• Journal of Biomedical Engineering Research
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• v.29 no.2
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• pp.151-158
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• 2008

To evaluate aortic wall stiffness without influence of different background blood pressure, a new technique was developed and verified. At eight swine descending aortae, volume-pressure measurement was performed using custom-made system. Based on averaged pressure-volume curve, aortic distensibility index was formulated to evaluate aortic wall stiffness regardless of variable blood pressure and aortic size. The variability of aortic distensibility index by pressure change was compared with other parameters for wall stiffness evaluation. Subsequently, the aortic distensibility index was calculated at 100 contrast-enhanced EBCT data sets of normal volunteers in regular health screening program. The measured aortic distensibility index was compared with age, coronary calcium score, and aortic calcium score. Between 50 and 360 mmHg of blood pressure, the coefficient of variance of aortic distensibility index was 22.00% as comparing with 88.99% of classical compliance. Based on age, aortic distensibility index showed correlation coefficient of 0.55, whereas classical compliance showed 0.26. The correlation coefficient with modified aortic calcification was 0.43. Linear regression study revealed statistical significance of correlation coefficients. The aortic distensibility index, the method to evaluate aortic wall stiffness free from variable blood pressure and aortic size, was developed and verified with significant practical feasibility.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1916-1917
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• 2007

Aortic AIx(augmentation index) has been used to measure aortic stiffness and evaluate ventricular load quantitatively. Algorithm for the detection of augmentation point gradually increases the differential order to detect inflection point rather than detects the distinctive point that appears after a specific time. Developed algorithm for AIx is proved to provide more accurate results than the ones developed by previous studies with the deviation from $-11.5{\pm}14.34$ points to $-3.75{\pm}1.26$ points. Results could provide the basis for the measurement of aortic stiffness using easily-measurable radial artery pulse waves, and could be extended to develop a system for early diagnosis of various vascular diseases.

• Journal of Chest Surgery
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• v.35 no.2
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• pp.133-136
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• 2002

A 28 year-old male who had received Konno procedure twelve years ago with 23mmmechanical aortic valve and bovine pericardium with which his small aortic annulus, ventricular septum and right ventricular outflow tract had been enlarged was transferred due to sudden congestive heart failure. There were perforations on aortic and interventricular portion of bovine pericardial patch above and below the aortic valve, respectively, which was calcified and denaturated severely. The perforations seemed to be attributed to the cracks, resulting from mobility of mechanical aortic valvc itself and stiffness of calcified and denaturated bovine patch. We performed a redo Konno procedure applying PTFE patch.

• Annals of Clinical Neurophysiology
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• v.20 no.2
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• pp.79-84
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• 2018

Background: Pulsatility of cerebral arteries and aortic stiffness have been associated with white matter hyperintensities (WMH). We explored which is better correlated with the severity of WMH in a population with acute lacunar infarct. Methods: We included patients with acute small subcortical infarcts who underwent transcranial Doppler (TCD) and brachial ankle pulse wave velocity (baPWV). Exclusion criteria were any stenosis or occlusion on major cerebral arteries on magnetic resonance angiography; poor temporal insonation windows; ankle brachial index < 0.9; and atrial fibrillation. We assessed the performance of the pulsatility index of bilateral middle cerebral arteries (PI-MCA) and baPWV for predicting moderate-to-severe WMH, defined as an Age Related White Matter Changes score > 5, and then sought to find independent predictors using binary logistic regression analysis. Results: Eighty-three patients (56 males, mean age $61.5{\pm}11.4$) participated in the study. Uni-variate analysis showed old age and high PI-MCA were significantly correlated with moderate-to-severe WMH. However, baPWV was not associated with the severity of WMH. Multivariate analysis revealed old age (odds ratio per 1-year increase, 1.068; p = 0.044) and upper tertile of PI-MCA (odds ratio, 5.138; p = 0.049) were independently associated with moderate-to-severe WMH. Receiver-operating characteristics showed PI-MCA differentiated those with and without moderate-to-severe WMH with an area under the curve of 0.719. Conclusions: PI-MCA derived from TCD was better correlated with the severity of WMH than baPWV in a population with lacunar infarction. Pulsatility of cerebral arteries may better predict cerebral small vessel disease than the aortic stiffness index.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.3
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• pp.68-79
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• 2008

Aortic AIx(augmentation index) has been used to measure aortic stiffness quantitatively and even to evaluate ventricular load. However, in order to calculate aortic AIx catheters should be inserted to the subjects' artery, which hampers its clinical usage. To overcome such limitation, aortic AIx has been indirectly calculated by estimating aortic pressure wave from the peripheral arterial pulse by applying transfer functions. In this study, central aortic pressure waves using Millar catheter and radial artery pulse waves using tonometry pressure sensor were measured to establish transfer functions for an estimation of central aortic pressure waves from radial artery pulse waves. Also, an algorithm which detects augmentation point for the calculation of AIx were developed. Developed algorithm for the detection of augmentation point gradually increases the differential order to detect inflection point rather than detects the distinctive point that appears after a specific time. Transfer functions were established using 10th order ARX model and were verified for the stability of the transfer function through residual analysis. Evaluation of an algorithm for the detection of augmentation point were performed by comparing the augmentation points obtained from developed algorithm with the known augmentation points synthesized in various conditions. In addition, developed algorithm for the AIx is proved to provide more accurate results than the ones developed by previous studies. The significance of the study was in two folds. Firstly, the results could provide the basis for the measurement of aortic stiffness using easily-measurable radial artery pulse waves, and secondly, extension of the study may enable the early diagnosis of various vascular diseases.

