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Sun H, Yao Y, Liu W, Zhou S, Du S, Tan J, Yu Y, Xu L, Avolio A. Wave reflection quantification analysis and personalized flow wave estimation based on the central aortic pressure waveform. Front Physiol 2023; 14:1097879. [PMID: 36909238 PMCID: PMC9996124 DOI: 10.3389/fphys.2023.1097879] [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: 11/14/2022] [Accepted: 02/13/2023] [Indexed: 02/25/2023] Open
Abstract
Pulse wave reflections reflect cardiac afterload and perfusion, which yield valid indicators for monitoring cardiovascular status. Accurate quantification of pressure wave reflections requires the measurement of aortic flow wave. However, direct flow measurement involves extra equipment and well-trained operator. In this study, the personalized aortic flow waveform was estimated from the individual central aortic pressure waveform (CAPW) based on pressure-flow relations. The separated forward and backward pressure waves were used to calculate wave reflection indices such as reflection index (RI) and reflection magnitude (RM), as well as the central aortic pulse transit time (PTT). The effectiveness and feasibility of the method were validated by a set of clinical data (13 participants) and the Nektar1D Pulse Wave Database (4,374 subjects). The performance of the proposed personalized flow waveform method was compared with the traditional triangular flow waveform method and the recently proposed lognormal flow waveform method by statistical analyses. Results show that the root mean square error calculated by the personalized flow waveform approach is smaller than that of the typical triangular and lognormal flow methods, and the correlation coefficient with the measured flow waveform is higher. The estimated personalized flow waveform based on the characteristics of the CAPW can estimate wave reflection indices more accurately than the other two methods. The proposed personalized flow waveform method can be potentially used as a convenient alternative for the measurement of aortic flow waveform.
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Affiliation(s)
- Hongming Sun
- College of Medicine and Biological and Information Engineering, Northeastern University, Shenyang, China
| | - Yang Yao
- School of Information Science and Technology, ShanghaiTech University, Shanghai, China
| | - Wenyan Liu
- College of Medicine and Biological and Information Engineering, Northeastern University, Shenyang, China
| | - Shuran Zhou
- College of Medicine and Biological and Information Engineering, Northeastern University, Shenyang, China
| | - Shuo Du
- College of Medicine and Biological and Information Engineering, Northeastern University, Shenyang, China
| | - Junyi Tan
- College of Medicine and Biological and Information Engineering, Northeastern University, Shenyang, China
| | - Yin Yu
- College of Medicine and Biological and Information Engineering, Northeastern University, Shenyang, China
| | - Lisheng Xu
- College of Medicine and Biological and Information Engineering, Northeastern University, Shenyang, China.,Key Laboratory of Medical Image Computing, Ministry of Education, Shenyang, China.,Neusoft Research of Intelligent Healthcare Technology, Co. Ltd, Shenyang, China
| | - Alberto Avolio
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
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Hungerford SL, Adji AI, Hayward CS, Muller DWM. Ageing, Hypertension and Aortic Valve Stenosis: A Conscious Uncoupling. Heart Lung Circ 2021; 30:1627-1636. [PMID: 34274230 DOI: 10.1016/j.hlc.2021.05.108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 04/17/2021] [Accepted: 05/18/2021] [Indexed: 10/20/2022]
Abstract
Aortic valve stenosis (AS) is no longer considered to be a disease of fixed left ventricular (LV) afterload (due to an obstructive valve), but rather, functions as a series circuit with important contributions from both the valve and ageing vasculature. Patients with AS are frequently elderly, with hypertension and a markedly remodelled aorta. The arterial component is sizable, and yet, the contribution of ventricular afterload has been difficult to determine. Arterial stiffening increases the speed of propagation of the blood pressure wave along the central arteries (estimated as the pulse wave velocity), which results in an earlier return of reflected waves. The effect is to augment blood pressure in the proximal aorta during systole, increasing the central pulse pressure and, in turn, placing even greater afterload on the heart. Elevated global LV afterload is known to have adverse consequences on LV remodelling, function and survival in patients with AS. Consequently, there is renewed focus on methods to estimate the relative contributions of local versus global changes in arterial mechanics and valvular haemodynamics in patients with AS. We present a review on existing and upcoming methods to quantify valvulo-arterial impedance and thereby global LV load in patients with AS.
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Affiliation(s)
- Sara L Hungerford
- Department of Cardiology, St Vincent's Hospital, Sydney, NSW, Australia; The University of New South Wales, Sydney, NSW, Australia; Victor Chang Cardiac Research Institute, Sydney, NSW, Australia.
