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Corliss BA, Doty RW, Mathews C, Yates PA, Zhang T, Peirce SM. REAVER: A program for improved analysis of high-resolution vascular network images. Microcirculation 2020; 27:e12618. [PMID: 32173962 PMCID: PMC7507177 DOI: 10.1111/micc.12618] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/09/2020] [Accepted: 03/11/2020] [Indexed: 12/17/2022]
Abstract
Alterations in vascular networks, including angiogenesis and capillary regression, play key roles in disease, wound healing, and development. The spatial structures of blood vessels can be captured through imaging, but effective characterization of network architecture requires both metrics for quantification and software to carry out the analysis in a high‐throughput and unbiased fashion. We present Rapid Editable Analysis of Vessel Elements Routine (REAVER), an open‐source tool that researchers can use to analyze high‐resolution 2D fluorescent images of blood vessel networks, and assess its performance compared to alternative image analysis programs. Using a dataset of manually analyzed images from a variety of murine tissues as a ground‐truth, REAVER exhibited high accuracy and precision for all vessel architecture metrics quantified, including vessel length density, vessel area fraction, mean vessel diameter, and branchpoint count, along with the highest pixel‐by‐pixel accuracy for the segmentation of the blood vessel network. In instances where REAVER's automated segmentation is inaccurate, we show that combining manual curation with automated analysis improves the accuracy of vessel architecture metrics. REAVER can be used to quantify differences in blood vessel architectures, making it useful in experiments designed to evaluate the effects of different external perturbations (eg, drugs or disease states).
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Affiliation(s)
- Bruce A Corliss
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Richard W Doty
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Corbin Mathews
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia
| | - Paul A Yates
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Tingting Zhang
- Department of Statistics, University of Virginia, Charlottesville, Virginia
| | - Shayn M Peirce
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia.,Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, Virginia
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Kallioinen N, Hill A, Horswill MS, Ward HE, Watson MO. Sources of inaccuracy in the measurement of adult patients' resting blood pressure in clinical settings: a systematic review. J Hypertens 2017; 35:421-441. [PMID: 27977471 PMCID: PMC5278896 DOI: 10.1097/hjh.0000000000001197] [Citation(s) in RCA: 203] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 09/13/2016] [Accepted: 11/05/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND To interpret blood pressure (BP) data appropriately, healthcare providers need to be knowledgeable of the factors that can potentially impact the accuracy of BP measurement and contribute to variability between measurements. METHODS A systematic review of studies quantifying BP measurement inaccuracy. Medline and CINAHL databases were searched for empirical articles and systematic reviews published up to June 2015. Empirical articles were included if they reported a study that was relevant to the measurement of adult patients' resting BP at the upper arm in a clinical setting (e.g. ward or office); identified a specific source of inaccuracy; and quantified its effect. Reference lists and reviews were searched for additional articles. RESULTS A total of 328 empirical studies were included. They investigated 29 potential sources of inaccuracy, categorized as relating to the patient, device, procedure or observer. Significant directional effects were found for 27; however, for some, the effects were inconsistent in direction. Compared with true resting BP, significant effects of individual sources ranged from -23.6 to +33 mmHg SBP and -14 to +23 mmHg DBP. CONCLUSION A single BP value outside the expected range should be interpreted with caution and not taken as a definitive indicator of clinical deterioration. Where a measurement is abnormally high or low, further measurements should be taken and averaged. Wherever possible, BP values should be recorded graphically within ranges. This may reduce the impact of sources of inaccuracy and reduce the scope for misinterpretations based on small, likely erroneous or misleading, changes.
