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Bianchini E, Guala A, Golemati S, Alastruey J, Climie RE, Dalakleidi K, Francesconi M, Fuchs D, Hartman Y, Malik AEF, Makūnaitė M, Nikita KS, Park C, Pugh CJA, Šatrauskienė A, Terentes-Printizios D, Teynor A, Thijssen D, Schmidt-Trucksäss A, Zupkauskienė J, Boutouyrie P, Bruno RM, Reesink KD. The Ultrasound Window Into Vascular Ageing: A Technology Review by the VascAgeNet COST Action. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2023; 42:2183-2213. [PMID: 37148467 DOI: 10.1002/jum.16243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 03/24/2023] [Accepted: 04/14/2023] [Indexed: 05/08/2023]
Abstract
Non-invasive ultrasound (US) imaging enables the assessment of the properties of superficial blood vessels. Various modes can be used for vascular characteristics analysis, ranging from radiofrequency (RF) data, Doppler- and standard B/M-mode imaging, to more recent ultra-high frequency and ultrafast techniques. The aim of the present work was to provide an overview of the current state-of-the-art non-invasive US technologies and corresponding vascular ageing characteristics from a technological perspective. Following an introduction about the basic concepts of the US technique, the characteristics considered in this review are clustered into: 1) vessel wall structure; 2) dynamic elastic properties, and 3) reactive vessel properties. The overview shows that ultrasound is a versatile, non-invasive, and safe imaging technique that can be adopted for obtaining information about function, structure, and reactivity in superficial arteries. The most suitable setting for a specific application must be selected according to spatial and temporal resolution requirements. The usefulness of standardization in the validation process and performance metric adoption emerges. Computer-based techniques should always be preferred to manual measures, as long as the algorithms and learning procedures are transparent and well described, and the performance leads to better results. Identification of a minimal clinically important difference is a crucial point for drawing conclusions regarding robustness of the techniques and for the translation into practice of any biomarker.
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Affiliation(s)
| | - Andrea Guala
- Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain
- CIBERCV, Instituto de Salud Carlos III, Madrid, Spain
| | - Spyretta Golemati
- Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Jordi Alastruey
- Department of Biomedical Engineering, King's College London, London, UK
| | - Rachel E Climie
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
- INSERM, U970, Paris Cardiovascular Research Center (PARCC), Université de Paris, Hopital Europeen Georges Pompidou - APHP, Paris, France
| | - Kalliopi Dalakleidi
- Biomedical Simulations and Imaging (BIOSIM) Laboratory, School of Electrical and Computer Engineering, National Technical University of Athens, Athens, Greece
| | - Martina Francesconi
- Institute of Clinical Physiology, CNR, Pisa, Italy
- University of Pisa, Pisa, Italy
| | - Dieter Fuchs
- Fujifilm VisualSonics, Amsterdam, The Netherlands
| | - Yvonne Hartman
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Afrah E F Malik
- CARIM School for Cardiovascular Diseases and Heart and Vascular Center, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Monika Makūnaitė
- Biomedical Engineering Institute, Kaunas University of Technology, Kaunas, Lithuania
| | - Konstantina S Nikita
- Biomedical Simulations and Imaging (BIOSIM) Laboratory, School of Electrical and Computer Engineering, National Technical University of Athens, Athens, Greece
| | - Chloe Park
- MRC Unit for Lifelong Health and Ageing, University College London, London, UK
| | - Christopher J A Pugh
- Cardiff School of Sport & Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - Agnė Šatrauskienė
- Clinic of Cardiac and Vascular Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
- Centre of Cardiology and Angiology, Vilnius University Hospital Santaros klinikos, Vilnius, Lithuania
| | - Dimitrios Terentes-Printizios
- First Department of Cardiology, Hippokration Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Alexandra Teynor
- Faculty of Computer Science, Augsburg University of Applied Sciences, Augsburg, Germany
| | - Dick Thijssen
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Arno Schmidt-Trucksäss
- Department of Sport, Exercise and Health, Division Sport and Exercise Medicine, University of Basel, Basel, Switzerland
| | - Jūratė Zupkauskienė
- Clinic of Cardiac and Vascular Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Pierre Boutouyrie
- INSERM, U970, Paris Cardiovascular Research Center (PARCC), Université de Paris, Hopital Europeen Georges Pompidou - APHP, Paris, France
| | - Rosa Maria Bruno
- INSERM, U970, Paris Cardiovascular Research Center (PARCC), Université de Paris, Hopital Europeen Georges Pompidou - APHP, Paris, France
| | - Koen D Reesink
- CARIM School for Cardiovascular Diseases and Heart and Vascular Center, Maastricht University Medical Center+, Maastricht, The Netherlands
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Xie QQ, Chen X, Tian Y, Fang L, Zhao H. Compromised cerebrovascular reactivity in migraineurs with right-to-left shunts: a potential mechanism of white matter hyperintensities. Neurol Res 2022; 44:754-760. [PMID: 35271423 DOI: 10.1080/01616412.2022.2051133] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Our study aims to explore the changes of cerebrovascular reactivity (CVR) in migraineurs with right-to-left shunts (RLS), and further evaluate the association between CVR and the occurrence of the white matter hyperintensities (WMHs). METHODS RLS was diagnosed based on a contrast enhancement transcranial Doppler (c-TCD) examination. The breath holding index (BHI), which represents CVR, was measured from the middle cerebral artery (MCA) using a TCD with the breath-holding method. WMHs was defined as clearly hyperintense areas in 3 T magnetic resonance imaging (MRI). All migraineurs underwent a standardized questionnaire for family and personal history and detailed migraine features. RESULTS Three hundred and ninety-seven migraineurs and 100 controls were included in our study. The BHI was significantly lower in migraineurs than controls (0.527 ± 0.709 vs. 0.674 ± 0.489, P = 0.016). Moreover, migraineurs with RLS had lower BHI than those without RLS (0.504 ± 0.671 vs. 0.674 ± 0.721, p = 0.024). Migraineurs with WMHs had lower BHI than those without (0.47 ± 0.71 vs. 0.75 ± 0.49, p = 0.035). The reduced BHI was an independent influencing factor for WMHs in our study (OR = 0.338; 95% CI = 0.142-0.806, p = 0.014). CONCLUSION Our results indicated that BHI was reduced in migraineurs, and the reduced BHI was associated with RLS. Moreover, the reduced CVR in migraineurs with RLS might be related to the occurrence of WMHs.
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Affiliation(s)
- Qian Qian Xie
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - Xiaoxiang Chen
- Department of Neurology, People's Hospital of Juxian, Rizhao, Shandong, China
| | - Yuxuan Tian
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - Le Fang
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - Hongqin Zhao
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
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Zhao Y, Dang L, Tian X, Yang M, Lv M, Sun Q, Du Y. Association Between Intracranial Pulsatility and White Matter Hyperintensities in Asymptomatic Intracranial Arterial Stenosis: A Population-Based Study in Shandong, China. J Stroke Cerebrovasc Dis 2022; 31:106406. [PMID: 35248835 DOI: 10.1016/j.jstrokecerebrovasdis.2022.106406] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 02/09/2022] [Accepted: 02/13/2022] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES The effects of increased intracranial pulsatility on the severity of white matter hyperintensities (WMH) in participants with asymptomatic intracranial arterial stenosis (aICAS) remain uncertain. We aimed to investigate whether an increased pulsatility index (PI) is associated with WMH volume (WMHV) in individuals with aICAS. MATERIALS AND METHODS All participants were recruited from the Kongcun Town aICAS Study, including a total of 103 participants with aICAS and 98 healthy controls (age- and sex-matched). PI was assessed using transcranial Doppler ultrasound. The WMHV was calculated through the lesion segmentation tool system for the Statistical Parametric Mapping package based on magnetic resonance imaging. The association between PI and lnWMHV was analyzed by linear regression models adjusting for demographics, lifestyle, and vascular risk factors. RESULTS The lnWMHV and PI between the aICAS and control groups showed no significant differences (P = 0.171 and 0.287, respectively). In a multivariable model, age ≥ 60 years and male sex (P = 0.000 and 0.006, respectively) were significant predictors of lnWMHV in the aICAS group. In sex-stratified analyses, there was a significant association between PI and lnWMHV in males with aICAS (P = 0.038). CONCLUSIONS This study suggest there might be a likely association between increased intracranial pulsatility and WMH burden in males with aICAS.
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Affiliation(s)
- Yuanyuan Zhao
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Liang Dang
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Xue Tian
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Meilan Yang
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Ming Lv
- Department of Clinical Epidemiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Qinjian Sun
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China.
| | - Yifeng Du
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
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Sato T, Niijima A, Arai A, Maku T, Motegi H, Takahashi M, Takatsu H, Tanabe M, Komatsu T, Sakuta K, Sakai K, Terasawa Y, Umehara T, Omoto S, Murakami H, Mitsumura H, Iguchi Y. Middle Cerebral Artery Pulsatility Index Correlates with Prognosis and Diastolic Dysfunctions in Acute Ischemic Stroke. J Stroke Cerebrovasc Dis 2022; 31:106296. [PMID: 35033988 DOI: 10.1016/j.jstrokecerebrovasdis.2021.106296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/06/2021] [Accepted: 12/24/2021] [Indexed: 10/19/2022] Open
Abstract
OBJECTIVE To determine transcranial Doppler ultrasonography (TCD) parameters related to unfavorable outcomes, and to clarify the correlations between those parameters and heart functions in acute ischemic stroke without major vessel stenoses and occlusions. MATERIALS AND METHODS Patients were selected from a comprehensive stroke center between October 2012 and June 2019. Inclusion criteria were: 1) acute ischemic stroke without major vessel stenoses and occlusions; and 2) ability to measure blood flow in the middle cerebral artery by TCD. Unfavorable outcomes were defined as a modified Rankin Scale score of 2-6 at 3 months after onset. First, we investigated TCD parameters related to unfavorable outcomes. Second, correlations between those parameters and heart functions as assessed by transthoracic echocardiography were evaluated. RESULTS We screened 1,527 consecutive ischemic stroke patients, including 130 patients (109 [83%] male; median age, 60 years). Middle cerebral artery pulsatility index (M1 PI) (Odds ratio (OR) 0.057, 95%confidence interval (CI) 0.007-0.494, p = 0.009) was independently associated with unfavorable outcomes. Concerning the relation between M1 PI and heart functions, peak early filling velocity/velocity of mitral annulus early diastolic motion (E/e') (OR 1.195, 95%CI 1.011-1.413, p = 0.037) was a factor independently associated with high M1 PI. CONCLUSIONS High M1 PI predicts unfavorable outcome regardless of ischemic stroke subtype without major vessel stenoses and occlusions. High M1 PI correlates with high E/e', suggesting diastolic dysfunction.