| | - Audrey I Adji
- Department of Cardiology, St Vincent's Hospital, Sydney, NSW, Australia; The University of New South Wales, Sydney, NSW, Australia; Victor Chang Cardiac Research Institute, Sydney, NSW, Australia; Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Christopher S Hayward
- Department of Cardiology, St Vincent's Hospital, Sydney, NSW, Australia; The University of New South Wales, Sydney, NSW, Australia; Victor Chang Cardiac Research Institute, Sydney, NSW, Australia
| | - David W M Muller
- Department of Cardiology, St Vincent's Hospital, Sydney, NSW, Australia; The University of New South Wales, Sydney, NSW, Australia; Victor Chang Cardiac Research Institute, Sydney, NSW, Australia
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Hungerford S, Adji A, Bart N, Lin L, Song N, Jabbour A, O'Rourke M, Hayward C, Muller D. Ageing, hypertension and aortic valve stenosis - Understanding the series circuit using cardiac magnetic resonance and applanation tonometry. Int J Cardiol Hypertens 2021; 9:100087. [PMID: 34124642 PMCID: PMC8173028 DOI: 10.1016/j.ijchy.2021.100087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 05/13/2021] [Accepted: 05/19/2021] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Aortic stenosis (AS) is no longer considered to be a disease of fixed left ventricular (LV) afterload, but rather, functions as a series circuit, with important contributions from both the valve and vasculature. Patients with AS are typically elderly, with hypertension and a markedly remodelled aorta. The arterial component is sizeable, and yet, quantifying this to-date has been difficult to determine. We compared measurement of aortic pressure, flow and global LV load using a cardiac magnetic resonance (CMR)/applanation tonometry (AT) technique to uncouple ventriculo-arterial (VA) interactions. METHODS 20 healthy elderly patients and 20 with AS underwent a CMR/AT protocol. CMR provided LV volume and aortic flow simultaneously with AT pressure acquisition. Aortic pressure was derived by transformation of the AT waveform. Systemic vascular resistance (SVR) and global LV load were determined as the relationship of pressure to flow in the frequency domain. Values from both cohorts were compared. RESULTS AS patients were older (p < 0.01) albeit with no significant difference in brachial or central aortic pressure. SVR (14228 vs 19906 dyne s.cm-3; p = 0.02) and load (740 vs 946 dyne s.cm-3; p = 0.02) were higher in patients with AS, whilst aortic peak flow velocity was lower (38 vs 58 cm/s; p < 0.01). CONCLUSIONS Quantification of aortic pressure, flow velocity and global LV load using a simultaneous CMR/AT technique is able to demonstrate the progressive effects of hypertension and aortic stiffening with advanced age and valvular stenosis. This technique may help to better identify future patients at risk of VA coupling mismatch after correction of AS.
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Affiliation(s)
- S.L. Hungerford
- Department of Cardiology, St Vincent's Hospital, Sydney, Australia
- The University of New South Wales, Sydney, Australia
- Victor Chang Cardiac Research Institute, Sydney, Australia
| | - A.I. Adji
- Department of Cardiology, St Vincent's Hospital, Sydney, Australia
- Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
| | - N.K. Bart
- Department of Cardiology, St Vincent's Hospital, Sydney, Australia
- Victor Chang Cardiac Research Institute, Sydney, Australia
| | - L. Lin
- Department of Cardiology, St Vincent's Hospital, Sydney, Australia
| | - N. Song
- Department of Cardiology, St Vincent's Hospital, Sydney, Australia
- Victor Chang Cardiac Research Institute, Sydney, Australia
| | - A. Jabbour
- Department of Cardiology, St Vincent's Hospital, Sydney, Australia
- Victor Chang Cardiac Research Institute, Sydney, Australia
| | - M.F. O'Rourke
- Department of Cardiology, St Vincent's Hospital, Sydney, Australia
- Victor Chang Cardiac Research Institute, Sydney, Australia
| | - C.S. Hayward
- Department of Cardiology, St Vincent's Hospital, Sydney, Australia
- Victor Chang Cardiac Research Institute, Sydney, Australia
| | - D.W.M. Muller
- Department of Cardiology, St Vincent's Hospital, Sydney, Australia
- The University of New South Wales, Sydney, Australia
- Victor Chang Cardiac Research Institute, Sydney, Australia
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Bernard S, Namasivayam M, Dudzinski DM. Reflections on Echocardiography in Pulmonary Embolism-Literally and Figuratively. J Am Soc Echocardiogr 2020; 32:807-810. [PMID: 31272591 DOI: 10.1016/j.echo.2019.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 05/09/2019] [Accepted: 05/09/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Samuel Bernard
- Cardiac Ultrasound Laboratory, Cardiology Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Mayooran Namasivayam
- Cardiac Ultrasound Laboratory, Cardiology Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - David M Dudzinski
- Cardiac Ultrasound Laboratory, Cardiology Division, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; Department of Critical Care, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
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Ohyama Y, Ambale-Venkatesh B, Noda C, Kim JY, Tanami Y, Teixido-Tura G, Chugh AR, Redheuil A, Liu CY, Wu CO, Hundley WG, Bluemke DA, Guallar E, Lima JAC. Aortic Arch Pulse Wave Velocity Assessed by Magnetic Resonance Imaging as a Predictor of Incident Cardiovascular Events: The MESA (Multi-Ethnic Study of Atherosclerosis). Hypertension 2017; 70:524-530. [PMID: 28674039 DOI: 10.1161/hypertensionaha.116.08749] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 12/02/2016] [Accepted: 06/04/2017] [Indexed: 01/25/2023]
Abstract
The predictive value of aortic arch pulse wave velocity (PWV) assessed by magnetic resonance imaging for cardiovascular disease (CVD) events has not been fully established. The aim of the present study was to evaluate the association of arch PWV with incident CVD events in MESA (Multi-Ethnic Study of Atherosclerosis). Aortic arch PWV was measured using magnetic resonance imaging at baseline in 3527 MESA participants (mean age, 62±10 years at baseline; 47% men) free of overt CVD. Cox regression was used to evaluate the risk of incident CVD (coronary heart disease, stroke, transient ischemic attack, or heart failure) in relation to arch PWV adjusted for age, sex, race, and CVD risk factors. The median value of arch PWV was 7.4 m/s (interquartile range, 5.6-10.2). There was significant interaction between arch PWV and age for outcomes, so analysis was stratified by age categories (45-54 and >54 years). There were 456 CVD events during the 10-year follow-up. Forty-five to 54-year-old participants had significant association of arch PWV with incident CVD independent of CVD risk factors (hazard ratio, 1.44; 95% confidence interval, 1.07-1.95; P=0.018; per 1-SD increase for logarithmically transformed PWV), whereas >54-year group did not (P=0.93). Aortic arch PWV assessed by magnetic resonance imaging is a significant predictor of CVD events among middle-aged (45-54 years old) individuals, whereas arch PWV is not associated with CVD among an elderly in a large multiethnic population.