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Affiliation(s)
- Noa Kallioinen
- School of Psychology, The University of Queensland, St. Lucia
| | - Andrew Hill
- School of Psychology, The University of Queensland, St. Lucia
- Clinical Skills Development Service, Metro North Hospital and Health Service, Herston
| | | | - Helen E. Ward
- The Prince Charles Hospital, Metro North Hospital and Health Service, Chermside
| | - Marcus O. Watson
- School of Psychology, The University of Queensland, St. Lucia
- Clinical Skills Development Service, Metro North Hospital and Health Service, Herston
- School of Medicine, The University of Queensland Mayne Medical School, Herston, Queensland, Australia
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3
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Shih YT, Cheng HM, Sung SH, Chuang SY, Hu WC, Chen CH. Is Noninvasive Brachial Systolic Blood Pressure an Accurate Estimate of Central Aortic Systolic Blood Pressure? Am J Hypertens 2016; 29:1283-1291. [PMID: 26437666 DOI: 10.1093/ajh/hpv164] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 09/11/2015] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVES Noninvasive brachial systolic blood pressure (nSBP-B) usually approaches invasive central systolic blood pressure (iSBP-C) with a high correlation. Whether nSBP-B is an accurate estimate of iSBP-C remained to be investigated. Thus, this study aimed to compare the errors of nSBP-B and noninvasive central systolic blood pressure (nSBP-C) with different techniques in estimating iSBP-C. METHODS Simultaneous invasive high-fidelity central aortic pressure waveforms and the noninvasive left brachial pulse volume recording (PVR) waveform were recorded in a Generation group ( N = 40) and a Validation group ( N = 100). The accuracy of the noninvasive estimates of iSBP-C obtained from analysis of the calibrated PVR waveform using the generalized transfer function (GTF), pulse waveform analysis (PWA), and N-point moving average (NPMA) methods was examined in the Validation group by calculating the mean absolute error (MAE). RESULTS In Generation group, the MAE was 4.6±4.1mm Hg between nSBP-B and invasive brachial SBP, and 6.8±5.5mm Hg between nSBP-B and iSBP-C. In comparison, the MAE of between iSBP-C and nSBP-C with PWA, NPMA, and GTF were 5.5±4.5, 5.8±4.9, and 5.9±5.0mm Hg, respectively. In Validation group, the MAE of nSBP-B (6.9±4.6mm Hg) for estimating iSBP-C was significantly greater than that of PWA (5.0±3.4mm Hg) and NPMA (6.1±4.4mm Hg), and GTF (6.1±4.9mm Hg). The percentage of absolute band error ≤5mm Hg was 62% for nSBP-B, 69% for GTF, 83% for PWA, and 69% for NPMA. CONCLUSIONS The accuracy of nSBP-B was inferior to the n SBP-C measures in estimating iSBP-C.
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Affiliation(s)
- Yuan-Ta Shih
- Molecular Imaging Center, National Taiwan University , Taipei , Taiwan
| | | | | | - Shao-Yuan Chuang
- Institute of Population Health Sciences, National Health Research Institutes , Miaoli , Taiwan
| | - Wei-Chih Hu
- Department of Biomedical Engineering, Chung Yuan Christian University , Chung-Li , Taiwan
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4
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Umana E, Ahmed W, Fraley MA, Alpert MA. Comparison of Oscillometric and Intraarterial Systolic and Diastolic Blood Pressures in Lean, Overweight, and Obese Patients. Angiology 2016; 57:41-5. [PMID: 16444455 DOI: 10.1177/000331970605700106] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
To assess the effect of obesity on blood pressure measurement the authors obtained simultaneous oscillometric and intraarterial systolic and diastolic blood pressures on 188 lean, overweight, class I/II obese, and class III obese subjects. Oscillometric arm cuff/bladder size was selected in accordance with standard guidelines. Oscillometry significantly underestimated systolic and significantly overestimated diastolic blood pressures in each of the 4 weight groups studied. The differences between oscillometric and intraarterial systolic and diastolic pressures were not significantly different among lean, overweight, class I/II obese, and class III obese subjects. Thus, obesity per se does not influence the accuracy of blood pressure measurement. However, oscillometric blood pressure measurement is associated with significant error when compared to intraarterial blood pressure.
