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Abstract
OBJECTIVES Hypertension leads to aortic stiffening and dilatation but unexpected data from the Framingham Heart Study showed an inverse relationship between brachial pulse pressure and aortic diameter. Aortic dilatation would not only lead to lower pulse pressure but also to a worse prognosis (cardiac events, heart failure). Invasive pressure may be more informative but data are lacking. AIM This study evaluated the relationship between invasively measured central blood pressure and proximal aortic diameter. METHODS In 71 consecutive patients referred to invasive haemodynamic study, proximal aortic remodelling was evaluated in terms of Z-score, comparing diameters measured at the sinus of Valsalva to the diameter expected according to patients' age, sex and body height. Pressures were recorded directly in the proximal aorta by means of a catheter before coronary assessment. RESULTS The mean invasive aortic SBPs and DBPs were 146 ± 23 and 78 ± 13 mmHg, respectively, giving a central pulse pressure (cPP inv) of 68 ± 21 mmHg. Proximal aortic diameter was 34.9 ± 19.4 mm, whereas Z-score was -0.3 ± 1.7. Patients with higher cPPinv showed a significantly lower Z-score (-0.789 vs. 0.155, P = 0.001). cPPinv was inversely related to Z-score (R = -0.271, P = 0.022) independently from age, mean blood pressure and heart rate (β = -0.241, P = 0.011). CONCLUSION Aortic root Z-score is inversely associated with invasively measured central pulse pressure in a cohort of patients undergoing invasive coronary assessment. Remodelling at the sinuses of Valsalva may be a compensatory mechanism to limit pulse pressure.
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Gallo C, Ridolfi L, Scarsoglio S. Cardiovascular deconditioning during long-term spaceflight through multiscale modeling. NPJ Microgravity 2020; 6:27. [PMID: 33083524 PMCID: PMC7529778 DOI: 10.1038/s41526-020-00117-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 08/10/2020] [Indexed: 12/20/2022] Open
Abstract
Human spaceflight has been fascinating man for centuries, representing the intangible need to explore the unknown, challenge new frontiers, advance technology, and push scientific boundaries further. A key area of importance is cardiovascular deconditioning, that is, the collection of hemodynamic changes-from blood volume shift and reduction to altered cardiac function-induced by sustained presence in microgravity. A thorough grasp of the 0G adjustment point per se is important from a physiological viewpoint and fundamental for astronauts' safety and physical capability on long spaceflights. However, hemodynamic details of cardiovascular deconditioning are incomplete, inconsistent, and poorly measured to date; thus a computational approach can be quite valuable. We present a validated 1D-0D multiscale model to study the cardiovascular response to long-term 0G spaceflight in comparison to the 1G supine reference condition. Cardiac work, oxygen consumption, and contractility indexes, as well as central mean and pulse pressures were reduced, augmenting the cardiac deconditioning scenario. Exercise tolerance of a spaceflight traveler was found to be comparable to an untrained person with a sedentary lifestyle. At the capillary-venous level significant waveform alterations were observed which can modify the regular perfusion and average nutrient supply at the cellular level. The present study suggests special attention should be paid to future long spaceflights which demand prompt physical capacity at the time of restoration of partial gravity (e.g., Moon/Mars landing). Since spaceflight deconditioning has features similar to accelerated aging understanding deconditioning mechanisms in microgravity are also relevant to the understanding of aging physiology on the Earth.