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Affiliation(s)
- Yoshiaki Ohyama
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - Bharath Ambale-Venkatesh
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - Chikara Noda
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - Jang-Young Kim
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - Yutaka Tanami
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - Gisela Teixido-Tura
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - Atul R Chugh
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - Alban Redheuil
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - Chia-Ying Liu
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - Colin O Wu
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - W Gregory Hundley
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - David A Bluemke
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - Eliseo Guallar
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.)
| | - Joao A C Lima
- From the Department of Cardiology (Y.O., C.N., J.-Y.K., Y.T., G.T.-T., A.R.C., J.A.C.L.), Department of Radiology (B.A.-V.), and Department of Epidemiology (E.G.), Johns Hopkins University, Baltimore, MD; Imagerie Cardiovasculaire/Department of Cardiovascular Imaging DICVRI, Institut de Cardiologie, Groupe Hospitalier Pitié Salpêtrière, Paris (A.R.); Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, MD (C.-Y.L., D.A.B.); Office of Biostatistics Research, National Heart, Lung, and Blood Institute, Bethesda, MD (C.O.W.); and Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC (W.G.H.).
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Magnetic resonance and applanation tonometry for noninvasive determination of left ventricular load and ventricular vascular coupling in the time and frequency domain. J Hypertens 2016; 34:1099-108. [DOI: 10.1097/hjh.0000000000000925] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Namasivayam M, Adji A, O'Rourke MF. Evaluating the Hemodynamic Basis of Age-Related Central Blood Pressure Change Using Aortic Flow Triangulation. Am J Hypertens 2016; 29:178-84. [PMID: 26045532 DOI: 10.1093/ajh/hpv080] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 05/05/2015] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Pulsatile blood pressure rises with age, especially in the aorta. The comparative role of forward and reflected pressure waves (FW and RW, respectively), determined by aortic flow triangulation has not previously been explored in a large clinical cohort. This study aimed to identify the role of FW and RW in the rise in aortic pulse pressure with age. METHODS For 879 outpatients, aortic pressure waveforms were generated using a validated generalized transfer function applied to radial pressure waves recorded using applanation tonometry. FW and RW were subsequently determined using aortic flow triangulation. Contributions of FW and RW to rise in aortic pulse pressure with age were determined using multivariate linear regression and product of coefficient mediation analysis, with adjustment for height, weight, heart rate, and mean arterial pressure. Comparisons were made by gender and before and after age 60. RESULTS In subjects aged 60 and below, RW was an important contributor to pulsatile pressure elevation with age, but FW was non-contributory in either gender after multivariate correction. In subjects aged above 60, both FW and RW were significant and equal contributors in both genders. CONCLUSIONS In a clinical setting, both FW and RW are important to pulsatile aortic blood pressure across the lifespan, but RW appears to have a more pronounced effect across all ages, whereas FW has less effect in younger persons.
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Affiliation(s)
- Mayooran Namasivayam
- Department of Cardiology, St. Vincent's Hospital and Clinic, Sydney, Australia; Faculty of Medicine, University of New South Wales, Sydney Australia; Vascular-Ventricular Interactions Laboratory, Cardiac Physiology and Transplantation Division, Victor Chang Cardiac Research Institute, Sydney, Australia
| | - Audrey Adji
- Department of Cardiology, St. Vincent's Hospital and Clinic, Sydney, Australia; Vascular-Ventricular Interactions Laboratory, Cardiac Physiology and Transplantation Division, Victor Chang Cardiac Research Institute, Sydney, Australia; Australian School of Advanced Medicine, Macquarie University, Sydney, Australia
| | - Michael F O'Rourke
- Department of Cardiology, St. Vincent's Hospital and Clinic, Sydney, Australia; Faculty of Medicine, University of New South Wales, Sydney Australia; Vascular-Ventricular Interactions Laboratory, Cardiac Physiology and Transplantation Division, Victor Chang Cardiac Research Institute, Sydney, Australia;
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8
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Bensalah MZ, Bollache E, Kachenoura N, Giron A, De Cesare A, Macron L, Lefort M, Redheuill A, Mousseaux E. Geometry is a major determinant of flow reversal in proximal aorta. Am J Physiol Heart Circ Physiol 2014; 306:H1408-16. [DOI: 10.1152/ajpheart.00647.2013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study is to quantify aortic backward flow (BF) using phase-contrast cardiovascular magnetic resonance (PC-CMR) and to study its associations with age, indexes of arterial stiffness, and geometry. Although PC-CMR blood flow studies showed a simultaneous presence of BF and forward flow (FF) in the ascending aorta (AA), the relationship between aortic flows and aging as well as arterial stiffness and geometry in healthy volunteers has never been reported. We studied 96 healthy subjects [47 women, 39 ± 15 yr old (19–79 yr)]. Aortic stiffness [arch pulse wave velocity (PWVAO), AA distensibility], geometry (AA diameter and arch length), and parameters related to AA BF and FF (volumes, peaks, and onset times) were estimated from CMR. Applanation tonometry carotid-femoral pulse-wave velocity (PWVCF), carotid augmentation index, and time to return of the reflected pressure wave were assessed. Whereas FF parameters remained unchanged, BF onset time shortened significantly ( R2 = 0.18, P < 0.0001) and BF volume and BF-to-FF peaks ratio increased significantly ( R2 = 0.38 and R2 = 0.44, respectively, P < 0.0001) with aging. These two latter BF indexes were also related to stiffness indexes (PWVCF, R2 > 0.30; PWVAO, R2 > 0.24; and distensibility, R2 > 0.20, P < 0.001), augmentation index ( R2 > 0.20, P < 0.001), and aortic geometry (AA diameter, R2 > 0.58; and arch length, R2 > 0.31, P < 0.001). In multivariate analysis, aortic diameter was the strongest independent correlate of BF beyond age effect. In conclusion, AA BF estimated using PC-CMR increased significantly in terms of magnitude and volume and appeared earlier with aging and was mostly determined by aortic geometry. Thus BF indexes could be relevant markers of subclinical arterial wall alterations.