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Affiliation(s)
- Ernesto Umana
- Department of Medicine, University of South Alabama Medical Center, Mobile, AL, USA
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5
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Method of calibration of measurement of central aortic pressure and prediction of all-cause mortality in chronic kidney disease. J Hypertens 2015; 33:1761-3. [DOI: 10.1097/hjh.0000000000000687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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6
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Misclassification of studies in ‘Brachial artery tonometry and the Popeye phenomenon’. J Hypertens 2013; 31:208-9. [DOI: 10.1097/hjh.0b013e32835a875f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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7
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Cheng HM, Sung SH, Shih YT, Chuang SY, Yu WC, Chen CH. Measurement accuracy of a stand-alone oscillometric central blood pressure monitor: a validation report for Microlife WatchBP Office Central. Am J Hypertens 2013; 26:42-50. [PMID: 23382326 DOI: 10.1093/ajh/hps021] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The superiority of prognostic value of blood pressure (BP) measured at central aorta (CBP) over conventional brachial BP measured by cuff-based BP monitors has reignited the development of new noninvasive techniques for estimating CBP. The present study validated the accuracy of CBP measured by a newly developed stand-alone CBP monitor. METHODS The CBP monitor provided readings of brachial systolic BP (SBP), brachial diastolic BP (DBP), central SBP, and central pulse pressure (PP). Brachial PP and central DBP were calculated from the relevant readings. The accuracy of the brachial and central SBP, PP, and DBP was validated against the simultaneously recorded invasively measured central aortic SBP, PP, and DBP, according to the invasive standard requirements for the noninvasive brachial BP monitors from the Association for the Advancement of Medical Instrumentation (AAMI) in 85 subjects (255 measurements; age range, 30-93 years). RESULTS The mean differences of cuff BP with reference to the invasively measured central SBP, PP, and DBP were -2.6 ± 9.0, -8.6 ± 11.2, and 6.1 ± 7.0 mm Hg, respectively, with the former two being obviously underestimated at high CBP and overestimated at low CBP. In contrast, the corresponding differences for the central SBP, PP, and DBP measured by the CBP monitor were -0.6 ± 5.5, -0.4 ± 7.0, and -0.2 ± 6.5 mm Hg, respectively, without obvious systematic bias. The distribution of measurement errors for central SBP, PP, and DBP surpassed the AAMI criteria. CONCLUSION Central SBP, PP, and DBP can be measured accurately by a stand-alone automatic BP monitor.
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Affiliation(s)
- Hao-Min Cheng
- The Joanna Briggs Institute, Faculty of Health Sciences, University of Adelaide, Australia
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Shih YT, Cheng HM, Sung SH, Hu WC, Chen CH. Comparison of two generalized transfer functions for measuring central systolic blood pressure by an oscillometric blood pressure monitor. J Hum Hypertens 2012; 27:204-10. [DOI: 10.1038/jhh.2012.17] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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9
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Abstract
The understanding of sepsis is continuously evolving. An overview of sepsis-induced tissue hypoperfusion has been provided herein. It is of critical importance that the clinician understands the pathophysiology of this emergent condition and is able to synthesize the available data in a rapid fashion so that tissue hypoperfusion is readily detected. Once detected, aggressive and endpoint-directed resuscitation should be implemented to reverse the hypoperfusion and to prevent further deterioration, organ dysfunction, and death.
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Affiliation(s)
- Alan E Jones
- Department of Emergency Medicine, Carolinas Medical Center, Charlotte, 28203, USA.
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Bhatt SD, Hinderliter AL, Stouffer GA. Influence of Sex on the Accuracy of Oscillometric-Derived Blood Pressures. J Clin Hypertens (Greenwich) 2010; 13:112-9. [DOI: 10.1111/j.1751-7176.2010.00391.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Reduced arterial stiffness may contribute to angiotensin-converting enzyme inhibitor induced improvements in walking time in peripheral arterial disease patients. J Hypertens 2008; 26:1037-42. [DOI: 10.1097/hjh.0b013e3282f8e3b6] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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Response to Effects of Angiotensin-Converting Enzyme Inhibitors on Central Blood Pressure. Hypertension 2007. [DOI: 10.1161/hypertensionaha.107.095752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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14