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Affiliation(s)
- Caterina Gallo
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy
| | - Luca Ridolfi
- Department of Environmental, Land and Infrastructure Engineering, Politecnico di Torino, Torino, Italy
| | - Stefania Scarsoglio
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy
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Bikia V, Pagoulatou S, Trachet B, Soulis D, Protogerou AD, Papaioannou TG, Stergiopulos N. Noninvasive Cardiac Output and Central Systolic Pressure From Cuff-Pressure and Pulse Wave Velocity. IEEE J Biomed Health Inform 2019; 24:1968-1981. [PMID: 31796418 DOI: 10.1109/jbhi.2019.2956604] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
GOAL We introduce a novel approach to estimate cardiac output (CO) and central systolic blood pressure (cSBP) from noninvasive measurements of peripheral cuff-pressure and carotid-to-femoral pulse wave velocity (cf-PWV). METHODS The adjustment of a previously validated one-dimensional arterial tree model is achieved via an optimization process. In the optimization loop, compliance and resistance of the generic arterial tree model as well as aortic flow are adjusted so that simulated brachial systolic and diastolic pressures and cf-PWV converge towards the measured brachial systolic and diastolic pressures and cf-PWV. The process is repeated until full convergence in terms of both brachial pressures and cf-PWV is reached. To assess the accuracy of the proposed framework, we implemented the algorithm on in vivo anonymized data from 20 subjects and compared the method-derived estimates of CO and cSBP to patient-specific measurements obtained with Mobil-O-Graph apparatus (central pressure) and two-dimensional transthoracic echocardiography (aortic blood flow). RESULTS Both CO and cSBP estimates were found to be in good agreement with the reference values achieving an RMSE of 0.36 L/min and 2.46 mmHg, respectively. Low biases were reported, namely -0.04 ± 0.36 L/min for CO predictions and -0.27 ± 2.51 mmHg for cSBP predictions. SIGNIFICANCE Our one-dimensional model can be successfully "tuned" to partially patient-specific standards by using noninvasive, easily obtained peripheral measurement data. The in vivo evaluation demonstrated that this method can potentially be used to obtain central aortic hemodynamic parameters in a noninvasive and accurate way.
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Pagoulatou SZ, Bikia V, Trachet B, Papaioannou TG, Protogerou AD, Stergiopulos N. On the importance of the nonuniform aortic stiffening in the hemodynamics of physiological aging. Am J Physiol Heart Circ Physiol 2019; 317:H1125-H1133. [DOI: 10.1152/ajpheart.00193.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mathematical models of the arterial tree constitute a valuable tool to investigate the hemodynamics of aging and pathology. Rendering such models as patient specific could allow for the assessment of central hemodynamic variables of clinical interest. However, this task is challenging, particularly with respect to the tuning of the local area compliance that varies significantly along the arterial tree. Accordingly, in this study, we demonstrate the importance of taking into account the differential effects of aging on the stiffness of central and peripheral arteries when simulating a person’s hemodynamic profile. More specifically, we propose a simple method for effectively adapting the properties of a generic one-dimensional model of the arterial tree based on the subject’s age and noninvasive measurements of aortic flow and brachial pressure. A key element for the success of the method is the implementation of different mechanisms of arterial stiffening for young and old individuals. The designed methodology was tested and validated against in vivo data from a population of n = 20 adults. Carotid-to-femoral pulse wave velocity was accurately predicted by the model (mean error = 0.14 m/s, SD = 0.77 m/s), with the greatest deviations being observed for older subjects. In regard to aortic pressure, model-derived systolic blood pressure and augmentation index were both in good agreement (mean difference of 2.3 mmHg and 4.25%, respectively) with the predictions of a widely used commercial device (Mobil-O-Graph). These preliminary results encourage us to further validate the method in larger samples and consider its potential as a noninvasive tool for hemodynamic monitoring. NEW & NOTEWORTHY We propose a technique for adapting the parameters of a validated one-dimensional model of the arterial tree using noninvasive measurements of aortic flow and brachial pressure. Emphasis is given on the adjustment of the arterial tree distensibility, which incorporates the nonuniform effects of aging on central and peripheral vessel elasticity. Our method could find application in the derivation of important hemodynamic indices, paving the way for novel diagnostic tools.