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Affiliation(s)
- Mourad Z. Bensalah
- Sorbonne Universités, UPMC/Université Paris 06, UMR 7371, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- Inserm, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- CNRS, UMR 7371, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France; and
- Hôpital Européen Georges Pompidou, Inserm, UMR 970, Université Paris Descartes and Assistance Publique Hôpitaux de Paris, Cardiovascular Imaging Department, Paris, France
| | - Emilie Bollache
- Sorbonne Universités, UPMC/Université Paris 06, UMR 7371, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- Inserm, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- CNRS, UMR 7371, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France; and
| | - Nadjia Kachenoura
- Sorbonne Universités, UPMC/Université Paris 06, UMR 7371, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- Inserm, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- CNRS, UMR 7371, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France; and
| | - Alain Giron
- Sorbonne Universités, UPMC/Université Paris 06, UMR 7371, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- Inserm, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- CNRS, UMR 7371, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France; and
| | - Alain De Cesare
- Sorbonne Universités, UPMC/Université Paris 06, UMR 7371, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- Inserm, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- CNRS, UMR 7371, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France; and
| | - Laurent Macron
- Hôpital Européen Georges Pompidou, Inserm, UMR 970, Université Paris Descartes and Assistance Publique Hôpitaux de Paris, Cardiovascular Imaging Department, Paris, France
| | - Muriel Lefort
- Sorbonne Universités, UPMC/Université Paris 06, UMR 7371, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- Inserm, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- CNRS, UMR 7371, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France; and
| | - Alban Redheuill
- Sorbonne Universités, UPMC/Université Paris 06, UMR 7371, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- Inserm, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- CNRS, UMR 7371, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France; and
| | - Elie Mousseaux
- Sorbonne Universités, UPMC/Université Paris 06, UMR 7371, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- Inserm, UMR S 1146, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France
- CNRS, UMR 7371, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France; and
- Hôpital Européen Georges Pompidou, Inserm, UMR 970, Université Paris Descartes and Assistance Publique Hôpitaux de Paris, Cardiovascular Imaging Department, Paris, France
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9
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Abstract
Current guidelines on isolated systolic hypertension (ISH) suggest the same treatment to patients of all ages. Application of these guidelines in youth with ISH may not be appropriate, as presently no data show adverse outcome or benefit of drug therapy in this group. Simple noninvasive tonometric techniques now enable physicians to measure the central aortic pressure waveform and amplification of the pressure pulse. ISH in youth is usually caused by high amplification of the central pressure wave, whereas ISH in the elderly (>age 60) is attributable to aortic stiffening. This is the only group with ISH shown to have an adverse prognosis and to warrant drug therapy.
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10
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Hashimoto J, Ito S. Aortic stiffness determines diastolic blood flow reversal in the descending thoracic aorta: potential implication for retrograde embolic stroke in hypertension. Hypertension 2013; 62:542-9. [PMID: 23798349 DOI: 10.1161/hypertensionaha.113.01318] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Aortic stiffening often precedes cardiovascular diseases, including stroke, but the underlying pathophysiological mechanisms remain obscure. We hypothesized that such abnormalities could be attributable to altered central blood flow dynamics. In 296 patients with uncomplicated hypertension, Doppler velocity pulse waveforms were recorded at the proximal descending aorta and carotid artery to calculate the reverse/forward flow ratio and diastolic/systolic flow index, respectively. Tonometric waveforms were recorded on the radial artery to estimate aortic pressure and characteristic impedance (Z0) and to determine carotid-femoral (aortic) and carotid-radial (peripheral) pulse wave velocities. In all subjects, the aortic flow waveform was bidirectional, comprising systolic forward and diastolic reverse flows. The aortic reverse/forward flow ratio (35 ± 10%) was positively associated with parameters of aortic stiffness (including pulse wave velocity, Z0, and aortic/peripheral pulse wave velocity ratio), independent of age, body mass index, aortic diameter, and aortic pressure. The carotid flow waveform was unidirectional and bimodal with systolic and diastolic maximal peaks. There was a positive relationship between the carotid diastolic/systolic flow index (28 ± 9%) and aortic reverse/forward flow ratio, which remained significant after adjustment for aortic stiffness and other related parameters. The Bland-Altman plots showed a close time correspondence between aortic reverse and carotid diastolic flow peaks. In conclusion, aortic stiffness determines the extent of flow reversal from the descending aorta to the aortic arch, which contributes to the diastolic antegrade flow into the carotid artery. This hemodynamic relationship constitutes a potential mechanism linking increased aortic stiffness, altered flow dynamics, and increased stroke risk in hypertension.
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Affiliation(s)
- Junichiro Hashimoto
- Department of Blood Pressure Research, Tohoku University Graduate School of Medicine, 1-1 Seiryo-cho, Aoba-ku, Sendai 980-8574, Japan.
