Artery Blood Flow Velocity Research Articles

The Usefulness of Carotid Artery Doppler Measurement as a Predictor of Early Death in Sepsis Patients Admitted to the Emergency Department.

Background: This study aims to verify whether the blood flow velocity and the diameter size, measured through intra-carotid artery Doppler measurements performed on sepsis patients visiting the emergency department, are useful as tools for predicting the risk of early death. Methods: As a prospective study, this research was performed on sepsis patients who visited a local emergency medical center from August 2021 to February 2023. The sepsis patients' carotid artery was measured using Doppler imaging, and they were divided into patients measured for the size of systolic and diastolic mean blood flow velocity and diameter size: those measured for their qSOFA (quick sequential organ failure assessment) score and those measured using the SIRS (systemic inflammatory response syndrome) criteria. By measuring and comparing their mortality prediction accuracies, this study sought to verify the usefulness of blood flow velocity and the diameter size of the intra-carotid artery as tools to predict early death. Results: This study was conducted on 1026 patients, excluding 45 patients out of the total of 1071 patients. All sepsis patients were measured using systolic and diastolic blood flow velocity and diameter by Doppler imaging of the intra-carotid artery, assessed using qSOFA and evaluated using SIRS criteria. The results of the analysis performed to compare the mortality prediction accuracy were as follows. First, the hazard ratio (95% CI) of the intra-carotid artery was significant (p < 0.05), at 1.020 (1.004-1.036); the hazard ratio (95% CI) of qSOFA was significant (p < 0.05), at 3.871 (2.526-5.931); and the hazard ratio (95% CI) of SIRS showed no significant difference, at 1.002 (0.995-1.009). After 2 h of infusion treatment, the diameter size was 4.72 ± 1.23, showing a significant difference (p < 0.05). After 2 h of fluid treatment, the blood flow velocity was 101 m/s ± 21.12, which showed a significant difference (p < 0.05). Conclusions: Measuring the mean blood flow velocity in the intra-carotid arteries of sepsis patients who visit the emergency department is useful for predicting the risk of death at an early stage. And this study showed that Doppler measurement of the diameter size of the carotid artery significantly increased after performing fluid treatment after early recognition.

Correlation between antihypertensive drugs and cerebral hemodynamic parameters: insights from observational findings using transcranial Doppler.

Antihypertensives (AHD) can influence cerebral autoregulation (CA) and attenuate hypertrophic concentric remodelling of arterioles. The aim of this study was to examine the associations between AHD, CA and structural and functional properties of cerebral arteries. In this observational, cross-sectional study 115 volunteers were divided in group 1 (non-hypertensive) [n = 30]; group 2 (hypertensive with systolic blood pressure [SBP] < 140 and diastolic blood pressure [DBP] < 90 mmHg) [n = 54]; group 3 (hypertensive with SBP ≥ 140 or DBP ≥ 90 mmHg) [n = 31] and simultaneous measurements of systemic blood pressure (BP) and middle cerebral artery blood flow velocity (CBFV) were obtained from digital plethysmography and transcranial Doppler. Beat-to-beat, critical closing pressure (CrCP), resistance-area product (RAP) and autoregulation index (ARI) values were extracted by linear regression analysis of instantaneous BP and CBFV waveforms using computerised analysis. Pulsatility index (PI) was calculated and CO2 reactivity was assessed by the breath-holding test. Despite their higher RAP (1.7 [±0.7], p < 0.001) compared to groups 1 and 2, uncontrolled hypertensive using diuretics (p = 0.047) and α2-agonists (p = 0.009) had significantly lower PI. Impaired CO2 reactivity was common between the two hypertensive groups (p = 0.008), however ARI, CrCP and CBFV did not differ between them and non-hypertensive individuals and also did not correlate with any AHD used. Unlike the RAP, PI does not seem to reflect the real cerebrovascular resistence resulting from chronic arterial remodelling. Despite impaired CO2 reactivity, hypertensivehavearterial tonus and CA comparable to non-hypertensive. Experimental studies involving an untreated hypertensive control group are required to robustly make definitive conclusions about these questions.

Cerebral Overperfusion Despite Reduced Cortical Metabolism Is Associated with Postoperative Delirium in Cardiac Surgery Patients: A Prospective Observational Study.

