Blood Flow Velocity Values Research Articles

P0213CHRONIC KIDNEY DISEASE AND ATRIAL FIBRILLATION: RISK OF COMPLICATIONS

Abstract Background and Aims The assessment of the thromboembolic risk (TE) and transient ischemic attacks (TIA) in patients with chronic kidney disease (CKD) in combination with atrial fibrillation (AF) and the effect of complex treatment, including rivoraxaban. Method The study included 28 patients, 16 men and 12 women, average age - 57.8 ± 6.9 years. Patients with 3rd stage CKD (GFR 30-50 ml/min) associated with various forms of non-valve AF were examined. All patients were at high risk according to the classification of stroke risk stratification. The risk of thromboembolic complications was assessed using the CHA2DS2-VASc scale. Depending on the form of AF, patients with CKD were divided into 2 groups: with paroxysmal AF and CKD (n = 9) and persistent AF and CKD (n = 19). The average age in the 2 groups was 52.7 ± 6.4 and 58.4 ± 7.4 years, respectively. A history of 11 patients (39.3%) had ischemic stroke and TIA. All patients underwent echocardiography and transesophageal echocardiography (TE EchoCG). The peak blood flow velocity was a quantitative reflection of the hemodynamic state of left atrium (LA). Hemoglobin, creatinine, eGFR (CKD-EPI) and coagulogram were also monitored. Results According to the results of TE echocardiography, the size of the LA in patients with stage 3 CKD and paroxysmal AF is less than in the group of persistent AF (43.7±2.8 mm and 48.6±5.8 mm, respectively, p<0.05). The average value of the peak blood flow velocity was reduced in all patients - 34.88±10.59 cm/sec, in the presence of thrombosis this parameter significantly decreased - 24.3±2.49 cm/sec (p<0.001). Atrial thrombi were detected in 10 patients (35.7%). Spontaneous echocardiographic contrast (SEC) was found in 7 people (25%). We found that in patients with a thrombus in the auricle of the LA ejection fraction (EF) was significantly lower than in patients without thrombi. The average score on the CHA2DS2-VASС scale was 5. A higher incidence of a thrombus in the auricle of the LA was revealed in patients with persistent AF than paroxysmal AF (7 and 3, respectively). Only 15 patients (53.6%) received oral anticoagulants (OAC) on an outpatient basis, and 2 (7.1%) took aspirin. In the hospital, everyone was prescribed rivoraxaban in a dose of 15 mg once a day. After 4 weeks of treatment with rivoraxaban, from 7 patients with a revealed SEC during repeated TE echocardiography, the disappearance of SEC was observed in 4 patients (57%). In 6 patients (60%) was revealed thrombus lysis in the LA. In 16 (57.1%) patients was noted an increase in GFR above 50 ml/min. Coagulogram values in all patients throughout the observation were within normal limits. Conclusion TE echocardiography allows to distinguish among patients with stage 3 CKD and AF group with a high risk of stroke and TIA. The use of rivoraxaban for 4 weeks allows lysis of blood clots in the auricle of the LA in 60% of patients, and the disappearance of the SEC effect in 57% of cases. This allows us to recommend rivoraxaban for the treatment of patients with AF, especially with a high risk of thromboembolic complications.

Evaluation of myocardial perfusion and systolic function in patients with different degree of coronary artery stenosis by MCE and 2D-STI.

To study myocardial perfusion and systolic function in patients with different coronary artery stenosis by myocardial contrast echocardiography (MCE) and two-dimensional speckle tracking imaging (2D-STI). MCE, 2D-STI and coronary angiography were conducted in patients with coronary heart disease in our hospital. Myocardial segments were divided into 4 groups according to the degree of coronary artery stenosis: group A (normal group), group B (mild stenosis, 50%-75%), group C (moderate stenosis, 76%-90%) and group D (severe stenosis, 91%-100%). Blood volume, blood flow velocity, blood flow and longitudinal myocardial strain value (SL) in each group were measured by analysis software for MCE and 2D-STI. The differences in blood volume, blood flow velocity, blood flow and SL were evaluated. The blood flow velocity and blood flow in B, C and D groups were decreased gradually, with significant difference (P<0.05). There was no significant difference in blood volume, blood flow velocity, blood flow between group A and group B (P>0.05). There were significant differences in SL among the 4 groups (P<0.05). There is a good correlation between coronary stenosis degree and myocardial perfusion or systolic function. The ability of 2D-STI to detect mild stenosis of coronary artery is better than MCE.

