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Akira Yamashina - One of the best experts on this subject based on the ideXlab platform.
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relationship between radial and central arterial pulse wave and evaluation of central Aortic Pressure using the radial arterial pulse wave
2007Co-Authors: Kenji Takazawa, Hideyuki Kobayashi, Naohisa Shindo, Nobuhiro Tanaka, Akira YamashinaAbstract:Relationship between Radial and Central Arterial Pulse Wave and Evaluation of Central Aortic Pressure Using the Radial Arterial Pulse Wave
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relationship between radial and central arterial pulse wave and evaluation of central Aortic Pressure using the radial arterial pulse wave
2007Co-Authors: Kenji Takazawa, Hideyuki Kobayashi, Naohisa Shindo, Nobuhiro Tanaka, Akira YamashinaAbstract:Since a decrease of central Aortic Pressure contributes to the prevention of cardiovascular events, simple measurement of not only brachial blood Pressure but also central Aortic Pressure may be useful in the prevention and treatment of cardiovascular diseases. In this study, we simultaneously measured radial artery pulse waves non-invasively and ascending Aortic Pressure invasively, before and after the administration of nicorandil. We then compared changes in central Aortic Pressure and radial arterial blood Pressure calibrated with brachial blood Pressure in addition to calculating the augmentation index (AI) at the aorta and radial artery. After nicorandil administration, the reduction in maximal systolic blood Pressure in the aorta (Δa-SBP) was −14±15 mmHg, significantly larger than that in early systolic Pressure in the radial artery (Δr-SBP) (−9±12 mmHg). The reduction in late systolic blood Pressure in the radial artery (Δr-SBP2) was −15±14 mmHg, significantly larger than Δr-SBP, but not significantly different from Δa-SBP. There were significant relationships between Δa-SBP and Δr-SBP (r=0.81, p<0.001), and between Δa-SBP and Δr-SBP2 (r=0.91, p<0.001). The slope of the correlation regression line with Δr-SBP2 (0.83) was larger and closer to 1 than that with Δr-SBP (0.63), showing that the relationship was close to 1:1. Significant correlations were obtained between Aortic AI (a-AI) and radial AI (r-AI) (before nicorandil administration: r=0.91, p<0.001; after administration: r=0.70, p<0.001). These data suggest that the measurement of radial artery pulse wave and observation of changes in the late systolic blood Pressure in the radial artery (r-SBP2) in addition to the ordinary measurement of brachial blood Pressure may enable a more accurate evaluation of changes in maximal systolic blood Pressure in the aorta (a-SBP).
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relationship between radial and central arterial pulse wave and evaluation of central Aortic Pressure using the radial arterial pulse wave
2007Co-Authors: Kenji Takazawa, Hideyuki Kobayashi, Naohisa Shindo, Nobuhiro Tanaka, Akira YamashinaAbstract:Since a decrease of central Aortic Pressure contributes to the prevention of cardiovascular events, simple measurement of not only brachial blood Pressure but also central Aortic Pressure may be useful in the prevention and treatment of cardiovascular diseases. In this study, we simultaneously measured radial artery pulse waves non-invasively and ascending Aortic Pressure invasively, before and after the administration of nicorandil. We then compared changes in central Aortic Pressure and radial arterial blood Pressure calibrated with brachial blood Pressure in addition to calculating the augmentation index (AI) at the aorta and radial artery. After nicorandil administration, the reduction in maximal systolic blood Pressure in the aorta (Deltaa-SBP) was -14+/-15 mmHg, significantly larger than that in early systolic Pressure in the radial artery (Deltar-SBP) (-9+/-12 mmHg). The reduction in late systolic blood Pressure in the radial artery (Deltar-SBP2) was -15+/-14 mmHg, significantly larger than Deltar-SBP, but not significantly different from Deltaa-SBP. There were significant relationships between Deltaa-SBP and Deltar-SBP (r=0.81, p<0.001), and between Deltaa-SBP and Deltar-SBP2 (r=0.91, p<0.001). The slope of the correlation regression line with Deltar-SBP2 (0.83) was larger and closer to 1 than that with Deltar-SBP (0.63), showing that the relationship was close to 1:1. Significant correlations were obtained between Aortic AI (a-AI) and radial AI (r-AI) (before nicorandil administration: r=0.91, p<0.001; after administration: r=0.70, p<0.001). These data suggest that the measurement of radial artery pulse wave and observation of changes in the late systolic blood Pressure in the radial artery (r-SBP2) in addition to the ordinary measurement of brachial blood Pressure may enable a more accurate evaluation of changes in maximal systolic blood Pressure in the aorta (a-SBP).