Background: Decreased cerebral oximetry (rSO2) in cardiac surgery is associated with postoperative delirium (POD). However, interventions optimizing intraoperative rSO2 are inconclusive. Methods: In this prospective observational cohort study, the relationship between rSO2, middle cerebral artery blood flow velocity (MCAV), and processed EEG was assessed in cardiac surgery patients with and without POD. MCAV was continuously recorded by transcranial Doppler sonography (TCD), together with continuous rSO2 and bispectral index (BIS) monitoring. Cardiopulmonary bypass (CPB) flow rate was adjusted according to body surface area. The cohort was divided into the POD and control groups, according to the postoperative results of the confusion assessment method (CAM/CAM-ICU), the 4A's test (4AT), and the Delirium Observation Scale (DOS). A mixed model analysis was performed for intraoperative raw data. The cerebral autoregulation index was calculated from TCD, rSO2, and arterial pressure values. Differences in impaired autoregulation were compared using the Mann-Whitney U test. Results: A total of 41 patients were included in this study. A total of 13 patients (36.11%) developed postoperative delirium. There were no significant differences in the baseline characteristics of patients with or without POD. Patients with POD had lower BIS values during CPB (adjusted mean difference -4.449 (95% CI [-7.978, -0.925])). RSO2 was not significantly reduced in POD, (adjusted mean difference: -5.320, 95% CI [-11.508, 0.874]). In contrast, MCAV was significantly increased in POD (10.655, 95% CI [0.491, 20.819]). The duration of cerebral autoregulation impairment did not differ significantly for TCD and cerebral oximetry-derived indices (p = 0.4528, p = 0.2715, respectively). Conclusions: Our results suggest that disturbed cerebral metabolism reflects a vulnerable brain which may be more susceptible to overperfusion during CPB, which can be seen in increased MCAV values. These phenomena occur irrespectively of cerebral autoregulation.

Ventilatory response to head-down-tilt in healthy human subjects.

Postural fluid shifts may directly affect respiratory control via a complex interaction of baro- and chemo-reflexes, and cerebral blood flow. Few data exist concerning the steady state ventilatory responses during head-down tilt. We examined the cardiorespiratory responses during acute 50° head-down tilt (HDT) in 18 healthy subjects (mean [SD] age 27 [10] years). Protocol 1 (n=8, two female) was 50° HDT from 60° head-up posture sustained for 10min, while exposed to normoxia, normoxic hypercapnia (5% CO2), hypoxia (12% inspired O2) or hyperoxic hypercapnia (95% O2, 5% CO2). Protocol 2 (n=10, four female) was 50° HDT from supine, sustained for 10min, while breathing either medical air or normoxic hypercapnic (5% CO2) gas. Ventilation ( , pneumotachograph), end-tidal O2 and CO2 concentration and blood pressure (Finapres) were measured continuously throughout each protocol. Middle cerebral artery blood flow velocity (MCAv; transcranial Doppler) was also measured during protocol 2. Ventilation increased significantly (P<0.05) compared to baseline during HDT in both hyperoxic hypercapnia (protocol 1 by mean [SD] 139 [26]%) and normoxic hypercapnia (protocol 1 by mean [SD] 131 [21]% and protocol 2 by 129 [23]%), despite no change in or from baseline. No change in was observed during HDT with medical air or hypoxia, and there was no significant change in MCAv during HDT compared to baseline. The absence of change in cerebral blood flow leads us to postulate that the augmented ventilatory response during steep HDT may involve mechanisms related to cerebral venous pressure and venous outflow.

Transcranial Doppler ultrasound in evaluating cerebral blood flow abnormalities in major depressive disorder.

Previous research has shown that blood flow abnormalities affect major depressive disorder (MDD) from multiple perspectives. Therefore, this study aims to investigate the relationship between middle cerebral artery (MCA) blood flow velocity parameters and clinical symptom scores (Hamilton Depression Rating Scale [HAMD] and Montgomery-Åsberg Depression Rating Scale [MADRS]) in patients with MDD. We compared the MCA blood flow velocity parameters, including peak systolic velocity (MCA-PSV), end-diastolic velocity (MCA-EDV), and mean velocity (MCA-MV), between 50 MDD patients and 50 control subjects. Additionally, we analyzed the correlation between these parameters and HAMD and MADRS scores. Hemodynamic parameters such as pulsatility index and resistance index were also compared between the 2 groups. MCA-PSV, MCA-EDV, and MCA-MV were significantly lower in MDD patients compared to the control group, while pulsatility index and resistance index were significantly higher. Correlation analysis revealed that MCA-PSV, MCA-EDV, and MCA-MV were significantly negatively correlated with HAMD and MADRS scores in MDD patients, indicating that cerebral blood flow velocity decreases as depressive symptoms worsen. Furthermore, regression analysis confirmed the negative relationship between blood flow velocity parameters and clinical symptom scores. The results of this study suggest that the reduction in cerebral blood flow velocity in MDD patients may be associated with the severity of depressive symptoms. This finding provides new insights into the pathophysiological mechanisms of MDD and offers a potential theoretical basis for developing depression treatment strategies based on cerebral blood flow velocity parameters.

