keyword
MENU ▼
Read by QxMD icon Read
search

cerebral blood flow velocity

keyword
https://www.readbyqxmd.com/read/28339483/temporal-evolution-of-vasospasm-and-clinical-outcome-after-intra-arterial-vasodilator-therapy-in-patients-with-aneurysmal-subarachnoid-hemorrhage
#1
Laleh Daftari Besheli, Can Ozan Tan, Donnie L Bell, Joshua A Hirsch, Rajiv Gupta
Intra-arterial (IA) vasodilator therapy is one of the recommended treatments to minimize the impact of aneurysmal subarachnoid hemorrhage-induced cerebral vasospasm refractory to standard management. However, its usefulness and efficacy is not well established. We evaluated the effect IA vasodilator therapy on middle cerebral artery blood flow and on discharge outcome. We reviewed records for 115 adults admitted to Neurointensive Care Unit to test whether there was a difference in clinical outcome (discharge mRS) in those who received IA infusions...
2017: PloS One
https://www.readbyqxmd.com/read/28334813/construction-of-ductal-diameter-centiles-in-the-first-24%C3%A2-h-of-life-and-their-relation-to-cerebral-blood-flow-in-neonates-weighing-less-than-1250%C3%A2-g-in-the-first-24%C3%A2-h-of-life
#2
Sunil Pawar, Deepak Sharma, Srinivas Murki, Sreeram Subramaniam, Hemashree Kandraju
Aims and objectives: To evaluate the ductal diameter centiles in the first 24 h of life and their relation to cerebral blood flow in neonates weighing <1250 g in the first 24 h of life. Method and material: This prospective observational cohort study enrolled 44 infants with birth weight <1250 g. Two-dimensional echocardiography and color Doppler were performed within the first 12 h of life and were repeated again in the next 12 h of life to assess the ductal size and middle cerebral artery (MCA) flows [peak systolic velocity (PSV), end diastolic velocity (EDV), mean velocity (MV) and pulsatility index (PI)]...
March 13, 2017: Journal of Tropical Pediatrics
https://www.readbyqxmd.com/read/28333037/cerebral-hemodynamic-with-intra-aortic-balloon-pump-business-as-usual
#3
Juliana Caldas, Ronney B Panerai, Edson Bor-Seng-Shu, Juliano Almeida, Graziela Ferreira, Ligia Cunha, Ricardo Nogueira, Marcelo Oliveira, Fabio Jatene, Thompson Robinson, Ludhmila Hajjar
Intra-aortic balloon pump (IABP) is commonly used as mechanical support after cardiac surgery or cardiac shock. Although its benefits for cardiac function have been well documented, its effects on cerebral circulation are still controversial. We hypothesized that transfer function analysis (TFA) and continuous estimates of dynamic cerebral autoregulation (CA) provide consistent results in the assessment of cerebral autoregulation in patients with IABP. Continuous recordings of blood pressure (BP, intra-arterial line), end-tidal CO2, heart rate and cerebral blood flow velocity (CBFV, transcranial Doppler) were obtained i) 5 minutes with IABP ratio 1:3, ii) 5 minutes, starting 1 minute with the IABP-ON, and continuing for another 4 minutes without pump assistance (IABP-OFF)...
March 23, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/28325558/l-citrulline-ameliorates-cerebral-blood-flow-during-cortical-spreading-depression-in-rats-involvement-of-nitric-oxide-and-prostanoids-mediated-pathway
#4
Yuki Kurauchi, Koichi Mokudai, Asami Mori, Kenji Sakamoto, Tsutomu Nakahara, Masahiko Morita, Ayako Kamimura, Kunio Ishii
l-Citrulline is a potent precursor of l-arginine, and exerts beneficial effect on cardiovascular system via nitric oxide (NO) production. Migraine is one of the most popular neurovascular disorder, and imbalance of cerebral blood flow (CBF) observed in cortical spreading depression (CSD) contributes to the mechanism of migraine aura. Here, we investigated the effect of l-citrulline on cardiovascular changes to KCl-induced CSD. in rats. Intravenous injection of l-citrulline prevented the decrease in CBF, monitored by laser Doppler flowmetry, without affecting mean arterial pressure and heart rate during CSD...