Kenji Takazawa - One of the best experts on this subject based on the ideXlab platform.
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relationship between radial and central arterial pulse wave and evaluation of central Aortic Pressure using the radial arterial pulse wave
2007Co-Authors: Kenji Takazawa, Hideyuki Kobayashi, Naohisa Shindo, Nobuhiro Tanaka, Akira YamashinaAbstract:Relationship between Radial and Central Arterial Pulse Wave and Evaluation of Central Aortic Pressure Using the Radial Arterial Pulse Wave
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relationship between radial and central arterial pulse wave and evaluation of central Aortic Pressure using the radial arterial pulse wave
2007Co-Authors: Kenji Takazawa, Hideyuki Kobayashi, Naohisa Shindo, Nobuhiro Tanaka, Akira YamashinaAbstract:Since a decrease of central Aortic Pressure contributes to the prevention of cardiovascular events, simple measurement of not only brachial blood Pressure but also central Aortic Pressure may be useful in the prevention and treatment of cardiovascular diseases. In this study, we simultaneously measured radial artery pulse waves non-invasively and ascending Aortic Pressure invasively, before and after the administration of nicorandil. We then compared changes in central Aortic Pressure and radial arterial blood Pressure calibrated with brachial blood Pressure in addition to calculating the augmentation index (AI) at the aorta and radial artery. After nicorandil administration, the reduction in maximal systolic blood Pressure in the aorta (Δa-SBP) was −14±15 mmHg, significantly larger than that in early systolic Pressure in the radial artery (Δr-SBP) (−9±12 mmHg). The reduction in late systolic blood Pressure in the radial artery (Δr-SBP2) was −15±14 mmHg, significantly larger than Δr-SBP, but not significantly different from Δa-SBP. There were significant relationships between Δa-SBP and Δr-SBP (r=0.81, p<0.001), and between Δa-SBP and Δr-SBP2 (r=0.91, p<0.001). The slope of the correlation regression line with Δr-SBP2 (0.83) was larger and closer to 1 than that with Δr-SBP (0.63), showing that the relationship was close to 1:1. Significant correlations were obtained between Aortic AI (a-AI) and radial AI (r-AI) (before nicorandil administration: r=0.91, p<0.001; after administration: r=0.70, p<0.001). These data suggest that the measurement of radial artery pulse wave and observation of changes in the late systolic blood Pressure in the radial artery (r-SBP2) in addition to the ordinary measurement of brachial blood Pressure may enable a more accurate evaluation of changes in maximal systolic blood Pressure in the aorta (a-SBP).
