighing 200–220 g, which were kept in standard vivarium conditions under natural light regimen. The animals were divided into two groups with 20 rats each. The animals in the first group were biological controls and were exposed to false EHF EMR (placebo); the animals in the second group were exposed to mm-exposure in the morning, 10 sessions daily. On the 10th day of EMR exposure, the indicators of skin tissue fluorescence on the tail base were recorded. Tenfold exposure to low-intensity EHF EMR was shown to increase the concentration and intensity of NADH fluorescence, as well as the FAD and redox ratio. This indicates an increased cellular demand for ATP and the predominance of oxidative phosphorylation over other processes, thus demonstrating the activation of the respiratory chain. At the same time, an increase in endothelium-dependent vasodilation, a decrease in peripheral resistance, an increase in blood flow to the nutritive microvascular bed, and an improvement in venular outflow were observed in the microcirculatory bed. The conclusion is made that the modulating effect of EHF EMR is manifested in the rearrangements of correlations. Thus, the coefficient of variation comes to the fore – the final calculated indicator of microcirculation, which has strong negative associations with all indicators of tissue metabolism (FAD, NADH, RR). In addition, the amplitudes of endothelial rhythms associated with periodic releasing of nitric oxide by the endothelium show a strong negative association with FAD.

Recurrent reflex syncope in idiopathic intracranial hypertension patient resolved after lumbar puncture: pathogenetic implications

BackgroundIdiopathic intracranial hypertension is a disease characterized by increased intracranial cerebrospinal fluid volume and pressure without evidence of other intracranial pathology. Dural sinuses are rigid structures representing a privileged low-pressure intracranial compartment. Rigidity of dural sinus ensures that the large physiologic fluctuations of cerebrospinal fluid pressure associated with postural changes or to Valsalva effect cannot be transmitted to the sinus. An abnormal dural sinus collapsibility, especially when associated with various anatomical sinus narrowing, has been proposed as a key factor in the pathogenesis of idiopathic intracranial hypertension. This pathogenetic model is based on an excessive collapsibility of the dural sinuses that leads to the triggering of a self-limiting venous collapse positive feedback-loop between the cerebrospinal fluid pressure, that compresses the sinus, and the increased dural sinus pressure upstream, that reduces the cerebrospinal fluid reabsorption rate, increasing cerebrospinal fluid volume and pressure at the expense of intracranial compliance and promoting further sinus compression. Intracranial compliance is the ability of the craniospinal space to accept small volumetric increases of one of its compartments without appreciable intracranial pressure rise. In idiopathic intracranial hypertension, a condition associated with a reduced rate of CSF reabsorption leading to its volumetric expansion, a pathologically reduced IC precedes and accompanies the rise of ICP. Syncope is defined as a transient loss of consciousness due to a transient cerebral hypoperfusion characterized by rapid onset, short duration, and spontaneous complete recovery. A transient global cerebral hypoperfusion represents the final mechanism of syncope determined by cardiac output and/or total peripheral resistance decrease. There are many causes determining low cardiac output including reflex bradycardia, arrhythmias, cardiac structural disease, inadequate venous return, and chronotropic and inotropic incompetence. Typically, syncopal transient loss of consciousness is mainly referred to an extracranial mechanism triggering a decrease in cardiac output and/or total peripheral resistance. Conversely, the association of syncope with a deranged control of intracranial compliance related to cerebral venous outflow disorders has been only anecdotally reported.Case PresentationWe report on a 57-year-old woman with daily recurrent orthostatic hypotension syncope and idiopathic intracranial hypertension-related headaches, which resolved after lumbar puncture with cerebrospinal fluid subtraction.ConclusionsA novel mechanism underlying the triggering of orthostatic syncope in the presence of intracranial hypertension-dependent reduced intracranial compliance is discussed.

Effects of aerospace environments on the cardiovascular system.