February 17, 2017: Journal of Pharmacological Sciences
https://www.readbyqxmd.com/read/28325005/dynamic-modeling-of-apnea-induced-concurrent-variations-in-arterial-blood-pressure-and-cerebral-blood-flow-velocity
#5
Raichel Alex, Rong Zhang, Donald E Watenpaugh, Khosrow Behbehani
Obstructive Sleep Apnea (OSA) is characterized by partial (hypopnea) or complete cessation (apnea) of airflow to the lungs during sleep. It has been previously reported that apnea episodes lead to significant rise in instantaneous blood pressure concomitant with a rise in cerebral blood flow velocity, indicating loss of cerebral autoregulation during the episodes. In this study, we have used Auto Regressive Moving Average model (ARMA (na, nb, nk)) to quantify OSA induced dynamic changes in cerebral blood flow velocity (CBFV) with beat to beat blood pressure (BP) as an input...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28314626/cerebral-hemodynamic-effects-of-cheyne-stokes-respiration-in-a-patient-with-stroke
#6
R C Nogueira, R B Panerai, M J Teixeira, T G Robinson, E Bor-Seng-Shu
INTRODUCTION: Cheyne-Stokes respiration (CSR) and central sleep apnea (CSA) are common in patients with heart failure and/or stroke. We aim to describe the cerebrovascular effects of CSR during the acute phase of stroke in a heart failure patient. CASE REPORT: A 74-year-old male with previous dilated cardiomyopathy had sudden onset of right hemiparesis and aphasia. A transcranial Doppler was performed with continuous measurement of blood pressure (BP) (Finometer) and end-tidal CO2 (nasal capnography)...
March 14, 2017: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/28293809/a-mesenteric-traction-syndrome-affects-near-infrared-spectroscopy-evaluated-cerebral-oxygenation-because-skin-blood-flow-increases
#7
Niels D Olesen, Henrik Sørensen, Rikard Ambrus, Lars B Svendsen, Anton Lund, Niels H Secher
During abdominal surgery manipulation of internal organs may induce a "mesenteric traction syndrome" (MTS) including a triad of flushing, hypotension, and tachycardia that lasts for about 30 min. We evaluated whether MTS affects near-infrared spectroscopy (NIRS) assessed frontal lobe oxygenation (ScO2) by an increase in forehead skin blood flow (SkBF). The study intended to include 10 patients who developed MTS during pancreaticoduodenectomy and 22 patients were enrolled (age 61 ± 8 years; mean ± SD)...
March 14, 2017: Journal of Clinical Monitoring and Computing
https://www.readbyqxmd.com/read/28289715/cerebrovascular-adaptations-to-cocaine-induced-transient-ischemic-attacks-in-the-rodent-brain
#8
Jiang You, Nora D Volkow, Kicheon Park, Qiujia Zhang, Kevin Clare, Congwu Du, Yingtian Pan
Occurrence of transient ischemic attacks (TIA) and cerebral strokes is a recognized risk associated with cocaine abuse. Here, we use a rodent model along with optical imaging to study cocaine-induced TIA and the associated dynamic changes in cerebral blood flow velocity (CBFv) and cerebrovasculature. We show that chronic cocaine exposure in mice resulted in marked cortical hypoperfusion, in significant arterial and venous vasoconstriction, and in a sensitized vascular response to an acute cocaine injection...
March 9, 2017: JCI Insight
https://www.readbyqxmd.com/read/28287282/cerebrovascular-reactivity-in-acute-hyperoxia-in-patients-with-acute-ischaemic-stroke
#9
Ivana Hegeduš, Jakov Milić, Anita Ćosić, Krunoslav Buljan, Ines Drenjančević
AIM: This study aimed to assess the effect of acute hyperoxia on cerebral and systemic heamodynamics and the plasma concentration of prostacyclin and thromboxane in patients with stroke. METHODS: Mean blood flow velocity (MBFV), pulsatility and resistance indices of the middle cerebral artery using transcranial Doppler ultrasound before and during acute hyperoxia (4 L of 100%O2/15' over facial mask) in 92 participants - 25 patients with acute ischaemic stroke (AIS) that occurred within 72 hours and diabetes mellitus (SPDM), 26 AIS patients without DM (SP) and in 41 healthy controls (HS), were measured...
March 13, 2017: Brain Injury: [BI]
https://www.readbyqxmd.com/read/28281372/carbon-monoxide-reduces-near-infrared-spectroscopy-determined-total-hemoglobin-a-human-volunteer-study
#10
Mads J Niemann, Henrik Sørensen, Christoph Siebenmann, Carsten Lundby, Niels H Secher
Carbon monoxide (CO) increases middle cerebral artery mean flow velocity (MCAVmean), but the effect of CO on the near-infrared spectroscopy (NIRS) determined cerebral oxygenation (ScO2) is not detailed. In our study, 11 non-smoking subjects breathed 100% O2 through a closed circuit. A CO2 scrubber with CO (1.5 mL kg(-1)) was added to the circuit. Two NIRS systems (NIRO-200NX and INVOS-5100) assessed ScO2 as the ratio of oxygenated to deoxygenated hemoglobin, while venous blood samples were analyzed for carboxyhemoglobin (COHb)...