Comparison of inhalational and intravenous anesthesia induction on electroencephalogram and cerebral perfusion in children with congenital heart disease: A secondary analysis of a randomized controlled trial

ObjectiveThe effects of anesthetics on electroencephalograms and cerebral perfusion remain understudied in children with congenital heart disease. With regard to this, we compared inhalational anesthesia induction and intravenous anesthesia induction. DesignA randomized controlled trial. SettingOperation room in two tertiary hospitals. ParticipantsA cohort of 116 pediatrics patients undergoing cardiac surgery. Measurements and main resultsThe patients were randomly assigned to either the intravenous group (n=58) or the inhalational group (n=58). The inhalational group received anesthesia induction with 4-6% sevoflurane and a bolus of pipecuronium 0.2 mg/kg, while the intravenous group received anesthesia induction with intravenous midazolam 0.2 mg/kg, pipecuronium 0.2 mg/kg, and sufentanil 1 μg/kg. Ten minutes after tracheal intubation, the following parameters were measured: spectral edge frequency, burst suppression event, patient state index, middle cerebral artery blood flow velocity, cerebral oxygen saturation, and hemodynamic parameters. In comparison to the intravenous group, the inhalational group exhibited significant increases in 95% spectral edge frequency, ratio of burst suppression event, blood flow velocity in the middle cerebral artery, and cerebral oxygen saturation (P<0.05 for all), as well as decreases in systolic pressure, diastolic pressure, cardiac index, and the maximal slope of systolic upstroke (P<0.05 for all). ConclusionThe administration of sevoflurane for anesthesia induction results in more burst suppression, while also demonstrating superior cerebral perfusion when compared to the use of intravenous medications for anesthesia induction.

Comparing Carotid Artery Velocities with Current ASCVD Risk Stratification: A Novel Approach to Simpler Risk Assessment

PurposeTo explore the potential of a novel approach to simplify risk assessment by comparing carotid artery velocities with current atherosclerotic cardiovascular disease (ASCVD) risk stratification method using nonlinear measurements.MethodsIn this prospective study conducted at a medical center in southern Taiwan from January 1, 2020, to December 31, 2021, 1636 participants aged 40–75 years without prior ASCVD events were enrolled. Carotid flow velocity was obtained through duplex ultrasonography. ASCVD risk was categorized into two groups according to the 2022 USPSTF guidelines for primary prevention. We analyzed associations between flow indices and ASCVD risk using logistic regression and generalized additive models (GAMs).ResultsThe end diastolic velocity (EDV) of common carotid artery (CCA) and the peak systolic velocity (PSV) of internal carotid artery (ICA) were inversely and nonlinearly associated with cardiovascular event risk. Multivariate logistic regression analysis with ROC curves revealed that the optimal speed for the EDV of CCA was approximately 23.75 cm/s, and the optimal PSV and EDV of ICA were approximately 81.75 cm/s and 26.75 cm/s, respectively. The GAMs showed U-shaped relationships between elevated ASCVD risk and blood flow velocity in the carotid arteries, with inflection points of approximately 82 cm/s in the PSV of ICA and near 25 cm/s in the EDV of CCA. Both methods revealed similar results.ConclusionsThe EDVs and PSVs of the CCA and ICA are associated with the development of cardiovascular events. Optimal velocity ranges were identified; however, further hemodynamic investigations are warranted.

Optimizing Brain-Computer Interfaces for Methampetamine Use Disorder through Quantitative Electroencephalography (QEEG) and Transcranial Doppler Analysis: Article Review