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Affiliation(s)
- Takeo Sato
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan.
| | - Akira Niijima
- Department of Cardiology, the Jikei University School of Medicine, Tokyo, Japan
| | - Ayumi Arai
- Department of Radiology, the Jikei University School of Medicine, Tokyo, Japan
| | - Takahiro Maku
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Haruhiko Motegi
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Maki Takahashi
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Hiroki Takatsu
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Maki Tanabe
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Teppei Komatsu
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Kenichi Sakuta
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Kenichiro Sakai
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Yuka Terasawa
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Tadashi Umehara
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Shusaku Omoto
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Hidetomo Murakami
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Hidetaka Mitsumura
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
| | - Yasuyuki Iguchi
- Department of Neurology, the Jikei University School of Medicine, Tokyo, Japan
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Vidal-González D, López-Sánchez GN, Concha-Rebollar LA, Rodríguez-Herrera A, Morales-Ramirez F, Chávez-Tapia N, Uribe M, Nader-Kawachi JA, Nuño-Lámbarri N. Cerebral hemodynamics in the non-alcoholic fatty liver. Ann Hepatol 2021; 19:668-673. [PMID: 32683094 DOI: 10.1016/j.aohep.2020.06.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 06/08/2020] [Indexed: 02/04/2023]
Abstract
INTRODUCTION AND OBJECTIVES The association between non-alcoholic fatty liver disease and cerebral hemodynamics arises from cardiovascular damage mechanisms such as endothelial dysfunction, arterial wall increased stiffness, high thickness of the intimate index of the internal carotid artery, left ventricular hypertrophy, left diastolic dysfunction, calcification coronary arteries and increased epicardial fat. The multidirectional relationship between systemic inflammation and lipid metabolism constitutes a common and simultaneous mechanism that causes vascular damage. This study aims to provide insight into the relationship between non-alcoholic fatty liver disease and the function of systemic circulation and cerebral circulation using Doppler ultrasound. PATIENTS AND METHODS Is an observational, cross-sectional, prospective, comparative study conducted at Medica Sur Hospital. Thirty-five patients were selected consecutively. The patients consulted neurological service for various symptoms without severity criteria, such as vertigo, primary headache and balance disturbances. RESULTS There is a difference in the variables mean of the right MCA PI (p = 0.023), left MCA PI" (p = 0.004), and left VA PI (p = 0.036) between the control and NAFLD groups. The correlation analysis between these variables and the CAP showed a positive correlation of the three variables with the CAP, "right MCA PI" (r = 0.384), left MCA PI "(r = 0.509) and" left VA PI " (r = 0.551). CONCLUSIONS This study demonstrates a subclinical process of the middle cerebral artery in subjects with NAFLD, which suggests it may be involved in the disease development and points the need to make decisions for this liver manifestation prevention and treatment.
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Affiliation(s)
| | | | | | | | | | - Norberto Chávez-Tapia
- Traslational Research Unit, Medica Sur Clinic & Foundation, Mexico; Obesity and Digestive Diseases Unit, Medica Sur Clinic & Foundation, Mexico.
| | - Misael Uribe
- Obesity and Digestive Diseases Unit, Medica Sur Clinic & Foundation, Mexico.
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Webb AJ, Lawson A, Li L, Mazzucco S, Rothwell PM. Physiological determinants of residual cerebral arterial pulsatility on best medical treatment after TIA or minor stroke. J Cereb Blood Flow Metab 2021; 41:1463-1471. [PMID: 33153374 PMCID: PMC8138338 DOI: 10.1177/0271678x20969984] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cerebral arterial pulsatility is strongly associated with cerebral small vessel disease and lacunar stroke yet its dependence on central versus local haemodynamic processes is unclear. In a population-based study of patients on best medical managment, 4-6 weeks after a TIA or non-disabling stroke, arterial stiffness and aortic systolic, diastolic and pulse pressures were measured (Sphygmocor). Middle cerebral artery peak and trough flow velocities and Gosling's pulsatility index were measured by transcranial ultrasound. In 981 participants, aortic and cerebral pulsatility rose strongly with age in both sexes, but aortic diastolic pressure fell more with age in men whilst cerebral trough velocity fell more in women. There was no significant association between aortic systolic or diastolic blood pressure with cerebral peak or trough flow velocity but aortic pulse pressure explained 37% of the variance in cerebral arterial pulsatility, before adjustment, whilst 49% of the variance was explained by aortic pulse pressure, arterial stiffness, age, gender and cardiovascular risk factors. Furthermore, arterial stiffness partially mediated the relationship between aortic and cerebral pulsatility. Overall, absolute aortic pressures and cerebral blood flow velocity were poorly correlated but aortic and cerebral pulsatility were strongly related, suggesting a key role for transmission of aortic pulsatility to the brain.
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Affiliation(s)
- Alastair Js Webb
- Wolfson Centre for Prevention of Stroke and Dementia, University of Oxford, Oxford, UK
| | - Amy Lawson
- Wolfson Centre for Prevention of Stroke and Dementia, University of Oxford, Oxford, UK
| | - Linxin Li
- Wolfson Centre for Prevention of Stroke and Dementia, University of Oxford, Oxford, UK
| | - Sara Mazzucco
- Wolfson Centre for Prevention of Stroke and Dementia, University of Oxford, Oxford, UK
| | - Peter M Rothwell
- Wolfson Centre for Prevention of Stroke and Dementia, University of Oxford, Oxford, UK
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- Wolfson Centre for Prevention of Stroke and Dementia, University of Oxford, Oxford, UK
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7
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Afkhami R, Wong R, Ramadan S, Walker FR, Johnson S. Indexing Cerebrovascular Health Using Transcranial Doppler Ultrasound. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:919-927. [PMID: 33494950 DOI: 10.1016/j.ultrasmedbio.2020.12.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 11/26/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
Transcranial Doppler (TCD) blood flow velocity has been extensively used in biomedical research as it provides a cost-effective and relatively simple approach to assess changes in cerebral blood flow dynamics and track cerebrovascular health status. In this article we introduce a new TCD-based timing index, TITCD, as an indicator of vascular stiffening and vascular health. We investigate the correlations of the new index and the existing indices, namely the pulsatility index and the augmentation index, with age, cardiorespiratory fitness (CRF) and magnetic resonance imaging (MRI) blood flow pulsatility index (PIMRI). Notably, the new index showed stronger correlations with CRF (r = -0.79) and PIMRI (r = 0.53) compared with the augmentation index (r = -0.65 with CRF and no significant correlation with PIMRI) and the pulsatility index (no significant correlations with CRF or PIMRI), and a similar correlation with age as the augmentation index. The clearer relationship of the proposed timing index with vascular aging factors underlines its utility as an early indicator of vascular stiffening.
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Affiliation(s)
- Rashid Afkhami
- School of Electrical Engineering & Computing, University of Newcastle, Callaghan, New South Wales, Australia.
| | - Rachel Wong
- School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia
| | - Saadallah Ramadan
- School of Health Science, University of Newcastle, Callaghan, New South Wales, Australia
| | - Frederick Rohan Walker
- School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia
| | - Sarah Johnson
- School of Electrical Engineering & Computing, University of Newcastle, Callaghan, New South Wales, Australia
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8
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Samora M, Vianna LC, Carmo JC, Macedo V, Dawes M, Phillips AA, Paton JFR, Fisher JP. Neurovascular coupling is not influenced by lower body negative pressure in humans. Am J Physiol Heart Circ Physiol 2020; 319:H22-H31. [PMID: 32442032 DOI: 10.1152/ajpheart.00076.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cerebral blood flow is tightly coupled with local neuronal activation and metabolism, i.e., neurovascular coupling (NVC). Studies suggest a role of sympathetic nervous system in the regulation of cerebral blood flow. However, this is controversial, and the sympathetic regulation of NVC in humans remains unclear. Since impaired NVC has been identified in several chronic diseases associated with a heightened sympathetic activity, we aimed to determine whether reflex-mediated sympathetic activation via lower body negative pressure (LBNP) attenuates NVC in humans. NVC was assessed using a visual stimulation protocol (5 cycles of 30 s eyes closed and 30 s of reading) in 11 healthy participants (aged 24 ± 3 yr). NVC assessments were made under control conditions and during LBNP at -20 and -40 mmHg. Posterior (PCA) and middle (MCA) cerebral artery mean blood velocity (Vmean) and vertebral artery blood flow (VAflow) were simultaneously determined with cardiorespiratory variables. Under control conditions, the visual stimulation evoked a robust increase in PCAVmean (∆18.0 ± 4.5%), a moderate rise in VAflow (∆9.6 ± 4.3%), and a modest increase in MCAVmean (∆3.0 ± 1.9%). The magnitude of NVC response was not affected by mild-to-moderate LBNP (all P > 0.05 for repeated-measures ANOVA). Given the small change that occurred in partial pressure of end-tidal CO2 during LBNP, this hypocapnia condition was matched via voluntary hyperventilation in absence of LBNP in a subgroup of participants (n = 8). The mild hypocapnia during LBNP did not exert a confounding influence on the NVC response. These findings indicate that the NVC is not influenced by LBNP or mild hypocapnia in humans.NEW & NOTEWORTHY Visual stimulation evoked a robust increase in posterior cerebral artery velocity and a modest increase in vertebral artery blood flow, i.e., neurovascular coupling (NVC), which was unaffected by lower body negative pressure (LBNP) in humans. In addition, although LBNP induced a mild hypocapnia, this degree of hypocapnia in the absence of LBNP failed to modify the NVC response.
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Affiliation(s)
- Milena Samora
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,NeuroV̇ASQ̇-Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Distrito Federal, Brazil
| | - Lauro C Vianna
- NeuroV̇ASQ̇-Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Distrito Federal, Brazil
| | - Jake C Carmo
- Biomechanics and Biological Signal Processing Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Distrito Federal, Brazil
| | - Victor Macedo
- Biomechanics and Biological Signal Processing Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Distrito Federal, Brazil
| | - Matthew Dawes
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Aaron A Phillips
- Departments of Physiology, Pharmacology, and Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Julian F R Paton
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - James P Fisher
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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9
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Abstract
PURPOSE OF REVIEW To review and summarize what is known about cerebrovascular derangements during preeclampsia. RECENT FINDINGS Preeclampsia is a devastating disorder of pregnancy with no known cure. Little is known about the pathophysiological mechanisms which lead to the symptoms of the disorder, particularly with regard to individual vascular beds such as the cerebral circulation. Studies suggest that the cerebrovascular dysfunction characteristic of the preeclampsia syndrome is characterized by alterations in cerebral blood flow autoregulation and opening of the blood-brain barrier. Mechanistic studies demonstrate that the same circulating factors implicated in the pathophysiology of other vascular beds may be operative in the cerebral circulation as well. However, significant knowledge gaps still exist, highlighting the need for more intense research in this field. Little is known about cerebrovascular dysfunction during preeclampsia, and detailed mechanistic studies are needed to identify the molecular pathways involved, the interactions thereof, and how those pathways lead to clinical disease.