Certain physical and physiological changes occur in the atmospheric levels where flight and space activities take place. Air pressure decreases with increasing altitude and the partial pres¬sure of O2 decreases in parallel with the atmospheric pressure drop and creates hypoxia in the flight crew and in the passen¬gers. In case of acute hypobaric hypoxia, blood is redistributed to the brain and the heart, whereas blood supply to internal organs, such as kidney and skin is reduced. Peripheral cyanosis can be observed on the fingertips and the lips during hypoxia-induced blood redistribution. Tachycardia develops, but the stroke volume does not change. The coronary blood flow increases in parallel with the rise of cardiac output; however, the presence of severe hypoxia leads to myocardial depression. Coronary reflex vasoconstriction is followed by cardiac arrest. Another important pathology caused by low pressure is decompression sickness. In this disease, immediate reduction of the environmental pressure leads to the dissolved nitrogen transforms into gas, and nitrogen bubbles form in the tissue and in the blood. These bubbles interfere the perfusion of the blood and cause ischemia. Symptoms and signs of cardiac decompression sicknesses are dyspnea, tachypnea, chest pain, cough, hemoptysis, cyanosis, retrosternal discomfort, and rarely, shock. Air embolism of coronary vessels manifests as rhythm disturbances, myocardial infarction, and circulatory collapse. The physical forces that occur because of aircraft move¬ment and affect both the pilot and the aircraft, are called acceleration (G) forces. The basic physical effect of G forces is weight increments and motion restriction. During high +Gz, blood pressure decreases in the brain and increases in the lower extremities. Blood forced to move into the lower parts of the body and lower extremities. Thus, brain perfusion cannot be achieved, and loss of consciousness occurs at approximately +4 Gz acceleration levels. Earth also applies an acceleration force to the objects on or around the world. Therefore, gravitational force is also applied to orbiting spacecraft by Earth. The centrifugal force and the gravitational force are in an equilibrium, weightlessness is created inside the orbiting spacecraft, and this is called microgravity. Blood redistributed to the neck and head veins, and astronauts feel nasal fullness, and bulging around the eyes during space missions. As the time spent in the space progresses, a 22% decrease in plasma volume is observed in the cardiovascular system within 1 week owing to increased venous return, and this causes a temporary hemoconcentration. After staying one week in space, cardiac output increases by 22% whereas peripheral resistance decreases by 14%. Rhythm disturbances are also seen during activities performed in space is and thought to be caused by electrolyte imbalance or stress. There is an increasing demand for high altitude and space travel nowadays. These trips cause several physical and physiological effects on both passenger and flight crew. Therefore, it is necessary to take precautionary measures to carry out these activities safely.

Self-Nanoemulsifying Drug Delivery System Loaded with Psiadia punctulata Major Metabolites for Hypertensive Emergencies: Effect on Hemodynamics and Cardiac Conductance.

Vasodilators are an important class of antihypertensive agents. However, they have limited clinical use due to the reflex tachycardia associated with their use which masks most of its antihypertensive effect and raises cardiac risk. Chemical investigation of Psiadia punctulata afforded five major methoxylated flavonoids (1–5) three of which (1, 4, and 5) showed vasodilator activity. Linoleic acid-based self-nanoemulsifying drug delivery system (SNEDDS) was utilized to develop intravenous (IV) formulations that contain compounds 1, 4, or 5. The antihypertensive effect of the prepared SNEDDS formulations, loaded with each of the vasodilator compounds, was tested in the angiotensin-induced rat model of hypertension. Rats were subjected to real-time recording of blood hemodynamics and surface Electrocardiogram (ECG) while the pharmaceutical formulations were individually slowly injected in cumulative doses. Among the tested formulations, only that contains umuhengerin (1) and 5,3′-dihydroxy-6,7,4′,5′-tetramethoxyflavone (5) showed potent antihypertensive effects. Low IV doses, from the prepared SNEDDS, containing either compound 1 or 5 showed a marked reduction in the elevated systolic blood pressure by 10 mmHg at 12 μg/kg and by more than 20 mmHg at 36 μg/kg. The developed SNEDDS formulation containing either compound 1 or 5 significantly reduced the elevated diastolic, pulse pressure, dicrotic notch pressure, and the systolic–dicrotic notch pressure difference. Moreover, both formulations decreased the ejection duration and increased the non-ejection duration while they did not affect the time to peak. Both formulations did not affect the AV conduction as appear from the lack of effect on p duration and PR intervals. Similarly, they did not affect the ventricular repolarization as no effect on QTc or JT interval. Both formulations decreased the R wave amplitude but increased the T wave amplitude. In conclusion, the careful selection of linoleic acid for the development of SNEDDS formulation rescues the vasodilating effect of P. punctulata compounds from being masked by the reflex tachycardia that is commonly associated with the decrease in peripheral resistance by most vasodilators. The prepared SNEDDS formulation could be suggested as an effective medication in the treatment of hypertensive emergencies, after clinical evaluation.