March 10, 2017: Scandinavian Journal of Clinical and Laboratory Investigation
https://www.readbyqxmd.com/read/28280106/dynamics-of-middle-cerebral-artery-blood-flow-velocity-during-moderate-intensity-exercise
#11
Sandra A Billinger, Jesse C Craig, Sarah J Kwapiszeski, Jason-Flor Villarosa Sisante, Eric Dennis Vidoni, Rebecca Maletsky, David C Poole
The dynamic response to a stimulus such as exercise can reveal valuable insights into systems control in health and disease that is not evident from the steady-state perturbation. However, the dynamic response profile and kinetics of cerebrovascular function have not been determined to date. We tested the hypotheses that bilateral middle cerebral artery blood flow velocity (MCAV) increases exponentially following the onset of moderate intensity exercise in ten healthy young subjects. The MCAV response profiles were well fit to a delay (TD) + exponential (time constant, τ) model with substantial agreement for baseline (L: 69, R: 64 cm·s(-1), coefficient of variation, c...
March 9, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/28277907/the-effect-of-maternal-hyperoxygenation-on-fetal-circulatory-system-in-normal-growth-and-iugr-fetuses-what-we-can-learn-from-this-impact
#12
Nizar Khatib, Israel Thaler, Ron Beloosesky, Hanin Dabaja, Nadir Ganem, Philippe Abecassis, Yuval Ginsberg, Zeev Weiner
PURPOSE: The study aims were to assess and compare the effects of maternal hyperoxygenation on fetal circulation, in fetuses with intra-uterine growth retardation and normal fetal growth. METHODS: Twelve singleton pregnant women with normal fetal growth and twelve singleton pregnant women with intrauterine growth restriction were recruited. Mean gestational age of 35.2±3.5 and 34.7±3.9 weeks respectively. Doppler blood flow velocity waveforms were obtained from the middle cerebral artery, umbilical, main and proximal right pulmonary arteries...
March 3, 2017: Journal of Maternal-fetal & Neonatal Medicine
https://www.readbyqxmd.com/read/28269229/a-study-of-apnea-induced-covariations-of-cerebral-blood-flow-and-exhaled-co2
#13
Varun Kanal, Raichel Alex, Nazaneen Mousavi, Kevin Jepsen, Donald E Watenpaugh, Rong Zhang, Khosrow Behbehani
Sleep apnea is identified by repetitive reduction or complete cessation of breathing during sleep. Sleep apnea affects cerebral hemodynamics and it is important to study this effect. Measuring cerebral blood flow during sleep is challenging due to the need to maintain a contact between the flow probe and the skull. It is hypothesized that there exists a relationship between the variations in the exhaled CO2 and Cerebral Blood Flow during sleep apnea. To test this hypothesis, the present study was conducted in two parts: simulated and nocturnal sleep study...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268423/dynamic-cerebral-autoregulation-in-young-athletes-following-concussion
#14
Kyriaki Kostoglou, Alexander D Wright, Jonathan D Smirl, Kelsey Bryk, Paul van Donkelaar, Georgios D Mitsis
The purpose of this study was to examine cerebral autoregulation (CA) in young athletes experiencing concussion. The subjects were monitored and repeatedly tested 72 hours, 2 weeks and 1 month post-injury. Mean arterial blood pressure (MABP), end-tidal partial pressure of carbon dioxide (PETCO2) and cerebral blood flow velocity (CBFV) in the middle and posterior cerebral arteries were monitored during mental activation paradigms. In order to characterize CA we employed autoregressive models with exogenous inputs (ARX) and impulse response models based on the Laguerre expansion technique (LET)...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268070/post-carotid-endarterectomy-hypertension-part-1-association-with-pre-operative-clinical-imaging-and-physiological-parameters
#15
J E Newman, M J Bown, R D Sayers, J P Thompson, T G Robinson, B Williams, R Panerai, P Lacy, A R Naylor
OBJECTIVE/BACKGROUND: Post-endarterectomy hypertension (PEH) is a well recognised, but poorly understood, phenomenon after carotid endarterectomy (CEA) that is associated with post-operative intracranial haemorrhage, hyperperfusion syndrome, and cardiac complications. The aim of the current study was to identify pre-operative clinical, imaging, and physiological parameters associated with PEH. METHODS: In total, 106 CEA patients undergoing CEA under general anaesthesia underwent pre-operative evaluation of 24 hour ambulatory arterial blood pressure (BP), baroreceptor sensitivity, cerebral autoregulation, and transcranial Doppler measurement of cerebral blood flow velocity (CBFv) and pulsatility index...