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relationship between radial and central arterial pulse wave and evaluation of central Aortic Pressure using the radial arterial pulse wave
2007Co-Authors: Kenji Takazawa, Hideyuki Kobayashi, Naohisa Shindo, Nobuhiro Tanaka, Akira YamashinaAbstract:Since a decrease of central Aortic Pressure contributes to the prevention of cardiovascular events, simple measurement of not only brachial blood Pressure but also central Aortic Pressure may be useful in the prevention and treatment of cardiovascular diseases. In this study, we simultaneously measured radial artery pulse waves non-invasively and ascending Aortic Pressure invasively, before and after the administration of nicorandil. We then compared changes in central Aortic Pressure and radial arterial blood Pressure calibrated with brachial blood Pressure in addition to calculating the augmentation index (AI) at the aorta and radial artery. After nicorandil administration, the reduction in maximal systolic blood Pressure in the aorta (Deltaa-SBP) was -14+/-15 mmHg, significantly larger than that in early systolic Pressure in the radial artery (Deltar-SBP) (-9+/-12 mmHg). The reduction in late systolic blood Pressure in the radial artery (Deltar-SBP2) was -15+/-14 mmHg, significantly larger than Deltar-SBP, but not significantly different from Deltaa-SBP. There were significant relationships between Deltaa-SBP and Deltar-SBP (r=0.81, p<0.001), and between Deltaa-SBP and Deltar-SBP2 (r=0.91, p<0.001). The slope of the correlation regression line with Deltar-SBP2 (0.83) was larger and closer to 1 than that with Deltar-SBP (0.63), showing that the relationship was close to 1:1. Significant correlations were obtained between Aortic AI (a-AI) and radial AI (r-AI) (before nicorandil administration: r=0.91, p<0.001; after administration: r=0.70, p<0.001). These data suggest that the measurement of radial artery pulse wave and observation of changes in the late systolic blood Pressure in the radial artery (r-SBP2) in addition to the ordinary measurement of brachial blood Pressure may enable a more accurate evaluation of changes in maximal systolic blood Pressure in the aorta (a-SBP).
Chenhuan Chen - One of the best experts on this subject based on the ideXlab platform.
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Parametric model derivation of transfer function for noninvasive estimation of Aortic Pressure by radial tonometry
1999Co-Authors: B. Fetics, Chenhuan Chen, E. Nevo, D.a. KassAbstract:Aortic Pressure can be estimated noninvasively by applying a transfer function (TF) to radial tonometry signals. This study compares the performance of prior approaches, based on Fourier transform and inverted Aortic-to-radial model, with direct radial-to-Aortic autoregressive exogenous (ARX) model. Simultaneous invasive Aortic Pressure and radial tonometry Pressure were recorded during rest in 39 patients in the supine position. Individual radial-Aortic TF's were estimated from 20 patients, and the average TF was used to predict Aortic Pressures in the remaining 19 patients. The direct average TF yielded accurate Aortic systolic Pressure estimation (error 0.4/spl plusmn/2.9 mmHg) and good reproduction of the Aortic Pressure waveform (root mean squared error 2.2/spl plusmn/0.9 mmHg). The inverted reverse TF (Aortic radial) yielded comparable results, while the Fourier-based TF had worse performance. Individual direct TF provided improved predictive accuracy only for indexes which are based on higher frequency components of the waveform (augmentation index, systolic time period). An ARX average TF can be used to accurately estimate central Aortic Pressure waveform parameters from noninvasive radial pulse tracings, and its performance is superior to previous techniques.
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estimation of central Aortic Pressure waveform by mathematical transformation of radial tonometry Pressure validation of generalized transfer function
1997Co-Authors: Chenhuan Chen, Erez Nevo, B. Fetics, William L Maughan, David A KassAbstract:Background Central Aortic Pressures and waveform convey important information about cardiovascular status, but direct measurements are invasive. Peripheral Pressures can be measured noninvasively, and although they often differ substantially from central Pressures, they may be mathematically transformed to approximate the latter. We tested this approach, examining intersubject and intrasubject variability and the validity of using a single averaged transformation, which would enhance its applicability. Methods and Results Invasive central Aortic Pressure by micromanometer and radial Pressure by automated tonometry were measured in 20 patients at steady state and during hemodynamic transients (Valsalva maneuver, abdominal compression, nitroglycerin, or vena caval obstruction). For each patient, transfer functions (TFs) between Aortic and radial Pressures were calculated by parametric model and results averaged to yield individual TFs. A generalized TF was the average of individual functions. TFs varied among patients, with coefficients of variation for peak amplitude and frequency at peak amplitude of 24.9% and 16.9%, respectively. Intrapatient TF variance with altered loading (>20% variation in peak amplitude) was observed in 28.5% of patients. Despite this, the generalized TF estimated central arterial Pressures to ≤0.2±3.8 mm Hg error, arterial compliance to 6±7% accuracy, and augmentation index to within −7% points (30±45% accuracy). Individual TFs were only marginally superior to the generalized TF for reconstructing central Pressures. Conclusions Central Aortic Pressures can be accurately estimated from radial tonometry with the use of a generalized TF. The reconstructed waveform can provide arterial compliance estimates but may underestimate the augmentation index because the latter requires greater fidelity reproduction of the wave contour.