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11
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Hypertension and Vascular Dynamics in Men and Women With Metabolic Syndrome. J Am Coll Cardiol 2013; 61:12-9. [DOI: 10.1016/j.jacc.2012.01.088] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 01/18/2012] [Accepted: 01/23/2012] [Indexed: 11/22/2022]
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12
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Adji A, O'Rourke MF, Namasivayam M. Arterial stiffness, its assessment, prognostic value, and implications for treatment. Am J Hypertens 2011; 24:5-17. [PMID: 20940710 DOI: 10.1038/ajh.2010.192] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Arterial stiffness has been known as a sign of cardiovascular risk since the 19th century. Despite this, accurate measurement and clinical utility have only emerged in recent times. Arterial stiffness and its hemodynamic consequences are now established as predictors of adverse cardiovascular outcome. They are easily and reliably measured using a range of noninvasive techniques, which can be used readily by risk assessment facilities or individual practitioners. The techniques described in this review are based on the pulsatility of the cardiovascular system, utilizing the timing of pulse travel along major arteries and the magnitude of wave reflection. These have enabled better understanding of the ill effects of arterial stiffening, not only on large arteries and the left ventricle, but also on tiny arteries in highly perfused organs such as brain and kidneys. Treatment options, which directly target the consequences of arterial stiffening, as opposed to arbitrary reduction of brachial blood pressure, have proved clinical superiority; optimal therapy entails use of angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, and calcium-channel blockers, as well as vasodilating β-blockers. Arterial stiffness will undoubtedly contribute to cardiovascular assessment and management in future clinical practice. Reviews such as this will hopefully increase awareness of the mounting evidence underlying this transition, and the relevant theory and methodology. As we begin the second decade of the 21st century, we are finally collectively coming to realize what pioneers such as Osler, Roy, Bramwell and Hill foresaw in the 19th and 20th centuries.
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13
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Namasivayam M, Adji A, O'Rourke MF. Aortic Augmentation Index and Aging: Mathematical Resolution of a Physiological Dilemma? Hypertension 2010; 56:e9-10. [DOI: 10.1161/hypertensionaha.110.153742] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Mayooran Namasivayam
- Department of Cardiology, St. Vincent’s Clinic, Sydney, Australia, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Audrey Adji
- Department of Cardiology, St. Vincent’s Clinic, Sydney, Australia, Australian School of Advanced Medicine, Sydney, Australia
| | - Michael F. O'Rourke
- Department of Cardiology, St. Vincent’s Clinic, Sydney, Australia, Faculty of Medicine, University of New South Wales, Sydney, Australia, Victor Chang Cardiac Research Institute, Sydney, Australia
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14
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Antihypertensive therapy and central hemodynamics in women with hypertensive disorders in pregnancy. Obstet Gynecol 2009; 113:646-654. [PMID: 19300330 DOI: 10.1097/aog.0b013e318197c392] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To estimate the changes in central hemodynamics features of pregnant women presenting with hypertensive disorders and to analyze the effects of standard antihypertensive treatment on maternal central hemodynamics. METHODS Applanation tonometry was used to record the radial artery pulse waveform in 80 women presenting with preeclampsia or gestational hypertension and 80 normotensive controls matched for gestational age. In each case, an averaged aortic waveform was derived and analyzed to calculate augmentation pressure and augmentation index at heart rate 75 beats per minute (bpm). RESULTS In women with preeclampsia and gestational hypertension, both augmentation pressure (P<.001 and P<.05, respectively) and augmentation index at heart rate 75 bpm (P<.001 and P<.001, respectively) were significantly higher than in controls. Augmentation pressure and augmentation index at heart rate 75 bpm were significantly higher in early- compared with late-onset preeclampsia (P<.001) and in severe compared with mild preeclampsia (P<.001). Antihypertensive therapy with alpha methyldopa resulted in a significant fall in both augmentation pressure and augmentation index at heart rate 75 bpm in preeclampsia (P<.001) but not in gestational hypertension. CONCLUSION Arterial stiffness is increased in women with hypertensive disorders of pregnancy compared with normotensive controls. In preeclampsia, vascular stiffness was significantly improved by antihypertensive treatment with alpha methyldopa, but remained higher than in normotensive controls.
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15
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Matsui Y, Ishikawa J, Eguchi K, Hoshide S, Miyashita H, Shimada K, Kario K. The influence of wave reflection on left ventricular hypertrophy in hypertensive patients is modified by age and gender. Hypertens Res 2008; 31:649-56. [PMID: 18633176 DOI: 10.1291/hypres.31.649] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
It has been established that a positive association exists between the augmentation index (AIx) and left ventricular mass (LVM) in hypertensives, but it remains unclear whether this association is affected by age or gender. The aim of the study was to assess the effect of age and gender on the association between carotid AIx and LVM in hypertensive patients. We performed arterial tonometry and echocardiography in 512 treated hypertensive patients who were divided into 4 groups by gender and age (older or younger than 65 years). Correlations between carotid AIx and echocardiographic indices were evaluated by univariable and multivariable models. In females, carotid AIx increased with age up to 60 years, but decreased thereafter. In univariable analyses, carotid AIx was positively correlated with the LVM index in younger females (r=0.25, p=0.04) and males (r=0.48, p<0.001), but not in the older age groups. Multivariable analyses showed that this positive correlation in younger males remained significant (beta=0.39, p<0.001) after adjusting for age, body mass index, and mean arterial pressure. In contrast, in the older subjects, carotid AIx was negatively correlated with relative wall thickness in females (beta= -0.14, p=0.034) and males (beta= -0.17, p=0.037) independent of age and mean arterial pressure. A significant association between carotid AIx and LVM index was seen only in younger males. The lack of any such association in older hypertensives can be explained by both the plateau in the values of carotid AIx, and the fact that LVM increased with age.
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Affiliation(s)
- Yoshio Matsui
- Division of Cardiovascular Medicine, Jichi Medical University School of Medicine, Shimotsuke, Japan.