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Dart AM, Cameron JD, Gatzka CD, Willson K, Liang YL, Berry KL, Wing LMH, Reid CM, Ryan P, Beilin LJ, Jennings GLR, Johnston CI, McNeil JJ, Macdonald GJ, Morgan TO, West MJ, Kingwell BA. Similar Effects of Treatment on Central and Brachial Blood Pressures in Older Hypertensive Subjects in the Second Australian National Blood Pressure Trial. Hypertension 2007; 49:1242-7. [PMID: 17470723 DOI: 10.1161/hypertensionaha.106.085803] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Second Australian National Blood Pressure Trial reported better prognosis for hypertensive subjects randomly assigned to an angiotensin-converting enzyme inhibitor (ACE-I) compared with a diuretic-based regimen despite no difference in brachial blood pressure control. A possible explanation is that there was a difference in central aortic pressures despite similar brachial pressure reductions. We examined this hypothesis in a subset of the Second Australian National Blood Pressure Trial cohort evaluated both before and after 4 years of treatment. The average age of the 479 subjects was 71.6+/-4.7 years (mean+/-SD), and 56% were women. Brachial systolic and pulse pressures after treatment were 145+/-1 (mean+/-SEM), 143+/-1, 72+/-1, and 70+/-1 mm Hg for diuretic and ACE-I groups, respectively. The respective changes from pretreatment values were -17+/-2, -16+/-2, -9+/-1, and -7+/-1 mm Hg. None of the differences between diuretic and ACE-I groups were significant. Central arterial pressure waveforms were acquired from carotid tonometry and calibrated from brachial pressures. Central systolic and pulse pressures posttreatment were 144+/-2, 144+/-2, 71+/-2, and 72+/-2 mm Hg for diuretic and ACE-I groups, respectively. The respective changes from pretreatment values were -15+/-2, -17+/-2, -6+/-2, and -8+/-2 mm Hg. None of the differences between diuretic and ACE-I groups were significant. The similarity of central and brachial pressures in this cohort of older hypertensive subjects is most likely because of the influences of age and hypertension in increasing arterial stiffness. There is no evidence that the better prognosis for patients randomly assigned to ACE-I in Second Australian National Blood Pressure Trial resulted from a disproportionate lowering of central blood pressure.
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Affiliation(s)
- Anthony M Dart
- Baker Heart Research Institute, Melbourne, Victoria 8008, Australia.
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Dart AM, Gatzka CD, Kingwell BA, Willson K, Cameron JD, Liang YL, Berry KL, Wing LMH, Reid CM, Ryan P, Beilin LJ, Jennings GLR, Johnston CI, McNeil JJ, Macdonald GJ, Morgan TO, West MJ. Brachial Blood Pressure But Not Carotid Arterial Waveforms Predict Cardiovascular Events in Elderly Female Hypertensives. Hypertension 2006; 47:785-90. [PMID: 16505196 DOI: 10.1161/01.hyp.0000209340.33592.50] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Central arterial waveforms and related indices of large artery properties can be determined with relative ease. This would make them an attractive adjunct in the risk stratification for cardiovascular disease. Although they have been associated with some classical risk factors and the presence of coronary disease, their prospective value in predicting cardiovascular outcomes is unknown. The present study determined the relative predictive value for cardiovascular disease-free survival of large artery properties as compared with noninvasive brachial blood pressure alone in a population of elderly female hypertensive subjects. We measured systemic arterial compliance, central systolic pressure, and carotid augmentation index in a subset of female participants in the Second Australian National Blood Pressure Study (untreated blood pressure 169/88±12/8 mm Hg). There were a total of 53 defined events during a median of 4.1 years of follow-up in 484 women with complete measurements. Although baseline blood pressures at the brachial artery predicted cardiovascular disease-free survival (hazard ratio [HR], 2.3; 95% CI, 1.3 to 4.1 for pulse pressure ≥81 versus <81 mm Hg;
P
=0.01), no such relation was found for carotid augmentation index (HR, 0.80; 95% CI, 0.44 to 1.44;
P
value not significant) or systemic arterial compliance (HR, 1.25; 95% CI, 0.72 to 2.16;
P
value not significant). Blood pressure, but not noninvasively measured central arterial waveforms, predict outcome in the older female hypertensive patient. Thus, blood pressure measurement alone is superior to measurement of arterial waveforms in predicting outcome in this group.
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Affiliation(s)
- Anthony M Dart
- Baker Medical Research Institute, Melbourne, Victoria, 8008, Australia.