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validation of carotid artery tonometry as a means of estimating augmentation index of ascending Aortic Pressure
1996Co-Authors: Chenhuan Chen, Chih Tai Ting, Amit Nussbacher, Erez Nevo, David A Kass, Shih Pu WangAbstract:Abstract Our objective was to validate a carotid artery tonometry–derived augmentation index as a means to estimate augmentation index (AI) of ascending Aortic Pressure under various physiological conditions. A total of 66 patients (50 men, 16 women; mean age, 55 years; range, 21 to 78 years; 44 in Taiwan and 22 in the Unites States) undergoing diagnostic catheterization were studied. Arterial Pressure contours were obtained simultaneously from the right common carotid artery by applanation tonometry with an external micromanometer-tipped probe and from the ascending aorta by a micromanometer-tipped catheter at baseline (n=62), after handgrip (n=36), or after sublingual nitroglycerin administration (n=17). The AI (expressed as percentage values) was calculated as the ratio of amplitude of the Pressure wave above its systolic shoulder to the total pulse Pressure. The carotid AI was consistently lower than the Aortic AI, but the two were highly correlated at baseline and after both handgrip and nitroglycerin. Mean±SD and correlation coefficients were baseline (14±16, 28+±17, .77), handgrip (18±19, 32+±15, .86), and nitroglycerin (7±12, 18+±13, .52). In addition, after adjusting for age, sex, height, blood Pressure, heart rate, and study site, the changes of both AIs from baseline values with handgrip or nitroglycerin were highly associated such that the Aortic AI could be approximated from the carotid AI with appropriate regression equations. The high correlations and predictable changes after interventions between the central AI and those estimated from noninvasive carotid tonometry suggest that this technique may have wide applicability for many cardiovascular studies.
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validation of carotid artery tonometry as a means of estimating augmentation index of ascending Aortic Pressure
1996Co-Authors: Chenhuan Chen, Chih Tai Ting, Amit Nussbacher, Erez Nevo, David A Kass, Shih Pu Wang, Peter H Pak, Mausong Chang, Frank C P YinAbstract:Abstract Our objective was to validate a carotid artery tonometry–derived augmentation index as a means to estimate augmentation index (AI) of ascending Aortic Pressure under various physiological ...
Francois Feihl - One of the best experts on this subject based on the ideXlab platform.
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pulse wave analysis of Aortic Pressure diastole should also be considered
2013Co-Authors: Abigael Heim, Bernard Waeber, Lucas Liaudet, Francois FeihlAbstract:BACKGROUND: The systolic augmentation index (sAix), calculated from the central Aortic pulse wave (reconstructed from the noninvasive recording of the radial pulse with applanation tonometry), is widely used as a simple index of central arterial stiffness, but has the disadvantage of also being influenced by the timing of the reflected with respect to the forward Pressure wave, as shown by its inverse dependence on heart rate (HR). During diastole, the central Aortic pulse also contains reflected waves, but their relationship to arterial stiffness and HR has not been studied. METHODS: In 48 men and 45 women, all healthy, with ages ranging from 19 to 70 years, we measured pulse wave velocity (PWV, patients supine), a standard evaluator of arterial stiffness, and carried out radial applanation tonometry (patients sitting and supine). The impact of reflected waves on the diastolic part of the Aortic Pressure waveform was quantified in the form of a diastolic augmentation index (dAix). RESULTS: Across ages, sexes, and body position, there was an inverse relationship between the sAix and the dAix. When PWV and HR were added as covariates to a prediction model including age, sex and body position as main factors, the sAix was directly related to PWV (P < 0.0001) and inversely to HR (P < 0.0001). With the same analysis, the dAix was inversely related to PWV (P < 0.0001) and independent of HR (P = 0.52). CONCLUSION: The dAix has the same degree of linkage to arterial stiffness as the more conventional sAix, while being immune to the confounding effect of HR. The quantification of diastolic Aortic Pressure augmentation by reflected waves could be a useful adjunct to pulse wave analysis.