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Affiliation(s)
- Subhi Talal Younes
- Department of Physiology & Biophysics, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216-4505, USA
| | - Michael J Ryan
- Department of Physiology & Biophysics, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216-4505, USA.
- G.V. (Sonny) Montgomery Veterans Affairs Medical Center, Jackson, MS, USA.
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10
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Cheng CY, Cheng HM, Chen SP, Chung CP, Lin YY, Hu HH, Chen CH, Wang SJ. White matter hyperintensities in migraine: Clinical significance and central pulsatile hemodynamic correlates. Cephalalgia 2017; 38:1225-1236. [PMID: 28853610 DOI: 10.1177/0333102417728751] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Background The role of central pulsatile hemodynamics in the pathogenesis of white matter hyperintensities in migraine patients has not been clarified. Methods Sixty patients with migraine (20-50 years old; women, 68%) without overt vascular risk factors and 30 demographically-matched healthy controls were recruited prospectively. Cerebral white matter hyperintensities volume was determined by T1-weighted magnetic resonance imaging with CUBE-fluid-attenuated-inversion-recovery sequences. Central systolic blood pressure, carotid-femoral pulse wave velocity, and carotid augmentation index were measured by applanation tonometry. Carotid pulsatility index was derived from Doppler ultrasound carotid artery flow analysis. Results Compared to the controls, the migraine patients had higher white matter hyperintensities frequency (odds ratio, 2.75; p = 0.04) and greater mean white matter hyperintensities volume (0.174 vs. 0.049, cm3, p = 0.04). Multivariable regression analysis showed that white matter hyperintensities volume in migraine patients was positively associated with central systolic blood pressure ( p = 0.04) and carotid-femoral pulse wave velocity ( p < 0.001), but negatively associated with carotid pulsatility index ( p = 0.04) after controlling for potential confounding factors. The interaction effects observed indicated that the influence of carotid-femoral pulse wave velocity ( p = 0.004) and central systolic blood pressure ( p = 0.03) on white matter hyperintensities formation was greater for the lower-carotid pulsatility index subgroup of migraine patients. White matter hyperintensities volume in migraine patients increased with decreasing carotid pulsatility index and with increasing central systolic blood pressure or carotid-femoral pulse wave velocity. Conclusions White matter hyperintensities are more common in patients with migraine than in healthy controls. Increased aortic stiffness or central systolic blood pressure in the presence of low intracranial artery resistance may predispose patients with migraine to white matter hyperintensities formation.
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Affiliation(s)
- Chun-Yu Cheng
- 1 Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,2 Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.,3 Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Hao-Min Cheng
- 3 Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.,4 Department of Medical Education, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Shih-Pin Chen
- 2 Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.,3 Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.,5 Brain Research Center, National Yang-Ming University, Taipei, Taiwan.,6 Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Chih-Ping Chung
- 2 Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.,3 Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Yung-Yang Lin
- 1 Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,2 Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.,3 Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Han-Hwa Hu
- 7 Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,8 Cerebrovascular Treatment and Research Center, College of Medicine, Taipei Medical University, Taipei, Taiwan.,9 Department of Neurology, Taipei Medical University-Shaung Ho Hospital, Taipei, Taiwan
| | - Chen-Huan Chen
- 3 Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.,4 Department of Medical Education, Taipei Veterans General Hospital, Taipei, Taiwan.,10 Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.,11 Department of Public Health, National Yang-Ming University, Taipei, Taiwan
| | - Shuu-Jiun Wang
- 1 Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,2 Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.,3 Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.,5 Brain Research Center, National Yang-Ming University, Taipei, Taiwan
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11
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Wang A, Yang L, Wen W, Zhang S, Hao D, Khalid SG, Zheng D. Quantification of radial arterial pulse characteristics change during exercise and recovery. J Physiol Sci 2016; 68:113-120. [PMID: 28028653 PMCID: PMC5799316 DOI: 10.1007/s12576-016-0515-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 12/13/2016] [Indexed: 12/02/2022]
Abstract
It is physiologically important to understand the arterial pulse waveform characteristics change during exercise and recovery. However, there is a lack of a comprehensive investigation. This study aimed to provide scientific evidence on the arterial pulse characteristics change during exercise and recovery. Sixty-five healthy subjects were studied. The exercise loads were gradually increased from 0 to 125 W for female subjects and to 150 W for male subjects. Radial pulses were digitally recorded during exercise and 4-min recovery. Four parameters were extracted from the raw arterial pulse waveform, including the pulse amplitude, width, pulse peak and dicrotic notch time. Five parameters were extracted from the normalized radial pulse waveform, including the pulse peak and dicrotic notch position, pulse Area, Area1 and Area2 separated by notch point. With increasing loads during exercise, the raw pulse amplitude increased significantly with decreased pulse period, reduced peak and notch time. From the normalized pulses, the pulse Area, pulse Area1 and Area2 decreased, respectively, from 38 ± 4, 61 ± 5 and 23 ± 5 at rest to 34 ± 4, 52 ± 6 and 13 ± 5 at 150-W exercise load. During recovery, an opposite trend was observed. This study quantitatively demonstrated significant changes of radial pulse characteristics during different exercise loads and recovery phases.
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Affiliation(s)
- Anran Wang
- College of Life Science and Bio-engineering, Beijing University of Technology, 100 Pingluoyuan Chaoyang District, Beijing, 100124, China
| | - Lin Yang
- College of Life Science and Bio-engineering, Beijing University of Technology, 100 Pingluoyuan Chaoyang District, Beijing, 100124, China.
| | - Weimin Wen
- College of Life Science and Bio-engineering, Beijing University of Technology, 100 Pingluoyuan Chaoyang District, Beijing, 100124, China
| | - Song Zhang
- College of Life Science and Bio-engineering, Beijing University of Technology, 100 Pingluoyuan Chaoyang District, Beijing, 100124, China
| | - Dongmei Hao
- College of Life Science and Bio-engineering, Beijing University of Technology, 100 Pingluoyuan Chaoyang District, Beijing, 100124, China
| | - Syed G Khalid
- Health and Wellbeing Academy, Faculty of Medical Science, Anglia Ruskin University, Chelmsford, CM1 1SQ, UK
| | - Dingchang Zheng
- Health and Wellbeing Academy, Faculty of Medical Science, Anglia Ruskin University, Chelmsford, CM1 1SQ, UK
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12
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Suministrado MSP, Shuang EWY, Xu J, Teoh HL, Chan BPL, Venketasubramanian N, Seet RCS, Chen CLH, Wong BS, Sharma VK, Dong Y. Poststroke Cognitive Decline is Independent of Longitudinal Changes in Cerebral Hemodynamics Parameters. J Neuroimaging 2016; 27:326-332. [PMID: 27623192 DOI: 10.1111/jon.12395] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 08/21/2016] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Poststroke vascular cognitive impairment is highly prevalent with significant functional consequences. However, reliable biomarkers for early prediction of cognitive decline after acute ischemic stroke (AIS) are not well established. Although parenchymal imaging in patients with AIS and transient ischemic attack (TIA) may predict the resultant cognitive impairment, it may not explain the progressive deterioration after the index event. We postulated that longitudinal changes in cerebral hemodynamic parameters may influence the cognitive performance after a cerebrovascular event. METHODS One-hundred consecutive AIS/TIA patients were recruited within 2 weeks following a cerebrovascular event. At 3-6 months, 69 patients were followed up with transcranial Doppler (TCD) and brief cognitive tests (Mini-Mental State Examination [MMSE]/Montreal Cognitive Assessment [MoCA]). Basic demographics, vascular risk factors, clinical, cognitive, and neurological status were recorded. RESULTS Considerable proportion (12%) of patients showed cognitive decline and changes in the hemodynamic parameters over 3-6 months after the index event. We showed that right middle cerebral artery (MCA) stenosis and right internal carotid artery/MCA tandem lesions at 3-6 months are associated with the change in the MMSE scores. Additionally, there was a trend toward association between increased pulsatility index of the right MCA and a decline in the MMSE score. However, we did not observe any association between cognitive decline and longitudinal changes in hemodynamic parameters. CONCLUSION Although hemodynamic parameters deteriorate in a considerable proportion of patients during first 3-6 months after a cerebrovascular event, cognitive decline appears to be an independent phenomenon.
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Affiliation(s)
| | | | - Jing Xu
- Department of Pharmacology, National University of Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Hock Luen Teoh
- Division of Neurology, National University Health System, Singapore
| | | | | | - Raymond Chee Seong Seet
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Division of Neurology, National University Health System, Singapore
| | - Christopher Li-Hsian Chen
- Department of Pharmacology, National University of Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Boon Seng Wong
- Department of Physiology, National University of Singapore
| | - Vijay Kumar Sharma
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Division of Neurology, National University Health System, Singapore
| | - YanHong Dong
- Department of Pharmacology, National University of Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Division of Neurology, National University Health System, Singapore
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13
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Ryu YG, Lee DK, Baek MJ, Kim H. Clinical Value of Intraoperative Transit-Time Flow Measurement for Autogenous Radiocephalic Arteriovenous Fistula in Patients with Chronic Kidney Disease. Ann Vasc Surg 2016; 35:53-9. [DOI: 10.1016/j.avsg.2016.02.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 02/09/2016] [Accepted: 02/14/2016] [Indexed: 11/28/2022]
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14
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Altmann M, Thommessen B, Rønning OM, Benth JŠ, Reichenbach AS, Fure B. Middle Cerebral Artery Pulsatility Index is Associated with Cognitive Impairment in Lacunar Stroke. J Neuroimaging 2016; 26:431-5. [PMID: 26800090 DOI: 10.1111/jon.12335] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 12/25/2015] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND AND PURPOSE Pulsatility index (PI) of the middle cerebral artery is postulated to reflect the vascular resistance in the artery distal of the probe, and has been reported to increase in small vessel disease, diabetes mellitus, ageing, and dementia. Lacunar infarcts are considered to be related to cognitive impairment. We therefore conducted a study to assess the association between cognitive impairment and PI in patients with a lacunar infarct. METHODS Consecutive patients presenting with an acute lacunar syndrome who were admitted to the stroke unit were enrolled. The patients were examined with Doppler ultrasonography of the intracranial arteries, and the PI of the middle cerebral artery was recorded. Cognitive function was evaluated by mini-mental state examination (MMSE), clock drawing test, and trail making test (TMT) A and B. RESULTS Among the 113 patients included, 85 patients had an acute lacunar infarct and 28 had one or more nonlacunar infarcts. The mean PI was 1.46 (SD = .33). PI was significantly (P < .05) associated with MMSE, TMT A and TMT B in patients with lacunar infarct, even after adjustment for multiple patient characteristics (age, sex, prestroke hypertension, smoking, previous stroke, and diabetes). CONCLUSIONS PI was associated with the cognitive performance in patients with lacunar infarcts and a lacunar syndrome. An elevated PI may be related to impairment in several cognitive domains. These findings suggest that transcranial Doppler ultrasonography could be an adjunct tool for early diagnosis of cognitive impairment after stroke.