A Brain-Computer Interface (BCI) is a system that allows a person to control external devices using only their brain activity. It works by translating brain signals into commands that can be understood by a computer. Several lines of evidence demonstrated the deleterious effect of methamphetamine (MA) on neurological and psychological functions. The use of amphetamines, such as MA, is associated with cerebrovascular complications such as cerebrovascular accidents (CVA) ,hemorrhage, hypoxic damage and vasculitis. Interestingly, while changes to cerebral blood flow (CBF) in response to acute amphetamine exposure have been reported. Transcranial Color Doppler (TCCD) is a non-invasive medical imaging technique that uses ultrasound waves to measure blood flow velocity in the major arteries of the brain, specifically within the circle of Willis. The research paper you referenced explores the use of TCCD as a potential measurement modality for BCIs. Quantitative electroencephalogram (qEEG) is a powerful tool for understanding brain function qEEG can reveal specific brain wave patterns associated with drug addiction, potentially providing insights into the neurobiological mechanisms underlying cravings, withdrawal symptoms, and relapse risk in Methamphetamine User Disorder (MUD). There is growing research interest in using Transcranial dopller as a measurement modality for BCIs.Here are some of the key considerations for using Transcranial doppler in BCIs: Mental Tasks, signal processing and classification, accuracy and reliability. Transcranial doppler provides information about blood flow in specific arteries but lacks detailed spatial information about brain activity. These patterns could vary depending on the type of drug, the severity of addiction, and individual differences. Transcranial doppler in measuring middle cerebral artery (MCA) blood flow velocity parameters (peak systolic velocity (PSV) and mean flow velocity (MFV)). qEEG can help researchers investigate the complex interplay between addiction and other brain disorders, like depression or anxiety. Characteristic qEEG in drugs addiction Increased Theta (4-8 Hz) and delta (1-4 Hz) brain waves are often associated with sleep and relaxation. However, research has shown that individuals with drug addiction may have increased theta and delta activity, particularly in the frontal and temporal regions of the brain. Altered Beta (13-30 Hz) brain waves are generally associated with wakefulness, alertness, and cognitive processing. Studies have observed both increases and decreases in beta activity in individuals with drug addiction, depending on the type of drug, the stage of addiction, and the specific brain regions being examined. The results of this research have important practical implications for building an diagnostic and functional assement with a better understanding of an using technology.

Ezetimibe protects against Gentamycin-induced ototoxicity in rats by antioxidants, anti-inflammatory mechanisms, and BDNF upregulation

Objective The threat of hearing loss has become a universal reality. Gentamycin (GM) can lead to ototoxicity and may result in permanent hearing loss. This study aimed to elucidate whether the hypolipidemic drug Ezetimibe (EZE) has a possible underlying mechanism for protecting rats from GM-induced ototoxicity. Methods and results 30 male Wister albino rats were separated into three groups, ten in each group: control, GM, and GM + EZE. At the end of the experiment, rats underwent hearing threshold evaluation via auditory brainstem response (ABR), carotid artery blood flow velocity (CBV), and resistance (CVR) measurement, in addition to a biochemical assessment of serum malondialdehyde (MDA), nitric oxide (NO), catalase (CAT), hemeOxygenase-1 (HO-1), and tumor necrosis factor-α (TNF-α). Also, real-time PCR was employed to quantify the levels of brain-derived neurotrophic factor (BDNF). Cochlea was also studied via histological and immunohistochemical methods. GM revealed a significant increase in CVR, MDA, NO, and TNF-α and a significant decrease in ABR, CBV, CAT, HO-1, and cochlear BDNF expression. EZE supplementation revealed a significant rise in ARB in addition to CBV and a decline in CVR and protected cochlear tissues via antioxidant, anti-inflammatory, and antiapoptotic mechanisms via downregulating Caspase-3 immunoreaction, upregulating proliferating cellular nuclear antigen (PCNA) immunoreaction, and upregulating of the cochlear BDNF expression. Correlations were significantly negative between BDNF and MDA, NO, TNF-α, COX 2, and caspase-3 immunoreaction and significantly positive with CAT, HO-1, and PCNA immunoreaction. Discussion EZE can safeguard inner ear tissues from GM via antioxidant, anti-inflammatory, and antiapoptotic mechanisms, as well as upregulation of BDNF mechanisms.

A prospective pilot study of gut microbiome in cerebral vasospasm and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

A recent systematic review indicated that gut–microbiota–brain axis contributes to growth and rupture of intracranial aneurysms. However, gaps were detected in the role of intestinal microbiome in cerebral vasospasm (CVS) after aneurysmal subarachnoid hemorrhage (aSAH). This is the first pilot study aiming to test study feasibility and identify differences in gut microbiota between subjects with and without CVS following aSAH. A prospective nested case–control pilot study with 1:1 matching was conducted recruiting subjects with aSAH: cases with CVS; and controls without CVS based on the clinical picture and structured bedside transcranial Doppler (TCD). Fecal samples for microbiota analyses by means of 16S rRNA gene amplicon sequencing were collected within the first 96 h after ictus. Operational taxonomic unit tables were constructed, diversity metrics calculated, phylogenetic trees built, and differential abundance analysis (DAA) performed. At baseline, the groups did not differ significantly in basic demographic and aneurysm-related characteristics (p > 0.05). Alpha-diversity (richness and Shannon Index) was significantly reduced in cases of middle cerebral artery (MCA) vasospasm (p < 0.05). In DAA, relative abundance of genus Acidaminococcus was associated with MCA vasospasm (p = 0.00013). Two butyrate-producing genera, Intestinimonas and Butyricimonas, as well as [Clostridium] innocuum group had the strongest negative correlation with the mean blood flow velocity in anterior cerebral arteries (p < 0.01; rho = − 0.63; − 0.57, and − 0.57, respectively). In total, 16 gut microbial genera were identified to correlate with TCD parameters, and two intestinal genera correlated with outcome upon discharge. In this pilot study, we prove study feasibility and present the first preliminary evidence of gut microbiome signature associating with CVS as a significant cause of stroke in subjects with aSAH.