Ketidaksesuaian Dosis dan Interval Pemberian Antibiotik pada Lansia di Bangsal Penyakit Dalam RSUD dr Moewardi Solo serta Gambaran Timbulnya Efek Samping yang Merugikan

Aging causes a decrease in renal blood flow velocity and clearance values ​​related to renal filtration function. A decrease in kidney filtration function results in a decrease in the ability of drug elimination so that the drug and its metabolites tend to accumulate in the blood. The dose of certain antibiotics must be adjusted to the patient's kidney function. Clinical estimates of kidney filtration function are expressed in terms of creatinine clearance (CrCl). This study aims to determine the percentage of suitability of the dose and interval of antibiotic administration with the CrCl value of elderly patients and to see description of the side effects arising from the administration of antibiotics.&#x0D; This research was observational with data retrospective retrieval of medical records. The subjects of the study were elderly patients who were hospitalized in the ward ward in dr. Moewardi Solo Hospital in the period January - May 2019 , ≥ 60 years aged with a diagnosis of Pneumonia, Urinary Tract Infection (UTI), Cellulitis and sepsis with complete medical record data. The antibiotics evaluated are all antibiotics given to the patient while being treated.&#x0D; The results showed the suitability of the dose and interval of antibiotic administration with the CrCl value of elderly patients hospitalized in the disease ward in RSUD Dr. Moewardi Solo for the period January-May 2019 was 63.35%, the incidence of side effects arising from the administration of antibiotics was nausea and vomiting (10 patients ) and diarrhea (4 patients).

The relationship of hemodynamic parameters of periodontal microvascular bed and lipid peroxidation products in adolescents with arterial hypertension

Of the study was to establish the relationship of hemodynamic parameters of periodontal tissues and lipid peroxidation products in adolescents with arterial hypertension (AH). The study included 132 adolescents (average age 14.51±1.91 years), from which 2 clinical groups (1 - the group with AH without periodontal disease (n=19, average age - 15±1.53 years) and 2 - the group with AH with periodontal diseases (n=57, average age - 14.7±1.89 years)) and 2 comparison groups (3 - the comparison group without AH and periodontal diseases (n=19, average age - 13.82±1.89 years) and 4 - comparison group without AH and with periodontal diseases (n=37, mean age - 14.57±2.01 years)) were formed. Hemodynamic analysis of the periodontal microcirculatory bed using the Doppler ultrasound method and the level of lipid peroxidation products using spectrophotometric and fluorometric methods was performed. In adolescents with hypertension without and with inflammatory periodontal diseases as a whole, unidirectional changes in the hemodynamics of the vascular bed of the periodontium were observed in the form of increased values of the maximum blood flow velocity in systole and an increase in the peripheral resistance index. At the same time, the group with hypertension and periodontal disease was distinguished by lower values of these indicators. In the system of lipid peroxidation, increased values of ketodienes and conjugated trienes occurred in patients with hypertension without periodontal disease and end products that actively reacting with thiobarbituric acid in patients with hypertension and periodontal disease. Correlation analysis showed the presence of intersystem relationships between the hemodynamic parameters of the vascular bed of periodontal adolescents with hypertension without periodontal disease. In the group of adolescents with arterial hypertension and periodontal disease, there was a decrease in the correlation coefficients between intersystem parameters by almost two times, as well as the appearance of pathological dependencies between toxic metabolites of the lipid peroxidation process - products that actively reacting with thiobarbituric acid and vascular blood flow indicators. It has been noted that in adolescent patients with hypertension and periodontal diseases on the background of lower vascular blood flow and accumulation of end toxic metabolites, pathological dependencies occur between them, which may contribute to more intense damage to the tissues of the periodontal complex in the presence of hypertension.

Towards the numerical assessment in solving the problem of the effectiveness of vascular anastomosis in neurosurgical operations

In this study we considered the effect of formation of cerebral bypass for the real clinical case. Three configurations of vessels of the circle of Willis for the real patient was constructed in the pre-operative, post-operative and the alternative (virtual--without bypass formation) treatment cases. All calculations were carried out in the commercial software ANSYS CFX 17.2. It is shown that after installation of the bypass the stagnation zone in patient`s vessel was formed with the consequent thrombus formation that required an urgent re-operation. The changes of hemodynamic parameters (blood flow velocity, WSS and viscous dissipation energy values) before and after operation as well as after alternative treatment were analysed. For the first time, a quantitative difference in hemodynamic characteristics between cases of the real and virtual (alternative) methods of the operation was shown.