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Affiliation(s)
- Marianne Altmann
- Department of Neurology, Medical Division, Akershus University Hospital, Lørenskog, Norway.,Institute of Clinical Medicine, Campus AHUS, University of Oslo, Norway
| | - Bente Thommessen
- Department of Neurology, Medical Division, Akershus University Hospital, Lørenskog, Norway
| | - Ole Morten Rønning
- Department of Neurology, Medical Division, Akershus University Hospital, Lørenskog, Norway.,Institute of Clinical Medicine, Campus AHUS, University of Oslo, Norway
| | - Jūratė Šaltytė Benth
- Institute of Clinical Medicine, Campus AHUS, University of Oslo, Norway.,HØKH, Research Centre, Akershus University Hospital, Norway
| | - Antje S Reichenbach
- Department of Neurology, Medical Division, Akershus University Hospital, Lørenskog, Norway
| | - Brynjar Fure
- Specialist Health Section, The Norwegian Knowledge Centre for the Health Services, Oslo, Norway.,Department of Geriatric Medicine, Oslo University Hospital, Oslo, Norway
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15
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Oughton JA, Rose S, Galloway G, Khoo SK, O'Neill S, Coulthard A. Carotid ultrasound pulsatility indices and cardiovascular risk in Australian women. J Med Imaging Radiat Oncol 2014; 59:20-5. [DOI: 10.1111/1754-9485.12250] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Accepted: 09/02/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Justin Alexander Oughton
- Department of Medical Imaging; Royal Brisbane and Womens Hospital; Brisbane Queensland Australia
| | - Stephen Rose
- The Australiane-Health Research Centre; Commonwealth Scientific and Industrial Research Organisation; Brisbane Queensland Australia
| | - Graham Galloway
- Centre for Advanced Imaging; University of Queensland; Brisbane Queensland Australia
| | - Soo Keat Khoo
- Department of Obstetrics and Gynaecology; Royal Brisbane and Womens Hospital; Brisbane Queensland Australia
- School of Medicine; University of Queensland; Brisbane Queensland Australia
| | - Sheila O'Neill
- Graduate School of Medicine; University of Wollongong; Wollongong New South Wales Australia
| | - Alan Coulthard
- Department of Medical Imaging; Royal Brisbane and Womens Hospital; Brisbane Queensland Australia
- School of Medicine; University of Queensland; Brisbane Queensland Australia
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16
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Aoki J, Raber LN, Katzan IL, Hussain MS, Hui FK, Uchino K. Post-intervention TCD examination may be useful to predict outcome in acute ischemic stroke patients with successful intra-arterial intervention. J Neurol Sci 2013; 334:26-9. [DOI: 10.1016/j.jns.2013.07.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/12/2013] [Accepted: 07/17/2013] [Indexed: 10/26/2022]
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17
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Mc Loughlin MJ, Mc Loughlin S. Diastolic retrograde arterial flow and biphasic abdominal aortic Doppler wave pattern: an early sign of arterial wall deterioration? ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:592-596. [PMID: 23384463 DOI: 10.1016/j.ultrasmedbio.2012.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 09/22/2012] [Accepted: 11/05/2012] [Indexed: 06/01/2023]
Abstract
Many authors have found that diastolic retrograde arterial flow is associated with increased stiffness of the arterial wall. Most of the studies were based in femoral or brachial artery examination. As the abdominal aorta is a large vessel routinely explored in abdominal ultrasound scans, we decided to study whether it could be useful for early identification of abnormalities of the arterial wall. Sixteen young and 16 old, healthy patients matched for sex, weight and height were studied using pulsed Doppler at the level of the abdominal aortic bifurcation. Different hemodynamic factors were measured and compared to establish the systolic and diastolic function of this artery. Triphasic wave pattern was present in 14 of 16 patients in the younger group and only in 4 of 16 in the older group. In addition, diastolic retrograde arterial flow duration and retrograde components of diastolic phase were more prominent in the advanced age group. Increased retrograde flow and incapacity to impulse arterial flow forward during diastolic time are early markers of vascular wall deterioration that can be observed easily in the abdominal aorta during routine abdominal ultrasound scans.
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Affiliation(s)
- Mario Jorge Mc Loughlin
- Hospital Militar Central, Buenos Aires, Argentina; Instituto de Investigaciones Cardiológicas Alberto C Taquini, Buenos Aires, Argentina.
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18
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Oguz A, Gumus M, Ipek A, Tuzun D, Ersoy R, Cakir B. Effects of menstrual cycle showing infradian rhythm on thyroid blood flow and thyroid volume in healthy women. BIOL RHYTHM RES 2013. [DOI: 10.1080/09291016.2011.652863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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19
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Mok V, Ding D, Fu J, Xiong Y, Chu WWC, Wang D, Abrigo JM, Yang J, Wong A, Zhao Q, Guo Q, Hong Z, Wong KS. Transcranial Doppler ultrasound for screening cerebral small vessel disease: a community study. Stroke 2012; 43:2791-3. [PMID: 22949475 DOI: 10.1161/strokeaha.112.665711] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE We explored the association between pulsatility index (PI) as derived from transcranial Doppler ultrasound with various measures of small vessel disease in the community. METHODS We performed transcranial Doppler and magnetic resonance imaging in 205 consecutive community-dwelling elderly subjects who were participants of the Shanghai Aging Study. We investigated the association between middle cerebral artery (MCA) PI with measures of white matter lesions (WML), lacunes, and microbleeds. RESULTS Multiple logistic regression found that MCA PI was associated with severe WML (odds ratio, 1.33 per 0.1 increase in PI; 95% confidence interval, 1.04-1.70; P=0.02). At optimal MCA PI cut-off, the area under curve, positive predictive value, and negative predictive value were 0.70 (95% confidence interval, 0.60-0.80), 34.9%, and 85.6%, respectively, for detection of severe WML. No association was found between MCA PI and measures of lacunes or microbleeds. CONCLUSIONS PI correlates with WML severity. With a high negative predictive value, the chance of having severe WML with a normal PI is low. Transcranial Doppler may guide selective magnetic resonance imaging scanning for the detection of WML in the community.
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Affiliation(s)
- Vincent Mok
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, China.
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20
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Lumped parameter model for heart failure with novel regulating mechanisms of peripheral resistance and vascular compliance. ASAIO J 2012; 58:223-31. [PMID: 22395118 DOI: 10.1097/mat.0b013e31824ab695] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
To research the change in the physiological mechanism between the heart failure (HF) patient and healthy persons, the physiology parameters, which include the myocardial contractility, systemic vascular resistance (SVR), and vascular compliance, were studied. Through clinical data of HF patients, the computing method of the myocardial contractility was proposed; SVR as a function with respect to mean arterial pressure (MAP) was represented; and the vascular compliance was defined as a function with respect to MAP and cardiac output. Based on these parameters, a lumped parameter model of the cardiovascular system was established to reproduce the hemodynamic status of HF patients and verify the validity of the physiological mechanism. The simulation results demonstrate that the proportional error of mean flow, arterial pressure, and systolic blood pressure is 11.9%, 2.3%, and 4.7% compared with the clinical data, respectively. The proportional error of end-diastolic volume, end-systolic volume , and ejection fraction is 13.4%, 3%, and 3.9%, respectively.
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21
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Muscular arterial impedance in dogs with chronic degenerative mitral valve disease. Res Vet Sci 2012; 93:1434-8. [PMID: 22854601 DOI: 10.1016/j.rvsc.2012.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 05/29/2012] [Accepted: 07/02/2012] [Indexed: 11/20/2022]
Abstract
Systemic vascular impedance represents the retrograde strength of the blood flow to the left ventricle, thus it is one of the main compounds of afterload. Mitral regurgitation is markedly sensitive to afterload alterations. The purpose of this study was to evaluate muscular arterial impedance in dogs with chronic degenerative mitral valve disease (CDMVD) by use of duplex Doppler ultrasonography (DDU), since its technique there was not used before to determine impedance index in dogs with CDMVD. For this purpose, ten healthy dogs and ten dogs with CDMVD were used. Some parameters related to blood flow impedance in the common femoral artery were measured by DDU: pulsatility index (PI), resistance index (RI), high-resistance index (HRI), and acceleration velocity (AC) and deceleration velocity (DC) of the systolic peak. The results showed that RI and HRI were significantly higher in animals with CDMVD than in healthy animals. These findings showed that DDU provides quantitative data related to vascular impedance. Broader studies may therefore provide new aspects related to physiopathology and therapy in CDMVD patients.
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22
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Ozari HO, Oktenli C, Celik S, Tangi F, Ipcioglu O, Terekeci HM, Top C, Uzun M, Sanisoglu YS, Nalbant S. Are increased carotid artery pulsatility and resistance indexes early signs of vascular abnormalities in young obese males? JOURNAL OF CLINICAL ULTRASOUND : JCU 2012; 40:335-340. [PMID: 22532370 DOI: 10.1002/jcu.21927] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Accepted: 03/19/2012] [Indexed: 05/31/2023]
Abstract
PURPOSE To provide insight into the factors by which obesity in itself may directly lead to early arterial damage, we aimed to determine early sonographic markers of obesity-related vascular dysfunction in young obese males. METHODS Thirty-five young obese males and 23 age-matched healthy male volunteers were recruited into the study. Common carotid artery pulsatility index and resistance index were calculated from blood flow velocities curves obtained by pulsed Doppler ultrasonography. RESULTS The mean pulsatility index, resistance index, body mass index, waist circumference, systolic and diastolic blood pressure, homeostasis model assessment for insulin resistance, plasma fasting glucose, insulin, C-peptide, triglycerides, low-density lipoprotein cholesterol, and high-sensitivity C-reactive protein were statistically higher in obese subjects than in healthy controls. CONCLUSIONS Our results suggest that depressed vessel compliance and increased vascular resistance are features of young, obese, normotensive subjects independently of and in addition to cardiovascular risk factors. As changes in arterial wall properties may be incipient in young obese subjects, future studies will be required to demonstrate whether early intervention such as diet and exercise in this population can improve vascular functions.