Glycated Haemoglobin Correlates With Carotid Intima-Media Thickness and Blood Flow Velocity in Carotid Arteries in Nondiabetic Patients—Preliminary Results

Glycated Haemoglobin Correlates With Carotid Intima-Media Thickness and Blood Flow Velocity in Carotid Arteries in Nondiabetic Patients—Preliminary Results

Dynamics of rheological and biochemical blood parameters of patients with an intermediate stage of the dry form of age-related macular degeneration before and after serum cascade filtration

BACKGROUND: One of the socially significant ophthalmic diseases is the dry form of the age-related macular degeneration, the key feature of which consists in a slowly progressing damage to the pigment epithelium and the formation of drusen. However, the basic mechanisms of pathogenesis are still not completely clear nowadays. AIM: The aim is, using the data of OCT, OCT-angiography and visometry, to study the dynamics of structural and functional parameters of the macular area, as well as the dynamics of rheological and biochemical blood parameters in patients with an intermediate stage of the dry form of age-related macular degeneration before and after the use of serum cascade filtration. MATERIALS AND METHODS: The study included 63 patients (94 eyes) with an intermediate stage of the dry form of age-related macular degeneration. Patients were randomly separated into two groups. The first (main) group consisted of 34 patients (52 eyes), in whom serum cascade filtration was performed; the second group (control) group included 29 patients (42 eyes) who did not receive any specific treatment. In patients of the main group, before and after the serum cascade filtration course (1 month after the start of follow-up), in 6 and 12 months, in addition to standard ophthalmological examination, as an indicator of the efficacy of performed serum cascade filtration, the ultrasound triplex scanning in color Doppler mapping mode with an assessment of blood flow velocity in the posterior short ciliary arteries, Fourier IR spectroscopy, and the testing of the serum and blood viscosity were performed. Patients in the control group also underwent a similar examination at 1, 6, 12 months after the start of follow-up. RESULTS: According to optical coherence tomography, optical coherence tomography-angiography and visometry data, we found a positive dynamics of structural and functional parameters of the macular retina and an improvement in blood rheological parameters with an increase in microcirculation indices against the background of the serum cascade filtration use in treatment of patients with an intermediate stage of the dry form of age-related macular degeneration. At the same time, a statistically significant difference between the two groups begins at 1 month and persists for 12 months of follow-up, being an evidence of the stabilization of the pathological process. CONCLUSIONS: This study showed that after the serum cascade filtration in patients with an intermediate stage of the dry form of age-related macular degeneration, against the background of an improvement in blood rheological and biochemical parameters, there was an improvement in structural and functional parameters of the macular area, which consisted in a decrease of the volume of the drusenoid retinal pigment epithelium detachment and in a visual acuity amelioration.

Assessment of Blood Flow Velocity in Retinal Vasculitis Using the Retinal Function Imager-A Pilot Study.

Background: This pilot study aimed to evaluate the Retinal Function Imager (RFI) for visualizing retinal vasculature and assessment of blood flow characteristics in patients with retinal vasculitis. The RFI is a non-invasive imaging device measuring the blood flow velocity (BFV) in secondary and tertiary retinal vessels using hemoglobin as an intrinsic motion-contrast agent. Methods: To test the feasibility of the RFI for patients with retinal vasculitis, capillary perfusion maps (nCPMs) were generated from 15 eyes of eight patients (five females; mean age: 49 ± 12 years) with a mean uveitis duration of 74 ± 85 months. Five of these patients had birdshot chorioretinopathy, and three had primarily non-occlusive venous retinal vasculitis of unknown origin. To reflect that the BFV may be more reduced in patients with prolonged disease, patients were classified into a short-term (uveitis duration: 8-15 months) and a long-term uveitis group (uveitis duration: 60-264 months). Data were compared with healthy controls (16 eyes of 11 patients; mean age 45 ± 12 years; 8 females). Results: The mean BFV in the controls was 3.79 ± 0.50 mm/s in the retinal arteries and 2.35 ± 0.44 mm/s in the retinal veins, which was significantly higher compared to the retinal vasculitis group. Patients revealed an arterial BFV of 2.75 ± 0.74 mm/s (p < 0.001) and a venous BFV of 1.75 ± 0.51 mm/s (p = 0.016). In the short-term group, a trend towards a decreased venular and arteriolar BFV was seen, while a significant reduction was observed in the long-term group. The patients' microvasculature anatomy revealed by the nCPMs appeared unevenly distributed and a lower number of blood vessels were seen, along with a lower degree of complexity of their branching patterns, when compared with controls. Conclusions: This study demonstrated a reduction in venular and arteriolar BFVs in patients with retinal vasculitis. BFV alterations were already observed in early disease stages and became more pronounced in progressed disease. Additionally, we showed that retinal microvasculature changes may be observed by nCPMs. Retinal imaging with the RFI may serve as a diagnostic and quantifying tool in retinal vasculitis.