Differential diagnosis of retinal capillary hemangiomas and vasoproliferative tumors

Purpose. To propose the major differential diagnostic criteria of retinal capillary hemangioma (RCH) and vasoproliferative tumor (VPT) aimed at increasing the efficiency of the diagnosis of these diseases.Material and methods. A comprehensive ophthalmologic examination off 19 (26 eyes) patients, aged 19 to 66 (ave. 31.89 ± 11.30 yrs), with vascular neoplasms of peripheral localization included, beside the standard techniques, fundus photoregistration, fluorescent angiography (FAG), optical coherence tomography of the retina and a combined ultrasound testing using B scanning, echographic densitometry, colour Doppler imaging (CDI), and pulse Doppler imaging.Results. Based on the analysis of the clinical picture and the results of the tests performed, the following differential diagnostic criteria were proposed: the age at which RCH and VPT developed, their localization in the eye fundus, and the value of the maximal systolic blood flow velocity in the central vein of the retina.Conclusion. Differential diagnostics of RCH and VPT requires combined approaches and should take into account, in addition to case history and the clinical picture, also the results of instrumental testing techniques: FAG, echography and CDI.

Tek taraflı intrakranial anevrizmalı hastalarda servikal kan akış hızı değerleri: Ön sonuçlar

Aim: Brain aneurysm is a balloon shaped dilatation of brain vessels as a result of attenuation of the vessel walls. The aim of this study was to evaluate the relationship between blood flow velocities in the right and left arterial vessels in an unruptured aneurysm and healthy group, and to investigate whether this analysis can help early diagnosis of aneurysm.Methods: Four aneurysm patients (four female, mean age 57.25 ± 0.75 years) and four healthy subjects (two female, 2 male male, mean age 36.35 ± 6.19 years) were included in the study. Blood flow velocity values ​​of right and left internal carotid arteries, vertebral artery and right and left internal jugular veins were obtained during a cardiac cycle with phase contrast technique. Spearman's correlation analysis was applied to flow velocity values. Statistically significant blood flow similarities between right and left brain were investigated.Results: In the aneurysm group, there was a significant difference between right and left cervical arterial blood flow velocity values (p=0.001). Spearman correlation coefficient values between right and left arterial blood flow velocity values and right and left side arteriovenous blood flow velocity values were lower in the aneurysm group compared to the control group however, there was no statistical significance (p≥0.05 for all). Conclusion: The difference between the right and left arterial blood flow velocities obtained in the aneurysm group and the low correlation values may be useful in early diagnosis of aneurysm.

Vector mapping of deformation and blood flows in patients with ascending aortic aneurysm

The authors performed clinical studies based on modelling of an ascending aortic aneurysm in 37 patients and 10 apparently healthy subjects. Echocardiography was carried out in the B-mode using the Vivid E9 device (USA, GE). The linear dimensions of the aorta were assessed at three points - in the immediate vicinity of the valves, in the area of the maximum dilatation and in the area of decreased dilatation with registration of blood flow velocity in the aorta. The aortic walls were contoured with the division of equal intervals into 4 portions in order to obtain longitudinal shear deformation velocity during the cardiac cycle. We worked out a system of assessing the velocity vector fields with the help of transthoracic echocardiography in patients with an ascending aortic aneurysm, based on registration of blood flows, which made it possible to obtain the components of velocity. We also determined an optimal method of assessing turbulence in the aorta taking into account the direction of the vectors. Obtained were the numerical data of aortic wall deformation velocity in the longitudinal direction and calculation of the weighting function with the distinction between pathology and the norm. Based on the deformation, the distance between the registered points, and the movement of the vascular wall, we determined the reference values of blood flow velocity inside the aorta and immediately close to its walls.

Cerebral Hemodynamic Changes During Migraine Attacks and After Triptan Treatments.