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16
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O’Rourke MF. Time domain analysis of the arterial pulse in clinical medicine. Med Biol Eng Comput 2008; 47:119-29. [DOI: 10.1007/s11517-008-0370-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2008] [Accepted: 06/24/2008] [Indexed: 10/21/2022]
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17
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Ho PC. The pulsewave reflections model: Exploring for a fundamental mechanism of cardiovascular calcification. Med Hypotheses 2007; 69:792-9. [PMID: 17391863 DOI: 10.1016/j.mehy.2006.12.059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Accepted: 12/19/2006] [Indexed: 12/28/2022]
Abstract
Cardiovascular calcification occurs in a variety of location and structure in the heart and the vasculature. Many hypotheses exist in describing local phenomena, however, there is no known global and unifying mechanism to explain all types of cardiovascular soft tissue calcification. The observed calcific changes in the cardiovascular system, however, does have a general pattern of occurring at structurally altered sites either due to disease processes or surgical manipulations. Areas of structural alterations, in conjunction with the pulsatile environment of the cardiovascular system, have been shown to disrupt normal pulsewave transmission throughout the arterial tree and induce local junctional or interfacial stress gradients. As such, these induced stress gradients can potentially aggregate and deposit cellular products and ionic particles at local sites to initiate calcification. A fundamental mechanism influencing all cardiovascular calcification is proposed based on pathophysiologic pulsewave propagations and reflections at these sites of structural changes. Initial supporting results of the theoretical model and experimentations are discussed leading to a call for future research in this direction.
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Affiliation(s)
- Paul C Ho
- Division of Cardiology, Hawaii Region Kaiser Permanente, Kaiser Foundation Hospital, 3288 Moanalua Road, Honolulu, HI 96819, USA.
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18
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Hirata K, Kawakami M, O'Rourke MF. Pulse wave analysis and pulse wave velocity: a review of blood pressure interpretation 100 years after Korotkov. Circ J 2006; 70:1231-9. [PMID: 16998252 DOI: 10.1253/circj.70.1231] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The pulsatile component of blood pressure (ie, pulse pressure) has received considerable attention as an important risk factor for cardiovascular disease. In particular, central blood pressure measurements in the ascending aorta or in the carotid artery are expected to be more useful than conventional brachial pressure measurements for predicting cardiovascular events because central pressure, not the brachial pressure, is the pressure that target organs encounter. Due to wave reflection, the blood pressure in the upper limb does not represent the central blood pressure; therefore, leading researchers have enthusiastically promoted a noninvasive method of measuring central blood pressure and the resulting aortic stiffness. Until now, there has been an increasing body of evidence to support the accuracy and superiority of central blood pressure measurements as well as the assessment of aortic properties over classical brachial pressure measurements. In this review, the information regarding these "central" indices derived from 2 main methods, namely "pulse wave analysis" and "pulse wave velocity", for the application of central blood pressure measurements and arterial stiffness to clinical study and practice, has been summarized.
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Affiliation(s)
- Kozo Hirata
- Department of Internal Medicine, Jichi Medical University Omiya Medical Center, Saitama, Japan.
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19
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Affiliation(s)
- Michael F O'Rourke
- University of New South Wales, Medical Professional Unit, St Vincent's Hospital, Darlinghurst, Australia.
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20
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Ho PC, Melbin J, Nesto RW. Scholarly review of geometry and compliance: biomechanical perspectives on vascular injury and healing. ASAIO J 2002; 48:337-45. [PMID: 12141460 DOI: 10.1097/00002480-200207000-00002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Mechanical stress and strain upon cardiovascular tissue are important factors that influence the ultimate configuration of clinically observed disease entities. Although mechanical forces can stimulate cellular changes and response, structural or geometric alterations introduced by disease processes can, in turn, influence local hemodynamic conditions. Dynamic interactions of structural parameters, such as arterial compliance and geometry, can further contribute to the final determination of the mechanical conditions and outcome of the vessel. Manipulation of vascular compliance and geometry may, therefore, have desirable effects. In this article, fundamental vascular biomechanical forces are defined and their association with cellular response and clinical disease processes are introduced. The interplay between vascular geometry and compliance is emphasized, and the potential for mechanical solutions to vascular diseases are explored.
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Affiliation(s)
- Paul C Ho
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
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21
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Huisman HW, Van Rooyen JM, Malan NT, Eloff FC, Laubscher PJ, Steyn HS, Pretorius PJ. Cardiovascular reactivity patterns elicited by the cold pressor test as a function of aging. Aging Clin Exp Res 2002; 14:202-7. [PMID: 12387528 DOI: 10.1007/bf03324437] [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: 01/19/2023]
Abstract
BACKGROUND AND AIMS The cold pressor test has been widely used in previous cardiovascular reactivity studies as a predictor of hypertension. However, the influence of the physical adaptations of the arterial wall with increasing age on reactivity has not been delineated. METHODS 64 men divided into 5 different age groups participated in a laboratory protocol consisting of submerging one hand in ice water for one minute while changes in blood pressure were continuously measured. RESULTS The results indicated that with increasing age, the systolic blood pressure change, especially the rate of change (slope) is more pronounced than changes in diastolic blood pressure. CONCLUSIONS With increasing age, there is a shift from a diastolic blood pressure reactivity pattern to a more systolic blood pressure reactivity pattern during application of the cold pressor test. This could be ascribed to a decrease in arterial compliance.
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Affiliation(s)
- Hugo W Huisman
- Department of Physiology, Potchefstroom University for Christian Higher Education, South Africa.