Bay 60-7550, a PDE2 inhibitor, exerts positive inotropic effect of rat heart by increasing PKA-mediated phosphorylation of phospholamban

This study investigated the hemodynamic effect of Bay 60-7550, a phosphodiesterase type 2 (PDE2) inhibitor, in healthy rat hearts both in vivo and ex vivo and its underlying mechanisms. In vivo rat left ventricular pressure-volume loop, Langendorff isolated rat heart, Ca2+ transient of left ventricular myocyte and Western blot experiments were used in this study. The results demonstrated that Bay 60-7550 (1.5 mg/kg, i. p.) increased the in vivo rat heart contractility by enhancing stroke work, cardiac output, stroke volume, end-diastolic volume, heart rate, and ejection fraction. The simultaneous aortic pressure recording indicated that the systolic blood pressure was increased and diastolic blood pressure was decreased by Bay 60-7550. Also, the arterial elastance which is proportional to the peripheral vessel resistance was significantly decreased. Bay 60-7550 (0.001, 0.01, 0.1, 1 μmol/l) also enhanced the left ventricular development pressure in non-paced and paced modes with a decrease of heart rate in non-paced model. Bay 60-7550 (1 μmol/l) increased SERCA2a activity and SR Ca2+ content and reduced SR Ca2+ leak rate. Furthermore, Bay 60-7550 (0.1 μmol/l) increased the phosphorylation of phospholamban at 16-serine without significantly changing the phosphorylation levels of phospholamban at 17-threonine and RyR2. Bay 60-7550 increased the rat heart contractility and reduced peripheral arterial resistance may be mediated by increasing the phosphorylation of phospholamban and dilating peripheral vessels. PDE2 inhibitors which result in a positive inotropic effect and a decrease in peripheral resistance might serve as a target for developing agents for the treatment of heart failure in clinical settings.

To contrast and reverse skeletal muscle weakness by Full-Body In-Bed Gym in chronic COVID-19 pandemic syndrome

Mobility-impaired persons, either very old or younger but suffering with systemic neuromuscular disorders or chronic organ failures, spend small amounts of time for daily physical activity, contributing to aggravate their poor mobility by resting muscle atrophy. Sooner or later the limitations to their mobility enforce them to bed and to more frequent hospitalizations. We include among these patients at risk those who are negative for the SARS-COV-2 infection, but suffering with COVID-19 pandemic syndrome. Beside managements of psychological symptoms, it is mandatory to offer to the last group physical rehabilitation approaches easy to learn and self-managed at home. Inspired by the proven capability to recover skeletal muscle contractility and strength by home-based volitional exercises and functional electrical stimulation, we suggest also for chronic COVID-19 pandemic syndrome a 10-20 min long daily routine of easy and safe physical exercises that can activate, and recover from weakness, the main 400 skeletal muscles used for every-day mobility activities. Persons can do many of them in bed (Full-Body in-Bed Gym), and hospitalized patients can learn this light training before leaving the hospital. It is, indeed, an extension of well-established cardiovascular-respiratory rehabilitation training performed after heavy surgical interventions. Blood pressure readings, monitored before and after daily routine, demonstrate a transient decrease in peripheral resistance due to increased blood flow of many muscles. Continued regularly, Full-Body in-Bed Gym may help maintaining independence of frail people, including those suffering with the COVID-19 pandemic syndrome.

To contrast and reverse skeletal muscle weakness by Full-Body In-Bed Gym in chronic COVID-19 pandemic syndrome.

Mobility-impaired persons, either very old or younger but suffering with systemic neuromuscular disorders or chronic organ failures, spend small amounts of time for daily physical activity, contributing to aggravate their poor mobility by resting muscle atrophy. Sooner or later the limitations to their mobility enforce them to bed and to more frequent hospitalizations. We include among these patients at risk those who are negative for the SARS-COV-2 infection, but suffering with COVID-19 pandemic syndrome. Beside managements of psychological symptoms, it is mandatory to offer to the last group physical rehabilitation approaches easy to learn and self-managed at home. Inspired by the proven capability to recover skeletal muscle contractility and strength by home-based volitional exercises and functional electrical stimulation, we suggest also for chronic COVID-19 pandemic syndrome a 10–20 min long daily routine of easy and safe physical exercises that can activate, and recover from weakness, the main 400 skeletal muscles used for every-day mobility activities. Persons can do many of them in bed (Full-Body in-Bed Gym), and hospitalized patients can learn this light training before leaving the hospital. It is, indeed, an extension of well-established cardiovascular-respiratory rehabilitation training performed after heavy surgical interventions. Blood pressure readings, monitored before and after daily routine, demonstrate a transient decrease in peripheral resistance due to increased blood flow of many muscles. Continued regularly, Full-Body in-Bed Gym may help maintaining independence of frail people, including those suffering with the COVID-19 pandemic syndrome.

Assessing Pressure-Volume Relationship in Developing Heart of Zebrafish In-Vivo.