Migraine has been known for many years, but its mechanism remains unclear. Different cerebral hemodynamic changes have been observed at different stages of a migraine attack. Published results on cerebral hemodynamics are contradictory. For this reason, we aimed to investigate cerebral hemodynamic changes during attacks as well as the effects of frovatriptan and rizatriptan. Forty migraine patients with aura using rizatriptan (n=20) and frovatriptan (n=20) and 20 healthy individuals were included in our study. Cerebral blood flow velocities and breath-holding indices were recorded bilaterally from middle and posterior cerebral arteries. All procedures were repeated one hour after treatments and one week after attacks. We observed similar values of cerebral blood flow velocities and breath holding indices in all patients with migraine during the attack-free period compared to the control group. All cerebral vascular structures in migraine patients had significantly lower cerebral blood flow velocities and higher values in breath-holding indices during attacks. After taking rizatriptan and frovatriptan for an attack, the changes in hemodynamics disappeared. During attacks of migraineurs with aura, vasodilatation develops. In addition, higher vasomotor reactivity during attacks supports hypersensitivity in migraine pathophysiology. Triptans, acting as vasoconstrictor agents, were able to stop over-vasodilatation during attacks. In other words, it is possible that triptans show their effects by eliminating vascular hypersensitivity during acute attacks.

Hemodynamics in diabetic human aorta using computational fluid dynamics.

Three-dimensional (3D) computational aortic models have been established to reproduce aortic diseases such as aortic aneurysm and dissection; however, no such models have been developed to study diabetes mellitus (DM). To characterize biomechanical properties of the human aorta with DM, reconstructed aortic CT images were converted into DICOM format, and imported into the 3D segmentation using Mimics software. This resulted in a 3D reconstruction of the complete aorta, including three branches. We applied a pulsatile blood pressure waveform for the ascending aorta to provide a biomimetic environment using COMSOL Multiphysics software. Hemodynamics were compared between the control and DM models. We observed that mean blood flow velocity, aortic pressure, and von Mises stress values were lower in the DM model than in the control model. Furthermore, the range of aortic movement was lower in the DM model than in the control model, suggesting that the DM aortic wall is more susceptible to rupture. When comparing biomechanical properties in discrete regions of the aorta, all values were higher in the ascending aorta for both control and DM models, corresponding to the location of most aortic lesions. We have developed a compute based that integrates advanced image processing strategies and computational techniques based on finite element method to perform hemodynamics analysis based on CT images. Our study of image-based CFD analysis hopes to provide a better understanding of the relationship between aortic hemodynamic and developing pathophysiology of aortic diseases.

The Rate of Cerebral Blood Flow in the Clinic of Traumatology and Orthopedics

Assessed by ultrasound Doppler blood flow velocity (BFV) in middle cerebral arteries (MCA) reflects the state of the body of patients. A study of representative samples of healthy people of different age showed that the BFV has been steadily declining with increasing age. In healthy people, the BFV is reduced from 123 cm/ s at a rate 0,707 cm/s per year. The decline of 60% from the original values leads to disruption ofthecapacityof the centers in the brain and infact the entire body.The value of BFV in the MCA, as well as the life expectancy of women is higher than men’s, increased by 6% in chronic inflammatory diseases of the joints and reduced by 8% in the treatment of fractures of the limbs. However, these changes in patients almost affect the life expectancy of the patients. In patients with congenital violation of the natural growth of the limbs from childhood BFV in the MCA falls to 30%. In subsequent years, the pace of decline is slowing.

Changes in Transcranial Ultrasound Velocities in Children with Sickle Cell Disease Undergoing Adenotonsillectomy.

Objectives (1) To assess for changes in cerebral blood flow velocity in children with sickle cell disease and obstructive sleep apnea (OSA) following adenotonsillectomy. (2) To determine if clinical factors such as OSA severity affect cerebral blood flow velocity values. Study Design Case series with chart review over 10 years. Settings Two tertiary children's hospitals. Subjects and Methods Children aged 2 to 18 years with a history of sickle cell disease and OSA, as defined by an apnea hypopnea index (AHI) >1 on polysomnography, were eligible for inclusion. Transcranial Doppler ultrasonography was used to assess cerebral blood flow velocity before and after adenotonsillectomy. Results Fifteen patients met inclusion criteria; 73% (n = 11) were female. The mean preoperative AHI was 8.9 (range, 1.2-22.2). Six (40%) patients had severe OSA (AHI >10). Following adenotonsillectomy, there was a significant reduction in mean (95% CI) cerebral blood flow velocities of the left terminal internal cerebral artery, 91.2 (79.4-103.1) to 75.7 (61.7-89.8; P = .018), and the right middle cerebral artery, 134.3 (119.2-149.3) to 116.5 (106.5-126.5; P = .003). There was not a significant correlation between baseline AHI and change in cerebral blood flow velocities. Conclusion Adenotonsillectomy may result in a reduction in some cerebral blood flow velocities. Further research is needed to determine if changes in cerebral velocities as assessed by transcranial Doppler ultrasonography translate into a reduced risk of stroke for children with sickle cell disease and OSA.