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Abstract
OBJECTIVES To assess whether an emergency department (ED) is a suitable location for the targeted screening of hypertension. METHODS This was a prospective targeted screening study based at the ED of an inner city teaching hospital. Non-acute subjects over 18 years were recruited consecutively from the "minors" section of the ED and invited to participate. All subjects had their blood pressure measured twice. A verbal numerical pain score (PS) out of 10 using a visual analogue scale was obtained. Those with a mean systolic blood pressure > 140 mmHg or a mean diastolic blood pressure > 90 mmHg (WHO JNC stage 1 hypertension) were invited for a subsequent follow up measurement. The primary outcome measure was the proportion of subjects with hypertension at follow up. The secondary outcome measure was the correlation between a subject's mid blood pressure (MBP) and their PS. RESULTS In total, 765 subjects were tested, of whom 213 subjects were hypertensive at presentation (28.7%). After excluding those on anti-hypertensive medication (n = 43; 5.6%) and those who were non-UK residents (n = 44; 5.8%), 126 subjects were invited for follow up, of whom 51 subjects actually attended (40% attendance, 6.6% of study population). The MBP of those who re-attended was significantly lower than at presentation (p < 0.001); 39 subjects (5% of the study population, 76.4% of those attending follow up) remained hypertensive. There was no correlation between a subject's PS and their MBP (Pearson correlation coefficient = -0.02). A 10/10 PS was associated with an 8.4 mmHg rise in MBP compared to the mean MBP of subjects with PS 0-9 (p < 0.1). Of those originally presenting with PS > 5/10, 62% still had hypertension at follow up when the painful stimulus was significantly reduced (mean PS = 0.6). CONCLUSION The ED provides an opportunity for identifying those individuals with hypertension who may otherwise remain undiagnosed. Caution is advised when diagnosing hypertension in those individuals suffering from anxiety and/or acute severe pain on presentation.
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Affiliation(s)
- J Fleming
- Academic Department of Accident and Emergency Medicine, Imperial College, St Mary's Hospital, London W2 1NY, UK.
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Williams C, Kingwell BA, Burke K, McPherson J, Dart AM. Folic acid supplementation for 3 wk reduces pulse pressure and large artery stiffness independent of MTHFR genotype. Am J Clin Nutr 2005. [DOI: 10.1093/ajcn/82.1.26] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | | | - Kevin Burke
- From the Baker Heart Research Institute, Melbourne, Australia
| | - Jane McPherson
- From the Baker Heart Research Institute, Melbourne, Australia
| | - Anthony M Dart
- From the Baker Heart Research Institute, Melbourne, Australia
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Camacho F, Avolio A, Lovell NH. Estimation of pressure pulse amplification between aorta and brachial artery using stepwise multiple regression models. Physiol Meas 2004; 25:879-89. [PMID: 15382828 DOI: 10.1088/0967-3334/25/4/008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The pressure pulse is amplified between the aorta and peripheral sites. This study compares two methods to estimate pressure pulse amplification (PPA) between the aorta and the brachial artery. Method 1: PPA was determined from a multi-parameter linear regression of subject parameters (gender, age, height, weight, heart rate (HR), brachial systolic pressure (BSP), diastolic pressure (BDP), mean pressure (MP)). Method 2: PPA was calculated from central aortic pressure waveforms (CW) estimated from the same subject parameters. The sample population (1421 male, 992 female) was selected from a database where aortic pressure was estimated by mathematical transformation of a peripheral (radial) pulse calibrated to sphygmomanometric BSP and BDP. The two methods were consistent in showing HR and MP as the most important parameters to estimate PPA. Correlation coefficients (R2) of 0.48 (method 1) and 0.44 (method 2) were obtained using height, weight, HR, BSP, BDP and age. Inclusion of MP increased R2 to 0.77 (method 1) and 0.71 (method 2). This study shows that databases containing peripheral and central aortic pressure waveforms can be used to construct multiple regression models for PPA estimation. These models could be applied to studies of similar subject groups where peripheral waveforms may not be available.
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Affiliation(s)
- F Camacho
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia.