During embryogenesis, the developing heart transforms from a linear peristaltic tube into a multi-chambered pulsatile pump with blood flow-regulating valves. In this work, we report how hemodynamic parameters evolve during the heart's development, leading to its rhythmic pumping and blood flow regulation as a functioning organ. We measured the time course of intra-ventricular pressure from zebrafish embryos at 3, 4, and 5 days post fertilization (dpf) using the servo null method. We also measured the ventricular volume and monitored the opening/closing activity of the AV and VB valves using 4D selective plane illumination microscopy (SPIM). Our results revealed significant increases in peak systolic pressure, stroke volume and work, cardiac output, and power generation, and a total peripheral resistance decrease from zebrafish at 4, 5 dpf versus 3 dpf. These data illustrate that the early-stage zebrafish heart's increasing efficiency is synchronous with the expected changes in valve development, chamber morphology and increasing vascular network complexity. Such physiological measurements in tractable laboratory model organisms are critical for understanding how gene variants may affect phenotype. As the zebrafish emerges as a leading biomedical model organism, the ability to effectively measure its physiology is critical to its translational relevance.

Changes in skin microcirculation in response to low-intensity electromagnetic radiation of the millimeter range

The tissue microhemodynamics plays a significant role in a tissue homeostasis. Any pathological processes were changes in functioning of microhemodynamics. This is causes is significant interesting to safe methods for its correction. One of such methods is exposure to low-intensity electromagnetic radiation of the millimeter (MM) range, which has pronounced of biological activity. The aim of the work was to identify changes in the processes of microcirculation in human skin when exposed to a low-intensity EMR MM range (wavelength - 7.1 mm; power flux density - 0.1 mW/cm2). The study was conducted on 40 volunteer girls aged 18-20 years. The exposure of low-intensity MM radiation was carried out daily for 10 days with an exposure of 30 minutes on the area of biologically active area GI-4. Microcirculation indices were recorded by laser Doppler flowmetry both in the area of influence of MM radiation (contact point of registration) and in the symmetrical effect of the area (distant point) to detect local and systemic changes in tissue blood flow under the action of this physical factor. The results of the study revealed for the first time that when exposed to low-intensity MM radiation, local changes in tissue blood flow in the contact point area were observed, manifested in changes in myogenic and endothelial oscillatory activity, starting from the first sessions of exposure, which indicates a decrease in peripheral resistance of precapillary sphincters and an increase in secretory activity of microvascular endothelium; changes in neurogenic oscillations-starting from the third session, which is accompanied by a decrease in arteriolar resistance; changes in pulse fluctuations - during the last tenth session of exposure, which is an indication of an increase in arteriolar blood filling. These changes were maintained during the entire period of exposure to this physical factor. Systemic changes in microcirculation parameters at a distant symmetrical point during the course action of MM radiation were characterized by changes in the neurogenic oscillator component, starting from the third session of exposure, and changes in the amplitude of endothelial and pulse oscillations - during the tenth session.

Decrease of peripheral resistance after intraoperative administration of iloprost in patients with and without type 2 diabetes mellitus and with peripheral arterial occlusive disease.

Background:In many cases, Ilomedin® infusions are applied as part of a perioperative measure in patients with peripheral arterial occlusive disease because it makes a relevant vasodilatatory effect in patients with type 2 diabetes mellitus and with/without peripheral neuropathy.Aims:A prospective case–control study was performed to investigate the effect of prostanoids on peripheral resistance in patients with type 2 diabetes mellitus and patients without type 2 diabetes mellitus, as well as the role of peripheral neuropathy in patients undergoing arterial reconstruction.Methods:Sixty patients undergoing arterial reconstruction were enrolled. Sufficient data were collected on 38 patients. Prior to surgery, peripheral nerve conduction velocity was measured. Blood flow volume at the common femoral artery was assessed intraoperatively using a Doppler flowmeter at four time points: at baseline before arterial reconstruction (T0), after reconstruction (T1), after 5 (T2) and 10 min (T3) after intra-arterial application of 3000 ng of Ilomedin. Peripheral resistance units were calculated as a function of mean arterial pressure and flow volume using the following formula: peripheral resistance unit = mean arterial pressure (mm Hg) / flow volume (mL/min).Results:Ilomedin produced an immediate and significant drop of peripheral resistance in patients without type 2 diabetes mellitus as well as in patients with type 2 diabetes mellitus. Patients with peripheral neuropathy showed a less pronounced effect to Ilomedin compared to individuals with normal nerve conduction velocity.