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Affiliation(s)
- Stamatia Z. Pagoulatou
- Laboratory of Hemodynamics and Cardiovascular Technology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Vasiliki Bikia
- Laboratory of Hemodynamics and Cardiovascular Technology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Bram Trachet
- Laboratory of Hemodynamics and Cardiovascular Technology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Institute of Biomedical Technology, IBiTech-bioMMeda, Ghent University, Ghent, Belgium
| | - Theodore G. Papaioannou
- Biomedical Engineering Unit, First Department of Cardiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Athanase D. Protogerou
- Cardiovascular Prevention and Research Unit, Department of Pathophysiology, National and Kapodistrian University Athens School of Medicine, Athens, Greece
| | - Nikolaos Stergiopulos
- Laboratory of Hemodynamics and Cardiovascular Technology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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Multiscale mathematical modeling vs. the generalized transfer function approach for aortic pressure estimation: a comparison with invasive data. Hypertens Res 2018; 42:690-698. [PMID: 30531842 DOI: 10.1038/s41440-018-0159-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 10/10/2018] [Accepted: 10/15/2018] [Indexed: 01/11/2023]
Abstract
We aimed to evaluate the performance of a mathematical model and currently available non-invasive techniques (generalized transfer function (GTF) method and brachial pressure) in the estimation of aortic pressure. We also aimed to investigate error dependence on brachial pressure errors, aorta-to-brachial pressure changes and demographic/clinical conditions. Sixty-two patients referred for invasive hemodynamic evaluation were consecutively recruited. Simultaneously, the registration of the aortic pressure using a fluid-filled catheter, brachial pressure and radial tonometric waveform was recorded. Accordingly, the GTF device and mathematical model were set. Radial invasive pressure was recorded soon after aortic measurement. The average invasive aortic pressure was 141.3 ± 20.2/76 ± 12.2 mm Hg. The simultaneous brachial pressure was 144 ± 17.8/81.5 ± 11.7 mm Hg. The GTF-based and model-based aortic pressure estimates were 133.1 ± 17.3/82.4 ± 12 and 137 ± 21.6/72.2 ± 16.7 mm Hg, respectively. The Bland-Altman plots showed a marked tendency to pressure overestimation for increasing absolute values, with the exclusion of mathematical model diastolic estimations. The systolic pressure was increased from the aortic to radial locations (7.5 ± 19 mm Hg), while the diastolic pressure was decreased (3.8 ± 9.8 mm Hg). The brachial pressure underestimated the systolic and overestimated diastolic intra-arterial radial pressure. GTF errors were independently correlated with the variability in pulse pressure amplification and with the brachial error. Errors of the mathematical model were related to only demographic and clinical conditions. Neither a multiscale mathematical model nor a generalized transfer function device substantially outperformed the oscillometric brachial pressure in the estimation of aortic pressure. Mathematical modeling should be improved by including further patient-specific conditions, while the variability in pulse pressure amplification may hamper the performance of the GTF method in patients at the risk of coronary artery disease.
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Non-invasive aortic systolic pressure and pulse wave velocity estimation in a primary care setting: An in silico study. Med Eng Phys 2017; 42:91-98. [PMID: 28236601 DOI: 10.1016/j.medengphy.2017.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 11/30/2016] [Accepted: 02/05/2017] [Indexed: 01/06/2023]
Abstract
Everyday clinical cardiovascular evaluation is still largely based on brachial systolic and diastolic pressures. However, several clinical studies have demonstrated the higher diagnostic capacities of the aortic pressure, as well as the need to assess the aortic mechanical properties (e.g., by measuring the aortic pulse wave velocity). In order to fill this gap, we propose to exploit a set of easy-to-obtain physical characteristics to estimate the aortic pressure and pulse wave velocity. To this aim, a large population of virtual subjects is created by a validated mathematical model of the cardiovascular system. Quadratic regressive models are then fitted and statistically selected in order to obtain reliable estimations of the aortic pressure and pulse wave velocity starting from the knowledge of the subject age, height, weight, brachial pressure, photoplethysmographic measures and either electrocardiogram or phonocardiogram. The results are very encouraging and foster clinical studies aiming to apply a similar technique to a real population.
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Guala A, Leone D, Milan A, Ridolfi L. In silico analysis of the anti-hypertensive drugs impact on myocardial oxygen balance. Biomech Model Mechanobiol 2017; 16:1035-1047. [PMID: 28070737 DOI: 10.1007/s10237-017-0871-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 01/02/2017] [Indexed: 01/09/2023]
Abstract
Hypertension is a very common pathology, and its clinical treatment largely relies on different drugs. Some of these drugs exhibit specific protective functions in addition to those resulting from blood pressure reduction. In this work, we study the impact of commonly used anti-hypertensive drugs (RAAS, [Formula: see text] and calcium channel blockers) on myocardial oxygen supply-consumption balance, which plays a crucial role in type 2 myocardial infarction. To this aim, 42 wash-out hypertensive patients were selected, a number of measured data were used to set a validated multi-scale cardiovascular model to subject-specific conditions, and the administration of different drugs was suitably simulated. Our results ascribe the well-known major cardioprotective efficiency of [Formula: see text] blockers compared to other drugs to a positive change of myocardial oxygen balance due to the concomitant: (1) reduction in aortic systolic, diastolic and pulse pressures, (2) decrease in left ventricular work, diastolic cavity pressure and oxygen consumption, (3) increase in coronary flow and (4) ejection efficiency improvement. RAAS blockers share several positive outcomes with [Formula: see text] blockers, although to a reduced extent. In contrast, calcium channel blockers seem to induce some potentially negative effects on the myocardial oxygen balance.