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20
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Hope SA, Meredith IT, Cameron JD. Effect of non-invasive calibration of radial waveforms on error in transfer-function-derived central aortic waveform characteristics. Clin Sci (Lond) 2004; 107:205-11. [PMID: 15139848 DOI: 10.1042/cs20030294] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2003] [Revised: 03/18/2004] [Accepted: 05/13/2004] [Indexed: 11/17/2022]
Abstract
Transfer function techniques are increasingly used for non-invasive estimation of central aortic waveform characteristics. Non-invasive radial waveforms must be calibrated for this purpose. Most validation studies have used invasive pressures for calibration, with little data on the impact of non-invasive calibration on transfer-function-derived aortic waveform characteristics. In the present study, simultaneous invasive central aortic (Millar Mikro-tip® catheter transducer) and non-invasive radial (Millar® Mikro-tip® tonometer) pressure waveforms and non-invasive brachial pressures (Dinamap®) were measured in 42 subjects. In this cohort, radial waveforms were calibrated to both invasive and non-invasive mean and diastolic pressures. From each of these, central waveforms were reconstructed using a generalized transfer function obtained by us from a previous cohort [Hope, Tay, Meredith and Cameron (2002) Am. J. Physiol. Heart Circ. Physiol. 283, H1150–H1156]. Waveforms were analysed for parameters of potential clinical interest. For calibrated radial and reconstructed central waveforms, different methods of calibration were associated with differences in pressure (P<0.001), but not time parameters or augmentation index. Whereas invasive calibration resulted in little error in transfer function estimation of central systolic pressure (difference −1±8 mmHg; P=not significant), non-invasive calibration resulted in significant underestimation (7±12 mmHg; P<0.001). Errors in estimated aortic parameters differed with non-invasively calibrated untransformed radial and transfer-function-derived aortic waveforms (all P<0.01), with smaller absolute errors with untransformed radial waveforms for most pressure parameters [systolic pressure, 5±16 and 7±12 mmHg; pulse pressure, 0±16 and 4±12 mmHg (radial and derived aortic respectively)]. When only non-invasive pressures are accessible, analysis of untransformed radial waveforms apparently produces smaller errors in the estimation of central aortic systolic pressure, and other waveform parameters, than using a generalized transfer function.
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Affiliation(s)
- Sarah A Hope
- Cardiovascular Research Centre, Monash University, Monash Medical Centre, 246 Clayton Road, Clayton, Victoria 3168, Australia
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Jönsson B, Lindberg LG, Skau T, Thulesius O. Is oscillometric ankle pressure reliable in leg vascular disease? CLINICAL PHYSIOLOGY (OXFORD, ENGLAND) 2001; 21:155-63. [PMID: 11318823 DOI: 10.1046/j.1365-2281.2001.00314.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The objective of the study was to evaluate the validity of oscillometric systolic ankle pressure in symptomatic leg arterial occlusive disease. Ankle pressure measurements using oscillometric curves obtained using a standard 12-cm cuff with a specially designed device for signal processing were validated against the continuous wave (CW) Doppler technique. Thirty-four subjects without signs or symptoms of peripheral vascular disease (68 legs) and 47 patients with leg ischaemia (85 legs) varying from moderate claudication to critical ischaemia were examined. The oscillometric curves were analysed using several algorithms reported in the literature, based on the assumption that maximum oscillations are recorded near mean arterial pressure. In normals, reasonable agreement between CW Doppler and oscillometric methods was seen. When an algorithm that determined the lowest cuff pressure at which maximum oscillations occurred, and a characteristic ratio for systolic pressure of 0.52 was used, the mean difference between CW Doppler and oscillometry was 1.7 mmHg [range -19 to +27, limits of agreement (2 SD) 21.1 mmHg]. In ischaemic legs, oscillometry overestimated systolic ankle pressure by a mean of 28.8 mmHg [range -126 to +65, limits of agreement 82.8 mmHg]. The difference was more pronounced among patients with critical ischaemia compared with claudicants, and also more evident among diabetics. The error of oscillometric pressure determination in subjects with leg arterial disease inversely increased with CW Doppler ankle pressure. In 39% of the recordings in legs with a CW Doppler systolic pressure below 100 mmHg, the oscillometric mean arterial pressure was higher than the recorded CW Doppler systolic pressure. In conclusion, the oscillometric method to determine systolic ankle pressure, based on the concept of maximum cuff oscillations occurring near mean arterial pressure, is not reliable in leg arterial disease, usually overestimating ankle pressure.
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Affiliation(s)
- B Jönsson
- Department of Vascular Surgery, University Hospital, Linköping, Sweden
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22
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Monitoring Techniques and Complications in Critical Care. Surgery 2001. [DOI: 10.1007/978-3-642-57282-1_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Mourad JJ, Hanon O, Girerd X, Boutouyrie P, Safar ME. Effect of hypertension on cardiac mass and radial artery wall thickness. Am J Cardiol 2000; 86:564-7, A9. [PMID: 11009282 DOI: 10.1016/s0002-9149(00)01018-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
In subjects with essential hypertension, increased cardiac and radial artery mass are positively associated. The mechanical factor that contributes in the larger extent to their enhancement is pulse pressure, not mean arterial pressure.
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Affiliation(s)
- J J Mourad
- Department of Internal Medicine, Broussais Hospital, Paris, France
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