Diagnostic value of transcranial doppler to predict delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

BackgroundTranscranial Doppler (TCD) is a technique to assess blood flow velocity in the cerebral arteries. TCD is frequently used to monitor aneurysmal subarachnoid hemorrhage (aSAH) patients. This study compares TCD-criteria for vasospasm and its association with Delayed Cerebral Ischemia (DCI). An overall score based on flow velocities of various intracranial arteries was developed and evaluated.MethodsA retrospective diagnostic accuracy study was conducted between 1998 and 2017 with 621 patients included. Mean flow velocity (MFV) of the cerebral artery was measured between 2–5 days and between 6–9 days after ictus. Cutoff values from the literature, new cutoff values, and a new composite score (Combined Severity Score) were used to predict DCI. Sensitivity, specificity, and area under the curve (AUC) were determined, and logistic regression analysis was performed.ResultsThe Combined Severity Score showed an AUC 0.64 (95%CI 0.56-.71) at days 2–5, with sensitivity 0.53 and specificity 0.74. The Combined Severity Score had an adjusted Odds Ratio of 3.41 (95CI 1.86–6.32) for DCI. MCA-measurements yielded the highest AUC to detect DCI at day 2–5: AUC 0.65 (95%CI 0.58–0.73). Optimal cutoff MFV of 83 cm/s for MCA resulted in sensitivity 0.73 and specificity 0.50 at days 2–5.ConclusionTCD-monitoring of aSAH patients may be a valuable strategy for DCI risk stratification. Lower cutoff values can be used in the early phase after the ictus (day 2–5) than are commonly used now. The Combined Severity Score incorporating all major cerebral arteries may provide a meaningful contribution to interpreting TCD measurements.

Коагуляційні характеристики пуповинної крові при затримці росту плода

Fetal growth restriction (FGR) is a common complication of pregnancy associated with severe perinatal consequences, a significant part of which is hemorrhagic and thrombotic disorders. Fetuses with FGR have thrombocytopenia, platelet dysfunction, and distortion of standard coagulation tests. There are few studies of the coagulation system in such newborns in vivo in the literature. Аim - to assess the relationship between the Doppler criteria of FGR and the kinetic manifestations of umbilical artery blood coagulation and fibrinolysis according to rotational thromboelastometry. Materials and methods. Prenatal Doppler parameters and postpartum kinetic parameters of blood coagulation and fibrinolysis in 118 newborns from singleton births were analyzed: the Group I - 67 newborns with FGR; the Group II - 51 full-term newborns from healthy mothers. Results. A significant decrease in the uterine and umbilical arteries resistance and blood flow velocity in FGR cases has been established. Thromboelastometric tests in the umbilical cord blood of the Group I newborns showed faster than in the Group II the blood clot formation, its greater firmness and delayed fibrinolysis. Comparison using rank correlation showed a relationship of average strength between the velocity of blood flow in the umbilical cord arteries and the blood clot firmness. Correlation between blood flow velocity in the midbrain and uterine arteries and coagulation indicators are weak. Conclusions. Reduced resistance index in the middle cerebral artery of fetuses with FGR indicates reduced resistance in these vessels, which should be regarded as signs of decentralization of fetal circulation. The blood of newborns with FGR is dominated by the processes of increased coagulation and slowing down of fibrinolysis, regardless of the date of birth. An increase in the pulsation index in the umbilical cord arteries during pregnancy can be considered a prognostically favorable hemodynamic characteristic in FGR. The study was carried out in accordance with the principles of the Helsinki Declaration. The research protocol was approved by the Local Ethics Committee of the institution mentioned in the work. The authors declare that there is no conflict of interest.

Posterior Tibial Artery Blood Flow Velocity Is Increased in Patients with Plantar Heel Pain.

