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Sample records for radial artery pressure

  1. Computer model analysis of the radial artery pressure waveform.

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    Schwid, H A; Taylor, L A; Smith, N T

    1987-10-01

    Simultaneous measurements of aortic and radial artery pressures are reviewed, and a model of the cardiovascular system is presented. The model is based on resonant networks for the aorta and axillo-brachial-radial arterial system. The model chosen is a simple one, in order to make interpretation of the observed relationships clear. Despite its simplicity, the model produces realistic aortic and radial artery pressure waveforms. It demonstrates that the resonant properties of the arterial wall significantly alter the pressure waveform as it is propagated from the aorta to the radial artery. Although the mean and end-diastolic radial pressures are usually accurate estimates of the corresponding aortic pressures, the systolic pressure at the radial artery is often much higher than that of the aorta due to overshoot caused by the resonant behavior of the radial artery. The radial artery dicrotic notch is predominantly dependent on the axillo-brachial-radial arterial wall properties, rather than on the aortic valve or peripheral resistance. Hence the use of the radial artery dicrotic notch as an estimate of end systole is unreliable. The rate of systolic upstroke, dP/dt, of the radial artery waveform is a function of many factors, making it difficult to interpret. The radial artery waveform usually provides accurate estimates for mean and diastolic aortic pressures; for all other measurements it is an inadequate substitute for the aortic pressure waveform. In the presence of low forearm peripheral resistance the mean radial artery pressure may significantly underestimate the mean aortic pressure, as explained by a voltage divider model.

  2. Correlation of femoral artery vs radial artery pressures with central pressure after cardiopulmonary bypass in children

    International Nuclear Information System (INIS)

    Yaseen, R.; Memon, H.

    2008-01-01

    To assess the effectiveness of femoral and radial arterial lines on the correlation of peripheral and central mean arterial blood pressure in children after discontinuation of cardiopulmonary bypass. Fifty children scheduled for cardiac surgery with cardiopulmonary bypass were included in the study. After approval from the hospital ethics committee and informed consent. 50 children undergoing cardiac surgical procedures with cardiopulmonary bypass were randomly assigned to two different groups. In Group- A (RAP, n-2) a radial arterial line and in Group-B (FAP, n-25) a femoral arterial line was used to monitor the blood pressure. Simultaneous mean peripheral arterial pressure and mean central aortic pressure were recorded before cardiopulmonary bypass and 5 mins after separation from the cardiopulmonary bypass. The correlation of mean peripheral arterial pressure (radial and femoral) versus mean aortic pressure were compared. The data was recorded as Mean +- SD and P-value. The ages of children ranged from 4-12 years and their weight from 14.1-28.5 kg. In all of them following cardiopulmonary bypass, aortic pressure correlates better with femoral arterial pressure (p<0.001). The radial arterial line readings under estimated central aortic pressure when compared to femoral arterial line readings. Aortic pressure readings correlate better with femoral arterial pressure than radial arterial pressure in children. (author)

  3. Simulations of piezoelectric pressure sensor for radial artery pulse measurement

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Abhay B. [Department of Electronic Science, University of Pune, Pune 411 007 (India); Kalange, Ashok E. [Department of Electronic Science, University of Pune, Pune 411 007 (India); Tuljaram Chaturchand College, Baramati 413 102 (India); Bodas, Dhananjay, E-mail: dhananjay.bodas@gmail.co [Center for Nanobio Sciences, Agharkar Research Institute, Pune 411 004 (India); Gangal, S.A. [Department of Electronic Science, University of Pune, Pune 411 007 (India)

    2010-04-15

    A radial artery pulse is used to diagnose human body constitution (Prakruti) in Ayurveda. A system consisting of piezoelectric sensor (22 mm x 12 mm), data acquisition card and LabView software was used to record the pulse data. The pulse obtained from the sensor was noisy, even though signal processing was done. Moreover due to large sized senor accurate measurements were not possible. Hence, a need was felt to develop a sensor of the size of the order of finger tip with a resonant frequency of the order of 1 Hz. A micromachined pressure sensor based on piezoelectric sensing mechanism was designed and simulated using CoventorWare. Simulations were carried out by varying dimensions of the sensor to optimize the resonant frequency, stresses and voltage generated as a function of applied pressure. All simulations were done with pressure ranging of 1-30 kPa, which is the range used by Ayurvedic practitioners for diagnosis. Preliminary work on fabrication of such a sensor was carried out successfully.

  4. Simulations of piezoelectric pressure sensor for radial artery pulse measurement

    International Nuclear Information System (INIS)

    Joshi, Abhay B.; Kalange, Ashok E.; Bodas, Dhananjay; Gangal, S.A.

    2010-01-01

    A radial artery pulse is used to diagnose human body constitution (Prakruti) in Ayurveda. A system consisting of piezoelectric sensor (22 mm x 12 mm), data acquisition card and LabView software was used to record the pulse data. The pulse obtained from the sensor was noisy, even though signal processing was done. Moreover due to large sized senor accurate measurements were not possible. Hence, a need was felt to develop a sensor of the size of the order of finger tip with a resonant frequency of the order of 1 Hz. A micromachined pressure sensor based on piezoelectric sensing mechanism was designed and simulated using CoventorWare. Simulations were carried out by varying dimensions of the sensor to optimize the resonant frequency, stresses and voltage generated as a function of applied pressure. All simulations were done with pressure ranging of 1-30 kPa, which is the range used by Ayurvedic practitioners for diagnosis. Preliminary work on fabrication of such a sensor was carried out successfully.

  5. Considerations for SphygmoCor radial artery pulse wave analysis: side selection and peripheral arterial blood pressure calibration.

    Science.gov (United States)

    Martin, Jeffrey S; Borges, Alexandra R; Christy, John B; Beck, Darren T

    2015-10-01

    Methods employed for pulse wave analysis (PWA) and peripheral blood pressure (PBP) calibration vary. The purpose of this study was to evaluate the agreement of SphygmoCor PWA parameters derived from radial artery tonometry when considering (1) timing (before vs. after tonometry) and side selection (ipsilateral vs. contralateral limb) for PBP calibration and (2) side selection for tonometry (left vs. right arm). In 34 subjects (aged 21.9 ± 2.3 years), bilateral radial artery tonometry was performed simultaneously on three instances. PBP assessment via oscillometric sphygmomanometry in the left arm only and both arms simultaneously occurred following the first and second instances of tonometry, respectively. Significant within arm differences in PWA parameters derived before and after PBP measurement were observed in the right arm only (for example, aortic systolic blood pressure, Δ=0.38 ± 0.64 mm Hg). Simultaneously captured bilateral PWA variables demonstrated significant between arm differences in 88% (14/16) and 56% (9/16) of outcome variables when calibrated to within arm and equivalent PBP, respectively. Moreover, the right arm consistently demonstrated lower values for clinical PWA variables (for example, augmentation index, bias=-2.79%). However, 26% (n=9) of participants presented with clinically significant differences (>10 mm Hg) in bilateral PBP and their exclusion from analysis abolished most between arm differences observed. SphygmoCor PWA in the right radial artery results in greater variability independent of the timing of PBP measurement and magnitude of calibration pressures in young subjects. Moreover, bilateral PBP measurement is imperative to identify subjects in whom a significant difference in bilateral PWA outcomes may exist.

  6. Differences in perioperative femoral and radial arterial blood pressure in neonates and infants undergoing cardiac surgery requiring cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    Hwa Jin Cho

    Full Text Available Abstract Objective: Several reports claim that blood pressure (BP in the radial artery may underestimate the accurate BP in critically ill patients. Here, the authors evaluated differences in mean blood pressure (MBP between the radial and femoral artery during pediatric cardiac surgery to determine the effectiveness of femoral arterial BP monitoring. Method: The medical records of children under 1 year of age who underwent open-heart surgery between 2007 and 2013 were retrospectively reviewed. Radial and femoral BP were measured simultaneously, and the differences between these values were analyzed at various times: after catheter insertion, after the initiation of cardiopulmonary bypass (CPB-on, after aortic cross clamping (ACC, after the release of ACC, after weaning from CPB, at arrival in the intensive care unit (ICU, and every 6 h during the first day in the ICU. Results: A total of 121 patients who underwent open-heart surgery met the inclusion criteria. During the intraoperative period, from the beginning to the end of CPB, radial MBPs were significantly lower than femoral MBPs at each time-point measured (p 60 min, odds ratio: 7.47 was a risk factor for lower radial pressure. However, discrepancies between these two values disappeared after arrival in the ICU. There was no incidence of ischemic complications associated with the catheterization of both arteries. Conclusion: The authors suggest that femoral arterial pressure monitoring can be safely performed, even in neonates, and provides more accurate BP values during CPB-on periods, and immediately after weaning from CPB, especially when CPB time was greater than 60 min.

  7. Effects of various factors on Doppler ultrasonographic measurements of radial and coccygeal arterial blood pressure in privately owned, conscious cats.

    Science.gov (United States)

    Whittemore, Jacqueline C; Nystrom, Michael R; Mawby, Dianne I

    2017-04-01

    OBJECTIVE To assess the effects of age, body condition score (BCS), and muscle condition score (MCS) on radial and coccygeal systolic arterial blood pressure (SAP) in cats. DESIGN Prospective randomized trial. ANIMALS 66 privately owned cats enrolled between May and December 2010. PROCEDURES BCS and MCS of cats were assessed by 2 investigators; SAP was measured via Doppler ultrasonic flow detector, with cats positioned in right lateral or sternal recumbency for measurements at the radial or coccygeal artery, respectively, with order of site randomized. Associations among variables were assessed through correlation coefficients, partial correlation coefficients, and ANCOVA. RESULTS Interrater reliability for BCS and MCS assessment was high (correlation coefficients, 0.95 and 0.83, respectively). No significant effect was identified for order of SAP measurement sites. Coccygeal and radial SAP were positively correlated (ρ = 0.45). The median difference in coccygeal versus radial SAP was 19 mm Hg, but differences were not consistently positive or negative. Radial SAP was positively correlated with age (ρ = 0.48) and negatively correlated with MCS (ρ = -0.30). On the basis of the correlation analysis, the association between radial SAP and MCS reflected the confounding influence of age. Coccygeal SAP was not significantly correlated with age, BCS, or MCS. CONCLUSIONS AND CLINICAL RELEVANCE Use of the coccygeal artery is recommended to reduce the confounding effects of age and sarcopenia on Doppler ultrasonographic SAP measurements in cats. Additionally, monitoring for changes in MCS is recommended for cats undergoing serial SAP measurement.

  8. Effects of arm elevation on radial artery pressure: a new method to distinguish hypovolemic shock and septic shock from hypotension.

    Science.gov (United States)

    Xie, Zhiyi; Zhang, Zhenyu; Xu, Yuan; Zhou, Hua; Wu, Sheng; Wang, Zhong

    2018-06-01

    In this prospective observational study, we investigated the variability in radial artery invasive blood pressure associated with arm elevation in patients with different hemodynamic types. We carried out a prospective observational study using data from 73 general anesthesia hepatobiliary postoperative adult patients admitted to an ICU over a 1-year period. A standard procedure was used for the arm elevation test. The value of invasive radial arterial pressure was recorded at baseline, and 30 and 60 s after the arm had been raised from 0° to 90°. We compared the blood pressure before versus after arm elevation, and between hemodynamically stable, hypovolemic shock, and septic shock patient groups. In all 73 patients, systolic arterial pressure (SAP) decreased, diastolic arterial pressure (DAP) increased, and pulse pressure (PP) decreased at 30 and 60 s after arm elevation (Ppressure (MAP) was unchanged (P>0.05). On comparing 30 and 60 s, there was no significant difference in SAP, DAP, PP, or MAP (P>0.05). In 40 hemodynamically stable patients, SAP and PP decreased, and DAP and MAP increased significantly at 30 and 60 s after arm elevation compared with baseline (P0.05). In 17 patients with septic shock, SAP, PP, and MAP decreased significantly versus baseline at 30 and 60 s (P0.05). Comparison of the absolute value of pressure change of septic shock patients at 30 s after raising the arm showed that SAP, DAP, and MAP changes were significantly lower compared with those in hypovolemic shock and hemodynamically stable patients (Parm elevation of SAP. The best cut-off point for the SAP change value was -5 mmHg or less, with a sensitivity of 94.12%, a specificity of 80.36%, a positive likelihood ratio of 4.79 (95% CI: 2.8-8.2), and a negative likelihood ratio of 0.073 (95% CI: 0.01-0.5). Our study shows that hypovolemic shock and septic shock patients have significantly different radial artery invasive blood pressure changes in an arm elevation test

  9. Differences in perioperative femoral and radial arterial blood pressure in neonates and infants undergoing cardiac surgery requiring cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    Hwa Jin Cho