ULTRASONIC AND DOPLEROMETRIC CHARACTERISTICS OF SMALL PELVIS ORGANS OF POSTMENOPAUSAL WOMEN WITH PHYSIOLOGICAL COURSE AND WITH INTRAUTERINE FLUID


 
 
 The article presents the peculiarities of ultrasound and Doppler measurements of the pelvic organs of postmenopausal women with physiological course and in the presence of intrauterine fluid. The main purpose of the study was to investigate the features of ultrasound and Doppler examination of the pelvic organs of postmenopausal women with physiological course and in the presence of intrauterine fluid. The relevance of the study of this pathology is that during menopause, the number of women with diseases of the female reproductive system increases. Therefore, the study of age-specific features of the internal genital organs is of funda- mental importance for the diagnosis of the initial manifestations of various pathological condi- tions in the postmenopausal period. The methodology of the study consisted of a prospective study of 130 postmenopausal women with intrauterine fluid and postmenopausal women with physiological course. Following a general clinical examination of patients in both groups, a comprehensive ultrasound study was performed, which included gray-scale ultrasound and Doppler imaging to assess vascular imaging. The article presents the result of the study and found that postmenopausal women with a physiological course revealed that the qualitative and quantitative parameters of blood flow in the uterine arteries change over the duration of the postmenopausal period. This process was characterized by a decrease in both Vmax and Vmin. The value of the peripheral resistance indices, especially IR, remained quite stable, indicating a decrease in the level of perfusion. With the progress of menopause, there is a gradual sclerosis of the vessels, which is determined by the gradual decrease in the indices of vascular resistance, in vessels as far from the main vessels that supply the uterus, to vessels of smaller diameter. In contrast, postmenopausal women with intrauterine fluid had decreased peripheral resistance, indicating an increase in circulatory intensity in the uterine bloodstream and an increase in perfusion. The results of the study indicate that postmenopausal women with intrauterine fluid have characteristic features when conducting ultrasound and doppler measurements of pelvic organs compared with postmenopausal women with physiological menopausal course. Thus, for postmenopausal women with a physiological course of menopause with an increase in the duration of menopause, there is a gradual sclerosis of the vessels, which is determined by the gradual decrease in the indicators of vascular resistance, in vessels as distant from the main ves- sels that feed the body of the uterus to the body of the uterus. In postmenopausal women with intrauterine fluid, and especially with an increase in its number, changes occur in the uterine vessels, as evidenced by changes in the Doppler measurement of peripheral resistance, indicat- ing an increase in blood circulation in the uterine blood vessels, and an increase in perfusion as a result of decrease of peripheral resistance.
 
 

Effectiveness of Cardiometabolic Therapy in the Treatment of Acute Coronary Syndrome without ST-segment Elevation in Perimenopausal Women

Acute forms of coronary heart disease (CHD) are one of the most pressing problems in the structure of morbidity and mortality, especially among perimenopausal women. Of particular interest are approaches to the medical correction of acute myocardial ischemia that occurs on the background of non-obstructive lesions or intact coronary arteries. The objective: to study the effectiveness of a fixed combination of meldonium with γ-butyrobetaine (γ-BB) as part of the optimal pharmacotherapy of GKSbelST. Materials and methods. 81 women with percutaneous and postmenopausal GKSbelST at the age of 39–69 years (mean age – 50.26 ± 1.24 years) were examined. Patients were evaluated major circadian blood pressure monitoring parameters (MMAD) was determined levels of female sex hormones (estradiol, follicle-stimulating hormone (FSH) and luteinizing hormone (LH)), circulating endothelial dysfunction markers (endothelial NO-synthase (eNOS), endothelin-1 (ET-1)), indicators of systemic inflammation (PSA) and POL (malonic dialdehyde (MDA), ceruloplasmin (CP)), the main indicators of lipid, carbohydrate and purine metabolism at the beginning of the study on the first day of hospitalization and after 2 weeks hospital treatment. Patients were divided into two groups. The 1-st group (n = 29) included women (average age – 51.26 ± 1.82 years), to whom a fixed combination of γ-BB dihydrate (60 mg) and meldonium dihydrate (180 mg) was added to the standard OMT (Kapikor, “Olainfarm”, Latvia) 2 capsules 2 times a day; in the 2nd group (n = 52) – women with GKSbelST women (average age – 49.64 ± 1.12 years), who received only the standard OMT complex. Results. On the first day of hospitalization of patients with GKSbelST, there was a decrease in eNOS and an increase in ET-1, MDA, CB, and SRP compared to practically healthy individuals, with ABPM, an increase in BP variability (VAD), an increase in BP (HV AD), time index (YV ) at night and insufficient nightly decrease in blood pressure. Compared with women of the 2 nd group, two-week treatment of patients of the 1st group significantly accelerates the restoration of endothelial function. The content of eNOS increased in the 1st group by 22.13% (from 191.76 ± 7.67 to 234.82 ± 17.26 pg / ml; p 0.05), levels of E T-1 decreased (by 23.45% in the 1st group (from 15 , 31 ± 0.60 to 11.71 ± 0.68 pg / ml; p 0.05). Conclusion. Adding to the GKSbelST treatment in women of a fixed combination of meldonium with γ-BB significantly speeds up the restoration of endothelial function and contributes to a decrease in peripheral resistance, balances vascular tone, stabilizes systemic and regional blood flow, which is manifested by the rapid positive dynamics of pressure loads, improved clinical course of NS and reduced hospitalization. Women who took the meldonium with γ-BB combination, in addition to the standard OMT, recorded significant positive changes in the content of female sex hormones in the blood, in particular estradiol (by 20.8%), which may be a consequence of the beneficial effect of meldonium with γ-BB on the microcirculation ovary.