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22
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O'Rourke MF, Pauca A, Jiang XJ. Pulse wave analysis. Br J Clin Pharmacol 2001; 51:507-22. [PMID: 11422010 PMCID: PMC2014492 DOI: 10.1046/j.0306-5251.2001.01400.x] [Citation(s) in RCA: 350] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2000] [Accepted: 03/01/2001] [Indexed: 11/20/2022] Open
Affiliation(s)
- M F O'Rourke
- UNSW, St Vincent's Clinic, Sydney, NSW 2010, Australia.
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23
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Nichols WW, Edwards DG. Arterial elastance and wave reflection augmentation of systolic blood pressure: deleterious effects and implications for therapy. J Cardiovasc Pharmacol Ther 2001; 6:5-21. [PMID: 11452332 DOI: 10.1177/107424840100600102] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Systolic and pulse blood pressures are stronger predictors of stroke, coronary heart disease, myocardial infarction, heart failure, end-stage renal disease, and cardiovascular mortality than diastolic pressure. Furthermore, diastolic pressure is inversely related to coronary heart disease and cardiovascular mortality. Increased elastance (or stiffness, inverse of compliance) of the central elastic arteries is the primary cause of increased systolic and pulse pressure with advancing age and in patients with cardiovascular disease, including hypertension, and is due to degeneration and hyperplasia of the arterial wall; diastolic pressure decreases as arterial elastance increases. As elastance increases, transmission velocity of both forward and backward (or reflected) traveling waves increases, which causes the reflected wave to arrive earlier in the central aorta and augments pressure in late systole. These changes in arterial wall properties cause an increase in left ventricular afterload and myocardial oxygen consumption and a decrease in myocardial perfusion pressure, which may induce an imbalance in the supply-demand ratio, especially in hypertrophied hearts with coronary artery disease. Also, an increase in systolic pressure increases arterial wall circumferential stress, which promotes fatigue and development of atherosclerosis. Vasodilator drugs have little direct active effect on large elastic arteries but can markedly reduce wave reflection amplitude and augmentation index by decreasing elastance of the muscular arteries and reducing pulse wave velocity of the reflected wave from the periphery to the heart. This decrease in intensity (or amplitude) and increase in travel time (or delay) of the reflected wave causes a generalized decrease in systolic pressure and arterial wall stress and an increase in ascending aortic flow during the deceleration phase. The decrease in systolic pressure brought about by this mechanism is grossly underestimated when systolic pressure is measured in the brachial artery.
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Affiliation(s)
- W W Nichols
- Department of Medicine, University of Florida College of Medicine, Gainesville, FL 32610, USA
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24
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Miyashita H, Sugimachi M, Sato T, Kawada T, Shishido T, Nakahara T, Yoshimura R, Takaki H, Miyano H, Sunagawa K. A novel servo-control system that imposes desired aortic input impedance on in situ rat heart. Am J Physiol Heart Circ Physiol 2000; 278:H998-H1007. [PMID: 10710370 DOI: 10.1152/ajpheart.2000.278.3.h998] [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: 11/22/2022]
Abstract
To clarify the pathophysiological role of dynamic arterial properties in cardiovascular diseases, we attempted to develop a new control system that imposes desired aortic impedance on in situ rat left ventricle. In 38 anesthetized open-chest rats, ascending aortic pressure and flow waveforms were continuously sampled (1,000 Hz). Desired flow waveforms were calculated from measured aortic pressure waveforms and target impedance. To minimize the difference between measured and desired aortic flow waveforms, the computer generated commands to the servo-pump, connected to a side branch of the aorta. By iterating the process, we could successfully control aortic impedance in such a way as to manipulate compliance and characteristic impedance between 60 and 160% of their respective native values. The error between desired and measured aortic flow waveforms was 70 +/- 34 microl/s (root mean square; 4.4 +/- 1.4% of peak flow), indicating reasonable accuracy in controlling aortic impedance. This system enables us to examine the importance of dynamic arterial properties independently of other hemodynamic and neurohumoral factors in physiological and clinical settings.
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Affiliation(s)
- H Miyashita
- Department of Cardiovascular Dynamics, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
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25
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Abstract
1. The conventional approach to drug therapy of hypertension and heart failure considers only effects of such drugs on peripheral resistance, cardiac output and heart rate. 2. A more complete approach needs to consider the pulsatile nature of cardiac ejection and so the influence of arterial stiffness and wave reflection properties and the effects of drugs on these. 3. Wave reflection normally aids cardiac function when full body height is achieved and arterial distensibility is high. However, with ageing or in hypertension the arteries stiffen and wave reflection returns early, augmenting systolic pressure, increasing pulse pressure and reducing the capacity for coronary perfusion. 4. In mature or older adults, delay of or reduction in wave reflection is an important therapeutic strategy for management of hypertension, angina pectoris and cardiac failure. 5. Beneficial effects of such therapy cannot always be gauged from conventional recordings of blood pressure, but can be inferred from analysis of pulse waveform.
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Affiliation(s)
- M F O'Rourke
- Medical Professorial Unit, St Vincent's Hospital, Darlinghurst, New South Wales, Australia
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26
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Kim SY, Euler DE, Jacobs WR, Montoya A, Sullivan HJ, Lonchyna VA, Pifarré R. Arterial impedance in patients during intraaortic balloon counterpulsation. Ann Thorac Surg 1996; 61:888-94. [PMID: 8619712 DOI: 10.1016/0003-4975(95)01168-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Symptomatic improvement of a patient's hemodynamic condition during intraaortic balloon counterpulsation (IABC) is considered to result largely from a reduction in afterload. Afterload can be accurately quantified by arterial input impedance measurements. Here we report the effect of IABC on arterial impedance in humans. METHODS To characterize the effects of IABC on arterial input impedance, impedance measurements were obtained using aortic annulus Doppler flow and pressure from the aortic balloon catheter. Impedance spectra were compared between the cardiac cycles preceding and following the cycle with IABC in 25 patients. RESULTS Intraaortic balloon counterpulsation increased stroke volume (23%; p = 0.001), reduced myocardial oxygen demand (11%; p = 0.02), and decreased the aortic pressure at the onset of systole (16%; p = 0.001). There was also a decrease in systemic vascular resistance (24%; p = 0.001), characteristic arterial impedance (21%; p = 0.002), and pulse wave reflection (20%; p = 0.006). Linear regression analysis showed that an increase in stroke volume was predicted only by the decrease in systemic vascular resistance (r = -0.81; p = 0.001). CONCLUSIONS The reduction in systemic vascular resistance appeared to be the major mechanism by which IABC improved cardiac pumping efficiency. This effect may result from the passive distention of the peripheral vascular bed due to the propagation of the balloon-augmented diastolic pressure through the arterial system.