    2018-01-01

    Full Text Available Objective: Several reports claim that blood pressure (BP in the radial artery may underestimate the accurate BP in critically ill patients. Here, the authors evaluated differences in mean blood pressure (MBP between the radial and femoral artery during pediatric cardiac surgery to determine the effectiveness of femoral arterial BP monitoring. Method: The medical records of children under 1 year of age who underwent open-heart surgery between 2007 and 2013 were retrospectively reviewed. Radial and femoral BP were measured simultaneously, and the differences between these values were analyzed at various times: after catheter insertion, after the initiation of cardiopulmonary bypass (CPB-on, after aortic cross clamping (ACC, after the release of ACC, after weaning from CPB, at arrival in the intensive care unit (ICU, and every 6 h during the first day in the ICU. Results: A total of 121 patients who underwent open-heart surgery met the inclusion criteria. During the intraoperative period, from the beginning to the end of CPB, radial MBPs were significantly lower than femoral MBPs at each time-point measured (p 60 min, odds ratio: 7.47 was a risk factor for lower radial pressure. However, discrepancies between these two values disappeared after arrival in the ICU. There was no incidence of ischemic complications associated with the catheterization of both arteries. Conclusion: The authors suggest that femoral arterial pressure monitoring can be safely performed, even in neonates, and provides more accurate BP values during CPB-on periods, and immediately after weaning from CPB, especially when CPB time was greater than 60 min. Resumo: Objetivo: Diversos relatos alegam que a pressão arterial (PA na artéria radial poderá subestimar a PA precisa em pacientes gravemente doentes. Aqui, avaliamos diferenças na pressão arterial média (PAM entre a artéria radial e femoral durante cirurgia cardíaca pediátrica para determinar a eficácia do

  10. Effects of gravity-induced upper-limb blood pressure changes on wave transmission and arterial radial waveform.

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    Pucci, Giacomo; Battista, Francesca; Anastasio, Fabio; Sanesi, Leandro; Gavish, Benjamin; Butlin, Mark; Avolio, Alberto; Schillaci, Giuseppe

    2016-06-01

    Local blood pressure (BP) changes induced by arm tilting may influence pressure wave transmission and reflection. We investigated the effects of upper-limb tilting on radial augmentation index (rAIx) and related central measures [aortic augmentation index (aAIx)]. In 45 volunteers (age 49 ± 19 years), supine brachial BP and radial artery waveforms were obtained by applanation tonometry with the dominant arm stretched and gently supported in three different positions: at the heart level, with the BP cuff 15 cm above heart level (approximately +30°), and 15 cm below heart level (-30°). Brachial SBP/DBP was 120/68 ± 17/8 mmHg. Mean arterial pressure changed predictably with arm tilting (99 ± 12 mmHg at -30°, 88 ± 10 mmHg at 0°, 77 ± 11 mmHg at +30°, all P < 0.001). rAIx decreased at -30° (69 ± 22%), and increased at +30° (93 ± 20%) compared with 0° (82 ± 20%, all P less than 0.001). Changes in rAIx (value at +30° minus value at -30°) showed an inverse relationship with age (r = -0.32, P = 0.03). Heart rate, BP and rAIx did not change in the contralateral arm, which was held at the heart level during the examination. aAIx followed the same pattern as rAIx (123 ± 27% at -30°, 144 ± 33% at +30°, 136 ± 31% at 0°, all P less than 0.001); changes in rAIx and aAIx were strongly related each other (r = 0.82, P < 0.001). Acute gravitational upper-limb BP changes generate opposite, profound changes in rAIx, and major artifactual changes in aAIx. These findings provide a rationale for recommending to keep the upper limb at the heart level during radial waveform assessment.

  11. Anomalies of radial and ulnar arteries

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    Rajani Singh

    Full Text Available Abstract During dissection conducted in an anatomy department of the right upper limb of the cadaver of a 70-year-old male, both origin and course of the radial and ulnar arteries were found to be anomalous. After descending 5.5 cm from the lower border of the teres major, the brachial artery anomalously bifurcated into a radial artery medially and an ulnar artery laterally. In the arm, the ulnar artery lay lateral to the median nerve. It followed a normal course in the forearm. The radial artery was medial to the median nerve in the arm and then, at the level of the medial epicondyle, it crossed from the medial to the lateral side of the forearm, superficial to the flexor muscles. The course of the radial artery was superficial and tortuous throughout the arm and forearm. The variations of radial and ulnar arteries described above were associated with anomalous formation and course of the median nerve in the arm. Knowledge of neurovascular anomalies are important for vascular surgeons and radiologists.

  12. Endoscopic Radial Artery Harvest for Coronary Artery Bypass Surgery

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    Kuan-Ming Chiu

    2006-01-01

    Conclusion: Endoscopic harvest of the radial artery is technically demanding, but excellent results can be achieved. The endoscopic approach can provide suitable conduits in a less invasive way than the open harvest technique.

  13. Intraluminal milrinone for dilation of the radial artery graft.

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    García-Rinaldi, R; Soltero, E R; Carballido, J; Mojica, J

    1999-01-01

    There is renewed interest in the use of the radial artery as a conduit for coronary artery bypass surgery. The radial artery is, however, a very muscular artery, prone to vasospasm. Milrinone, a potent vasodilator, has demonstrated vasodilatory properties superior to those of papaverine. In this report, we describe our technique of radial artery harvesting and the adjunctive use of intraluminal milrinone as a vasodilator in the preparation of this conduit for coronary artery bypass grafting. We have used these techniques in 25 patients who have undergone coronary artery bypass grafting using the radial artery. No hand ischemic complications have been observed in this group. Intraluminal milrinone appears to dilate and relax the radial artery, rendering this large conduit spasm free and very easy to use. We recommend the skeletonization technique for radial artery harvesting and the use of intraluminal milrinone as a radial artery vasodilator in routine myocardial revascularization. PMID:10524740

  14. Anomalous Medial Branch of Radial Artery: A Rare Variant

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    Surbhi Wadhwa

    2016-10-01

    Full Text Available Radial artery is an important consistent vessel of the upper limb. It is a useful vascular access site for coronary procedures and its reliable anatomy has resulted in an elevation of radial forearm flaps for reconstructive surgeries of head and neck. Technical failures, in both the procedures, are mainly due to anatomical variations, such as radial loops, ectopic radial arteries or tortuosity in the vessel. We present a rare and a unique anomalous medial branch of the radial artery spiraling around the flexor carpi radialis muscle in the forearm with a high rising superficial palmar branch of radial artery. Developmentally it probably is a remanent of the normal pattern of capillary vessel maintenance and regression. Such a case is of importance for reconstructive surgeons and coronary interventionists, especially in view of its unique medial and deep course.

  15. Pseudoaneurysm of the Radial Artery After a Bicycle Fall.

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    Ratschiller, Thomas; Müller, Hannes; Schachner, Thomas; Zierer, Andreas

    2018-07-01

    We report a case of a 64-year-old man who developed a painful pulsatile mass in the distal forearm after a bicycle fall with fracture of the wrist. Ultrasonography confirmed a 2.5-cm large pseudoaneurysm of the radial artery. The patient underwent surgical exploration. The pseudoaneurysm was resected and the defect in the arterial wall was reconstructed with an autologous saphenous vein patch. We suggest that the double arterial supply of the hand should be preserved whenever possible.

  16. Sharp Dissection versus Electrocautery for Radial Artery Harvesting

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    Marzban, Mehrab; Arya, Reza; Mandegar, Mohammad Hossein; Karimi, Abbas Ali; Abbasi, Kiomars; Movahed, Namvar; Abbasi, Seyed Hesameddin

    2006-01-01

    Radial arteries have been increasingly used during the last decade as conduits for coronary artery revascularization. Although various harvesting techniques have been described, there has been little comparative study of arterial damage and patency. A radial artery graft was used in 44 consecutive patients, who were randomly divided into 2 groups. In the 1st group, the radial artery was harvested by sharp dissection and in the 2nd, by electrocautery. These groups were compared with regard to radial artery free flow, harvest time, number of clips used, complications, and endothelial damage. Radial artery free flow before and after intraluminal administration of papaverine was significantly greater in the electrocautery group (84.3 ± 50.7 mL/min and 109.7 ± 68.5 mL/min) than in the sharp-dissection group (52.9 ± 18.3 mL/min and 69.6 ± 28.2 mL/ min) (P =0.003). Harvesting time by electrocautery was significantly shorter (25.4 ± 4.3 min vs 34.4 ± 5.9 min) (P =0.0001). Electrocautery consumed an average of 9.76 clips, versus 22.45 clips consumed by sharp dissection. The 2 groups were not different regarding postoperative complications, except for 3 cases of temporary paresthesia of the thumb in the electrocautery group; histopathologic examination found no endothelial damage. We conclude that radial artery harvesting by electrocautery is faster and more economical than harvesting by sharp dissection and is associated with better intraoperative flow and good preservation of endothelial integrity. PMID:16572861

  17. Reliability of palpation of the radial artery compared with auscultation of the brachial artery in measuring SBP

    NARCIS (Netherlands)

    van der Hoeven, Niels V.; van den Born, Bert-Jan H.; van Montfrans, Gert A.

    2011-01-01

    Background Systolic blood pressure contributes more to cardiovascular disease than DBP, especially in elderly persons. Palpation of the radial artery to assess SBP - Riva-Rocci's technique-may be an attractive alternative for auscultatory SBP in these patients. Therefore, we investigated the

  18. A novel compliance measurement in radial arteries using strain-gauge plethysmography

    International Nuclear Information System (INIS)

    Liu, Shing-Hong; Tyan, Chu-Chang; Chang, Kang-Ming

    2009-01-01

    We propose a novel method for assessing the compliance of the radial artery by using a two-axis mechanism and a standard positioning procedure for detecting the optimal measuring site. A modified sensor was designed to simultaneously measure the arterial diameter change waveform (ADCW) and pressure pulse waveform with a strain gauge and piezoresistor. In the x-axis scanning, the sensor could be placed close to the middle of the radial artery when the ADCW reached the maximum amplitude. In the z-axis scanning, the contact pressure was continuously increased for data measurement. Upon the deformation of the strain gauge following the change in the vascular cross-section, the ADCW was transferred to the change of the vascular radius. The loaded strain compliance of the radial artery (C strain ) can be determined by dividing the dynamic changed radius by the pulse pressure. Twenty-three untreated, mild or moderate hypertensive patients aged 29–85 were compared with 14 normotensive patients aged 25–62. The maximum strain compliance between the two groups was significantly different (p < 0.005). Of the hypertensive patients, 14 were at risk of developing hyperlipidemia. There was a significant difference between this and the normotension group (p < 0.005)

  19. A novel compliance measurement in radial arteries using strain-gauge plethysmography.

    Science.gov (United States)

    Liu, Shing-Hong; Tyan, Chu-Chang; Chang, Kang-Ming

    2009-09-01

    We propose a novel method for assessing the compliance of the radial artery by using a two-axis mechanism and a standard positioning procedure for detecting the optimal measuring site. A modified sensor was designed to simultaneously measure the arterial diameter change waveform (ADCW) and pressure pulse waveform with a strain gauge and piezoresistor. In the x-axis scanning, the sensor could be placed close to the middle of the radial artery when the ADCW reached the maximum amplitude. In the Z-axis scanning, the contact pressure was continuously increased for data measurement. Upon the deformation of the strain gauge following the change in the vascular cross-section, the ADCW was transferred to the change of the vascular radius. The loaded strain compliance of the radial artery (C(strain)) can be determined by dividing the dynamic changed radius by the pulse pressure. Twenty-three untreated, mild or moderate hypertensive patients aged 29-85 were compared with 14 normotensive patients aged 25-62. The maximum strain compliance between the two groups was significantly different (p < 0.005). Of the hypertensive patients, 14 were at risk of developing hyperlipidemia. There was a significant difference between this and the normotension group (p < 0.005).

  20. Development of a Tonometric Sensor with a Decoupled Circular Array for Precisely Measuring Radial Artery Pulse

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    Min-Ho Jun

    2016-05-01

    Full Text Available The radial artery pulse is one of the major diagnostic indices used clinically in both Eastern and Western medicine. One of the prominent methods for measuring the radial artery pulse is the piezoresistive sensor array. Independence among channels and an appropriate sensor arrangement are important for effectively assessing the spatial-temporal information of the pulse. This study developed a circular-type seven-channel piezoresistive sensor array using face-down bonding (FDB as one of the sensor combination methods. The three-layered housing structure that included independent pressure sensor units using the FDB method not only enabled elimination of the crosstalk among channels, but also allowed various array patterns to be created for effective pulse measurement. The sensors were arranged in a circular-type arrangement such that they could estimate the direction of the radial artery and precisely measure the pulse wave. The performance of the fabricated sensor array was validated by evaluating the sensor sensitivity per channel, and the possibility of estimating the blood vessel direction was demonstrated through a radial artery pulse simulator. We expect the proposed sensor to allow accurate extraction of the pulse indices for pulse diagnosis.

  1. Rare high origin of the radial artery: a bilateral, symmetrical case ...

    African Journals Online (AJOL)

    Arterial variations in the upper limb can occur at the level of the axillary, brachial, radial and ulnar arteries as well as the palmar arches. This is a report of bilateral, symmetrical high origin of the radial artery from the axillary artery. Knowledge of such variations is important in vascular and reconstructive surgery. (Nig J Surg ...