• Advances in nano research
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• v.12 no.5
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• pp.501-514
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• 2022

This study aimed to investigate the effects and potential mechanisms of Chikusetsusaponin V (CsV) on endothelial nitric oxide synthase (eNOS) and vascular endothelial cell functions. Different concentrations of CsV were added to animal models, bovine aorta endothelial cells (BAECs) and human umbilical vein endothelial cells (HUVECs) cultured in vitro. qPCR, Western blotting (WB), and B ultrasound were performed to explore the effects of CsV on mouse endothelial cell functions, vascular stiffness and cellular eNOS mRNA, protein expression and NO release. Bioinformatics analysis, network pharmacology, molecular docking and protein mass spectrometry analysis were conducted to jointly predict the upstream transcription factors of eNOS. Furthermore, pulldown and ChIP and dual luciferase assays were employed for subsequent verification. At the presence or absence of CsV stimulation, either overexpression or knockdown of purine rich element binding protein A (PURA) was conducted, and PCR assay was employed to detect PURA and eNOS mRNA expressions, Western blot was used to detect PURA and eNOS protein expressions, cell NO release and serum NO levels. Tube formation experiment was conducted to detect the tube forming capability of HUVECs cells. The animal vasodilation function test detected the vasodilation functions. Ultrasonic detection was performed to determine the mouse aortic arch pulse wave velocity to identify aortic stiffness. CsV stimulus on bovine aortic cells revealed that CsV could upregulate eNOS protein levels in vascular endothelial cells in a concentration and time dependent manner. The expression levels of eNOS mRNA and phosphorylation sites Ser1177, Ser633 and Thr495 increased significantly after CsV stimulation. Meanwhile, CsV could also enhance the tube forming capability of HUVECs cells. Following the mice were gavaged using CsV, the eNOS protein level of mouse aortic endothelial cells was upregulated in a concentration- and time-dependent manner, and serum NO release and vasodilation ability were simultaneously elevated whereas arterial stiffness was alleviated. The pulldown, ChIP and dual luciferase assays demonstrated that PURA could bind to the eNOS promoter and facilitate the transcription of eNOS. Under the conditions of presence or absence of CsV stimulation, overexpression or knockdown of PURA indicated that the effect of CsV on vascular endothelial function and eNOS was weakened following PURA gene silence, whereas overexpression of PURA gene could enhance the effect of CsV upregulating eNOS expression. CsV could promote NO release from endothelial cells by upregulating the expression of PURA/eNOS pathway, improve endothelial cell functions, enhance vasodilation capability, and alleviate vessel stiffness. The present study plays a role in offering a theoretical basis for the development and application of CsV in vascular function improvement, and it also provides a more comprehensive understanding of the pharmacodynamics of CsV.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.1012-1017
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• 2008

Purpose : This study aimed to assess the mechanical properties of the abdominal aorta in school-aged patients treated for Kawasaki disease and in normal, healthy children. Methods : This study examined 28 children with Kawasaki disease who had been followed up on and 30 healthy subjects of the same age and gender. We recorded systolic (Ps) and diastolic (Pd) blood pressure values and the aortic diameter at both minimum diastolic (Dd) and maximum systolic (Ds) expansion using two-dimensional echocardiography. These measurements were used to determine 1) aortic strain: S=(Ds-Dd)/Dd; 2) pressure strain elastic modulus: Ep=(Ps-Pd)/S; and 3) normalized Ep: $Ep^*=Ep/Pd$. Results : Ep (P=0.008) and $Ep^*$ (P=0.043) of the Kawasaki disease group were relatively high compared to those of the control group. Ep (P=0.002) and $Ep^*$ (P=0.015) of patients with coronary aneurysm were also relatively high compared with those of patients without coronary aneurysm, but lipid profiles did not differ, except for homocysteine (P=0.008). Therefore, in patients with coronary aneurysm, aortic stiffness was higher, compared to not only the control group but also patients without coronary aneurysm. However, in patients without coronary aneurysm, aortic stiffness was not significant, different compared to the control group. Conclusion : Measuring aortic distensibility may be helpful in assessing the risk of early atheroscletic change in the long-term management of Kawasaki disease.