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Affiliation(s)
- S Y Kim
- Department of Thoracic and Cardiovascular Surgery, Loyola University Medical Center, Maywood, Illinois 60153, USA
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27
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Chen CH, Ting CT, Nussbacher A, Nevo E, Kass DA, Pak P, Wang SP, Chang MS, Yin FC. Validation of carotid artery tonometry as a means of estimating augmentation index of ascending aortic pressure. Hypertension 1996; 27:168-75. [PMID: 8567037 DOI: 10.1161/01.hyp.27.2.168] [Citation(s) in RCA: 251] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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 United 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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Affiliation(s)
- C H Chen
- Department of Medicine, Veterans General Hospital-Taipei, Republic of China
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28
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Ting CT, Chen CH, Chang MS, Yin FC. Short- and long-term effects of antihypertensive drugs on arterial reflections, compliance, and impedance. Hypertension 1995; 26:524-30. [PMID: 7649593 DOI: 10.1161/01.hyp.26.3.524] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This article reviews our work on the effects of different classes of antihypertensive agents on the hemodynamic alterations in essential human hypertension. Short-term studies were done during cardiac catheterization in young normotensive subjects (mean age, 33 years; range, 19 to 40) and several different age-matched (range, 25 to 53 years) groups of patients with essential hypertension. Aortic impedance, resistance, wave reflections, and compliance were calculated from high-fidelity recordings of ascending aortic pressure and flow signals during baseline and after nitroprusside, propranolol followed by phentolamine, phentolamine, captopril, and nifedipine, respectively, at doses sufficient to normalize blood pressure in each hypertensive group. Propranolol exacerbated all the hemodynamic parameters; these effects were only partially overcome by phentolamine. Among the other agents only phentolamine did not completely normalize compliance, and only captopril did not completely normalize wave reflections. The long-term study was a randomized, double-blind comparison of fosinopril and atenolol in 79 normotensive subjects and 79 essential hypertensive patients. Baseline 24-hour ambulatory blood pressures and carotid artery tonometry to index wave reflections were performed in all subjects and in hypertensive patients after 8 weeks of therapy. Both fosinopril and atenolol normalized blood pressure and lowered the elevated augmentation index, but fosinopril had a significantly larger effect than atenolol. Both short- and long-term beta-blockade did not have as beneficial an effect as the other agents. Thus, the differing hemodynamic effects of the various classes of antihypertensive agents might be a consideration in the choice of therapy.
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Affiliation(s)
- C T Ting
- Veterans General Hospital, Taichung, Taipei, Taiwan
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Miyashita H, Ikeda U, Irokawa M, Yaginuma T, Shimada K. Importance of aortic wave reflections in age-associated central blood pressure changes in nonhypertensive humans. J Am Geriatr Soc 1995; 43:1069-70. [PMID: 7657931 DOI: 10.1111/j.1532-5415.1995.tb05584.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Chen CH, Ting CT, Lin SJ, Hsu TL, Yin FC, Siu CO, Chou P, Wang SP, Chang MS. Different effects of fosinopril and atenolol on wave reflections in hypertensive patients. Hypertension 1995; 25:1034-41. [PMID: 7737712 DOI: 10.1161/01.hyp.25.5.1034] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We conducted this study to compare the effects of fosinopril versus atenolol on peripheral blood pressure, central arterial wave reflection, and left ventricular mass in a group of patients with essential hypertension. We conducted a double-blind, randomized trial of fosinopril and atenolol in 79 hypertensive patients (52 men, 27 women; mean age, 45.8 +/- 8.5 years; range, 30 to 68 years). Carotid pressure waveforms were recorded noninvasively by applanation tonometry with a Millar micromanometer-tipped probe. The extent of wave reflection was estimated by the augmentation index defined as the ratio of the amplitude of pressure wave above its systolic shoulder to the pulse pressure. The augmentation index, left ventricular mass index by two-dimensional echocardiography, and 24-hour ambulatory blood pressures were determined before and after 8 weeks of daily treatment with fosinopril (10 to 20 mg) or atenolol (50 to 100 mg) with or without diuretics and compared with those values in 79 normotensive control subjects. After 8 weeks of treatment, both drugs lowered 24-hour ambulatory peripheral systolic and diastolic pressures into the normal range to a similar extent (fosinopril, -18/-13 mm Hg; atenolol, -23/-17 mm Hg, both P = NS). On the other hand, whereas the elevated augmentation index in hypertensive patients compared with normotensive subjects (16 +/- 11% versus 10 +/- 8%) was completely normalized by fosinopril (-9.3 +/- 9.8%, P < or = .002), it was lowered by atenolol (-4.8 +/- 8.9%, P < .002) but to a significantly smaller extent (fosinopril versus atenolol effect, P = .04).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- C H Chen
- Division of Cardiology, Veterans General Hospital-Taipei, Shih-Pai, Taiwan, ROC
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