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Affiliation(s)
- H Onur Ozari
- Division of Internal Medicine, GATA Haydarpasa Training Hospital, Tibbiye Caddesi TR-34668 Uskudar-Istanbul, Turkey
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23
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Zhou JQ, Zhou P, Zhan WW, Zhou C, Zhou W, Dong YJ. Blood flow resistance in lesion vessels and normal host vessels evaluated by pulsed Doppler ultrasound. Microvasc Res 2012; 84:99-104. [PMID: 22465813 DOI: 10.1016/j.mvr.2012.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2011] [Revised: 01/19/2012] [Accepted: 03/01/2012] [Indexed: 11/25/2022]
Abstract
Blood flow rate in the microcirculation is proportional to the arteriole-venule pressure difference and inversely proportional to the blood flow resistance (BFR). Generally, the BFR studies to date have focused on using invasive methods and were carried out in non-physiological conditions. Moreover, few studies have been concerned with the relationships of BFR between the tumor vessels and the normal host vessels. The present study investigated the BFR in malignant lesion vessels, benign lesion vessels and normal host vessels in physiological conditions using pulsed Doppler ultrasound as a tool and the thyroid as a model, A total of 133 patients with thyroid nodules were included in the study. The results revealed that most of the BFR parameters were higher in malignant lesion vessels than in benign lesion vessels (P=0.001-0.029), as well as lower in normal host vessels than in malignant or benign lesion vessels (P=0.000-0.017); Low to moderate significant positive correlations of BFR between benign lesion vessels and normal host vessels were also found (r=0.358-0.480, P=0.000 for all). Finally and interestingly, low negative correlations between the malignant nodule sizes and some of the BFR parameters were revealed, though these correlations were not statistically significant (r=-0.205--0.261, P=0.108-0.211). Our results suggested that pulsed Doppler ultrasound could be successfully used to measure BFR in physiological conditions and to reveal the BFR relationship between lesion vessels and normal host vessels, as well as the relationship between the lesion sizes and the BFR.
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Affiliation(s)
- Jian-Qiao Zhou
- Department of Ultrasound, Shanghai Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
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24
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Blissitt KJ, Raisis AL, Adams VJ, Rogers KH, Henley WE, Young LE. The effects of halothane and isoflurane on cardiovascular function in dorsally recumbent horses undergoing surgery. Vet Anaesth Analg 2008; 35:208-19. [DOI: 10.1111/j.1467-2995.2007.00376.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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25
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Topal NB, Kaya E, Ercan I, Pourbagher MA, Topal U. The role of Doppler sonography in predicting severity of acute pancreatitis. JOURNAL OF CLINICAL ULTRASOUND : JCU 2008; 36:141-147. [PMID: 18088057 DOI: 10.1002/jcu.20447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
PURPOSE To investigate the role of Doppler sonography (DUS) examination of major abdominal arteries in predicting severity of acute pancreatitis (AP). METHODS Twenty-nine patients diagnosed with AP and 14 controls were blindly and prospectively evaluated with Doppler sonography. Disease severity was defined clinically according to acute physiology and chronic health evaluation (APACHE II) score and was classified as severe for APACHE II score > or =8. DUS examination included the measurement of peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI), and resistance index (RI) of the celiac artery (CA) and superior mesenteric artery (SMA). Statistical analysis included Mann-Whitney U test, Student t test, and receiver operating characteristic curve analysis. RESULTS Twelve patients had severe AP and 17 had mild AP. PSV, EDV, and PI of the CA and RI of the SMA were higher in the severe AP group than in the mild AP and control groups (p < 0.001 and p < 0.0001, respectively). The sensitivity and specificity were 100% and 94%, respectively, for a 87 cm/second CA PSV cutoff value, 75% and 100%, respectively, for a 22 cm/second CA EDV cutoff value, 92% and 82%, respectively, for a 1.29 CA PI cutoff value, and 100% and 100%, respectively, for a 0.86 SMA RI cutoff value. CONCLUSION DUS can be useful in predicting the severity of AP in the early period of admission phase of the disease.
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Affiliation(s)
- Naile Bolca Topal
- Department of Radiology, Uludag University School of Medicine, 16059 Gorukle, Bursa, Turkey
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26
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Kassab MY, Majid A, Bakhtar O, Farooq MU, Patel K, Bednarczyk EM. Transcranial Doppler measurements in migraine and nitroglycerin headache. J Headache Pain 2007; 8:289-93. [PMID: 17955171 PMCID: PMC3476155 DOI: 10.1007/s10194-007-0413-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2007] [Accepted: 09/14/2007] [Indexed: 12/04/2022] Open
Abstract
The objective of this study was to examine the cerebral circulation during spontaneous migraine attacks and to compare changes to an experimental headache model induced by nitroglycerin (NTG) infusion. This prospective study was carried out in a tertiary care hospital on migraineurs with or without aura. Healthy volunteers served as controls. There were no interventions. Flow velocity (FV) and pulsatility index (PI) were measured in migraineurs between and during headache attacks. In controls, FV and PI of the middle cerebral arteries were performed at baseline and after each IV infusion of 0.125, 0.25 and 0.5 microg/kg/min of NTG. In migraineurs, a significant increase in the mean flow velocity (MFV) in the left vertebral artery (VA) and the PI of the right VA during spontaneous migraine headache was found. In controls, all FV significantly decreased after infusion of NTG. The NTG model produces expected and substantially different vascular effects than those seen with spontaneous migraine headache.
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Affiliation(s)
- Mounzer Y Kassab
- Department of Neurology, Michigan State University, 138 Service Road, A-217, East Lansing, MI 48824, USA.
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27
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Maurits NM, Loots GE, Veldman AEP. The influence of vessel wall elasticity and peripheral resistance on the carotid artery flow wave form: A CFD model compared to in vivo ultrasound measurements. J Biomech 2007; 40:427-36. [PMID: 16464454 DOI: 10.1016/j.jbiomech.2005.12.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Accepted: 12/14/2005] [Indexed: 01/01/2023]
Abstract
The Doppler flow wave form and its derived measures such as the pulsatility index provide clinically important tools for the investigation of arterial disease. The typical shape of Doppler flow wave forms is physiologically known to be largely determined by both peripheral resistance and elastic properties of the arterial wall. In the present study we systematically investigate the influence of both vessel wall elasticity and peripheral resistance on the flow wave form obtained from a CFD-simulation of blood flow in the carotid bifurcation. Numerical results are compared to in vivo ultrasound measurements. The in vivo measurement provides a realistic geometry, local elasticities and an input flow wave form for the numerical experiment. Numerical and experimental results are compared at three different sites in the carotid branches. Peripheral resistance has a profoundly decreasing effect on velocities in the external carotid artery. If elasticity is taken into account, the computed peak systolic velocities are considerably lower and a more realistic smoothing of the flow wave form is found. Together, the results indicate that only if both vessel wall elasticity and positive peripheral resistance are taken into account, experimentally obtained Doppler flow wave forms can be reproduced numerically.
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Affiliation(s)
- N M Maurits
- Department of Neurology, University Medical Center Groningen, V4, P.O. Box 30.001, 9700 RB Groningen, The Netherlands.
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Wongaumnuaykul S, Siedler C, Schobesberger H, Stanek C. Doppler sonographic evaluation of the digital blood flow in horses with laminitis or septic pododermatitis. Vet Radiol Ultrasound 2006; 47:199-205. [PMID: 16553154 DOI: 10.1111/j.1740-8261.2006.00128.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The aim of this study was to evaluate the use of Doppler ultrasonography to monitor vascular blood flow dynamics in defined diseases of the equine digit in a noninvasive way. Doppler sonography was used to evaluate medial digital artery blood flow in eight horses with septic pododermatitis and four horses with laminitis in comparison with 10 horses of a control group. Doppler sonographic measurement and lameness examinations were performed in lame horses before treatment (day 0) and at 3, 6, and 9 days following treatment. Before treatment, blood flow velocities, arterial diameter, and flow volume were significantly higher in the lame horses, while pulsatility indices (PIs) were significantly lower (P < 0.05). Compared with the control group, there was no significant difference of resistive indices (RI) in the septic pododermatitis group, but these indices were significantly lower in the laminitis group. No significant difference between the two lame groups was recorded. After treatment, blood flow velocities and flow volume decreased significantly and PIs increased significantly in both lame groups, while RI and arterial diameter did not change. No correlation between Doppler parameters and the degree of lameness was found. Doppler sonography can be used to monitor vascular blood flow dynamics in horses suffering from septic pododermatitis and laminitis, while blood flow velocities and PI can serve as parameters for monitoring the course of the disease.
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Affiliation(s)
- Santi Wongaumnuaykul
- From the Clinic of Orthopaedics in Ungulates, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Vienna, Austria
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Marval PD, Perrin ME, Hancock SM, Mahajan RP. The Effects of Propofol or Sevoflurane on the Estimated Cerebral Perfusion Pressure and Zero Flow Pressure. Anesth Analg 2005; 100:835-840. [PMID: 15728076 DOI: 10.1213/01.ane.0000146522.84181.d3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The zero flow pressure (ZFP) is the pressure at which blood flow ceases through a vascular bed. Using transcranial Doppler ultrasonography, we investigated the effects of propofol or sevoflurane on the estimated cerebral perfusion pressure (eCPP) and ZFP in the cerebral circulation. Twenty-three healthy patients undergoing nonneurosurgical procedures under general anesthesia were studied. After induction of anesthesia using propofol, the anesthesia was maintained with either propofol infusion (n = 13) or sevoflurane (n = 10). Middle cerebral artery flow velocity, noninvasive arterial blood pressure, and end-tidal carbon dioxide partial pressure were recorded awake as a baseline, and during steady-state anesthesia at normocapnia (baseline end-tidal carbon dioxide partial pressure) and hypocapnia (1 kPa below baseline). The eCPP and ZFP were calculated using an established formula. The mean arterial blood pressure decreased in both groups. The eCPP decreased significantly in the propofol group (median, from 58 to 41 mm Hg) but not in the sevoflurane group (from 60 to 62 mm Hg). Correspondingly, ZFP increased significantly in the propofol group (from 25 to 33 mm Hg) and it decreased significantly in the sevoflurane group (from 27 to 7 mm Hg). Hypocapnia did not change eCPP or ZFP in the propofol group, but it significantly decreased eCPP and increased ZFP in the sevoflurane group.
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Affiliation(s)
- Paul D Marval
- University Departments of Anesthesia and Intensive Care, Queens Medical Centre and City Hospital NHS Trust, Nottingham, United Kingdom
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30
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Athanassiou L, Hancock SM, Mahajan RP. Doppler estimation of zero flow pressure during changes in downstream pressure in a bench model of a circulation using pulsatile flow. Anaesthesia 2005; 60:133-8. [PMID: 15644009 DOI: 10.1111/j.1365-2044.2004.04036.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Zero flow pressure is the arterial pressure at which blood flow ceases in the cerebral circulation and may represent the effective downstream pressure of this system. We used a bench model of pulsatile fluid flow to determine whether simulated changes in downstream pressure may be detected by estimation of zero flow pressure. A Doppler probe was used to record flow velocity and a pressure transducer was used to measure driving pressure. Eight different configurations of the circuit were produced, and at each configuration the external pressure around a collapsible segment of the circuit was changed in order to simulate intracranial pressure. Perfusion pressure and zero flow pressure were estimated for each configuration and each level of external pressure. The sensitivity of the model in predicting the change in external pressure from the change in zero flow pressure was 94%. This indicates that estimation of zero flow pressure by this method is a sensitive way of monitoring trends in changes in downstream pressure.