March 3, 2017: European Journal of Vascular and Endovascular Surgery
https://www.readbyqxmd.com/read/28262564/is-dynamic-cerebral-autoregulation-bilaterally-impaired-after-unilateral-acute-ischemic-stroke
#16
Li Xiong, Ge Tian, Wenhua Lin, Wei Wang, Lijuan Wang, Thomas Leung, Vincent Mok, Jia Liu, Xiangyan Chen, Ka Sing Wong
OBJECTIVE: Whether dynamic cerebral autoregulation (dCA) is impaired focally in the affected hemisphere or bilaterally in both the affected and nonaffected hemispheres after ischemic stroke remains controversial. We therefore investigated the pattern of dCA in acute ischemic stroke patients with different subtypes. METHODS: Sixty acute ischemic stroke patients with unilateral anterior circulation infarct [30 with large artery atherosclerosis (LAA), 13 with small vessel disease (SVD), and 17 with coexisting LAA and SVD] and 16 healthy controls were enrolled...
March 3, 2017: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/28262007/muscle-oxygen-saturation-increases-during-head-up-tilt-induced-pre-syncope
#17
A Lund, H Sørensen, T W Jensen, M J Niemann, N D Olesen, H B Nielsen, N V Olsen, N H Secher
AIM: To evaluate whether muscle vasodilatation plays a role for hypotension developed during central hypovolaemia, muscle oxygenation (Sm O2 ) was examined during (pre)syncope induced by head-up tilt (HUT). Skin blood flow (SkBF) and oxygenation (Sskin O2 ) were determined because evaluation of Sm O2 may be affected by superficial tissue oxygenation. Furthermore, we evaluated cerebral oxygenation (Sc O2 ) and middle cerebral artery mean blood flow velocity (MCAvmean ). METHODS: Twenty healthy male volunteers (median age 24 years; range 19-38) were subjected to passive 50° HUT for 1 hour or until (pre)syncope...
March 6, 2017: Acta Physiologica
https://www.readbyqxmd.com/read/28261153/non-invasive-respiratory-impedance-enhances-cerebral-perfusion-in-healthy-adults
#18
Christopher G Favilla, Ashwin B Parthasarathy, John A Detre, Arjun G Yodh, Michael T Mullen, Scott E Kasner, Kimberly Gannon, Steven R Messé
Optimization of cerebral blood flow (CBF) is the cornerstone of clinical management in a number of neurologic diseases, most notably ischemic stroke. Intrathoracic pressure influences cardiac output and has the potential to impact CBF. Here, we aim to quantify cerebral hemodynamic changes in response to increased respiratory impedance (RI) using a non-invasive respiratory device. We measured cerebral perfusion under varying levels of RI (6 cm H2O, 9 cm H2O, and 12 cm H2O) in 20 healthy volunteers. Simultaneous measurements of microvascular CBF and middle cerebral artery mean flow velocity (MFV), respectively, were performed with optical diffuse correlation spectroscopy and transcranial Doppler ultrasound...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28258058/impact-of-mild-orthostatic-stress-on-aortic-cerebral-hemodynamic-transmission-insight-from-the-frequency-domain
#19
Jun Sugawara, Tsubasa Tomoto, Tomoko Imai, Seiji Maeda, Shigehiko Ogoh
High cerebral pressure and flow fluctuations could be a risk for future cerebrovascular disease. This study aims to determine whether acute systemic vasoconstriction affects the dynamic pulsatile hemodynamic transmission from the aorta to the brain. We applied a stepwise lower body negative pressure (LBNP) (-10, -20, and -30 mmHg) in 15 young men to induce systemic vasoconstriction. To elucidate the dynamic relationship between the changes in aortic pressure (AoP, estimated from the radial arterial pressure waveforms) and the cerebral blood flow velocity (CBFV) at the middle cerebral artery (via a transcranial Doppler), frequency-domain analysis characterized the beat-to-beat slow oscillation (0...
March 3, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28245505/change-of-cerebral-oxygenation-during-surfactant-treatment-in-preterm-infants-lisa-versus-insure-procedures
#20
Giovanna Bertini, Caterina Coviello, Elena Gozzini, Tommaso Bianconi, Cecilia Bresci, Valentina Leonardi, Carlo Dani
Objectives The aim of the study was to compare the effects on cerebral oxygenation in preterm infants of two different procedures for surfactant administration: the LISA (low-invasive method of surfactant administration) and the InSurE (Intubation, SURfactant administration, Extubation). Study Design Twenty premature infants with respiratory distress syndrome were assigned to receive surfactant either by "LISA" (n = 10) or "InSurE" (n = 10) procedure. Patients were continuously studied by near-infrared spectroscopy (NIRS) for the measurement of cerebral regional oxygenation (rSO2C) and calculation of cerebral fractional oxygen extraction rate (cFTOE), and NIRS data were recorded 30 minutes before (T0) surfactant administration, during the procedure (Tproc), and 30 (T1), 60 (T2T2), and 120 minutes (T3) afterward...
April 2017: Neuropediatrics
keyword
keyword
79756
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"