  2. Long-term outcomes of internal carotid artery disease treated using radial artery graft

    International Nuclear Information System (INIS)

    Murai, Yasuo; Teramoto, Akira; Mizunari, Takayuki; Kobayashi, Shiro; Umeoka, Katsuya; Tateyama, Kojiro

    2009-01-01

    Complex internal carotid artery disease presents a surgical challenge because limitations and difficulty are encountered with either clipping or endovascular treatment. Our review of previous reports suggests that no current vascular assessment can accurately predict occurrence of ischemic complications after internal carotid artery ligation. The present study concerns long-term clinical outcome of radial artery grafting followed by parent artery trapping or proximal occlusion for management of these difficult lesions. Between September 1997 and October 2007, we performed radial artery grafting followed immediately by parent artery occlusion in 20 sides of 19 patients with complex internal carotid arteries disease with follow-up for more than 36 months (5 men, 14 women; mean follow-up duration, 62 months). All patients underwent postoperative MRI and MR angiography (MRA) every year to assess graft patency, ischemic complications, and de novo aneurysm. Another 20 carotid aneurysms with visual disturbance were assessed concerning outcome. Among 13 patients with cranial nerve (III and VI) disturbances, all dysfunctions were improved in cases treated within 8 months of onset to operation. On the other hand, patients with second cranial nerve disturbances were not improved in cases treated after 4 months of onset. No long-term complications were discovered with MRI and MRA. With appropriate attention to surgical technique, radial artery grafting followed by acute parent artery occlusion is a safe treatment for complex internal carotid artery aneurysms. Long-term safety is satisfactory, with no delayed complications such as graft stenosis, ischemic complications or de novo aneurysm formations in follow-up periods of more than 3 years. Good clinical outcome of cranial nerve palsy was achieved in patients treated within 8 months of onset for cranial nerve (CN) III and VI, and 4 of CN II palsy. (author)

  3. Endoscopic versus open radial artery harvest and mammario-radial versus aorto-radial grafting in patients undergoing coronary artery bypass surgery

    DEFF Research Database (Denmark)

    Carranza, Christian L; Ballegaard, Martin; Werner, Mads U

    2014-01-01

    the postoperative complications will be registered, and we will evaluate muscular function, scar appearance, vascular supply to the hand, and the graft patency including the patency of the central radial artery anastomosis. A patency evaluation by multi-slice computer tomography will be done at one year...... to aorto-radial revascularisation techniques but this objective is exploratory. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01848886.Danish Ethics committee number: H-3-2012-116.Danish Data Protection Agency: 2007-58-0015/jr.n:30-0838....

  4. Radial artery approach for coronary intervention - early experience

    International Nuclear Information System (INIS)

    Jan, H.; Hadi, A.; Fahim, M.; Gul, A.M.; Irfan, M.; Khan, S.B.; Hafizullah, M.

    2012-01-01

    Objective: To see the clinical outcome of patients undergoing Transradial Coronary Angioplasty with stable Angina. Methodology: This was a single center observational study with prospective data collection of 338 patients who underwent transradial coronary angioplasty from September 2009 to August 2011, at Post Graduate Medical Institute, Lady Reading Hospital, Peshawar. Patients of both genders and all ages who had transradial coronary angioplasty for chronic stable angina were included in the study. Patients were clinically examined in out patients department on first month of hospital discharge and clinical outcome data was recorded. Results: A total of 338 patients were included in the study. Male were 58.8% and 41.2% were female with mean age of 52+-7 years. All the patients had coronary intervention through right radial artery. Baseline characteristics of the patients were; 48.2% diabetic, 43.2% hypertensive, 30.5% smokers, dyslipidemia was 45.7% and mean values of serum creatinine and Hemoglobin were 1.1+-0.3 and 11.5+-1.5, respectively. The frequency of various complications were as follow; hematoma 1.3%, nausea and vomiting 2.2%, pain in hand 11.2%, re admission to hospital for chest pain 6.5%, need for revascularization 2.2%, hand ischemia 1.8%, minor bleeding 0.9%, no major bleeding and 1.9% mortality. Conclusion: The radial artery approach for coronary intervention is useful with low degree of access site vascular complications and an early mobilization. (author)

  5. Radial artery approach for coronary intervention - early experience

    Energy Technology Data Exchange (ETDEWEB)

    Jan, H; Hadi, A; Fahim, M; Gul, A M; Irfan, M; Khan, S B; Hafizullah, M [Lady Reading Hospital and Khyber Medical University, Peshawar (Pakistan). Dept. of Cardiology

    2012-01-15

    Objective: To see the clinical outcome of patients undergoing Transradial Coronary Angioplasty with stable Angina. Methodology: This was a single center observational study with prospective data collection of 338 patients who underwent transradial coronary angioplasty from September 2009 to August 2011, at Post Graduate Medical Institute, Lady Reading Hospital, Peshawar. Patients of both genders and all ages who had transradial coronary angioplasty for chronic stable angina were included in the study. Patients were clinically examined in out patients department on first month of hospital discharge and clinical outcome data was recorded. Results: A total of 338 patients were included in the study. Male were 58.8% and 41.2% were female with mean age of 52+-7 years. All the patients had coronary intervention through right radial artery. Baseline characteristics of the patients were; 48.2% diabetic, 43.2% hypertensive, 30.5% smokers, dyslipidemia was 45.7% and mean values of serum creatinine and Hemoglobin were 1.1+-0.3 and 11.5+-1.5, respectively. The frequency of various complications were as follow; hematoma 1.3%, nausea and vomiting 2.2%, pain in hand 11.2%, re admission to hospital for chest pain 6.5%, need for revascularization 2.2%, hand ischemia 1.8%, minor bleeding 0.9%, no major bleeding and 1.9% mortality. Conclusion: The radial artery approach for coronary intervention is useful with low degree of access site vascular complications and an early mobilization. (author)

  6. Radial artery spasm occurred in transradial coronary intervention for coronary heart disease: its occurrence and predictors

    International Nuclear Information System (INIS)

    Zhong Jiming; Li Lang; Lu Yongguang; Zeng Shuyi

    2011-01-01

    Objective: To discuss the incidence and clinical predictors of radial artery spasm occurred in performing transradial coronary intervention for coronary heart disease. Methods: A total of 1020 patients, who underwent transradial coronary procedures for coronary heart disease during the period of May 2007 Jan 2010 in authors' hospital, were enrolled in this study. All clinical information and medication were recorded in detail. Arteriography via radial artery was performed in all patients. The diameter of the radial artery as well as the arterial anatomy, including arterial variations, were determined and observed, which was follow by coronary angiography or percutaneous coronary intervention. Multivariate Logistic regression analysis was adopted to evaluate the variables, such as clinical parameters, angiographic characteristics of the radial artery and procedure-related factors, in predicting the occurrence of radial artery spasm. Results: Radial artery spasm occurred in 209 (20.5%) patients. Multivariate Logistic regression analysis showed that the following eight factors were independently associated with the occurrence of radial artery spasm. These factors were as follows: female gender (OR=2.8, 95% CI 2.5-5.8; P=0.001), age (OR=0.68, 95% CI 0.60-0.92; P=0.003), smoking (OR=2.3, 95% CI 1.8-4.1; P=0.026), moderate-to-severe pain of forearm during radial artery cannulation (OR=3.0, 95% CI 2.3-4.8; P=0.006), radial artery anatomical abnormalities (OR=4.7, 95% CI 3.6-7.2; P=0.002), the ratio of radial artery diameter to patient's height (RAH) (OR=5.2, 95% CI 3.7-8.1; P=0.012), the ratio of radial artery diameter to outer diameter of the sheath (RAOD) (OR=5.8, 95% CI 4.2-6.9; P=0.006) and the number of catheter exchange (OR=2.3, 95% CI 1.4-4.3; P=0.038). Conclusion: Radial artery spasm occurred in performing transradial coronary intervention for coronary heart disease is frequently seen in clinical practice. Female gender, younger age, smoking, forearm pain during

  7. Accurate evaluation of viscoelasticity of radial artery wall during flow-mediated dilation in ultrasound measurement

    Science.gov (United States)

    Sakai, Yasumasa; Taki, Hirofumi; Kanai, Hiroshi

    2016-07-01

    In our previous study, the viscoelasticity of the radial artery wall was estimated to diagnose endothelial dysfunction using a high-frequency (22 MHz) ultrasound device. In the present study, we employed a commercial ultrasound device (7.5 MHz) and estimated the viscoelasticity using arterial pressure and diameter, both of which were measured at the same position. In a phantom experiment, the proposed method successfully estimated the elasticity and viscosity of the phantom with errors of 1.8 and 30.3%, respectively. In an in vivo measurement, the transient change in the viscoelasticity was measured for three healthy subjects during flow-mediated dilation (FMD). The proposed method revealed the softening of the arterial wall originating from the FMD reaction within 100 s after avascularization. These results indicate the high performance of the proposed method in evaluating vascular endothelial function just after avascularization, where the function is difficult to be estimated by a conventional FMD measurement.

  8. Optimal management of radial artery grafts in CABG: Patient and target vessel selection and anti-spasm therapy.

    Science.gov (United States)

    Schwann, Thomas A; Gaudino, Mario; Baldawi, Mustafa; Tranbaugh, Robert; Schwann, Alexandra N; Habib, Robert H

    2018-05-01

    The current literature on radial artery grafting is reviewed focusing on the optimal deployment of radial artery grafts in coronary artery bypass surgery with specific attention to the selection of patients and target vessels for radial artery grafting. © 2018 Wiley Periodicals, Inc.

  9. Utility of the puncture of the radial artery in interventionist radiology

    International Nuclear Information System (INIS)

    Triana Rodriguez, Carlos Eduardo; Montes S, Mauricio; Barragan F, Jaime; Ucros Diaz Pablo; Ucros Diaz, Ignacio; Castillo, Luis Fernando

    1998-01-01

    We present the radial artery access, previous evaluation of collateral circulation with Allen's Test, as an alternative vascular access in patients with contraindications for femoral or axillary approaches. The radial artery puncture offers advantages, such as diminished bleeding and hematoma formation

  10. Arterial pressure profile in patients with cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens H; Fuglsang, Stefan; Bendtsen, Flemming

    2012-01-01

    Patients with cirrhosis have cardiovascular dysfunction and altered mechanical properties of large and small arteries. This study was undertaken in order to analyze the arterial pressure curve in relation to mean arterial pressure level, stroke volume, and severity of liver disease....

  11. Aneurisma idiopático de artéria radial: relato de caso Idiopathic radial artery aneurysm: case report

    Directory of Open Access Journals (Sweden)

    Luiz Ernani Meira Jr.

    2011-12-01

    Full Text Available Os aneurismas da artéria radial são extremamente raros. Em sua maioria, consistem de pseudoaneurismas pós-traumáticos. Os aneurismas da artéria radial verdadeiros podem ser idiopáticos, congênitos, pós-estenóticos ou associados a patologias, tais como vasculites e doenças do tecido conjuntivo. Foi relatado um caso de aneurisma idiopático de artéria radial em uma criança de três anos, que, após completa investigação diagnóstica complementar, foi submetida à ressecção cirúrgica.Radial artery aneurysms are extremely rare. Post-traumatic pseudoaneurysms are the vast majority. True radial artery aneurysms can be idiopathic, congenital, poststenotic, or associated with some pathologies, such as vasculitis and conjunctive tissue diseases. We report a case of an idiopathic aneurysm of the radial artery in a three-year-old child who was submitted to surgical resection after a complete diagnostic approach.

  12. Treatment of complex internal carotid artery aneurysms using radial artery grafts. Surgical technique, perioperative complications, and results in 17 patients

    International Nuclear Information System (INIS)

    Murai, Yasuo; Teramoto, Akira; Mizunari, Takayuki; Kobayashi, Shiro; Kamiyama, Hiroyasu

    2007-01-01

    Complex giant or large internal carotid artery aneurysms present a surgical challenge because limitations and difficulty are encountered with either clipping or endovascular treatment. Our review of previous reports suggests that no current vascular assessment can accurately predict the occurrence of ischemic complications after internal carotid artery ligation. The present study concerns surgical technique, complications, and clinical outcome of radial artery grafting followed by parent artery trapping or proximal occlusion for management of these difficult lesions. Between September 1997 and October 2005, we performed radial artery grafting followed immediately by parent artery occlusion in 17 patients with giant or large complex intracranial carotid aneurysms (3 men, 14 women; mean follow-up duration, 62 months). All patients underwent postoperative digital subtraction angiography to assess graft patency and aneurysm obliteration. All 17 aneurysms were excluded from the cerebral circulation, with all radial artery grafts patent. Among 4 patients with cranial nerve disturbances, dysfunction was temporary in 5; in the others, oculomotor nerve paresis persisted. No perioperative cerebral infarction occurred. Sensory aphasia reflecting cerebral contusions caused by temporal lobe retraction resolved within 2 months, as did hemiparesis from a postoperative epidural hematoma. With appropriate attention to surgical technique, radial artery grafting followed by acute parent artery occlusion is a safe treatment for complex internal carotid artery aneurysms. Graft patency and aneurysm thrombosis were achieved in all patients. Cranial nerve dysfunction (III, VI) caused by altered blood flow from the internal carotid artery after occlusion was the most common complication and typically was temporary. In our experience with these difficult aneurysms, not only clipping but also reconstruction of the internal carotid artery was required, especially for wide-necked symptomatic

  13. Analysis of linguistic terms of variables representing the wave of arterial diameter variation in radial arteries using fuzzy entropies

    International Nuclear Information System (INIS)

    Nuno Almirantearena, F; Introzzi, A; Clara, F; Burillo Lopez, P

    2007-01-01

    In this work we use 53 Arterial Diameter Variation (ADV) waves extracted from radial artery of normotense males, along with the values of variables that represent the ADV wave, obtained by means of multivariate analysis. Then, we specify the linguistic variables and the linguistic terms. The variables are fuzzified using triangular and trapezoidal fuzzy numbers. We analyze the fuzziness of the linguistic terms by applying discrete and continuous fuzzy entropies. Finally, we infer which variable presents the greatest disorder associated to the loss of arterial elasticity in radial artery

  14. Development of a Tonometric Sensor with a Decoupled Circular Array for Precisely Measuring Radial Artery Pulse

    OpenAIRE

    Jun, Min-Ho; Kim, Young-Min; Bae, Jang-Han; Jung, Chang Jin; Cho, Jung-Hee; Jeon, Young Ju

    2016-01-01

    The radial artery pulse is one of the major diagnostic indices used clinically in both Eastern and Western medicine. One of the prominent methods for measuring the radial artery pulse is the piezoresistive sensor array. Independence among channels and an appropriate sensor arrangement are important for effectively assessing the spatial-temporal information of the pulse. This study developed a circular-type seven-channel piezoresistive sensor array using face-down bonding (FDB) as one of the s...