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Affiliation(s)
- L Athanassiou
- IASO General Hospital, 264 Mesogion Avenue, Holargos, Athens 155 62, Greece
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31
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Barutcu I, Esen AM, Degirmenci B, Acar M, Kaya D, Turkmen M, Melek M, Onrat E, Esen OB, Kirma C. Acute Cigarette Smoking-Induced Hemodynamic Alterations in the Common Carotid Artery-A Transcranial Doppler Study-. Circ J 2004; 68:1127-31. [PMID: 15564695 DOI: 10.1253/circj.68.1127] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Cigarette smoking has been shown to temporarily alter cerebral flow velocity and vasomotor reactivity, so the aim of this study was to assess the acute effects of smoking a single cigarette on the common carotid artery (CCA) hemodynamics in healthy nonsmokers. METHOD AND RESULTS Using a 7.0 MHz linear transducer of a computed sonography system, the CCA hemodynamics, including the diameter of the left and right CCA, peak systolic velocity, maximum end-diastolic velocity, time-averaged maximum velocity pulsatility index, resistivity index, flow volume, diameter and area of the CCAs, were measured in 16 healthy nonsmokers before and immediately after smoking a cigarette. Compared with the baseline, heart rate and blood pressure significantly increased, the diameter, flow volume and area of each CCA were unchanged, and the pulsatility index and resistivity index were significantly altered after smoking. In addition, the peak systolic velocity, maximum end-diastolic velocity and time-averaged maximum velocity were significantly altered after smoking. CONCLUSIONS Cigarette smoking significantly altered the CCA hemodynamics in nonsmokers, probably as a consequence of enhanced adrenergic activity.
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Affiliation(s)
- Irfan Barutcu
- Department of Cardiology, Kosuyolu Heart Education and Research Hospital, Istanbul, Turkey.
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32
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Krejza J, Siemkowicz J, Sawicka M, Szylak A, Kochanowicz J, Mariak Z, Lewko J, Spektor V, Babikian V, Bert R. Oscillations of cerebrovascular resistance throughout the menstrual cycle in healthy women. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2003; 22:627-632. [PMID: 14689537 DOI: 10.1002/uog.907] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
OBJECTIVES Increased concentration of endogenous estrogen during a typical menstrual cycle has been shown to correlate with augmentation of blood flow through the internal carotid arteries (ICAs), which may be related to changes in vascular resistance within the brain. In this study we investigated the effects of endogenous estrogen and progesterone on cerebrovascular impedance in young healthy women. METHODS The blood flow in the ICA and the common (CCA) and external (ECA) carotid arteries was studied with duplex Doppler sonography. The resistance index (RI) was determined and correlated with plasma 17beta-estradiol concentration in 14 young healthy women throughout their menstrual cycle. RESULTS The concentration of 17beta-estradiol increased in the follicular phase of the cycle and reached a peak on day 14, whereas concentration of progesterone remained low. Along with an increase in estrogen concentration, the ICA RI had decreased from its initial level on average by 9.2% on day 13 and by 6.7% on day 14 (P < 0.05). In contrast, the trend of the ECA RI was to increase during the peak of estrogen concentration. There were no significant changes in the CCA RI or in the systolic blood pressure, heart rate, hematocrit and hemoglobin concentration through the menstrual cycle. CONCLUSIONS Estrogen-related augmentation of blood flow through the ICA is caused mainly by decreased cerebrovascular impedance, as shown by a decrease in the ICA RI. These changes in RI suggest that estrogen influences cerebral impedance mainly by altering the resistance of cerebral microvasculature.
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Affiliation(s)
- J Krejza
- Department of Radiology, Bialystok Medical Academy, Bialystok, Poland.
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Walker RD, Sherriff SB, Wood RFM. The development of a model of the femoral artery bifurcation for use with duplex Doppler systems. ULTRASOUND IN MEDICINE & BIOLOGY 2003; 29:487-494. [PMID: 12706201 DOI: 10.1016/s0301-5629(02)00728-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The ability to reproduce physiologic blood flow characteristics in vitro, combined with the ability to extract data using duplex Doppler ultrasound (US), is a desirable characteristic in a model of the femoral artery. This would allow duplex Doppler measurement protocols to be studied and developed on a realistic and repeatable platform. This paper describes the development and limitations of a model with these design specifications. The model features pulsatile pressure and flow, a source impedance and compliant vessels including bifurcations. The effects of bifurcation angle on the volume flow division ratio between the superficial femoral and the profunda femoris sections of the model were measured using a transit time flowmeter. No significant dependence on bifurcation angle was detected. Duplex Doppler US was also used to measure the volumetric flow in each arm of the bifurcation. Readings were compared with the transit time flowmeter. Measurements were overestimated by approximately 30% in the profunda femoris and underestimated by approximately 20% in the superficial femoral sections of the model. These errors were larger than those predicted by other theoretical studies. The model has been shown to be a useful platform on which to perform haemodynamic simulations. The model demonstrated that bifurcation angle does not influence the volumetric flow in the downstream arteries. Volumetric flow measurements using duplex Doppler US are erroneous around the bifurcation and need to be treated with great care. The model shows excellent potential to be a useful tool in duplex Doppler-based studies.
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Affiliation(s)
- Richard D Walker
- Section of Surgery, Division of Clinical Sciences (NGH), Clinical Sciences Centre, University of Sheffield, Northern General Hospital, Sheffield, UK.
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Pawson P, Nolan AM, Reid J, Boyd JS, Paterson C. Changes in the Doppler waveform of the ovine femoral artery following infusion of vasoactive agents: a preliminary study. Res Vet Sci 2002; 73:215-21. [PMID: 12443677 DOI: 10.1016/s0034-5288(02)00009-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The aim of this study was to investigate whether femoral artery pulsatility index (PI) can be used as an indicator of vasomotor tone in the digit of an ungulate species by measuring the change in PI induced by infusion of vasoactive agents in halothane-anaesthetised sheep. Intra-arterial infusion of the vasoconstrictor phenylephrine (9 microg min(-1)) tended to increase waveform PI (3.89-6.24, n=4, P=0.100). Infusion of a low dose (3 microg min(-1)) of the vasodilator sodium nitroprusside did not alter femoral artery PI, however infusion of a higher dose (30 microg min(-1)) tended to increase PI (5.39-6.70, n=5, P=0.059). During these studies heart rate, mean ABP and p(a)CO(2) did not change significantly. The tendency for PI to increase in response to vasodilation was unexpected and the mechanism involved is unclear. It appears that femoral artery PI cannot be used to predict vasomotor tone in the digit of the anaesthetised sheep.
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Affiliation(s)
- P Pawson
- Department of Veterinary Preclinical Studies, University of Glasgow, UK
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Sakagami J, Kataoka K, Sogame Y, Usui N, Mitsuyoshi M. Ultrasonographic splanchnic arterial flow measurement in severe acute pancreatitis. Pancreas 2002; 24:357-64. [PMID: 11961488 DOI: 10.1097/00006676-200205000-00006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
INTRODUCTION Duplex ultrasonographic technology is now capable of detecting flow signals in the various splanchnic vessels and calculating the concomitant flow velocities using fast-Fourier transformation. AIM To use Doppler sonography to investigate how splanchnic hemodynamics vary during the early stage of severe acute pancreatitis. METHODOLOGY Six patients with severe acute pancreatitis (age, 59.0 +/- 6.57 years; four men, two women) and seven with mild to moderate acute pancreatitis (age, 60.1 +/- 7.41 years; five men, two women) were examined with Doppler sonography immediately after disease onset. The maximum velocity, minimum velocity, mean velocity, pulsatility index, and resistive index were determined from the Doppler spectra from the proper hepatic artery, celiac artery, and superior mesenteric artery. We also examined 15 healthy subjects (age, 59.3 +/- 4.60 years; 10 men, five women) as controls. RESULTS The maximum velocity of the proper hepatic artery in patients with severe acute pancreatitis was significantly higher than that in patients with mild to moderate acute pancreatitis (p = 0.011) and in control subjects (p = 0.0047). Similarly, significant increases in both the minimum velocity and the mean velocity of the proper hepatic artery were observed in patients with severe acute pancreatitis. Neither pulsatility index nor resistive index of the proper hepatic artery showed a significant difference among the three groups. There were no significant differences among the three groups with respect to the flow velocity of the superior mesenteric artery. In contrast, the pulsatility index of the superior mesenteric artery in patients with severe acute pancreatitis was significantly lower than that in patients with mild to moderate acute pancreatitis (p = 0.0058) or in control subjects (p = 0.0024). For patients with acute pancreatitis, a significant inverse correlation was obtained between the maximum velocity of the proper hepatic artery and the pulsatility index of the superior mesenteric artery (r = -0.658, p = 0.0145). CONCLUSION The increase in the hepatic arterial flow velocity and the decrease in the superior mesenteric arterial pulsatility index may represent early events of the severe type of acute pancreatitis.
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Affiliation(s)
- Junichi Sakagami
- Third Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan.
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Kidwell CS, el-Saden S, Livshits Z, Martin NA, Glenn TC, Saver JL. Transcranial Doppler pulsatility indices as a measure of diffuse small-vessel disease. J Neuroimaging 2001; 11:229-35. [PMID: 11462287 DOI: 10.1111/j.1552-6569.2001.tb00039.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Elevation in pulsatility indices (PIs) as measured by transcranial Doppler (TCD) have been postulated to reflect downstream increased vascular resistance caused by small-vessel ischemic disease. METHODS The authors retrospectively compared TCD PIs and magnetic resonance imaging (MRI) manifestations of small-vessel disease in 55 consecutive patients who underwent TCD studies and brain MRI within 6 months of each other during a 2-year period. RESULTS Correlations between TCD middle cerebral artery PIs and MRI measures were as follows: periventricular hyperintensity (PVH) = 0.52 (P < .0001), deep white matter hyperintensity (DWMH) = 0.54 (P < .0001), lacunar disease = 0.31 (P = .02), and combined PVH/DWMH/lacunes = 0.54 (P < .0001). Correlation between pontine ischemia and vertebrobasilar PIs was 0.46 (P = .0004). Univariate analysis showed that age, elevated PI, and hypertension strongly correlated with white matter disease measures. After adjusting for these factors in a multivariate Poisson regression analysis, PI remained an independent predictor of white matter disease. Receiver operator curve analyses identified PI cut points that allowed discrimination of PVH with 89% sensitivity and 86% specificity and discrimination of DWMH with 70% sensitivity and 73% specificity. CONCLUSIONS Elevation in PIs as measured by TCD shows strong correlation with MRI evidence of small-vessel disease. TCD may be a useful physiologic index of the presence and severity of diffuse small-vessel disease.