Background/Objectives: This study aimed to investigate the relationship between posterior tibial artery blood flow velocity and plantar heel pain (PHP). Methods: The PHP group comprised patients diagnosed with plantar fasciitis with plantar heel pain during gait, and the control group comprised healthy participants without plantar heel pain. The peak systolic velocity of the posterior tibial artery was measured using ultrasonography; it was measured three times on each side, and the mean value was calculated. Receiver operating characteristic curve analysis was performed to calculate the peak systolic velocity cutoff value for plantar heel pain. Results: 23 patients (age 58.0 ± 16.5 years; 13 males and 10 females) and 23 healthy participants (age 51.3 ± 17.3 years; 10 males and 13 females) formed the PHP and control groups, respectively. Peak systolic velocity on the affected side was significantly greater in the PHP group (44.1 ± 13.1 cm/s) than in the control group (32.7 ± 5.9 cm/s). No significant difference was observed between the left and right sides in the PHP (7.1 ± 9.8 cm/s) and control (3.7 ± 3.0 cm/s) groups. A cutoff value of 38.2 cm/s was observed on the affected side. Conclusions: We quantified the increase in posterior tibial artery blood flow velocity in patients with plantar heel pain. Peak systolic velocity measurements can aid in quantitatively evaluating these patients. This study was registered as a clinical trial (UMIN000046875) on 1 October 2021.

SEX DIFFERENCES IN CEREBRAL BLOOD FLOW VELOCITY RESPONSES TO EXERCISE IN THE HEAT

INTRODUCTION &amp; AIMS Global warming poses a risk for the development of heat-related physiological impairment, which can be aggravated when exercising in hot conditions. The aim of the present study was to investigate acute effects of exercising in hot conditions on cerebral blood flow velocity and systolic function in healthy individuals and to explore possible sex differences. METHODS The experimental condition consisted of walking on a treadmill, at 5km/h and 2% incline, inside a heat chamber at 40°C (50%RH), for 90 minutes. Middle cerebral artery blood flow velocity (MCAv) and left ventricular global longitudinal strain (GLS; a sensitive index of systolic function), were assessed at baseline and every 30 minutes by means of transcranial Doppler and speckle-tracking echocardiography, respectively. Data is expressed in delta (Δ) and standard error. RESULTS Twenty-six individuals (13♂,13♀ 27.1±1.0yrs, P=0.02) completed the experimental protocol. Both males and females exhibited non-significant increases in MCAv from baseline at 30 minutes (♂Δ=2.55±2.15 P&amp;gt;0.05; ♀Δ=0.54±2.53cm.s-1, P&amp;gt;0.05; interaction P=0.63), followed by significant decreases relative to 30min, at 60min (♂Δ=-4.0±1.23 P=0.04; ♀Δ=-5.41±1.56cm.s-1, P=0.03; interaction P=0.63) and 90 minutes (♂Δ=-6.08±1.37 P&amp;lt;0.01; ♀Δ=-7.39±1.40cm.s-1, P&amp;lt;0.01; interaction P=0.63). In males, there was a significant decrease in GLS from baseline at 30min (Δ=2.44±0.69%, P&amp;lt;0.05), 60 (Δ=2.79±0.73%, P=0.03), and 90 (Δ=3.49±0.89%, P=0.03) minutes; no significant changes were observed in females. CONCLUSION Males and females presented similar patterns of change in cerebral blood flow velocity, including significant decreases with prolonged heat exertion. These changes occur in both sexes, despite changes in systolic strain only being apparent in males. These data suggest that sex differences may exist in the regulation of cerebrovascular responses to exercise in the heat in humans.

Non-vascular ATP-sensitive potassium channel activation does not trigger migraine attacks: A randomized clinical trial.

To investigate the role of NN414, a selective KATP channel opener for the Kir6.2/SUR1 channel subtype found in neurons and β-pancreatic cells, in inducing migraine attacks in individuals with migraine without aura. Thirteen participants were randomly allocated to receive NN414 and placebo on two days separated by at least one week. The primary endpoint was the difference in the incidence of migraine attacks after NN414 compared with placebo. The secondary endpoints were the difference in the area under the curve for headache intensity scores, middle cerebral artery blood flow velocity (VMCA), superficial temporal artery diameter, heart rate and mean arterial pressure. Twelve participants completed the study, with two (16.6%) reporting migraine attacks after NN414 compared to one (8.3%) after placebo (p = 0.53). The area under the curve for headache intensity, VMCA, superficial temporal artery diameter, heart rate and mean arterial pressure did not differ between NN414 and placebo (p > 0.05, all comparisons). The lack of migraine induction upon activation of the Kir6.2/SUR1 channel subtype suggests it may not contribute to migraine pathogenesis. Our findings point to KATP channel blockers that target the Kir6.1/SUR2B subtype, found in cerebral vasculature, as potential candidates for innovative antimigraine treatments.Registration number: NCT04744129.