  15. Radial Artery as a Coronary Artery Bypass Conduit: 20-Year Results.

    Science.gov (United States)

    Gaudino, Mario; Tondi, Paolo; Benedetto, Umberto; Milazzo, Valentina; Flore, Roberto; Glieca, Franco; Ponziani, Francesca Romana; Luciani, Nicola; Girardi, Leonard N; Crea, Filippo; Massetti, Massimo

    2016-08-09

    There is a lack of evidence for the choice of the second conduit in coronary surgery. The radial artery (RA) is a possible option, but few data on very-long-term outcomes exist. This study describes 20-year results of RA grafts used for coronary artery bypass grafting and the effects of RA removal on forearm circulation. We report the results of the prospective 20-year follow-up of the first 100 consecutive patients who received the RA as a coronary bypass conduit at our institution. Follow-up was 100% complete. There were 64 deaths, 23 (35.9%) from cardiovascular causes. Kaplan-Meier 20-year survival was 31%. Of the 36 survivors, 33 (91.6%) underwent RA graft control at a mean of 19.0 ± 2.5 years after surgery. The RA was found to be patent in 24 cases (84.8% patency). In the overall population, probability of graft failure at 20 years was 19.0 ± 0.2% for the left internal thoracic artery (ITA), 25.0 ± 0.2% for the RA, and 55.0 ± 0.2% for the saphenous vein (p = 0.002 for RA vs. saphenous vein, 0.11 for RA vs. ITA, and p 90%, but not location of distal anastomosis, significantly influenced long-term RA graft patency. No patients reported hand or forearm symptoms. The ulnar artery diameter was increased in the operated arm (2.44 ± 0.43 mm vs. 2.01 ± 0.47 mm; p 90% stenosis. RA harvesting does not lead to hand or forearm symptoms, even at a very-long-term follow-up. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  16. Pre-ejection period by radial artery tonometry supplements echo doppler findings during biventricular pacemaker optimization

    Directory of Open Access Journals (Sweden)

    Qamruddin Salima

    2011-07-01

    Full Text Available Abstract Background Biventricular (Biv pacemaker echo optimization has been shown to improve cardiac output however is not routinely used due to its complexity. We investigated the role of a simple method involving computerized pre-ejection time (PEP assessment by radial artery tonometry in guiding Biv pacemaker optimization. Methods Blinded echo and radial artery tonometry were performed simultaneously in 37 patients, age 69.1 ± 12.8 years, left ventricular (LV ejection fraction (EF 33 ± 10%, during Biv pacemaker optimization. Effect of optimization on echo derived velocity time integral (VTI, ejection time (ET, myocardial performance index (MPI, radial artery tonometry derived PEP and echo-radial artery tonometry derived PEP/VTI and PEP/ET indices was evaluated. Results Significant improvement post optimization was achieved in LV ET (286.9 ± 37.3 to 299 ± 34.6 ms, p Conclusion An acute shortening of PEP by radial artery tonometry occurs post Biv pacemaker optimization and correlates with improvement in hemodynamics by echo Doppler and may provide a cost-efficient approach to assist with Biv pacemaker echo optimization.

  17. High Origin of Radial Arteries: A Report of Two Rare Cases

    Directory of Open Access Journals (Sweden)

    Dong Zhan

    2010-01-01

    Full Text Available Variations in the arterial supply of the upper limb are relatively common, with reported prevalence rates ranging from 11 to 24.4%. Of these, the most commonly encountered variation in the arm is a high origin of the radial artery. However, after consecutively dissecting and examining 600 Singaporean Chinese cadavers (1,200 upper limbs, we found only two cases of this. In both cases, the brachioradial artery originated from the upper one-third of the brachial artery and continued distally as the radial artery in the forearm. The local prevalence of 0.33% of this variation is significantly lower compared against populations from other geographical regions. Although rare, recognition of the variation is of fundamental importance to clinical practice.

  18. Radiation exposure and patient experience during percutaneous coronary intervention using radial and femoral artery access

    International Nuclear Information System (INIS)

    Geijer, Haakan; Persliden, Jan

    2004-01-01

    The aim of this study was to evaluate radiation dose and patient discomfort/pain in radial artery access vs femoral artery access in percutaneous coronary intervention (PCI). Dose-area product (DAP) was measured non-randomised for 114 procedures using femoral access and for 55 using radial access. The patients also responded to a questionnaire concerning discomfort and pain during and after the procedure. The mean DAP was 69.8 Gy cm 2 using femoral access and 70.5 Gy cm 2 using radial access. Separating the access site from confounding factors with a multiple regression, there was a 13% reduction in DAP when using radial access (p=0.038). Procedure times did not differ (p=0.81). Bed confinement was much longer in the femoral access group (448 vs 76 min, p=0.000). With femoral access, there was a significantly higher patient grading for chest (p=0.001) and back pain (p=0.003) during the procedure and for access site (p=0.000) and back pain (p=0.000) after the procedure. Thirty-two femoral access patients (28%) were given morphine-type analgesics in the post-procedure period compared to three radial access patients (5%, p=0.001). DAP does not increase when using radial instead of femoral access and the patients grade discomfort and pain much lower when using radial access. Radial access is thus beneficial to use. (orig.)

  19. Intra-arterial vasodilators to prevent radial artery spasm: a systematic review and pooled analysis of clinical studies

    Energy Technology Data Exchange (ETDEWEB)

    Kwok, Chun Shing, E-mail: shingkwok@doctors.org.uk [Keele Cardiovascular Research Group, Keele University, Stoke-on-Trent (United Kingdom); Rashid, Muhammad [St. Helens & Knowsley Teaching Hospital (NHS) Trust, Whiston Hospital, Prescot (United Kingdom); Fraser, Doug [Manchester Heart Centre, Manchester Royal Infirmary (United Kingdom); Nolan, James [University Hospital of North Midlands, Stoke-on-Trent (United Kingdom); Mamas, Mamas [Keele Cardiovascular Research Group, Keele University, Stoke-on-Trent (United Kingdom); Farr Institute, Institute of Population Health, University of Manchester, Manchester (United Kingdom)

    2015-12-15

    Objectives: The aim of this study is to review the available literature on the efficacy and safety of agents used for prevention of RAS. Background: Different vasodilator agents have been used to prevent radial artery spasm (RAS) in patients undergoing transradial cardiac catheterization. Methods: We included studies that evaluated any intra-arterial drug administered in the setting cardiac catheterization that was undertaken through the transradial access site (TRA). We also compared studies for secondary outcomes of major bleeding, procedure time, and procedure failure rate in setting of RAS prevention, patent hemostasis and radial artery occlusion. Results: 22 clinical studies met the inclusion criteria. For placebo, RAS rate was 12% (4 studies, 638 participants), which was similar to 2.5 mg of verapamil 12% (3 studies, 768 participants) but greater than 5 mg of verapamil (4%, 2 studies, 497 participants). For nicorandil, there was a much higher RAS rate compared to placebo (16%, 3 studies, 447 participants). The lowest rates of RAS was found for nitroglycerin at both 100 μg (4%) and 200 μg (2%) doses, isosorbide mononitrate (4%) and nicardipine (3%). We found no information regarding the procedure failure rates, patent hemostasis, and radial artery occlusion in these studies. Conclusions: In this largest and up-to-date review on intra-arterial vasodilators use to reduce RAS, we have found that the verapamil at a dose of 5 mg or verapamil in combination with nitroglycerine are the best combinations to reduce RAS. - Highlights: • Radial artery spasm (RAS) causes procedural failure in transradial catheterization. • RAS may complicate 10–15% procedures undertaken through the radial approach. • We reviewed the efficacy of vasodilators that have been used to minimize RAS. • The pooled RAS rate was lowest with 5 mg of verapamil (4%) compared to placebo (12%). • The best combination of drugs to minimize RAS is nitroglycerine and verapamil.

  20. Radial motion of the carotid artery wall: A block matching algorithm approach

    Directory of Open Access Journals (Sweden)

    Effat Soleimani

    2012-06-01

    Full Text Available Introduction: During recent years, evaluating the relation between mechanical properties of the arterialwall and cardiovascular diseases has been of great importance. On the other hand, motion estimation of thearterial wall using a sequence of noninvasive ultrasonic images and convenient processing methods mightprovide useful information related to biomechanical indexes and elastic properties of the arteries and assistdoctors to discriminate between healthy and diseased arteries. In the present study, a block matching basedalgorithm was introduced to extract radial motion of the carotid artery wall during cardiac cycles.Materials and Methods: The program was implemented to the consecutive ultrasonic images of thecommon carotid artery of 10 healthy men and maximum and mean radial movement of the posterior wall ofthe artery was extracted. Manual measurements were carried out to validate the automatic method andresults of two methods were compared.Results: Paired t-test analysis showed no significant differences between the automatic and manualmethods (P>0.05. There was significant correlation between the changes in the instantaneous radialmovement of the common carotid artery measured with the manual and automatic methods (withcorrelation coefficient 0.935 and P<0.05.Conclusion: Results of the present study showed that by using a semi automated computer analysismethod, with minimizing the user interfere and no attention to the user experience or skill, arterial wallmotion in the radial direction can be extracted from consecutive ultrasonic frames

  1. PROLONGED RADIAL ARTERY SPASM IN THE CATHETERIZATION LABORATORY - RELIEF BY PHARMACOLOGICAL INTERVENTION

    Directory of Open Access Journals (Sweden)

    Krishna Kumar

    2010-11-01

    Full Text Available Radial spasm is often very prolonged and painful to the patient. Here, we describe a novel way to deal with the same. The total spasm lasted over 4 hours. A 3.4 6 JR catheter was introduced via the femoral route and papav arine one ampoule was injected directly into the right subclavian artery. After about 10 min we were able to pull out the radial catheter. Radial angiography is a simple procedure with reportedly less complications 1,2. How ever ,it has one major complication radial spasm. We describe here a patient with radial spasm that persisted for more than 2 hours and how we dealt with it.

  2. [Digital necrosis in a patient with anorexia nervosa. Association of vasculopathy and radial artery injury].

    Science.gov (United States)

    Launay, D; Queyrel, V; Hatron, P Y; Michon-Pasturel, U; Hachulla, E; Devulder, B

    2000-11-13

    Patients with anorexia nervosa can develop distal vasculopathy sometimes leading to severe Raynaud's phenomenon or acrocyanosis. We report a cas of anorexia nervosa-related vasculopathy associated with iatrogenic injury to the radial artery that led to digital necrosis. An 18-year-old woman, with a history of severe anorexia nervosa of 5 years duration and who acknowledged regular use of tobacco and cannabis, was hospitalized for necrosis of the left index and thumb that had occurred shortly after left radial artery puncture for blood gas analysis. Acrocyanosis of the 4 limbs had been present since the onset of anorexia nervosa. Arteriography of the upper limbs showed major spasm of the left radial and cubital arteries and thromboses in the left interdigital arteries of the left index and thumb. The distal portions of the arteries were then on the left and on the right. The nectrotic lesions healed after intravenous administration of ilomedine and interruption of tobacco and cannabis. Acrocyanosis of the four limbs persisted. We report a case of digital necrosis occurring after arterial puncture for blood gas analysis in a patient with a vascular bed weakened by tobacco and cannabis intoxication but also by anorexia nervosa-related vasculopathy. This observation underlines the potentially dangerous nature of invasive intravascular procedures in this context. Indications for vessel puncture must be assessed with prudence.

  3. Assessing the blood pressure waveform of the carotid artery using an ultrasound image processing method

    Energy Technology Data Exchange (ETDEWEB)

    Soleimani, Effat; Mokhtari-Dizaji, Manijhe [Dept. of Medical Physics, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Fatouraee, Nasser [Dept. of Medical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Saben, Hazhir [Dept. Radiology, Imaging Center of Imam Khomaini Hospital, Tehran Medical Sciences University, Tehran (Iran, Islamic Republic of)

    2017-04-15

    The aim of this study was to introduce and implement a noninvasive method to derive the carotid artery pressure waveform directly by processing diagnostic sonograms of the carotid artery. Ultrasound image sequences of 20 healthy male subjects (age, 36±9 years) were recorded during three cardiac cycles. The internal diameter and blood velocity waveforms were extracted from consecutive sonograms over the cardiac cycles by using custom analysis programs written in MATLAB. Finally, the application of a mathematical equation resulted in time changes of the arterial pressure. The resulting pressures were calibrated using the mean and the diastolic pressure of the radial artery. A good correlation was found between the mean carotid blood pressure obtained from the ultrasound image processing and the mean radial blood pressure obtained using a standard digital sphygmomanometer (R=0.91). The mean absolute difference between the carotid calibrated pulse pressures and those measured clinically was -1.333±6.548 mm Hg. The results of this study suggest that consecutive sonograms of the carotid artery can be used for estimating a blood pressure waveform. We believe that our results promote a noninvasive technique for clinical applications that overcomes the reproducibility problems of common carotid artery tonometry with technical and anatomical causes.