• Clinical and Experimental Pediatrics
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• v.57 no.5
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• pp.217-221
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• 2014

Purpose: The aim of this study was to determine whether school-aged children with Kawasaki disease (KD) have an increased risk for early atherosclerosis. Methods: The study included 98 children. The children were divided into the following groups: group A (n=19), KD with coronary arterial lesions that persisted or regressed; group B (n=49), KD without coronary arterial lesions; and group C (n=30), healthy children. Anthropometric variables and the levels of biochemical markers, including total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A, apolipoprotein B, homocysteine, highsensitivity C-reactive protein (hs-CRP), and brachial artery stiffness using pulse wave velocity were compared among the three groups. Results: There were no significant differences in blood pressure and body index among the three groups. Additionally, there was no sex-specific difference. Moreover, the levels of triglyceride, HDL-C, apolipoprotein A, and hs-CRP did not differ among the three groups. However, the levels of total cholesterol (P =0.018), LDL-C (P =0.0003), and apolipoprotein B (P =0.029) were significantly higher in group A than in group C. Further, the level of homocysteine and the aortic pulse wave velocity were significantly higher in groups A and B than in group C (P=0.0001). Conclusion: School-aged children after KD have high lipid profiles and arterial stiffness indicating an increased risk for early atherosclerosis.

• Nutrition Research and Practice
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• v.10 no.3
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• pp.288-293
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• 2016

BACKGROUND/OBJECTIVES: We compared changes in heart-femoral pulse wave velocity (hfPWV) in response to low sodium and high sodium diet between individuals with sodium sensitivity (SS) and resistance (SR) to evaluate the influence of sodium intake on arterial stiffness. SUBJECTS/METHODS: Thirty-one hypertensive and 70 normotensive individuals were given 7 days of low sodium dietary approach to stop hypertension (DASH) diet (LSD, 100 mmol NaCl/day) followed by 7 days of high sodium DASH diet (HSD, 300 mmol NaCl/day) during 2 weeks of hospitalization. The hfPWV was measured and compared after the LSD and HSD. RESULTS: The hfPWV was significantly elevated from LSD to HSD in individuals with SS (P = 0.001) independently of changes in mean arterial pressure (P = 0.037). Conversely, there was no significant elevation of hfPWV from LSD to HSD in individuals with SR. The percent change in hfPWV from the LSD to the HSD in individuals with SS was higher than that in individuals with SR. Subgroup analysis revealed that individuals with both SS and hypertension showed significant elevation of hfPWV from LSD to HSD upon adjusted analysis using changes of the means arterial pressure (P = 0.040). However, there was no significant elevation of hfPWV in individuals with SS and normotension. CONCLUSION: High sodium intake elevated hfPWV in hypertensive individuals with SS, suggesting that high sodium intake increases aortic stiffness, and may contribute to enhanced cardiovascular risk in hypertensive individuals with SS.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.9 no.1
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• pp.112-124
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• 2005

Background: PWV is determined by dividing the distance by the time taken for the pulses traveling between two measuring sites, used as a marker of arterial stiffness and an important indicator for cardiovascular disease. Methods: A PWV measurement system, which offers a non-invasive, simple method of measurement, and simultaneous recording of six signlas(ECG, PCG and four pulse waves from carotid, femoral, radial and dorsalis pedis arteries) was developed. Seventeen healthy subjects with a mean age of 33 years(22 to 52) without any cardiovascular disease were participated for the experiment. Two observers(A and B) performed two consecutive measurements from the same subject in a random order. For the evaluation of stability and accuracy of the PWV measurement system, reproducibility of PWV from between-observer were also evaluated. Results: PWV $values(Mean{\pm}SD)$ measured by A were $7.07{\pm}1.48m/s$, $8.43{\pm}1.14m/s$ , $8.09{\pm}0.98m/s$ for aorta, arm, and leg, respectively. The values obtained from B were $6.76{\pm}1.00m/s$, $7.97{\pm}0.80m/s$, and $7.97{\pm}0.72m/s$ for aorta, arm, and leg, respectively. Between-observer $differences(mean{\pm}SEM)$ from the aorta, arm and leg were $0.14{\pm}0.15m/s$, $0.18{\pm}0.10m/s$ and $0.07{\pm}0.10m/s$. Reproducibility coefficients(2SD) from the aorta, arm, and leg were 0.62m/s, 0.84m/s and 0.86m/s. Correlation coefficients were significantly higher in aortic PWV, 0.93, compared to the coefficients for arm and leg. Coefficient of variance which reflects the reproducibility of the system ranged from $4.4{\sim}5.8%$ in all regional PWV. , Conclusion: Reproducibility of PWV in the study shows that the developed system has reliable and reproducible characteristics. The PWV measurement system used for the study offers comfortable and simple operation and provides accurate analysis and results with high reproducibility. Results of the PWV measurement system could contribute to various clinical applications in the future.