Orbital hemangiomas: capabilities of modern neuroradiological diagnostics

In the period from 2010 to 2016. 14 patients with cavernous hemangioma (CH) and 2 patients with capillary hemangioma (CapH) of the orbit were examined. The age of CH patients varied from 17 to 67 years (median, 53 years); 8 females and 6 males. The age of CapH patients was 35 and 54 years. All patients underwent surgery with subsequent histological verification. CT-perfusion was performed in 10 CH patients and 2 CapH patients according to a developed low-dose protocol (80 kV, 200 mAs, tscan=40 s) with allowance for a target localizer (80 kV, 120 mAs) and at a maximum radiation dose of not more than 4.0 mZv. Neoplasm microcirculation was quantitatively assessed by calculating hemodynamic parameters: blood flow velocity (BFV), blood volume (BV), and mean transit time (MTT). MRI without and with contrast enhancement was performed in 11 CH patients and 2 CapH patients according to the ophthalmologic protocol (Signa GE, 3.0 T) accepted at the Institute: without contrast enhancement - T1, T2, and T2-FLAIR modes, T1 and T2 with a Fat Sat technique at a scan thickness of 3 mm, and DWI MRI; contrast enhancement - T1 (three projections) mode, including the Fat Sat technique. SWAN (n=2) and non-contrast MR perfusion ASL (n=3) were also used. Diffusion-weighted images (DWI) were processed with calculation of the apparent diffusion coefficient (ACD). In all CH patients, CT-perfusion revealed low perfusion parameters of blood flow: BVCH=0.86±0.37 mL/100 g, BFVCH= 4.89±2.01 mL/100 g/min with a high mean transit time MTTCH=10.13±3.05 s compared to the same parameters of blood flow in the normal white matter: CBVNormWM=1.63±2.22 mL/100 g, CBFVNormWM=9.72±3.13 mL/100 g/min, and MTTNormWM=6.76±2.78 s. In CapH cases, significantly increased blood flow velocity and volume values and a low MTT value in the tumor were observed: BVCapH=10.30±4.10 mL/100 g, BFVCapH=119.72±53.13 mL/100 g/min, and MTTCapH=4.35±1.79 s. In the case of orbital hemangiomas, optimal MRI modes were T1 and T2 with the Fat Sat technique, a scan thickness of 3 mm, and intravenous contrast enhancement. The revealed pattern of contrast agent accumulation by CH, initially in the central part and then in the periphery, may be a useful radiographic sign in the differential diagnosis with other orbital tumors. Modern CT- and MRI-based diagnostics of orbital hemangiomas provides not only the exact location, size, and spread of the lesion but also reveals the characteristic structural features of these tumors, and the use of perfusion techniques visualizes hemodynamics of the tumors. CT-perfusion-based hemodynamic parameters of cavernous hemangiomas typical of this type of hemangiomas may be used in the differential diagnosis with other tumors of this location. The use of contrast enhancement and the Fat Sat technique with a scan thickness of not more than 3 mm is optimal for MRI diagnostics of orbital hemangiomas.