  4. Assessing the blood pressure waveform of the carotid artery using an ultrasound image processing method

    International Nuclear Information System (INIS)

    Soleimani, Effat; Mokhtari-Dizaji, Manijhe; Fatouraee, Nasser; Saben, Hazhir

    2017-01-01

    The aim of this study was to introduce and implement a noninvasive method to derive the carotid artery pressure waveform directly by processing diagnostic sonograms of the carotid artery. Ultrasound image sequences of 20 healthy male subjects (age, 36±9 years) were recorded during three cardiac cycles. The internal diameter and blood velocity waveforms were extracted from consecutive sonograms over the cardiac cycles by using custom analysis programs written in MATLAB. Finally, the application of a mathematical equation resulted in time changes of the arterial pressure. The resulting pressures were calibrated using the mean and the diastolic pressure of the radial artery. A good correlation was found between the mean carotid blood pressure obtained from the ultrasound image processing and the mean radial blood pressure obtained using a standard digital sphygmomanometer (R=0.91). The mean absolute difference between the carotid calibrated pulse pressures and those measured clinically was -1.333±6.548 mm Hg. The results of this study suggest that consecutive sonograms of the carotid artery can be used for estimating a blood pressure waveform. We believe that our results promote a noninvasive technique for clinical applications that overcomes the reproducibility problems of common carotid artery tonometry with technical and anatomical causes

  5. Measurement of Blood Pressure Using an Arterial Pulsimeter Equipped with a Hall Device

    Directory of Open Access Journals (Sweden)

    Jong-Gu Choi

    2011-01-01

    Full Text Available To measure precise blood pressure (BP and pulse rate without using a cuff, we have developed an arterial pulsimeter consisting of a small, portable apparatus incorporating a Hall device. Regression analysis of the pulse wave measured during testing of the arterial pulsimeter was conducted using two equations of the BP algorithm. The estimated values of BP obtained by the cuffless arterial pulsimeter over 5 s were compared with values obtained using electronic or liquid mercury BP meters. The standard deviation between the estimated values and the measured values for systolic and diastolic BP were 8.3 and 4.9, respectively, which are close to the range of values of the BP International Standard. Detailed analysis of the pulse wave measured by the cuffless radial artery pulsimeter by detecting changes in the magnetic field can be used to develop a new diagnostic algorithm for BP, which can be applied to new medical apparatus such as the radial artery pulsimeter.

  6. Vasodilatory effect and endothelial integrity in papaverine- and milrinone-treated human radial arteries.

    Science.gov (United States)

    Rudzinski, P; Wegrzyn, P; Lis, G J; Piatek, J; Konstanty-Kalandyk, J; Nosalski, R; Mikolajczyk, T; Jasinska, M; Pyka-Fosciak, G; Guzik, T; Litwin, J A; Korbut, R; Sadowski, J

    2013-02-01

    Prevention of the vasospasm is an important aspect of coronary artery bypass grafting (CABG) with the use of radial artery (RA) as the conduit. We compared the effect of two phosphodiesterase inhibitors papaverine and milrinone on vasodilation and endothelial integrity of human RA segments harvested from 20 CABG patients. Vasodilatory effect of the drugs were assessed by organ bath technique in RA rings precontracted with KCl and phenylephrine. Endothelial integrity was evaluated by CD34 immunofluorescence in frozen sections. Vasorelaxation induced by papaverine was significantly greater as compared to that induced by milrinone (90.47% ± 10.16% vs. 78.98% ± 19.56%, pmilrinone in the preservation of endothelial integrity (75.3% ± 12.9% vs. 51.8% ± 18.0%, pmilrinone for prevention of vasospasm in radial artery conduits used for CABG.

  7. Radial artery pulse waveform analysis based on curve fitting using discrete Fourier series.

    Science.gov (United States)

    Jiang, Zhixing; Zhang, David; Lu, Guangming

    2018-04-19

    Radial artery pulse diagnosis has been playing an important role in traditional Chinese medicine (TCM). For its non-invasion and convenience, the pulse diagnosis has great significance in diseases analysis of modern medicine. The practitioners sense the pulse waveforms in patients' wrist to make diagnoses based on their non-objective personal experience. With the researches of pulse acquisition platforms and computerized analysis methods, the objective study on pulse diagnosis can help the TCM to keep up with the development of modern medicine. In this paper, we propose a new method to extract feature from pulse waveform based on discrete Fourier series (DFS). It regards the waveform as one kind of signal that consists of a series of sub-components represented by sine and cosine (SC) signals with different frequencies and amplitudes. After the pulse signals are collected and preprocessed, we fit the average waveform for each sample using discrete Fourier series by least squares. The feature vector is comprised by the coefficients of discrete Fourier series function. Compared with the fitting method using Gaussian mixture function, the fitting errors of proposed method are smaller, which indicate that our method can represent the original signal better. The classification performance of proposed feature is superior to the other features extracted from waveform, liking auto-regression model and Gaussian mixture model. The coefficients of optimized DFS function, who is used to fit the arterial pressure waveforms, can obtain better performance in modeling the waveforms and holds more potential information for distinguishing different psychological states. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. The effect of vasodilatory medications on radial artery spasm in patients undergoing transradial coronary artery procedures: a systematic review.

    Science.gov (United States)

    Curtis, Elizabeth; Fernandez, Ritin; Lee, Astin

    2017-07-01

    The uptake of percutaneous coronary procedures via the radial artery has increased internationally due to the decreased risk of complications and increased patient satisfaction. The increased susceptibility of the radial artery to spasm however presents a potential risk for procedural failure. Although most experts agree on the need for prophylactic medications to reduce radial artery spasm, currently there is inconsistency in literature regarding the most effective vasodilatory medication or combination of medications. The objective of this study is to identify the effectiveness of vasodilatory medications on radial artery spasm in patients undergoing transradial coronary artery procedures. This review considered studies that included participants aged 18 years and over undergoing non-emergent transradial percutaneous coronary artery procedures. This review considered studies that used vasodilating intravenous and intra-arterial medications or combinations of medications prior to commencing and during transradial coronary approaches to reduce radial artery spasm. The outcomes of interest were the incidence of radial artery spasm during percutaneous coronary procedure using objective and/or subjective measures and its effect on the successful completion of the procedure. Randomized controlled trials published in the English language between 1989 to date were considered for inclusion. The search strategy aimed to find both published and unpublished studies. A three-step search strategy was utilized in this review. An initial search of MEDLINE, CINAHL and Scopus was undertaken, followed by a search for unpublished studies. Papers selected for retrieval were assessed by two independent reviewers for methodological validity prior to inclusion in the review using standardized critical appraisal instruments. Any disagreements that arose between the reviewers were resolved through discussion. Quantitative data was extracted from papers included in the review using the

  9. Evaluación de hipertensos en base a registros de variación de diámetro arterial radial Evaluation of hypertensive patients by radial arterial diameter variation recording

    Directory of Open Access Journals (Sweden)

    Fernando M. Clara

    2006-12-01

    Full Text Available Se utilizó la técnica de análisis del registro incruento de las variaciones de diámetro de arteria radial para evaluar el deterioro arterial y el riesgo cardiovascular en pacientes hipertensos. El transductor utilizado consistió en un sensor de movimiento apoyado sobre la zona de palpación del pulso radial. Se efectuó la determinación del índice de aumentación radial, un parámetro que cuantifica la magnitud de las reflexiones de la onda de presión en la región aórtica, sobre un conjunto de 47 hipertensos, y se lo comparó con otro estudio similar efectuado sobre 81 normotensos sanos. Estos últimos presentaron menores valores de dicho índice, pero al avanzar la edad los valores de ambos grupos tendieron a coincidir. Esto fue confirmado al comparar morfológicamente los registros de ambos grupos, hallándose que los registros de ancianos normotensos sanos e hipertensos de edades similares resultaron visiblemente parecidos. Se halló también que determinados hipertensos jóvenes presentaron ciertas características morfológicas similares a las de normotensos de la misma edad, indicando que aún conservaban las características elásticas propias de su grupo etario. Los resultados fueron similares a los logrados sobre registros de presión arterial radial obtenidos mediante tonometría de aplanación, utilizándose una tecnología disponible en nuestro medio y de menor costo.A blood less analysis technique of the diameter variation signal at radial artery was used to evaluate the arterial disease and the cardiovascular risk in hypertensive patients. A movement transducer was used to record the wrist pulse. A radial augmentation index was proposed to quantify the magnitude of the pressure wave reflections in the aortic region. The experiment was carried out with a group of 47 hypertensive men and compared with a similar study performed on 81 normotensive healthy men. The last ones presented smaller values of this index, but as age

  10. Combined Endovascular Treatment with Distal Radial Artery Coil Embolization and Angioplasty in Steal Syndrome Associated with Forearm Dialysis Fistula

    Energy Technology Data Exchange (ETDEWEB)

    Tercan, Fahri, E-mail: ftercan@yahoo.com; Koçyiğit, Ali, E-mail: alkoc@yahoo.com [Pamukkale University, Department of Radiology, School of Medicine (Turkey); Güney, Bünyamin [Muğla Sıtkı Kocman University, Department of Radiology, School of Medicine (Turkey)

    2016-09-15

    PurposeThe present study was performed to define the results of the endovascular treatment with angioplasty and distal radial artery embolization in ischemic steal syndrome associated with forearm arteriovenous accesses.MethodThe cases referred to our interventional radiology unit with symptoms and physical examination findings suggestive of ischemic steal syndrome were retrospectively evaluated first by Doppler ultrasonography, and then by angiography. Cases with proximal artery stenosis were applied angioplasty, and those with steal syndrome underwent coil embolization to distal radial artery.ResultsOf 589 patients who underwent endovascular intervention for dialysis arteriovenous fistulae (AVF)-associated problems, 6 (1.01 %) (5 female, 1 males; mean age 62 (range 41–78) with forearm fistula underwent combined endovascular treatment for steal syndrome. In addition to steal phenomenon, there were stenosis and/or occlusion in proximal radial and/or ulnar artery in 6 patients concurrently. Embolization of distal radial artery and angioplasty to proximal arterial stenoses were performed in all patients. Ischemic symptoms were eliminated in all patients and the AVF were in use at the time of study. In one patient, ischemic symptoms recurring 6 months later were alleviated by repeat angioplasty of ulnar artery.ConclusionIn palmar arch steal syndrome affecting forearm fistulae, combined distal radial embolization and angioplasty is also an effective treatment method in the presence of proximal radial and ulnar arterial stenoses and occlusions.

  11. Complications and nursing care in interventional treatment of diabetic foot via radial artery access

    International Nuclear Information System (INIS)

    Liu Lingyun; Zhou Xiaoxiang; Zeng Yongmei; Chen Junfei; Lai Lisha; Pang Pengfei; Zhu Kangshun

    2009-01-01

    Objective: To evaluate the therapeutic effect of interventional treatment via radial artery access for diabetic foot and to summarize its complications and nursing care. Methods: The interventional treatment via radial artery access was performed in twenty patients with diabetic foot. The preoperative psychological nursing care, the nursing of the punctured site of radial artery and the indwelling catheter, the complications of the puncture site and thrombolytic therapy were reviewed and retrospectively analyzed. Results: Some complications occurred in eight cases, including hematoma at puncture site (n= 1), oozing of blood (n=3), gingival bleeding (n=1) and pain (n=3). No retention of urine or infection occurred. Conclusion: It is very important to pay enough attention to the nursing care of puncture site and indwelling catheter sheath and to make a close observation of patient's condition in order to reduce the occurrence of complications. Rich clinical experience and careful observation after the operation can definitely reduce the occurrence of thrombolytic complications and improve the patient's living quality. (authors)

  12. Ultrasound evaluation of forearm arteries in patients undergoing percutaneous coronary intervention via radial artery access: results of one-year follow-up.

    Science.gov (United States)

    Peruga, Jan Przemysław; Peruga, Jan Zbigniew; Kasprzak, Jarosław D; Kręcki, Radosław; Jankowski, Łukasz; Zając, Piotr; Plewka, Michał

    2015-01-01

    A proven advantage of radial over femoral arterial access has led to an increase in the number of interventions performed via radial artery access in patients with acute coronary syndromes. Both assessment of the pulse volume and the Allen's test are subjective and subject to investigator bias. An ultrasound examination of the forearm arteries provides important information about the anatomy of the forearm vessels, and indirectly also about the efficiency of collateral blood supply to the hand. It also enables determination of the relevant vessel diameter before the planned intervention, and may be used to assess local complications. To assess the morphology of forearm blood vessels and measure the diameter of both radial and ulnar arteries at the cannulation site using ultrasound imaging. We also aimed to identify potential vascular anomalies and local complications associated with radial artery puncture. The study included 109 patients with cardiologic indications for coronary angiography or coronary angioplasty. An ultrasound evaluation of forearm arteries was performed prior to the intervention, and the vascular anatomy was later verified by angiography during the procedure. Ultrasound measurements of the vessel diameter were also performed and local complications of the cannulation were assessed. Measurements were performed immediately after the procedure and at 30 days and 12 months. Fifty-nine right and 50 left forearm arteries were evaluated. Women were 29% of the study population. The mean patient age was 59.2 ± 7.9 years. The mean diameter of the right radial artery was 2.17 ± 0.54 mm, and the mean diameter of the left radial artery was 2.25 ± 0.43 mm. The measurements revealed gender-related differences in forearm artery diameter (p = 0.003). Vascular anomalies of the radial artery were identified by ultrasound examination in 10% of subjects. A significant dilatation of the cannulated blood vessel was observed which lasted up to 12 months. An

  13. Combined Radial-Pedal Access Strategy and Radial-Pedal Rendezvous in the Revascularization of Complex Total Occlusions of the Superficial Femoral Artery (the "No Femoral Access" Strategy).