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bilateral symmetry of radial pulse in high level tennis players implications for the validity of central Aortic pulse wave analysis
2009Co-Authors: Boris Gojanovic, Bernard Waeber, Lucas Liaudet, G Gremion, Francois FeihlAbstract:BackgroundReconstruction of the central Aortic Pressure wave from the noninvasive recording of the radial pulse with applanation tonometry has become a standard tool in the field of hypertension. It is not presently known whether recording the radial pulse on the dominant or the nondominant side has
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profound impact of uncomplicated pregnancy on diastolic but not systolic pulse contour of Aortic Pressure
2006Co-Authors: Anne Delachaux, Bernard Waeber, Lucas Liaudet, Patrick Hohlfeld, Francois FeihlAbstract:OBJECTIVE: To evaluate the impact of uncomplicated pregnancy on the pulse contour of central Aortic Pressure. METHODS: A total of 66 women with singleton pregnancy were grouped according to pregnancy duration: first trimester (T1, n = 22), second trimester (T2, n = 20), and third trimester (T3, n = 24). Non-pregnant healthy women, who took combined oral contraception, were included as controls (C, n = 21). The pulse contour of Aortic Pressure was obtained with radial applanation tonometry, using a commercial device (SphygmoCor). The influence of reflected waves on the contour was evaluated not only in systole, as usual with pulse contour analysis (systolic augmentation), but also in diastole (diastolic augmentation). RESULTS: Throughout pregnancy, central systolic and diastolic blood Pressure remained unchanged and comparable to values in the non-pregnant state. Systolic augmentation amounted to 8.1 +/- 7.5% of pulse Pressure in the control group (mean +/- SD), and there was no statistically significant deviation from this value at any stage of pregnancy (T1, 4.6 +/- 11.4%; T2, 5.0 +/- 9.3%; T3, 4.7 +/- 8.1%). In contrast, the amplitude of the diastolic augmentation wave progressively declined with advancing pregnancy (C, 6.5 +/- 2.4%; T1, 5.2 +/- 3.1%; T2, 3.8 +/- 2.6%; P = 0.002 versus C, T3, 2.3 +/- 2.0%; P < 0.0001 versus C and P = 0.0004 versus T1). CONCLUSION: The systolic shape of the central Aortic Pressure contour is left unaltered by pregnancy, implying a finely tuned adaptation of the cardiovascular system to the increased demand for blood flow at all stages of the gravid state. In contrast, the amplitude of reflection waves reaching the Aortic root in diastole progressively decreases with advancing pregnancy.