The state of the fetus circulation in congenital malformations of the fetus with placental dysfunction

Introduction. Improvement of perinatal care in Ukraine has led to a decrease in early neonatal mortality, but a decrease in antenatal losses has not occurred. In the structure of antenatal fetal death (AFD), congenital malformations (CM) account for about one fifth of reproductive losses and their percentage increases annually. A frequent complication during pregnancy with CM is placental dysfunction (PD), which occurs according to different authors in 19-69%. Primary dysfunction of the placenta with CM has a progressive nature, the consequence of which is AFD in various periods of pregnancy.The aim of the study - to reduce the frequency of antenatal fetal death in women with CM based on the determination of Doppler blood flow indicators in the feto-placental complex (FPC) and their timely delivery. Materials and Methods. The state of the feto-placental complex was monitored in 100 pregnant women with CM of the fetus in the period of 37-40 weeks of pregnancy. Studies were conducted in the uterine arteries (UA), umbilical arteries (UA), mid-cerebral artery (MCA) and fetal aorta (FA) with the definition of indicators of resistance index (RI), systolic-diastolic ratio (SDR) and pulse index (PI) . The control group (CG) consisted of 25 pregnant women, who gave birth to healthy children. The results of the study and their discussion. Examination and dynamic observation of 100 pregnant women with CM of the fetus allowed us to diagnose PD in the overwhelming number of pregnant women (41 pregnant - 41%), who manifested manifestations of fetal distress at 8.0 ± 2.71%, FGR at 29.76 ± 4.46% and FGR in combination with shallow water 3.24 ± 0.91%. For the purpose of a detailed analysis of the possible mechanisms of antenatal tanathogenesis, the patients were divided into two groups - with impaired blood flow in the FPC (OG1 - 41 pregnant) and without them (OG2 - 59 pregnant). It was pregnant OG1 that had manifestations of PD (distress, FGR and combination of FGR with low water). This separation allowed us to see the following picture of blood flow disorders.Analysis of the Doppler indices in UA showed that there is an increase in SDR in both UA, while the RI did not have a significant difference compared with CG and pregnant MG2. However, the correlation analysis did not indicate the presence of a relationship between blood flow disorders in UA and antenatal fetal death, which does not allow considering blood flow disorders in UA as stage of antenatal tanathogenesis.In pregnant MG1, a significantly higher RI index was found in UA compared with CG and MG2. PI did not have a significant difference compared with CG and pregnant women withCDF without PD. An analysis of blood flow in the MCA revealed a significant decrease in PI in pregnant MG1. A significant decrease in peripheral resistance to blood flow in the MCA can be a compensatory response to the deterioration of the fetal-placental blood circulation and is considered as indirect sign of brain congestion (the phenomenon of centralized blood flow). Analysis of the Doppler parameters in the AP testified to an increase in RI compared with the CG. An increase in RI in the aorta of the fetus may indicate a strain on the fetal heart during PD and may be a marker of the formation of congenital cardiomegaly in them.Conclusions. With CM of the fetus in combination with PD, deeper disturbances are observed in the utero-placental and placental-fetal complexes. In-time diagnosis of impaired blood flow allows in-time delivery of women with CM and reducing the risk of AFD.