    Science.gov (United States)

    Hanna, Elias B; Prout, Davey L

    2016-04-01

    To describe the combined use of radial-pedal access for recanalization of complex superficial femoral artery (SFA) occlusions unsuitable for transfemoral recanalization. Patients are selected for this strategy if they have a long (≥ 10 cm) SFA occlusion with unfavorable aortoiliac anatomy, an absent ostial stump, or severely diseased and calcified distal reconstitution. Left radial artery and distal anterior or posterior tibial artery are accessed with 6-F and 4-F sheaths, respectively. The SFA lesion is crossed retrogradely with a 0.035-inch wire system. If retrograde crossing is not immediately successful, transradial subintimal tracking and radial-pedal subintimal rendezvous are used to allow retrograde reentry. Fifteen patients (mean age 62 ± 5 years; 11 men) have been treated in this fashion, and frequently stented, through the tibiopedal access. Seven patients required radial-pedal rendezvous to facilitate retrograde reentry. Two patients underwent transradial iliac stenting during the same session, and 1 patient underwent transradial kissing angioplasty of the profunda. No major complication occurred in any patient. After the procedure, the pulse across the accessed tibial artery was palpable in all patients. In patients with long and complex SFA occlusion unsuitable for transfemoral recanalization, a radial-pedal strategy can overcome revascularization obstacles. © The Author(s) 2016.

  14. A new noninvasive device for continuous arterial blood pressure monitoring in the superficial temporal artery

    International Nuclear Information System (INIS)

    Chin, K Y; Panerai, R B

    2013-01-01

    Continuous recording of arterial blood pressure (ABP) has many applications in cardiovascular physiology, but existing alternatives rely on measurements performed in the fingers or radial artery. Peripheral recordings have significant differences from central ABP regarding the pattern of the waveform and corresponding systolic and diastolic values. To address the need for noninvasive measurements closer to the ascending aorta, a new device was constructed to measure ABP in the superficial temporal artery (STA) using photoplethysmography and the arterial volume clamping technique. The optoelectronic circuitry to generate the photoplethysmogram is contained in a specially designed probe placed over the STA and kept in place with a head frame. The prototype (STAbp) also includes original designs for the pneumatic, electronic, signal processing, control and display sub-systems. A self-calibration feature regularly updates the photoplethysmogram operating point to improve accuracy. The performance of the STAbp was compared against the Finapres in 19 healthy subjects. At rest, the bias (SD d ) was −23.1 (15.05), −10.8 (13.83) and −12.4 (12.93) mmHg for systolic, mean and diastolic pressures respectively, without significant differences in drift between the two devices. The 99% bandwidth (SD) for the spectral distribution of ABP waveforms was 5.3 (1.46) Hz for STAbp and 6.8 (0.73) Hz for the Finapres (p < 0.01). Handgrip manoeuvre showed a very similar response to the Finapres, including the rapid return to baseline on release. The new STAbp device has considerable potential as a new tool for clinical and research applications where continuous recording of more central ABP is advantageous compared to peripheral alternatives. (paper)

  15. Transluminal recanalization of chronic total occlusion of radial artery using rendezvous technique: a case report and literature review.

    Science.gov (United States)

    Arabi, Mohammad; Ahmed, Ishtiaq; Qattan, Nabeel

    2014-01-01

    Although endovascular management of lower extremity peripheral arterial disease (PAD) is well studied, little information exists regarding endovascular treatment of critical upper limb ischemia. We report a case of transluminal recanalization of right radial artery chronic total occlusion (CTO) using rendezvous technique in a patient with critical hand ischemia and dry gangrene of the right index finger.

  16. Transluminal Recanalization of Chronic Total Occlusion of Radial Artery Using Rendezvous Technique: A Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Mohammad Arabi

    2014-01-01

    Full Text Available Although endovascular management of lower extremity peripheral arterial disease (PAD is well studied, little information exists regarding endovascular treatment of critical upper limb ischemia. We report a case of transluminal recanalization of right radial artery chronic total occlusion (CTO using rendezvous technique in a patient with critical hand ischemia and dry gangrene of the right index finger.

  17. radial

    Directory of Open Access Journals (Sweden)

    JOHN WILLIAM BRANCH

    2007-01-01

    Full Text Available La creación de modelos de objetos reales es una tarea compleja para la cual se ha visto que el uso de técnicas tradicionales de modelamiento tiene restricciones. Para resolver algunos de estos problemas, los sensores de rango basados en láser se usan con frecuencia para muestrear la superficie de un objeto desde varios puntos de vista, lo que resulta en un conjunto de imágenes de rango que son registradas e integradas en un modelo final triangulado. En la práctica, debido a las propiedades reflectivas de la superficie, las oclusiones, y limitaciones de acceso, ciertas áreas de la superficie del objeto usualmente no son muestreadas, dejando huecos que pueden crear efectos indeseables en el modelo integrado. En este trabajo, presentamos un nuevo algoritmo para el llenado de huecos a partir de modelos triangulados. El algoritmo comienza localizando la frontera de las regiones donde están los huecos. Un hueco consiste de un camino cerrado de bordes de los triángulos en la frontera que tienen al menos un borde que no es compartido con ningún otro triangulo. El borde del hueco es entonces adaptado mediante un B-Spline donde la variación promedio de la torsión del la aproximación del B-spline es calculada. Utilizando un simple umbral de la variación promedio a lo largo del borde, se puede clasificar automáticamente, entre huecos reales o generados por intervención humana. Siguiendo este proceso de clasificación, se usa entonces una versión automatizada del interpolador de funciones de base radial para llenar el interior del hueco usando los bordes vecinos.

  18. Ulnar Artery Compression: A Feasible and Effective Approach to Prevent the Radial Artery Occlusion after Coronary Intervention

    Directory of Open Access Journals (Sweden)

    Jun Tian

    2015-01-01

    Full Text Available Background: Radial artery (RA occlusion (RAO is not rare in patients undergoing coronary intervention by transradial approach (TRCI. Predictors of and prevention from RAO have not been systematically studied. This study aimed to analyze the risk factors of the weakness of RA pulsation (RAP and its predictive value for RAO after TRCI, and simultaneously to describe a feasible and effective approach to maintain RA patency. Methods: Between June 2006 and March 2010, all patients who underwent TRCI were classified according to the weakness of RAP after removing compression bandage with confirmation by Doppler ultrasound for the first 30 consecutive patients. Among a total of 2658 patients studied, 187 (7% patients having a weaker RAP were prospectively monitored. At 1 h after bandage removal, the ulnar artery in puncture side of all patients was blocked with manual compression to favor brachial and collateral artery blood flow through the RA until a good RAP was restored. The primary analysis was the occurrence of RAO. Results: Doppler ultrasound demonstrated the significant reduction of both systolic velocity (61.24 ± 3.95 cm/s vs. 72.31 ± 3.57 cm/s and diastolic velocity (1.83 ± 0.32 cm/s vs. 17.77 ± 3.97 cm/s in RA at access side as compared to the contralateral RA (all P < 0.001, but these velocities in ipsilateral ulnar artery (81.2 ± 2.16 cm/s and 13.1 ± 2.86 cm/s, respectively increased profoundly. The average time of ulnar artery compression was 4.1 ± 1.2 h (ranged 2.5-6.5 h. There were two patients experienced persistent RAO with a success rate of 98.9% and RAO in 0.075% of patients after ulnar artery compression was applied. The pulsation of the ulnar artery after compression was removed had not been influenced by the compression. Conclusions: After intervention using TRCI approach, the presence of a weaker RAP is an indicator of imminent RAO. The continuing compression of ipsilateral ulnar artery is an effective approach to

  19. Energy harvesting from arterial blood pressure for powering embedded brain sensors

    Science.gov (United States)

    Nanda, Aditya; Karami, M. Amin

    2016-04-01

    This paper investigates energy harvesting from arterial blood pressure via the piezoelectric effect by using a novel streaked cylinder geometry for the purpose of powering embedded micro-sensors in the brain. Initially, we look at the energy harvested by a piezoelectric cylinder placed inside an artery acted upon by blood pressure. Such an arrangement would be tantamount to constructing a stent out of piezoelectric materials. A stent is a cylinder placed in veins and arteries to prevent obstruction in blood flow. The governing equations of a conductor coated piezoelectric cylinder are obtained using Hamilton's principle. Pressure acting in arteries is radially directed and this is used to simplify the modal analysis and obtain the transfer function relating pressure to the induced voltage across the surface of the harvester. The power harvested by the cylindrical harvester is obtained for different shunt resistances. Radially directed pressure occurs elsewhere and we also look at harvesting energy from oil flow in pipelines. Although the energy harvested by the cylindrical energy harvester is significant at resonance, the natural frequency of the system is found to be very high. To decrease the natural frequency, we propose a novel streaked stent design by cutting it along the length, transforming it to a curved plate and decreasing the natural frequency. The governing equations corresponding to the new geometry are derived using Hamilton's principle and modal analysis is used to obtain the transfer function.

  20. Determination of the luminal diameter of the radial artery in man by high frequency ultrasound

    DEFF Research Database (Denmark)

    Nielsen, T H; Iversen, Helle Klingenberg; Tfelt-Hansen, P

    1990-01-01

    measurements. By comparing the diameter of the reference object either filled with water or blood at 37 degrees C, the ultrasound velocity in human blood at 37 degrees C was calculated to be 1605 m/s. The intraobserver repeatability coefficients of in-vivo measurements of the radial artery in man were...... in the same range, whether measurements were repeated after 30 min (14%) or from day to day (12%). The interobserver repeatability coefficient was acceptable (15%) when the site of measurements was marked, whereas measurements without a mark resulted in a repeatability coefficient of 24%. The intravenous...

  1. Radial Pressure Pulse and Heart Rate Variability in Heat- and Cold-Stressed Humans

    Directory of Open Access Journals (Sweden)

    Chin-Ming Huang

    2011-01-01

    Full Text Available This study aims to explore the effects of heat and cold stress on the radial pressure pulse (RPP and heart rate variability (HRV. The subjects immersed their left hand into 45°C and 7°C water for 2 minutes. Sixty healthy subjects (age 25±4 yr; 29 men and 31 women were enrolled in this study. All subjects underwent the supine temperature measurements of the bilateral forearms, brachial arterial blood pressure, HRV and RPP with a pulse analyzer in normothermic conditions, and thermal stresses. The power spectral low-frequency (LF and high-frequency (HF components of HRV decreased in the heat test and increased in the cold test. The heat stress significantly reduced radial augmentation index (AIr (P<.05, but the cold stress significantly increased AIr (P<.01. The spectral energy of RPP did not show any statistical difference in 0∼10 Hz region under both conditions, but in the region of 10∼50 Hz, there was a significant increase (P<.01 in the heat test and a significant decrease in the cold test (P<.01. The changes in AIr induced by heat and cold stress were significantly negatively correlated with the spectral energy in the region of 10∼50 Hz (SE10−50 Hz but not in the region of 0∼10 Hz (SE0−10 Hz. The results demonstrated that the SE10−50 Hz, which only possessed a small percentage in total pulse energy, presented more physiological characteristics than the SE0−10 Hz under the thermal stresses.

  2. Radial Pressure Pulse and Heart Rate Variability in Heat- and Cold-Stressed Humans

    Science.gov (United States)

    Huang, Chin-Ming; Chang, Hsien-Cheh; Kao, Shung-Te; Li, Tsai-Chung; Wei, Ching-Chuan; Chen, Chiachung; Liao, Yin-Tzu; Chen, Fun-Jou

    2011-01-01

    This study aims to explore the effects of heat and cold stress on the radial pressure pulse (RPP) and heart rate variability (HRV). The subjects immersed their left hand into 45°C and 7°C water for 2 minutes. Sixty healthy subjects (age 25 ± 4 yr; 29 men and 31 women) were enrolled in this study. All subjects underwent the supine temperature measurements of the bilateral forearms, brachial arterial blood pressure, HRV and RPP with a pulse analyzer in normothermic conditions, and thermal stresses. The power spectral low-frequency (LF) and high-frequency (HF) components of HRV decreased in the heat test and increased in the cold test. The heat stress significantly reduced radial augmentation index (AIr) (P < .05), but the cold stress significantly increased AIr (P < .01). The spectral energy of RPP did not show any statistical difference in 0 ~ 10 Hz region under both conditions, but in the region of 10 ~ 50 Hz, there was a significant increase (P < .01) in the heat test and a significant decrease in the cold test (P < .01). The changes in AIr induced by heat and cold stress were significantly negatively correlated with the spectral energy in the region of 10 ~ 50 Hz (SE10−50 Hz) but not in the region of 0 ~ 10 Hz (SE0−10 Hz). The results demonstrated that the SE10−50 Hz, which only possessed a small percentage in total pulse energy, presented more physiological characteristics than the SE0−10 Hz under the thermal stresses. PMID:21113292

  3. Study of radial die-wall pressure changes during pharmaceutical powder compaction.

    Science.gov (United States)

    Abdel-Hamid, Sameh; Betz, Gabriele

    2011-04-01

    In tablet manufacturing, less attention is paid to the measurement of die-wall pressure than to force-displacement diagrams. Therefore, the aim of this study was to investigate radial stress change during pharmaceutical compaction. The Presster(TM), a tablet-press replicator, was used to characterize compaction behavior of microcrystalline cellulose (viscoelastic), calcium hydrogen phosphate dihydrate (brittle), direct compressible mannitol (plastic), pre-gelatinized starch (plastic/elastic), and spray dried lactose monohydrate (plastic/brittle) by measuring radial die-wall pressure; therefore powders were compacted at different (pre) compaction pressures as well as different speeds. Residual die-wall pressure (RDP) and maximum die-wall pressure (MDP) were measured. Various tablet physical properties were correlated to radial die-wall pressure. With increasing compaction pressure, RDP and MDP (P compaction behavior of materials and detecting friction phenomena in the early stage of development.