Оценка проходимости синтетических кондуитов из пористого политетрафторэтилена при реконструкции магистральных вен (экспериментальное исследование)

Цель - изучение проходимости синтетических кондуитов из пористого политетрафторэтилена при реконструкции магистральных вен и обоснование их применения в клинической практике. Методика. Исследование выполнено на 70 кроликах половозрелого возраста мужского пола породы «Белый новозеландский» массой 3,0-3,5 кг. 40 кроликам выполнено линейное протезирование инфраренального отдела задней полой вены. 30 кроликам выполнено линейное протезирование инфраренального отдела брюшной аорты (группа сравнения). Оперативные вмешательства были выполнены в асептических условиях под внутримышечным наркозом. Для протезирования брюшной аорты и задней полой вены использовали политетрафторэтиленовые протезы (7 поколение, 2010) производства ЗАО «НПК «Экофлон» (Россия) с внутренним диаметром 4,0 мм и длиной 20,0 мм. Все анастомозы формировали атравматическим шовным материалом 7/0 или 8/0 с использованием микроинструментов. На протяжении всего срока эксперимента антикоагулянтной и антиагрегантной терапии не проводилось. В течение всего срока наблюдения контроль проходимости протезов осуществляли ультразвуковой допплерографией скоростных показателей кровотока дистальнее и проксимальнее протеза на сроках 3, 10, 30, 90, 180, 270 сут. На контрольных сроках наблюдения проходимость протеза оценивали прямым инвазивным измерением давления крови, а также интраоперационной ультразвуковой допплерографией линейной скорости кровотока дистальнее и проксимальнее протеза. После вывода животного из эксперимента протез иссекали с окружающими тканями для дальнейшего изучения. При сравнении показателей давления крови и линейной скорости кровотока дистальнее и проксимальнее протеза на разных сроках использовали критерий Манна-Уитни. Критический уровень значимости при проверке статистических гипотез принимался &lt;0,05. Результаты. Статистически значимой разницы линейных скоростей кровотоков и давления крови проксимальнее и дистальнее протеза на всех сроках наблюдения не выявлено. Проходимость протезов из политетрафторэтилена в венозной позиции не отличается от таковой в артериальной позиции. Тромбозов и гемодинамически значимых стенозов синтетических кондуитов из пористого политетрафторэтилена, как в венозной, так и в артериальной позиции не отмечено на всех сроках. Заключение. Проходимость синтетических кондуитов из пористого политетрафторэтилена в венозной позиции сравнима и не отличается от таковой в артериальной позиции. Полученные данные позволяют получить экспериментальное обоснование возможности использования синтетических кондуитов из пористого политетрафторэтилена при реконструкции магистральных вен в клинической практике. Aim. To study patency of synthetic, porous polytetrafluoroethylene (PTFE) conduits in reconstruction of great veins and to justify their use in clinical practice. Methods. The study was conducted on 70 New Zealand male rabbits weighing 3.0-3.5 kg. Infrarenal linear prosthetic reconstruction of posterior vena cava was performed in 40 rabbits. Infrarenal linear prosthetic reconstruction of abdominal aorta was performed in 30 rabbits (control group). All surgical procedures were conducted in aseptic conditions under intramuscular anesthesia. Porous PTFE conduits with 4 mm internal diameter and 20 mm length (7th generation, 2010; ZAO NPK Ecoflon, Russia) were used for prostheses of aorta and posterior vena cava. All anastomoses were made of atraumatic 7/0-8/0 ligature using microsurgical instruments. No anticoagulant therapy was used throughout the experimental period. During the study, conduit patency was controlled by ultrasound Doppler monitoring of blood flow velocity distal and proximal to the conduit and direct, invasive BP measurements during the surgery and at 3, 10, 30, 90, 180, and 270 days of surgery. At the end of experiment, the conduit was removed from the animal together with adjacent structures. The Mann-Whitney U-test was used for comparison of BP and blood flow velocity distal and proximal to the conduit. Differences were considered significant at p ?0.05. Results. Significant differences between values of linear blood flow velocity and BP distal and proximal to the conduit were absent in the entire follow up period. The patency of porous PTFE conduits was similar in both arterial and venous positions. No conduit thrombosis or hemodynamically significant stenosis were observed in arterial or venous positions in the entire follow up period. Conclusion. The patency of PTFE conduits in the venous position is similar to and not different from the arterial position. The obtained experimental data support the use of synthetic PTFE conduits for reconstruction of great veins in clinical practice. Conclusion. The polytetrafluoroethylene conduits patency of in venous position is similar and does not differ from arterial position. Obtained experimental data gives the opportunity for synthetic polytetrafluoroethylene conduits appliance for main vein reconstruction in clinical practice.