49. Adaptation of cardiac output and systemic vascular resistance during pregnancy: Systematic review and meta-analysis

Introduction Insights in the adaptation of cardiac output (CO) and peripheral systemic vascular resistance in normal pregnancy may aid in identifying women with deviant adaptation. These women are thought to be at risk for hypertensive related complications during pregnancy. Objectives First, to describe the pattern of CO and peripheral resistance changes in normotensive singleton pregnancies. Second, to explore the adaptation of these variables in pregnancies complicated by hypertension, pre-eclampsia and/or foetal growth restriction. Methods We performed a meta-analysis of systematically reviewed literature on CO and peripheral resistance throughout normotensive and complicated pregnancies, using PubMed (NCBI) and Embase (Ovid) databases. Only studies reporting measurements during pregnancy and non-pregnant reference values were included. Pooled mean differences between pregnant and non-pregnant women were calculated for predefined intervals of gestational age using a random-effects model. Results In total, 92 studies were included in this meta-analysis. In uncomplicated pregnancies, CO progressively increased from the first weeks on. After peaking in the early third trimester (+1.47 L/min, over 30% increase as compared to the non-pregnant reference group), CO declined slightly until term. Next to that, peripheral resistance decreased progressively until early third trimester (−316 dyn · s · cm−5, −24% as compared to the non-pregnant group), after which it increased a little. In the first trimester of complicated pregnancies, an augmented increase in CO was observed (+1.36 L/min versus +0.73 L/min in the uncomplicated pregnancies, p Discussion During normal pregnancy, CO increases and peripheral resistance decreases by 30% and 24% respectively, reaching their maximum measure in the second half of pregnancy. Deviant hemodynamic adaptations showing an initial augmented increase with a cross-over to a low cardiac output might identify pregnancies that will be complicated by hypertension and/or growth restriction.

The Effect of Microgravity on Central Aortic Blood Pressure.

Background Blood pressure has been traditionally measured at peripheral arteries. In the past decade, evidence has grown that central aortic blood pressure may be a more powerful predictor for cardiovascular events, but data on its regulation are rare. The present work examines the impact of microgravity on central blood pressure for the first time. Methods We performed 7 parabolic flights with 22 seconds of weightlessness in each parabola. Hemodynamic parameters including central systolic blood pressure were measured noninvasively in a free-floating position in 20 healthy subjects (19-43 years of age). Results Arterial elasticity at rest was normal in all participants (augmentation index 14% (interquartile range (IQR) 10-22), pulse wave velocity 5.2 m/s (IQR 5.0-5.4)). Transition of 1g to 0g led to a significant increase of central systolic blood pressure from 124 (IQR 118-133) to 127 (IQR 119-133) mm Hg (P = 0.017). Cardiac index augmented significantly from 2.5 (IQR 2.2-2.8) to 2.7 (IQR 2.3-3.0) l/min/m2 (P 0.05). Conclusion Whereas there is a multitude of studies on the effects of microgravity on peripheral blood pressure, this study provides first data on central aortic blood pressure. An acute loss of gravity leads to a central blood volume shift with an augmentation of cardiac output. In healthy subjects with normal arterial stiffness, the compensatory decrease of peripheral resistance does not outweigh this effect resulting in an increase of central blood pressure.

The Effect of Microgravity on Central Aortic Blood Pressure.

Blood pressure has been traditionally measured at peripheral arteries. In the past decade, evidence has grown that central aortic blood pressure may be a more powerful predictor for cardiovascular events, but data on its regulation are rare. The present work examines the impact of microgravity on central blood pressure for the first time. We performed 7 parabolic flights with 22 seconds of weightlessness in each parabola. Hemodynamic parameters including central systolic blood pressure were measured noninvasively in a free-floating position in 20 healthy subjects (19-43 years of age). Arterial elasticity at rest was normal in all participants (augmentation index 14% (interquartile range (IQR) 10-22), pulse wave velocity 5.2 m/s (IQR 5.0-5.4)). Transition of 1g to 0g led to a significant increase of central systolic blood pressure from 124 (IQR 118-133) to 127 (IQR 119-133) mm Hg (P = 0.017). Cardiac index augmented significantly from 2.5 (IQR 2.2-2.8) to 2.7 (IQR 2.3-3.0) l/min/m2 (P < 0.001), while peripheral vascular resistance showed a decrease from 1.30 (IQR 1.14-1.48) to 1.25 (IQR 1.15-1.40) s × mm Hg/ml (P = 0.037). Peripheral systolic blood pressure did not change significantly (P > 0.05). Whereas there is a multitude of studies on the effects of microgravity on peripheral blood pressure, this study provides first data on central aortic blood pressure. An acute loss of gravity leads to a central blood volume shift with an augmentation of cardiac output. In healthy subjects with normal arterial stiffness, the compensatory decrease of peripheral resistance does not outweigh this effect resulting in an increase of central blood pressure.