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Affiliation(s)
- C S Kidwell
- Stroke Center, Department of Neurology, 710 Westwood Plaza, UCLA Medical Center, Los Angeles, CA 90095, USA.
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Raisis AL, Young LE, Meire HB, Taylor PM, Blissitt KJ, Marlin D, Lekeux P. Measurements of hindlimb blood flow recorded using Doppler ultrasound during administration of vasoactive agents in halothane-anesthetized horses. Vet Radiol Ultrasound 2000; 41:64-72. [PMID: 10695883 DOI: 10.1111/j.1740-8261.2000.tb00429.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The purpose of the study was to determine the ability of Doppler ultrasound to detect changes in femoral blood flow during pharmacologic manipulation of arterial blood pressure. Doppler ultrasonography was performed in the femoral vessels of six halothane-anesthetized horses before and during administration of phenylephrine HCI and sodium nitroprusside. The time-averaged mean velocity and volumetric flow were calculated. The contour of the velocity waveform was assessed, and the early diastolic deceleration slope (EDDS) and pulsatility index (PI) were calculated. Administration of phenylephrine HCI resulted in increased mean aortic blood pressure (MABP) by 40% (29.3-53.0%). This caused significant decrease in cardiac output (26.8 to 13.5 l/min), femoral arterial velocity (left artery 7.20 to 4.00 cm/s; right artery 5.01 to 3.39 cm/s) and volumetric flow (left artery 556 to 221 ml/min; right artery 397 to 193 ml/min) in the femoral vessels and significant increase in systemic vascular resistance (163 to 433 dyn-s/cm5), EDDS (1a: 285 to 468: ra: 250 to 481) and PI (1a: 9.38 to 20.4; ra 17.1 to 29.1). Administration of sodium nitroprusside resulted in a decreased MABP of 27.2% (22.5-33%). This increased cardiac output (20.8 to 32.4 L/min), however, no significant changes were observed in femoral blood flow. Despite obvious changes in the waveform contour, no significant change occurred in EDDS or PI. These results suggest that Doppler ultrasound may be useful for measuring femoral blood flow in anesthetized horses. However, waveform analysis appears to be limited when multiple changes occur in central and peripheral haemodynamics.
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Affiliation(s)
- A L Raisis
- Centre for Equine Studies, The Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk.
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Evans DW, Harris A, Cantor LB. Primary open-angle glaucoma patients characterized by ocular vasospasm demonstrate a different ocular vascular response to timolol versus betaxolol. J Ocul Pharmacol Ther 1999; 15:479-87. [PMID: 10609770 DOI: 10.1089/jop.1999.15.479] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We evaluated the retrobulbar response to a selective versus nonselective beta blocker in a subgroup of primary open-angle glaucoma patients (POAG) characterized by ocular vasospasm. Eleven patients who exhibited ocular vasospasm (i.e. a significant increase in ophthalmic artery blood flow velocity or a significant decrease in ophthalmic artery resistance index during hypercapnia) underwent medication washout for 4 weeks and were enrolled in a double-masked cross-over study (betaxolol versus timolol). Patients were evaluated for blood flow velocity of the retrobulbar vessels using color Doppler imaging, intraocular pressure, visual field sensitivity and contrast sensitivity at the beginning and end of each 4 week treatment period. Timolol treatment caused a significant reduction in IOP (p = .007), but no change in retrobulbar hemodynamics or visual function. After betaxolol treatment, resistance index fell significantly (p = .040) in the ophthalmic artery and increased significantly in both the central retinal (p = .003) and temporal posterior ciliary arteries (p = .030). Also following betaxolol treatment, contrast sensitivity improved significantly (p = .006), and a significant positive correlation was shown between change in contrast sensitivity and change in resistance index (r = .70; p = .015) of the ciliary arteries. POAG patients characterized by ocular vasospasm display a significant hemodynamic response to betaxolol, but not to timolol.
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Affiliation(s)
- D W Evans
- Department of Ophthalmology, Indiana University, Indianapolis, USA
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Walker RD, Smith RE, Sherriff SB, Wood RF. Latex vessels with customized compliance for use in arterial flow models. Physiol Meas 1999; 20:277-86. [PMID: 10475581 DOI: 10.1088/0967-3334/20/3/305] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The physical characteristics of the arterial wall exert a major influence over blood flow patterns and the pulse wave velocity is strongly affected by the elasticity of the vessel. We have developed a technique for manufacturing latex tubing which has physical characteristics similar to those of human arteries. Tubes were produced by painting a plastic rod of diameter 7 x 10(-3) m (the internal diameter of the superficial femoral artery) with liquid latex. The number of coats applied controlled the thickness, and hence the elasticity of the resulting tube. Values of compliance and pulse wave velocity were similar to those observed in vivo. The tubing was tested in a model of the femoral arterial circulation and the typical triphasic arterial now was seen. The mean flow in the vessels was also analysed, and found to be higher for the more elastic vessels, supporting existing mathematical theories and qualitative physiological data. These vessels provide a reliable method of producing physiologically accurate test segments for use in a range of arterial flow models.
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Affiliation(s)
- R D Walker
- Northern General Hospital, Section of Surgery, University of Sheffield, UK
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Abstract
PURPOSE To evaluate the dependence of the resistive index (RI) on not only vascular resistance but also vascular compliance. MATERIALS AND METHODS An in vitro model that made use of a pulsatile pump, blood-mimicking fluid, and variable compliance and resistance was used to investigate the relationship between the RI and both vascular compliance and resistance. RESULTS In the absence of vascular compliance, the RI was independent of vascular resistance. With vascular compliance, the RI was dependent on vascular resistance and increased with increasing resistance. The higher the compliance, the more the RI was affected by resistance. CONCLUSION The RI is misnamed and should actually be called the "impedance index" because resistance and compliance interact to alter the Doppler arterial waveform. A greater understanding of this relationship may enable future studies that take both resistance and compliance into account to better detect pathologic conditions.
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Affiliation(s)
- R O Bude
- Department of Radiology, University of Michigan Medical Center, Ann Arbor 48109, USA
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Arangino S, Cagnacci A, Angiolucci M, Longu G, Melis GB, Volpe A. Effect of desogestrel-containing oral contraceptives on vascular reactivity and catecholamine levels. Contraception 1998; 58:289-93. [PMID: 9883384 DOI: 10.1016/s0010-7824(98)00113-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The modifications induced by new oral contraceptives (OC) on blood pressure, great vessel vascular reactivity by color Doppler, and catecholamine levels were investigated. Young healthy women not taking OC (n = 22; controls) or receiving, for > or = 6 months, OC containing desogestrel with either 30 micrograms (n = 14) or 20 micrograms of EE (n = 8) were enrolled. Blood pressure measured at rest in supine position was similar between controls and OC users. The pulsatility index (PI), an indirect index of resistance to blood flow, of axillary artery was significantly higher (p < 0.05) in 30 micrograms than in 20 micrograms EE OC users or controls. A similar trend, albeit not significant, was observed for the internal carotid artery PI. Norepinephrine (p < 0.01) and dopamine (p < 0.05) but not epinephrine levels, were lower in 30 micrograms EE OC users than in 20 micrograms EE OC users or controls. Thus, both 20 micrograms and 30 micrograms EE OC had no negative effect on blood pressure, but the 30 micrograms EE OC tended to increase great vessel resistance to blood flow, independently of catecholamine levels.
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Affiliation(s)
- S Arangino
- Institute of Obstetrics and Gynecology, Modena, Italy
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Someda H, Moriyasu F, Hamato N, Fujimoto M, Okuma M. Change in hepatic arterial hemodynamics induced by hepatocellular carcinoma detected with Doppler sonography. JOURNAL OF CLINICAL ULTRASOUND : JCU 1997; 25:359-365. [PMID: 9282800 DOI: 10.1002/(sici)1097-0096(199709)25:7<359::aid-jcu2>3.0.co;2-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
PURPOSE To understand the hemodynamic differences between the hepatic arterial branches that supply hepatocellular carcinomas (HCCs) and those that do not, we compared the velocity waveforms of both types of arteries. METHODS Using duplex color Doppler sonography, we examined 38 patients with HCC localized within a single lobe of the liver and 34 patients with chronic liver disease but without HCC (controls). We measured angle-corrected peak systolic velocity and the pulsatility index (PI) of color-coded hepatic arteries along the right anterior segmental portal branch and the vertical segment of the left portal vein. RESULTS There was no significant difference in peak systolic velocity and PI between the arterial branches tested in the controls. In contrast, we found a significantly lower PI and a higher peak systolic velocity in the arterial branches supplying the tumor than in those not supplying the tumor in patients with an HCC 3 cm or larger in diameter (p < 0.05). The degree of these hemodynamic changes correlated with the tumor size and the presence or absence of tumor thrombus in the major portal branches. CONCLUSIONS These results indicate that the hepatic arterial branch supplying an HCC has a lower impedance than the branch not supplying the tumor.
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Affiliation(s)
- H Someda
- First Department of Internal Medicine, Kyoto University School of Medicine, Japan
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Martin NA, Patwardhan RV, Alexander MJ, Africk CZ, Lee JH, Shalmon E, Hovda DA, Becker DP. Characterization of cerebral hemodynamic phases following severe head trauma: hypoperfusion, hyperemia, and vasospasm. J Neurosurg 1997; 87:9-19. [PMID: 9202259 DOI: 10.3171/jns.1997.87.1.0009] [Citation(s) in RCA: 303] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The extent and timing of posttraumatic cerebral hemodynamic disturbances have significant implications for the monitoring and treatment of patients with head injury. This prospective study of cerebral blood flow (CBF) (measured using 133Xe clearance) and transcranial Doppler (TCD) measurements in 125 patients with severe head trauma has defined three distinct hemodynamic phases during the first 2 weeks after injury. The phases are further characterized by measurements of cerebral arteriovenous oxygen difference (AVDO[2]) and cerebral metabolic rate of oxygen (CMRO[2]). Phase I (hypoperfusion phase) occurs on the day of injury (Day 0) and is defined by a low CBF calculated from cerebral clearance curves integrated to 15 minutes (mean CBF 32.3 +/- 2 ml/100 g/minute), normal middle cerebral artery (MCA) velocity (mean V[MCA] 56.7 +/- 2.9 cm/second), normal hemispheric index ([HI], mean HI 1.67 +/- 0.11), and normal AVDO(2) (mean AVDO[2] 5.4 +/- 0.5 vol%). The CMRO, is approximately 50% of normal (mean CMRO(2) 1.77 +/- 0.18 ml/100 g/minute) during this phase and remains depressed during the second and third phases. In Phase II (hyperemia phase, Days 1-3), CBF increases (46.8 +/- 3 ml/100 g/minute), AVDO(2) falls (3.8 +/- 0.1 vol%), V(MCA) rises (86 +/- 3.7 cm/second), and the HI remains less than 3 (2.41 +/- 0.1). In Phase III (vasospasm phase, Days 4-15), there is a fall in CBF (35.7 +/- 3.8 ml/100 g/minute), a further increase in V(MCA) (96.7 +/- 6.3 cm/second), and a pronounced rise in the HI (2.87 +/- 0.22). This is the first study in which CBF, metabolic, and TCD measurements are combined to define the characteristics and time courses of, and to suggest etiological factors for, the distinct cerebral hemodynamic phases that occur after severe craniocerebral trauma. This research is consistent with and builds on the findings of previous investigations and may provide a useful temporal framework for the organization of existing knowledge regarding posttraumatic cerebrovascular and metabolic pathophysiology.