Investigation of blood flow parameters in the microvasculature in adolescents football teams during the training process

The limiting role of the cardiovascular system when performing sports loads is associated not only with central hemodynamics, but peripheral mechanisms, regulating blood flow. One of the indicators playing a significant role is a velocity of capillary blood flow. Using the method of high-frequency ultrasound dopplerography, the study of blood flow characteristics in a microvasculature at rest and after exercise session was conducted in 53 adolescents at the age of 9-15 years with different sport experience. During these studies it was found that background blood flow velocity values in the arteriolar and capillary bed (p≤0.05) are higher, and vascular tone is lower in adolescents of 14-15 years and adolescents having a longer sport experience, compared with adolescents of 9-13 years. Blood flow indicators in a microvasculature of the older age group are closer to the values recorded in adults. Various mechanisms aimed at maintenance of muscle oxygenation during exercise, are revealed after exercise session. It is confirmed visually (on the dopplerogram) and quantitatively that mechanisms increasing blood flow to muscles are activated at less-trained adolescents (9-13 years old) during exercise. More efficient mechanisms are observed at the older age group: redistribution of blood flow and increase in number of functioning capillaries.

Management of Portal Hypertension After Liver Transplantation

IntroductionPost-transplantation portal hypertension has severe complications, such as esophageal varix bleeding, therapy refractory ascites, extreme splenomegaly, and graft dysfunction. The aim of our study was to analyze the effectiveness of the therapeutic strategies and how to visualize the procedure. MethodsA retrospective study involving liver transplantation patients from the Semmelweis University Department of Transplantation and Surgery was performed between 2005 and 2015. The prevalence, etiology, and leading complications of the condition were determined. The applied interventions' effects on the patients' ascites volume, splenic volume, and the occurrence of variceal bleeding were determined. Mean portal blood flow velocity and congestion index values were calculated using Doppler ultrasonography. ResultsThe prevalence of post-transplantation portal hypertension requiring intervention was 2.8%. The most common etiology of the disease was portal anastomotic stenosis. The most common complications were esophageal varix bleeding and therapy refractory ascites. The patients' ascites volume decreased significantly (2923.3 ± 1893.2 mL vs. 423.3 ± 634.3 mL; P < .05), their splenic volume decreased markedly. After the interventions, only one case of recurrent variceal bleeding was reported. The calculated Doppler parameters were altered in the opposite direction in cases of pre-hepatic versus intra- or post-hepatic portal hypertension. After the interventions, these parameters shifted towards the physiologic ranges. ConclusionThe interventions performed in our clinic were effective in most cases. The patients' ascites volume, splenic volume, and the prevalence of variceal bleeding decreased after the treatment. Doppler ultrasonography has proved to be a valuable imaging modality in the diagnosis and the follow-up of post-transplantation portal hypertension.

Measurement of Blood Flow Velocity in the Middle Cerebral Artery During Spontaneous Migraine Attacks: A Systematic Review.

To assess the evidence for blood flow velocity changes in the middle cerebral artery during and outside of spontaneous migraine attacks. A systematic literature search on PubMed was performed and reference lists of assessed articles to identify studies on spontaneous migraine attacks that used transcranial Doppler on the middle cerebral artery with comparisons to interictal measurements were reviewed. Studies on non-spontaneous attacks and intervention studies were excluded. A total of 17 original articles reporting blood flow velocity values in the middle cerebral artery using transcranial Doppler in migraine patients both with and without aura were identified. A total of 24 subgroups (ie, migraine patients without aura = 11, migraine patients with aura = 9, and mixed = 4) of migraine patients were investigated during and outside spontaneous migraine attacks in the 17 studies. No change was reported in 15 subgroups (63%), while decreased blood flow velocity was found in 8 subgroups (33%) and increased blood flow velocity was found in one study (4%). Exploratory analysis revealed that studies showing decreased blood flow velocity were carried out earlier after onset of attack (mean time, 4.1 h) compared with those showing no change (mean time, 6.0 h). Overall, spontaneous migraine attacks are not accompanied by blood flow velocity changes in the middle cerebral artery. However, explorative analyses on the time from attack onset to examination revealed side-specific attack-related decrease in blood flow velocity in the early, but not late phases. This is the first systematic review focusing on the flow changes in the middle cerebral artery of spontaneous migraine attacks. Future studies should focus on the early blood flow velocity changes in migraine attacks.