THE EFFECT OF MICROGRAVITY ON CENTRAL AORTIC BLOOD PRESSURE

Objective: BACKGROUND: Blood pressure has been traditionally measured at peripheral arteries. In the past decade evidence has grown, that central aortic blood pressure may be a more powerful predictor for cardiovascular events, but data on its regulation are rare. The present works examines the impact of microgravity on central blood pressure for the first time. Methods: We performed seven parabolic flights with 22 seconds of weightlessness in each parabola. Hemodynamic parameters including central systolic blood pressure were measured non-invasively in a free-floating position in 20 healthy subjects (19–43 years of age). Results: Arterial elasticity at rest was normal in all participants (augmentation index 14% [interquartile range IQR 10–22], pulse wave velocity 5.2 m/s [IQR 5.0–5.4]). Transition of 1 g to 0 g led to a significant increase of central systolic blood pressure from 124 (IQR 118–133) to 127 (IQR 119–133) mmHg (p = 0.017). Cardiac index propelled significantly from 2.5 (IQR 2.2–2.8) to 2.7 (IQR 2.3–3.0) l/min/m2 (p < 0.001), whilst peripheral vascular resistance showed a decrease from 1.30 (IQR 1.14–1.48) to 1.25 (IQR 1.15–1.40) s*mmHg/ml (p = 0.037). Peripheral systolic blood pressure did not change significantly (p > 0.05). Conclusion: Whereas there is a multitude of studies on the effects of microgravity on peripheral blood pressure, this study provides first data on central aortic blood pressure. An acute loss of gravity leads to a central blood volume shift with an augmentation of cardiac output. In healthy subjects with normal arterial stiffness the compensatory decrease of peripheral resistance does not outweigh this effect resulting in an increase of central blood pressure.

Validating the Physiologic Model HumMod as a Substitute for Clinical Trials Involving Acute Normovolemic Hemodilution.

Blood conservation strategies and transfusion guidelines remain a heavily debated clinical topic. Previous investigational trials have shown that acute isovolemic hemodilution does not limit adequate oxygen delivery; however, a true critical hemoglobin level has never been investigated or defined due to safety concerns for human volunteers. Validated physiologic modeling may be useful to investigate hemodilution at critical hemoglobin levels without the ethical or safety hazards of clinical trials. Our hypothesis is that HumMod, an integrative physiological model, can replicate the cardiovascular and metabolic findings of previous clinical studies of acute isovolemic hemodilution and use coronary blood flow and coronary oxygen delivery in extreme hemodilution to predict a safety threshold. By varying cardiovascular and sizing parameters, unique individuals were generated to simulate a population using HumMod, an integrative mathematical model of human physiology. Hemodilution was performed by simultaneously hemorrhaging 500 mL aliquots of blood while infusing equal volumes of hetastarch, 5% albumin balanced salt solution, or triple volumes of lactated Ringer's solution over 10 minutes. Five hemodilution protocols reported over 3 studies were directly replicated with HumMod to compare and validate essential cardiovascular and metabolic responses to hemodilution in moderately healthy, awake adults. Cardiovascular parameters, mental status, arterial and mixed venous oxygen content, and oxyhemoglobin saturation were recorded after the removal of each aliquot. The outputs of this simulation were considered independent variables and were stratified by hemoglobin concentration at the time of measurement to assess hemoglobin as an independent predictor of hemodynamic and metabolic behavior. The published reports exhibited discrepancies: Weiskopf saw increased heart rate and cardiac index, while Jones and Ickx saw no change in these variables. In HumMod, arterial pressure was maintained during moderate hemodilution due to decreases in peripheral resistance opposing increases in cardiac index. HumMod showed preserved ventilation through moderate hemodilution, compensated for by an increased oxygen extraction similar to the studies of Jones and Ickx. The simulation results qualitatively followed the clinical studies, but there were statistical differences. In more extreme hemodilution, HumMod had a lesser increase in cardiac index, which led to deficiencies in oxygen delivery and low venous saturation. In the simulations, coronary blood flow and oxygen delivery increase up to a critical hemoglobin threshold of 55-75 g/L in HumMod. In this range, coronary blood flow and oxygen delivery fell, leading to cardiac injury. The allowable amount of hemodilution before reaching the critical point is most closely correlated with nonmuscle mass (r = 0.69) and resting cardiac output (r = 0.67). There were significant statistical differences in the model population and the clinical populations, but overall, the model responses lay within the clinical findings. This suggests our model is an effective replication of hemodilution in conscious, healthy adults. A critical hemoglobin range of 5.5-7.5 g/L was predicted and found to be highly correlated with nonmuscle mass and resting cardiac output.