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Affiliation(s)
- A Guala
- DIATI, Politecnico di Torino, Turin, Italy.
- Vall D'Hebron Institute of Research (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain.
| | - D Leone
- Department of Medical Sciences, Hypertension Unit, University of Torino, Turin, Italy
| | - A Milan
- Department of Medical Sciences, Hypertension Unit, University of Torino, Turin, Italy
| | - L Ridolfi
- DIATI, Politecnico di Torino, Turin, Italy
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Luo JW, Guo SW, Cao SS, Lin N, Ye ZS, Wei SC, Zheng XY, Guo MM, Meng XR, Huang FM. The Construction of Unsmooth Pulse Images in Traditional Chinese Medicine Based on Wave Intensity Technology. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2016; 2016:2468254. [PMID: 27999604 PMCID: PMC5143737 DOI: 10.1155/2016/2468254] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 09/24/2016] [Accepted: 10/04/2016] [Indexed: 11/22/2022]
Abstract
Unsmooth pulse is one of the most important pulses in TCM diagnostics. We constructed the wave intensity (WI) images of unsmooth pulse based on the pressure wave (P), flow velocity wave (U), and WI [(dP/dt)(dU/dt)] by ALOKA Prosound α 10 Color Doppler. The characteristic of Cunkou normal pulse could be summarized as follows: compared to Renying pulse, its W1 amplitude is smaller and NA wave is more obvious, while the W2 wave is indistinct or even invisible, and the R-1st is longer than that of Renying pulse. The principal U wave of Renying pulse looks like "Λ" shape, while it looks like an arched blunt "∩" shape in Cunkou pulse, and the amplitude of U wave in Cunkou pulse is smaller. The direction of the principal U wave in Cunkou unsmooth pulse is up, which shows hoof boots "h" shape with high amplitude and a significant notch on declined branch; the amplitude of predicrotic wave in unsmooth pulse P wave is significantly higher, which could be even higher than that of h1, resulting in early appearance of h3 or integrating with h1, which forms a wide and blunt peak. Unsmooth pulse shows poorer vascular elasticity and greater vascular stiffness.
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Affiliation(s)
- Jie-wei Luo
- Provincial Clinical Medical College, Fujian Medical University, Fuzhou 350001, China
- Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fuzhou 350001, China
| | - Si-wei Guo
- Provincial Clinical Medical College, Fujian Medical University, Fuzhou 350001, China
- Fujian University of Traditional Chinese Medicine, Fuzhou 350108, China
| | - Shuang-shuang Cao
- Fujian University of Traditional Chinese Medicine, Fuzhou 350108, China
| | - Ning Lin
- Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fuzhou 350001, China
| | - Zhen-sheng Ye
- Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fuzhou 350001, China
| | - Shi-chao Wei
- Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fuzhou 350001, China
| | - Xing-yu Zheng
- Provincial Clinical Medical College, Fujian Medical University, Fuzhou 350001, China
- Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fuzhou 350001, China
| | - Miao-miao Guo
- Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fuzhou 350001, China
| | - Xiao-rong Meng
- Provincial Clinical Medical College, Fujian Medical University, Fuzhou 350001, China
- Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fuzhou 350001, China
| | - Fang-meng Huang
- Provincial Clinical Medical College, Fujian Medical University, Fuzhou 350001, China
- Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fuzhou 350001, China
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Correction: Central Pressure Appraisal: Clinical Validation of a Subject-Specific Mathematical Model. PLoS One 2016; 11:e0157117. [PMID: 27257961 PMCID: PMC4892493 DOI: 10.1371/journal.pone.0157117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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