Cerebrovascular Dysfunction in a Mouse Model of Marfan Syndrome: Increased Vulnerability to Neuropathology &amp; Mild Traumatic Brain Injury

Marfan syndrome (MFS) is a connective tissue disorder (CTD) associated with mutations in fibrillin-1 ( Fbn1), leading to chronic systemic increases in transforming growth factor-β (TGF-β) availability and signaling that could lead to aortic wall weakening and aneurysm/rupture. TGF-β has been implicated in cerebrovascular dysfunction, loss of blood-brain barrier (BBB) integrity, age-related neuroinflammation and neurological deficits. Improvements in MFS treatment and life expectancy have uncovered a risk for systemic vascular dysfunction including cerebrovascular complications such as stroke, and cerebral aneurysm. Therefore, we hypothesized that Fbn1 mutation ( Fbn1C1041G/+) is associated with systemic vascular dysfunction, BBB permeability, neuroinflammation, neurobehavioral alterations, and impaired glutamate homeostasis, leaving the brain more vulnerable to mild traumatic brain injury (mTBI). Our experimental groups included: 6M-old male and female MFS ( Fbn1C1041G/+) and C57BL/6 (WT) control, and middle-aged 12M WT mice (N=3-10/group, P &lt; 0.05). In vivo ultrasound imaging analyzed by two blinded investigators demonstrated increased aortic root diameters and stiffness in MFS mice compared to 6M and 12M WT mice, where MFS male diameters were affected more than females. Vascular dysfunction measured by blood flow velocity (BFV) extended to the left pulmonary artery where 6M MFS and 12M WT mice were reduced compared to 6M WT mice. This reduction continued through decreased posterior cerebral artery BFV in MFS males, where MFS females were comparable to 6 and 12M WT females. In 6M MFS male mice, Evans blue extravasation and Immunoglobulin G staining demonstrated increased BBB permeability in the hippocampus to large and small molecules, respectively, as well as to small molecules in the lateral hypothalamus as compared to 6M WT and like 12M WT. In adjacent sections, iba-1-stained cells had morphologies indicative of reactive microglia. In vivo electrochemical recordings in the hippocampus showed a trend towards lowered peak glutamate amplitudes and elevated baseline glutamate concentrations in MFS and 12M WT mice demonstrating disrupted glutamate homeostasis. Furthermore, exogenous TGF-β applied in the lateral hippocampus of 6M WT males revealed an evoked glutamate response that may support this elevated baseline in MFS mice. Higher neurobehavioral severity scale (NSS) scores in 6M MFS mice suggested neurobehavioral alterations that were more like 12M WT. Midline fluid percussion was used to induce mTBI, where 6M MFS male mice and both female groups required a 15% lower pressure to induce mTBI righting reflex times (5-10 minutes) compared to 6M WT male mice. Mice were evaluated at 1-day post injury, where BBB permeability to large and small molecules and microglia activation were increased, glutamate clearance was slowed, and NSS scores were increased compared to 6M WT and were like 6M MFS and 12M WT mice. These novel findings signify MFS as a condition of systemic vascular dysfunction and pre-mature cerebrovascular aging phenotype with more vulnerability to brain injury. Funding: NIH-R36AG083385, Valley Research Partnership-P1A-5012, NIH-R15HL145646, NIH-R01NS100793, Midwestern Graduate Funds, Phoenix Children’s Hospital Leadership Circle, Graduate and Professional Council Research and Projects Grant. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Ultrasound indicators of blood flow in the eyes and orbits at different durations of type 1 diabetes mellitus in childhood and adolescence

Diabetic retinopathy is a complication of type 1 diabetes mellitus with high social significance, especially in childhood and adolescence.Aim: To evaluate ultrasound indicators of retrobulbar blood flow at different durations of type 1 diabetes mellitus in childhood and adolescence.Material and Methods. Ultrasound examinations were performed in 70 patients with type 1 diabetes mellitus aged from 5 to 18 years, with disease duration of up to 5 years, from 5 to 10 years, and more than 10 years. The analysis included an assessment of the linear velocity of blood flow and the index of peripheral resistance in the ophthalmic arteries, central arteries and retinal veins, posterior short ciliary arteries, and ophthalmic veins at different times of the duration of type 1 diabetes mellitus.Results. The study revealed a decrease in blood flow velocity in the central retinal arteries, in the posterior short ciliary arteries with an increase in the duration of type1 diabetes mellitus. The greatest decrease in blood flow velocity was recorded in the group with duration of diabetes mellitus of more than 10 years.Conclusion. The obtained data on a decrease in blood flow velocity in the retrobulbar arteries can be used for the assessment and dynamic monitoring of early disorders of the blood supply to the eye and orbit in patients with type 1 diabetes mellitus in childhood and adolescence.