Hideyuki Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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relationship between radial and central arterial pulse wave and evaluation of central Aortic Pressure using the radial arterial pulse wave
2007Co-Authors: Kenji Takazawa, Hideyuki Kobayashi, Naohisa Shindo, Nobuhiro Tanaka, Akira YamashinaAbstract:Relationship between Radial and Central Arterial Pulse Wave and Evaluation of Central Aortic Pressure Using the Radial Arterial Pulse Wave
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relationship between radial and central arterial pulse wave and evaluation of central Aortic Pressure using the radial arterial pulse wave
2007Co-Authors: Kenji Takazawa, Hideyuki Kobayashi, Naohisa Shindo, Nobuhiro Tanaka, Akira YamashinaAbstract:Since a decrease of central Aortic Pressure contributes to the prevention of cardiovascular events, simple measurement of not only brachial blood Pressure but also central Aortic Pressure may be useful in the prevention and treatment of cardiovascular diseases. In this study, we simultaneously measured radial artery pulse waves non-invasively and ascending Aortic Pressure invasively, before and after the administration of nicorandil. We then compared changes in central Aortic Pressure and radial arterial blood Pressure calibrated with brachial blood Pressure in addition to calculating the augmentation index (AI) at the aorta and radial artery. After nicorandil administration, the reduction in maximal systolic blood Pressure in the aorta (Δa-SBP) was −14±15 mmHg, significantly larger than that in early systolic Pressure in the radial artery (Δr-SBP) (−9±12 mmHg). The reduction in late systolic blood Pressure in the radial artery (Δr-SBP2) was −15±14 mmHg, significantly larger than Δr-SBP, but not significantly different from Δa-SBP. There were significant relationships between Δa-SBP and Δr-SBP (r=0.81, p<0.001), and between Δa-SBP and Δr-SBP2 (r=0.91, p<0.001). The slope of the correlation regression line with Δr-SBP2 (0.83) was larger and closer to 1 than that with Δr-SBP (0.63), showing that the relationship was close to 1:1. Significant correlations were obtained between Aortic AI (a-AI) and radial AI (r-AI) (before nicorandil administration: r=0.91, p<0.001; after administration: r=0.70, p<0.001). These data suggest that the measurement of radial artery pulse wave and observation of changes in the late systolic blood Pressure in the radial artery (r-SBP2) in addition to the ordinary measurement of brachial blood Pressure may enable a more accurate evaluation of changes in maximal systolic blood Pressure in the aorta (a-SBP).
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relationship between radial and central arterial pulse wave and evaluation of central Aortic Pressure using the radial arterial pulse wave
2007Co-Authors: Kenji Takazawa, Hideyuki Kobayashi, Naohisa Shindo, Nobuhiro Tanaka, Akira YamashinaAbstract:Since a decrease of central Aortic Pressure contributes to the prevention of cardiovascular events, simple measurement of not only brachial blood Pressure but also central Aortic Pressure may be useful in the prevention and treatment of cardiovascular diseases. In this study, we simultaneously measured radial artery pulse waves non-invasively and ascending Aortic Pressure invasively, before and after the administration of nicorandil. We then compared changes in central Aortic Pressure and radial arterial blood Pressure calibrated with brachial blood Pressure in addition to calculating the augmentation index (AI) at the aorta and radial artery. After nicorandil administration, the reduction in maximal systolic blood Pressure in the aorta (Deltaa-SBP) was -14+/-15 mmHg, significantly larger than that in early systolic Pressure in the radial artery (Deltar-SBP) (-9+/-12 mmHg). The reduction in late systolic blood Pressure in the radial artery (Deltar-SBP2) was -15+/-14 mmHg, significantly larger than Deltar-SBP, but not significantly different from Deltaa-SBP. There were significant relationships between Deltaa-SBP and Deltar-SBP (r=0.81, p<0.001), and between Deltaa-SBP and Deltar-SBP2 (r=0.91, p<0.001). The slope of the correlation regression line with Deltar-SBP2 (0.83) was larger and closer to 1 than that with Deltar-SBP (0.63), showing that the relationship was close to 1:1. Significant correlations were obtained between Aortic AI (a-AI) and radial AI (r-AI) (before nicorandil administration: r=0.91, p<0.001; after administration: r=0.70, p<0.001). These data suggest that the measurement of radial artery pulse wave and observation of changes in the late systolic blood Pressure in the radial artery (r-SBP2) in addition to the ordinary measurement of brachial blood Pressure may enable a more accurate evaluation of changes in maximal systolic blood Pressure in the aorta (a-SBP).