  4. A Novel Interpretation for Arterial Pulse Pressure Amplification in Health and Disease

    Directory of Open Access Journals (Sweden)

    Manuel R. Alfonso

    2018-01-01

    Full Text Available Arterial pressure waves have been described in one dimension using several approaches, such as lumped (Windkessel or distributed (using Navier-Stokes equations models. An alternative approach consists of modeling blood pressure waves using a Korteweg-de Vries (KdV equation and representing pressure waves as combinations of solitons. This model captures many key features of wave propagation in the systemic network and, in particular, pulse pressure amplification (PPA, which is a mechanical biomarker of cardiovascular risk. The main objective of this work is to compare the propagation dynamics described by a KdV equation in a human-like arterial tree using acquired pressure waves. Furthermore, we analyzed the ability of our model to reproduce induced elastic changes in PPA due to different pathological conditions. To this end, numerical simulations were performed using acquired central pressure signals from different subject groups (young, adults, and hypertensive as input and then comparing the output of the model with measured radial artery pressure waveforms. Pathological conditions were modeled as changes in arterial elasticity (E. Numerical results showed that the model was able to propagate acquired pressure waveforms and to reproduce PPA variations as a consequence of elastic changes. Calculated elasticity for each group was in accordance with the existing literature.

  5. Comparison of femoropopliteal artery stents under axial and radial compression, axial tension, bending, and torsion deformations.

    Science.gov (United States)

    Maleckis, Kaspars; Deegan, Paul; Poulson, William; Sievers, Cole; Desyatova, Anastasia; MacTaggart, Jason; Kamenskiy, Alexey

    2017-11-01

    High failure rates of Peripheral Arterial Disease (PAD) stenting appear to be associated with the inability of certain stent designs to accommodate severe biomechanical environment of the femoropopliteal artery (FPA) that bends, twists, and axially compresses during limb flexion. Twelve Nitinol stents (Absolute Pro, Supera, Lifestent, Innova, Zilver, Smart Control, Smart Flex, EverFlex, Viabahn, Tigris, Misago, and Complete SE) were quasi-statically tested under bench-top axial and radial compression, axial tension, bending, and torsional deformations. Stents were compared in terms of force-strain behavior, stiffness, and geometrical shape under each deformation mode. Tigris was the least stiff stent under axial compression (6.6N/m axial stiffness) and bending (0.1N/m) deformations, while Smart Control was the stiffest (575.3N/m and 105.4N/m, respectively). Under radial compression Complete SE was the stiffest (892.8N/m), while Smart Control had the lowest radial stiffness (211.0N/m). Viabahn and Supera had the lowest and highest torsional stiffness (2.2μNm/° and 959.2μNm/°), respectively. None of the 12 PAD stents demonstrated superior characteristics under all deformation modes and many experienced global buckling and diameter pinching. Though it is yet to be determined which of these deformation modes might have greater clinical impact, results of the current analysis may help guide development of new stents with improved mechanical characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Pressure anisotropy and radial stress balance in the Jovian neutral sheet

    Science.gov (United States)

    Paranicas, C. P.; Mauk, B. H.; Krimigis, S. M.

    1991-01-01

    By examining particle and magnetic field data from the Voyager 1 and 2 spacecraft, signatures were found indicating that the (greater than about 28 keV) particle pressure parallel to the magnetic field is greater than the pressure perpendicular to the field within the nightside neutral sheet (three nightside neutral sheet crossings, with favorable experimental conditions, were used). By incorporating the pressure anisotropy into the calculation of radial forces within the hightside neutral sheet, it is found that (1) force balance is approximately achieved and (2) the anisotropy force term provides the largest contribution of the other particle forces considered (pressure gradients and the corotation centrifugal force). With regard to the problem of understanding the balance of radial forces within the dayside neutral sheet (McNutt, 1984; Mauk and Krimigis, 1987), the nightside pressure anisotropy force is larger than the dayside pressure gradient forces at equivalent radial distances; however, a full accounting of the dayside regions remains to be achieved.

  7. Determinants of systemic zero-flow arterial pressure.

    Science.gov (United States)

    Brunner, M J; Greene, A S; Sagawa, K; Shoukas, A A

    1983-09-01

    Thirteen pentobarbital-anesthetized dogs whose carotid sinuses were isolated and perfused at a constant pressure were placed on total cardiac bypass. With systemic venous pressure held at 0 mmHg (condition 1), arterial inflow was stopped for 20 s at intrasinus pressures of 50, 125, and 200 mmHg. Zero-flow arterial pressures under condition 1 were 16.2 +/- 1.3 (SE), 13.8 +/- 1.1, and 12.5 +/- 0.8 mmHg, respectively. In condition 2, the venous outflow tube was clamped at the instant of stopping the inflow, causing venous pressure to rise. The zero-flow arterial pressures were 19.7 +/- 1.3, 18.5 +/- 1.4, and 16.4 +/- 1.2 mmHg for intrasinus pressures of 50, 125, and 200 mmHg, respectively. At all levels of intrasinus pressure, the zero-flow arterial pressure in condition 2 was higher (P less than 0.005) than in condition 1. In seven dogs, at an intrasinus pressure of 125 mmHg, epinephrine increased the zero-flow arterial pressure by 3.0 mmHg, whereas hexamethonium and papaverine decreased the zero-flow arterial pressure by 2 mmHg. Reductions in the hematocrit from 52 to 11% resulted in statistically significant changes (P less than 0.01) in zero-flow arterial pressures. Thus zero-flow arterial pressure was found to be affected by changes in venous pressure, hematocrit, and vasomotor tone. The evidence does not support the literally interpreted concept of the vascular waterfall as the model for the finite arteriovenous pressure difference at zero flow.

  8. Experimental Feasibility Study of Estimation of the Normalized Central Blood Pressure Waveform from Radial Photoplethysmogram

    Directory of Open Access Journals (Sweden)

    Edmond Zahedi

    2015-01-01

    Full Text Available The feasibility of a novel system to reliably estimate the normalized central blood pressure (CBPN from the radial photoplethysmogram (PPG is investigated. Right-wrist radial blood pressure and left-wrist PPG were simultaneously recorded in five different days. An industry-standard applanation tonometer was employed for recording radial blood pressure. The CBP waveform was amplitude-normalized to determine CBPN. A total of fifteen second-order autoregressive models with exogenous input were investigated using system identification techniques. Among these 15 models, the model producing the lowest coefficient of variation (CV of the fitness during the five days was selected as the reference model. Results show that the proposed model is able to faithfully reproduce CBPN (mean fitness = 85.2% ± 2.5% from the radial PPG for all 15 segments during the five recording days. The low CV value of 3.35% suggests a stable model valid for different recording days.

  9. Gravitational collapse from smooth initial data with vanishing radial pressure

    International Nuclear Information System (INIS)

    Mahajan, Ashutosh; Goswami, Rituparno; Joshi, Pankaj S

    2005-01-01

    We study here the spherical gravitational collapse assuming initial data to be necessarily smooth, as motivated by requirements based on physical reasonableness. A tangential pressure model is constructed and analysed in order to understand the final fate of collapse explicitly in terms of the density and pressure parameters at the initial epoch from which the collapse develops. It is seen that both black holes and naked singularities are produced as collapse end states even when the initial data are smooth. We show that the outcome is decided entirely in terms of the initial data, as given by density, pressure and velocity profiles at the initial epoch, from which the collapse evolves

  10. Intravascular Papillary Endothelial Hyperplasia (Masson’s Tumor) of the Radial Artery: A Case Report

    International Nuclear Information System (INIS)

    Stark, Christopher; Olsen, Daniel; Morris, Christopher; Bertges, Daniel; Najarian, Kenneth

    2016-01-01

    Intravascular papillary endothelial hyperplasia (IPEH), often referred to as Masson’s tumor, is a benign non-neoplastic vascular lesion of the skin and subcutaneous tissues. Although it is rare, knowledge of the existence of IPEH is important as it can mimic other benign and malignant tumors, most notably angiosarcoma. IPEH remains an incompletely understood entity; however, most consider it to be the result of reactive endothelial proliferation following thrombus formation within a vessel, vascular malformation, or adjacent to a vessel. In this article, we report a case of IPEH arising within an arteriovenous malformation of the radial artery and present accompanying multimodality imaging and pathology figures. We will also describe the clinical presentation, pathophysiology, histology, imaging features, and management of IPEH.

  11. Intravascular Papillary Endothelial Hyperplasia (Masson’s Tumor) of the Radial Artery: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Stark, Christopher, E-mail: Christopher.stark@uvmhealth.org [University of Vermont Medical Center, Department of Radiology (United States); Olsen, Daniel [Mayo Clinic, Department of Pathology (United States); Morris, Christopher [University of Vermont Medical Center, Department of Radiology (United States); Bertges, Daniel [University of Vermont Medical Center, Department of Surgery (United States); Najarian, Kenneth [University of Vermont Medical Center, Department of Radiology (United States)

    2016-11-15

    Intravascular papillary endothelial hyperplasia (IPEH), often referred to as Masson’s tumor, is a benign non-neoplastic vascular lesion of the skin and subcutaneous tissues. Although it is rare, knowledge of the existence of IPEH is important as it can mimic other benign and malignant tumors, most notably angiosarcoma. IPEH remains an incompletely understood entity; however, most consider it to be the result of reactive endothelial proliferation following thrombus formation within a vessel, vascular malformation, or adjacent to a vessel. In this article, we report a case of IPEH arising within an arteriovenous malformation of the radial artery and present accompanying multimodality imaging and pathology figures. We will also describe the clinical presentation, pathophysiology, histology, imaging features, and management of IPEH.

  12. Tire-rim interface pressure of a commercial vehicle wheel under radial loads: theory and experiment

    Science.gov (United States)

    Wan, Xiaofei; Shan, Yingchun; Liu, Xiandong; He, Tian; Wang, Jiegong

    2017-11-01

    The simulation of the radial fatigue test of a wheel has been a necessary tool to improve the design of the wheel and calculate its fatigue life. The simulation model, including the strong nonlinearity of the tire structure and material, may produce accurate results, but often leads to a divergence in calculation. Thus, a simplified simulation model in which the complicated tire model is replaced with a tire-wheel contact pressure model is used extensively in the industry. In this paper, a simplified tire-rim interface pressure model of a wheel under a radial load is established, and the pressure of the wheel under different radial loads is tested. The tire-rim contact behavior affected by the radial load is studied and analyzed according to the test result, and the tire-rim interface pressure extracted from the test result is used to evaluate the simplified pressure model and the traditional cosine function model. The results show that the proposed model may provide a more accurate prediction of the wheel radial fatigue life than the traditional cosine function model.

  13. Endothelial dysfunction and the occurrence of radial artery spasm during transradial coronary procedures: The ACRA-Spasm study

    NARCIS (Netherlands)

    Van Der Heijden, D.J. (Dirk J.); M.A.H. van Leeuwen (Maarten); G.N. Janssens (Gladys N.); Hermie, J. (Jailen); M.J. Lenzen (Mattie); M.J.P.F. Ritt; P.M. van de Ven (Peter); F. Kiemeneij (Ferdinand); N. van Royen (Niels)

    2016-01-01

    textabstractAims: The aim of this study was to analyse the relation between endothelial dysfunction (ED) and the occurrence of radial artery spasm (RAS) during transradial coronary procedures. Methods and results: From May 2014 to June 2015, endothelial function was assessed by EndoPAT and FMD

  14. Lack of tolerance of headache and radial artery diameter during a 7 hour intravenous infusion of nitroglycerin

    DEFF Research Database (Denmark)

    Iversen, Helle Klingenberg; Nielsen, T H; Tfelt-Hansen, P

    1993-01-01

    . The intensity of the headache was mild to medium (median headache score 3, range 1-7). The mean dilatation of the radial artery was 36%. The dilatation in each individual, was stable over time, both during NTG and placebo, and it did not change with the double infusion rate. The headache score in each......Nitroglycerin-(NTG)-induced headache and dilatation of the radial artery were followed in a double blind, randomized, placebo-controlled, cross-over study in 6 healthy volunteers. NTG 0.5 microgram.kg-1 x min-1 or saline were infused i.v. for 7 h, and subsequently the infusion rate was doubled...... individual was more fluctuant. No tolerance either to the NTG-induced headache or arterial dilatation was observed....

  15. Long-term facial artery catheter implantation for serial arterial blood sampling and invasive arterial blood pressure measurement in horses.