Value of blood flow velocity on color Doppler ultrasonography for optimization of delay in scanning time on computed tomography venography in patients with Budd-Chiari syndrome and inferior vena cava obstruction.

To prospectively determine the value of blood flow velocity in the inferior vena cava (IVC) on color Doppler ultrasonography for the optimization of the delay in scanning time after contrast injection during computed tomography (CT) venography in patients with Budd-Chiari syndrome (BCS) with IVC obstruction. We enrolled 122 consecutive BCS patients with IVC obstruction. All patients underwent color Doppler ultrasonography, CT venography, and digital subtraction angiography (DSA) in that order prior to treatment. The delay in scanning time during CT venography was set at 120, 180, 240, and 300s after contrast injection. The correlation between delay in CT scanning and IVC blood flow velocity on color Doppler ultrasonography was explored. Image quality was classified as good, moderate, or poor. Patients with good CT image quality were considered to have an optimal delay in scanning time. Delays in scanning time of 120, 180, 240, and 300s yielded good-quality images in 2, 7, 49, and 64 patients, respectively. The corresponding IVC blood flow velocities in these patients were 16.10±0.42cm/s (range 15.8-16.4cm/s), 12.90±1.58cm/s (range, 11-15cm/s), 7.53±1.35cm/s (range 5-10cm/s), and 1.95±1.75cm/s (range 0-5.5cm/s). IVC blood flow velocity on color Doppler ultrasonography could serve as a useful tool for the optimization of the delay in scanning time during CT venography to ensure good-quality images for the diagnosis of BCS with IVC obstruction.

Uncertainty quantification of inflow boundary condition and proximal arterial stiffness-coupled effect on pulse wave propagation in a vascular network.

This work aims at quantifying the effect of inherent uncertainties from cardiac output on the sensitivity of a human compliant arterial network response based on stochastic simulations of a reduced-order pulse wave propagation model. A simple pulsatile output form is used to reproduce the most relevant cardiac features with a minimum number of parameters associated with left ventricle dynamics. Another source of significant uncertainty is the spatial heterogeneity of the aortic compliance, which plays a key role in the propagation and damping of pulse waves generated at each cardiac cycle. A continuous representation of the aortic stiffness in the form of a generic random field of prescribed spatial correlation is then considered. Making use of a stochastic sparse pseudospectral method, we investigate the sensitivity of the pulse pressure and waves reflection magnitude over the arterial tree with respect to the different model uncertainties. Results indicate that uncertainties related to the shape and magnitude of the prescribed inlet flow in the proximal aorta can lead to potent variation of both the mean value and standard deviation of blood flow velocity and pressure dynamics due to the interaction of different wave propagation and reflection features. Lack of accurate knowledge in the stiffness properties of the aorta, resulting in uncertainty in the pulse wave velocity in that region, strongly modifies the statistical response, with a global increase in the variability of the quantities of interest and a spatial redistribution of the regions of higher sensitivity. These results will provide some guidance in clinical data acquisition and future coupling of arterial pulse wave propagation reduced-order model with more complex beating heart models.

A noninvasive method for the prediction of fetal hemolytic disease

Objective: to improve the diagnosis of fetal hemolytic disease. Subjects and methods. A study group consisted of 42 pregnant women whose newborn infants had varying degrees of hemolytic disease. The women were divided into 3 subgroups according to the severity of neonatal hemolytic disease: 1) pregnant women whose neonates were born with severe hemolytic disease (n = 14); 2) those who gave birth to babies with moderate hemolytic disease (n = 11); 3) those who delivered infants with mild hemolytic disease (n = 17). A comparison group included 42 pregnant women whose babies were born without signs of hemolytic disease. Curvesfor blood flow velocity in the middle cerebral artery were analyzed in a fetus of 25 to 39 weeks’ gestation. Results. The peak systolic blood flow velocity was observed in Subgroup 1; however, the indicator did not exceed 1.5 MoM even in severe fetal anemic syndrome. The fetal middle artery blood flow velocity rating scale was divided into 2 zones: 1) the boundary values of peak systolic blood flow velocity from the median to the obtained midscore; 2) the boundary values of peak systolic blood flow velocity of the obtained values of as high as 1.5 MoM. Conclusion. The value of peak systolic blood flow velocity being in Zone 2, or its dynamic changes by transiting to this zone can serve as a prognostic factor in the development of severe fetal hemolytic disease.