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Affiliation(s)
- N A Martin
- Brain Injury Research Center, and Division of Neurosurgery, University of California at Los Angeles School of Medicine, 90024-7039, USA.
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Sturgiss SN, Dunlop W, Davison JM. Renal haemodynamics and tubular function in human pregnancy. BAILLIERE'S CLINICAL OBSTETRICS AND GYNAECOLOGY 1994; 8:209-34. [PMID: 7924006 DOI: 10.1016/s0950-3552(05)80319-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In human pregnancy, effective renal plasma flow and glomerular filtration rate increase to levels 50-80% above non-pregnant values. The increments occur shortly after conception, persist throughout the second trimester and reduce slightly in late pregnancy. The hyperfiltration of pregnancy does not seem to be a potentially damaging process, as intraglomerular pressure remains unchanged. The increased excretion of glucose and other nutrients, as well as uric acid and protein, is related in part to altered tubular function. Renal physiology is altered so much in pregnancy that non-pregnant norms cannot be used in antenatal care.
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Affiliation(s)
- S N Sturgiss
- Department of Obstetrics and Gynaecology, University of Newcastle-upon-Tyne, Royal Infirmary, UK
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Legarth J, Lingman G, Stangenberg M, Rahman F. Umbilical artery Doppler flow-velocity waveforms in Rhesus-isoimmunized fetuses before and after fetal blood sampling or transfusion. JOURNAL OF CLINICAL ULTRASOUND : JCU 1994; 22:43-47. [PMID: 8294577 DOI: 10.1002/jcu.1870220109] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Pulsed-Doppler examinations of blood-flow velocities in the umbilical artery were carried out before and after 15 diagnostic cordocenteses and 34 fetal blood transfusions into the umbilical vein. There were decreases in the systolic/diastolic ratio (A/B) (p < 0.01), the pulsatility index (PI) (p < 0.05), and the resistance index (RI) (p < 0.01) after cordocentesis but not after fetal blood transfusion. There were no correlations between the initial hematocrit and the umbilical artery Doppler indices in the sample nor in the fetal blood sampling group. In the fetal blood transfusion group, on the other hand, there was a negative correlation between the initial hematocrit and A/B (r = -0.44; p < 0.01) and the RI (r = -0.35; p < 0.05). The umbilical artery Doppler flow-velocity indices did not predict the fetal hematocrit.
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Affiliation(s)
- J Legarth
- Department of Obstetrics and Gynaecology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
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Dauzat M, Lafortune M, Patriquin H, Pomier-Layrargues G. Meal induced changes in hepatic and splanchnic circulation: a noninvasive Doppler study in normal humans. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1994; 68:373-80. [PMID: 8076615 DOI: 10.1007/bf00843732] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The haemodynamic effects of a meal on the splanchnic and hepatic circulation were evaluated in 30 healthy volunteers, using Doppler ultrasonography. The resistance index (RI) of the superior mesenteric artery and of the left and right intrahepatic arteries, the portal vein blood flow as well as the ratio between maximal velocity in the left and right intrahepatic arteries and the adjacent portal vein were measured initially, then 15, 30, 45, and 60 min after the ingestion of a standard balanced liquid meal. Postprandial haemodynamic changes were maximal 30 min after the meal; at that time, mesenteric artery RI decreased significantly [mean -11% (SEM 14%)] whereas portal vein blood flow increased markedly [mean +79% (SEM 14%)]; a significant increase in hepatic artery RI was observed in both liver lobes. The ratio between maximal velocities of the intrahepatic artery and the intrahepatic portal vein was reduced significantly; this ratio decreased more markedly in the right lobe of the liver. These findings would suggest that there was an adaptation of hepatic artery to portal vein blood flow after a meal. The subsequent increase in intrahepatic portal vein flow velocity was found to be greater in the right lobe of the liver.
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Affiliation(s)
- M Dauzat
- Vascular Laboratory, University Hospital, Nîmes, France
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Downing GJ, Maulik D, Phillips C, Kadado TR. In vivo correlation of Doppler waveform analysis with arterial input impedance parameters. ULTRASOUND IN MEDICINE & BIOLOGY 1993; 19:549-559. [PMID: 8310551 DOI: 10.1016/0301-5629(93)90078-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Previous studies have confirmed that Doppler waveform analysis (DWA) offers a valid reflection of changes in peripheral vascular resistance. However, the ability of the pulsatility index (PI), a parameter of DWA, to reflect the dynamic components of the circulation, as assessed by arterial input parameters, remains uncertain. In addition, the state of the central circulation is considered an important factor influencing the accuracy of this technique. This study evaluated the ability of the aortic PI to reflect alterations of input impedance in a chronically instrumented lamb model that was subjected to pharmacologic alteration of the circulation. Pressure, volumetric flow and continuous-wave Doppler frequency shift measurements were recorded from the infrarenal abdominal aorta. The parameters of input impedance, peripheral vascular resistance (Zpr), characteristic impedance (Zo) and reflection coefficient (Rc), were determined and then correlated with changes in the aortic PI. Initially, perturbations of the circulatory state were created with a vasodilator, hydralazine (HY) and a vasoconstrictor, phenylephrine (PE). During a second set of experiments, the effect of the reflex heart rate (HR) responses on the PI was evaluated. This was accomplished by inhibiting reflex HR responses to these vasoactive agents with either trimethophan (TM) or atropine methyl bromide (AMB). In response to HY and HY with TM, significant decreases in the PI and impedance parameters occurred. Administration of PE and PE with AMB resulted in significant increases in PI and each of the impedance parameters. HY and PE induced changes in PI correlated significantly with changes in volumetric flow (r = 0.82, 0.80; p < 0.001), mean arterial blood pressure (r = 0.64, 0.70; p < 0.001) and Zpr (r = 0.77, 0.80; p < 0.001), but not with Zo (r = 0.34, 0.36) and Rc (r = 0.26, 0.31). However, when reflex HR responses were inhibited during the administration of the vasoactive agents, HY with TM and PE with AMB, induced changes in PI correlated significantly with Zo (r = 0.93, 0.89; p < 0.001) and Rc (r = 0.84, 0.83; p < 0.001), and the correlation with mean arterial pressure (r = 0.78, 0.87; p < 0.05) and Zpr (r = 0.92, 0.91; p < 0.05) was significantly greater. These findings indicate that the PI accurately assesses pharmacologically induced changes in the downstream arterial input impedance. The accuracy of this assessment is enhanced further when central circulatory factors such as changes in HR are considered.
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Affiliation(s)
- G J Downing
- Department of Pediatrics, Kansas City School of Medicine, University of Missouri
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Sturgiss SN, Martin K, Whittingham A, Davison JM. Assessment of the renal circulation during pregnancy with color Doppler ultrasonography. Am J Obstet Gynecol 1992; 167:1250-4. [PMID: 1442973 DOI: 10.1016/s0002-9378(11)91696-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVES A non-invasive method of assessing the renal vasculature during pregnancy would be useful in the management of patients with renal dysfunction resulting from preeclampsia or chronic renal disease. The objectives of this study were to determine (1) whether color ultrasonography during pregnancy facilitates Doppler interrogation of renal and intrarenal arteries, allowing (2) the assessment of differences between waveforms from nonpregnant and pregnant women and (3) the analysis of waveform variability throughout the kidney and between the right and left kidneys. STUDY DESIGN In a cross-sectional study renal and intrarenal artery flow waveforms were obtained from women in early (12 to 19 weeks; n = 8), mid (20 to 29 weeks; n = 11), and late (30 to 37 weeks; n = 14) pregnancy with eight age-matched, nonpregnant women acting as controls. Waveforms were analyzed for pulsatility index, resistive index, and systolic/diastolic ratio. RESULTS Left or right renal and upper- and lower-pole interlobar artery waveforms were obtained from all women. The mean pulsatility index values for the nonpregnant women were not significantly different from those women in early, mid, or late pregnancy. In the nonpregnant women, the left renal artery pulsatility index (1.13 +/- 0.13) was greater than the left lower interlobular artery pulsatility index (0.91 +/- 0.08; p < 0.05). During pregnancy renal and interlobar artery pulsatility index values were greater than those for the corresponding interlobular arteries, but the differences were not significant. Mean renal and intrarenal artery pulsatility index values were greater on the right, but the difference was significant only for the lower interlobular artery in midpregnancy. CONCLUSIONS Pregnancy does not significantly affect renal and intrarenal artery flow waveforms, nor are there significant differences between waveforms from the renal and interlobar arteries.
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Affiliation(s)
- S N Sturgiss
- Department of Obstetrics and Gynaecology, University of Newcastle upon Tyne, Princess Mary Maternity Hospital, England
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Merkus JW, van Asten WN, Hoitsma AJ, Koene RA, Skotnicki SH. Assessment of hemodynamic changes in human kidney grafts induced by cyclosporin infusion. Transpl Int 1991; 4:136-9. [PMID: 1958277 DOI: 10.1007/bf00335333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cyclosporin A (CyA) nephrotoxicity is at least partly caused by the vasoconstrictive action of the drug. In this study we set out to assess this hemodynamic effect of CyA on Doppler spectra obtained in arteries of human renal allografts. Doppler spectra of renal arteries were obtained shortly before and after the start of CyA infusion in renal transplant recipients. Doppler spectrum analysis revealed a significant change in several spectrum-derived parameters. Tmax (acceleration time of the systolic frequency peak), in particular, showed a decrease after 4 h of CyA administration (106 +/- 58 ms vs 76 +/- 36 ms in segmental arteries; P less than 0.05). On day 2 the Tmax returned to its original value (117 +/- 57 ms). Thus, Doppler spectrum analysis enables one to detect temporary hemodynamic changes in the transplanted kidney following CyA administration. These observations may be useful in differentiating causes of renal dysfunction by Doppler spectrum analysis in clinical transplantation.
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Affiliation(s)
- J W Merkus
- Clinical Vascular Laboratory, University Hospital St. Radboud, Nijmegen, The Netherlands
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50
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Merkus J, Asten V, Hoitsma A, Koene R, Skotnicki S. Assessment of hemodynamic changes in human kidney grafts induced by cyclosporin infusion. Transpl Int 1991. [DOI: 10.1111/j.1432-2277.1991.tb01966.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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