    Science.gov (United States)

    Dias, Deborah Penteado Martins; Teixeira, Luisa Gouvêa; Canola, Paulo Aléscio; Albernaz, Raquel Mincarelli; Marques, José Antônio; Neto, José Corrêa de Lacerda

    2012-06-01

    The purpose of this investigation was to evaluate surgical catheter implantation in the facial artery of horses and the long-term maintenance of such arteries using heparin and ascorbic acid as filling solution. Nine horses were implanted with a polyurethane catheter. The catheters were flushed with a heparin/ascorbic acid solution every 8h and remained patent for 25 days. Arterial blood samples were collected twice a day, and one exercise test that included serial blood samples and arterial pressure recordings was performed on a treadmill. Polyurethane catheters surgically implanted in the facial artery can be kept patent by filling with a heparin/ascorbic acid solution and provide convenient invasive arterial access in horses which is suitable for use for serial blood sampling and blood pressure recordings, even during exercise on treadmill. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Dual-modality arterial pulse monitoring system for continuous blood pressure measurement.

    Science.gov (United States)

    Wen-Xuan Dai; Yuan-Ting Zhang; Jing Liu; Xiao-Rong Ding; Ni Zhao

    2016-08-01

    Accurate and ambulatory measurement of blood pressure (BP) is essential for efficient diagnosis, management and prevention of cardiovascular diseases (CVDs). However, traditional cuff-based BP measurement methods provide only intermittent BP readings and can cause discomfort with the occlusive cuff. Although pulse transit time (PTT) method is promising for cuffless and continuous BP measurement, its pervasive use is restricted by its limited accuracy and requirement of placing sensors on multiple body sites. To tackle these issues, we propose a novel dual-modality arterial pulse monitoring system for continuous blood pressure measurement, which simultaneously records the pressure and photoplethysmography (PPG) signals of radial artery. The obtained signals can be used to generate a pressure-volume curve, from which the elasticity index (EI) and viscosity index (VI) can be extracted. Experiments were carried out among 7 healthy subjects with their PPG, ECG, arterial pressure wave and reference BP collected to examine the effectiveness of the proposed indexes. The results of this study demonstrate that a linear regression model combining EI and VI has significantly higher BP tracking correlation coefficient as compared to the PTT method. This suggests that the proposed system and method can potentially be used for convenient and continuous blood pressure estimation with higher accuracy.

  17. Treatment of giant and large fusiform middle cerebral artery aneurysms with excision and interposition radial artery graft in a 4-year-old child: case report.

    Science.gov (United States)

    Mrak, Goran; Paladino, Josip; Stambolija, Vasilije; Nemir, Jakob; Sekhar, Laligam N

    2014-03-01

    We report an unusual case of complex giant and large fusiform aneurysms not amenable for clipping or coiling in a 4-year-old child managed with aneurysm resection and radial artery interposition graft. A 4-year-old child presented with repeated severe headache and vomiting. Computed tomography, magnetic resonance imaging, and magnetic resonance angiography and digital subtraction angiography showed a giant fusiform aneurysm on the right middle cerebral artery (MCA). Because of the complex shape, endovascular treatment or clip reconstruction was not possible, and a bypass procedure was planned. Right frontotemporal craniotomy and orbitotomy was performed. Two aneurysms involving the M1 segment of the MCA were found in line, 1 giant, and the other large in size. The aneurysms were resected and treated with short radial artery interposition graft, which was narrower than the proximal or distal MCA. The child recovered normally, and the bypass was patent after 1 year. Large fusiform MCA aneurysms may be difficult to treat, but there are treatment options that include a bypass procedure. Resection and short interposition radial artery graft is an excellent but rare treatment option in a very young child. This was a very successful treatment in this child.

  18. Femoral artery pressure measurement to predict the outcome of arterial surgery in patients with multilevel disease

    DEFF Research Database (Denmark)

    Faris, I; Tønnesen, K H; Agerskov, K

    1982-01-01

    Direct measurement of the femoral artery pressure before operation has been used to predict the postoperative change in ankle and toe pressure in 102 limbs (83 patients) that underwent aortoiliac surgery for the treatment of atherosclerotic occlusion or stenosis affecting both the aortoiliac...... and femoral artery segments. Rest pain or gangrene was present in 74 limbs. In 26 other limbs simultaneous aortoiliac and femoral artery reconstructions were performed. The changes in both toe and ankle pressures could be confidently predicted from the preoperative data. A predicted toe pressure of lower than...... 25 mm Hg was associated with a high probability that amputation would be required. The chances of an amputation were less than 3% if a toe pressure higher than 40 mm Hg was predicted. If the predicted ankle pressure index was lower than 0.56, there was a 90% chance that intermittent claudication...

  19. Investigation of occupational radiation exposure during interventional cardiac catheterizations performed via radial artery

    International Nuclear Information System (INIS)

    Goni, H.; Papadopoulou, D.; Yakoumakis, Em; Stratigis, N.; Benos, J.; Siriopoulou, V.; Makri, Tr; Georgiou, Ev

    2005-01-01

    The purpose of this study was to determine the thyroid, sternum and hand radiation doses of radiologists who perform angiographies and angio-plasties via the radial artery. Staff radiation dose was estimated for 21 cardiac interventional catheterizations. Thermoluminescence dosemeters (TLDs) were used to determine radiation dose for each procedure at the right and left wrist, at the sternum and the thyroid. A dose area product (DAP) meter was also attached to give a direct value in Gy cm 2 for each procedure. Staff radiation doses varied between 34 and 235 μGy per procedure at the left wrist, 28 and 172 μGy at the right wrist, 16 and 106 μGy at the level of the thyroid and 16 and 154 μGy at the level of the sternum. The DAP values varied between 25 and 167 Gy cm 2 . Radiation doses in this study are comparable to those reported in previous studies. Moreover, good correlation was found between the DAP values and the occupational dose measured with TLDs. (authors)

  20. Relationship between preoperative radial artery and postoperative arteriovenous fistula blood flow in hemodialysis patients.

    Science.gov (United States)

    Sato, Michiko; Io, Hiroaki; Tanimoto, Mitsuo; Shimizu, Yoshio; Fukui, Mitsumine; Hamada, Chieko; Horikoshi, Satoshi; Tomino, Yasuhiko

    2012-01-01

    It is recommended that arteriovenous fistula (AVF) blood flow should be more than 425 ml/min before cannulation. However, the relationship between preoperative radial artery flow (RAF) and postoperative AVF blood flow has still not been examined. Sixty-one patients with end-stage kidney disease (ESKD) were examined. They had an AVF prepared at Juntendo University Hospital from July 2006 through August 2007. Preoperative RAF and postoperative AVF blood flows were measured by ultrasonography. AVF blood flow gradually increased after the operation. AVF blood flow was significantly correlated with preoperative RAF. When preoperative RAF exceeded 21.4 ml/min, AVF blood flow rose to more than 425 ml/min. The postoperative AVF blood flow in the group with RAF of more than 20 ml/min was significantly higher than that in those with less than 20 ml/min. Preoperative RAF of less than 20 ml/min had a significantly high risk of primary AVF failure within 8 months compared with that of more than 20 ml/min. It appears that measurement of RAF by ultrasonography is useful for estimating AVF blood flow postoperatively and can predict the risk of complications in ESKD patients.

  1. Arterial pressure measurement: Is the envelope curve of the oscillometric method influenced by arterial stiffness?

    International Nuclear Information System (INIS)

    Gelido, G; Angiletta, S; Pujalte, A; Quiroga, P; Cornes, P; Craiem, D

    2007-01-01

    Measurement of peripheral arterial pressure using the oscillometric method is commonly used by professionals as well as by patients in their homes. This non invasive automatic method is fast, efficient and the required equipment is affordable with a low cost. The measurement method consists of obtaining parameters from a calibrated decreasing curve that is modulated by heart beats witch appear when arterial pressure reaches the cuff pressure. Diastolic, mean and systolic pressures are obtained calculating particular instants from the heart beats envelope curve. In this article we analyze the envelope of this amplified curve to find out if its morphology is related to arterial stiffness in patients. We found, in 33 volunteers, that the envelope waveform width correlates to systolic pressure (r=0.4, p<0.05), to pulse pressure (r=0.6, p<0.05) and to pulse pressure normalized to systolic pressure (r=0.6, p<0.05). We believe that the morphology of the heart beats envelope curve obtained with the oscillometric method for peripheral pressure measurement depends on arterial stiffness and can be used to enhance pressure measurements

  2. Pressure drop and arterial compliance - Two arterial parameters in one measurement.

    Science.gov (United States)

    Rotman, Oren M; Zaretsky, Uri; Shitzer, Avraham; Einav, Shmuel

    2017-01-04

    Coronary artery pressure-drop and distensibility (compliance) are two major, seemingly unrelated, parameters in the cardiovascular clinical setting, which are indicative of coronary arteries patency and atherosclerosis severity. While pressure drop is related to flow, and therefore serves as a functional indicator of a stenosis severity, the arterial distensibility is indicative of the arterial stiffness, and hence the arterial wall composition. In the present study, we hypothesized that local pressure drops are dependent on the arterial distensibility, and hence can provide information on both indices. The clinical significance is that a single measurement of pressure drop could potentially provide both functional and bio-mechanical metrics of lesions, and thus assist in real-time decision making prior to stenting. The goal of the current study was to set the basis for understanding this relationship, and define the accuracy and sensitivity required from the pressure measurement system. The investigation was performed using numerical fluid-structure interaction (FSI) simulations, validated experimentally using our high accuracy differential pressure measurement system. Simplified silicone mock coronary arteries with zero to intermediate size stenoses were used, and various combinations of arterial distensibility, diameter, and flow rate were simulated. Results of hyperemic flow cases were also compared to fractional flow reserve (FFR). The results indicate the potential clinical superiority of a high accuracy pressure drop-based parameter over FFR, by: (i) being more lesion-specific, (ii) the possibility to circumvent the FFR dependency on pharmacologically-induced hyperemia, and, (iii) by providing both functional and biomechanical lesion-specific information. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. The effects of cigarette smoking on intraocular pressure and arterial ...

    African Journals Online (AJOL)

    This study was designed to determine the effects of cigarette Smoking on intra ocular pressure and arterial blood pressure of normotensive young male adults. Fifty male students (who met the screening conditions and devoid of obvious ocular pathology and systemic diseases and nonsmokers) had their intra ocular ...

  4. Carotid artery disease and low cerebral perfusion pressure

    DEFF Research Database (Denmark)

    Schroeder, T; Utzon, N P; Aabech, J

    1990-01-01

    Direct internal carotid artery blood pressure measurements in patients undergoing carotid endarterectomy identified 49 patients, among 239 consecutive cases (21%), who had a reduction in perfusion pressure of 20% or more. The clinical history, objective findings and angiographic data were compared...

  5. Feasibility of ambulatory, continuous 24-hour finger arterial pressure recording

    NARCIS (Netherlands)

    Imholz, B. P.; Langewouters, G. J.; van Montfrans, G. A.; Parati, G.; van Goudoever, J.; Wesseling, K. H.; Wieling, W.; Mancia, G.

    1993-01-01

    We tested Portapres, an innovative portable, battery-operated device for the continuous, noninvasive, 24-hour ambulatory measurement of blood pressure in the finger. Portapres is based on Finapres, a stationary device for the measurement of finger arterial pressure. Systems were added to record

  6. Two dimensional radial gas flows in atmospheric pressure plasma-enhanced chemical vapor deposition

    Science.gov (United States)

    Kim, Gwihyun; Park, Seran; Shin, Hyunsu; Song, Seungho; Oh, Hoon-Jung; Ko, Dae Hong; Choi, Jung-Il; Baik, Seung Jae

    2017-12-01

    Atmospheric pressure (AP) operation of plasma-enhanced chemical vapor deposition (PECVD) is one of promising concepts for high quality and low cost processing. Atmospheric plasma discharge requires narrow gap configuration, which causes an inherent feature of AP PECVD. Two dimensional radial gas flows in AP PECVD induces radial variation of mass-transport and that of substrate temperature. The opposite trend of these variations would be the key consideration in the development of uniform deposition process. Another inherent feature of AP PECVD is confined plasma discharge, from which volume power density concept is derived as a key parameter for the control of deposition rate. We investigated deposition rate as a function of volume power density, gas flux, source gas partial pressure, hydrogen partial pressure, plasma source frequency, and substrate temperature; and derived a design guideline of deposition tool and process development in terms of deposition rate and uniformity.

  7. Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure

    NARCIS (Netherlands)

    L.V. Wain (Louise); G.C. Verwoert (Germaine); P.F. O'Reilly (Paul); G. Shi (Gang); T. Johnson (Toby); M. Bochud (Murielle); K. Rice (Kenneth); P. Henneman (Peter); A.V. Smith (Albert Vernon); G.B. Ehret (Georg); N. Amin (Najaf); M.G. Larson (Martin); V. Mooser (Vincent); D. Hadley (David); M. Dörr (Marcus); J.C. Bis (Joshua); T. Aspelund (Thor); T. Esko (Tõnu); A.C.J.W. Janssens (Cécile); J.H. Zhao (Jing Hua); S.C. Heath (Simon); M. Laan (Maris); J. Fu (Jingyuan); G. Pistis (Giorgio); J. Luan; G. Lucas (Gavin); N. Pirastu (Nicola); I. Pichler (Irene); A.U. Jackson (Anne); R.J. Webster (Rebecca J.); F.F. Zhang; J. Peden (John); R. Schmidt (Reinhold); T. Tanaka (Toshiko); H. Campbell (Harry); W. Igl (Wilmar); Y. Milaneschi (Yuri); J.J. Hottenga (Jouke Jan); V. Vitart (Veronique); D.I. Chasman (Daniel); S. Trompet (Stella); J.L. Bragg-Gresham (Jennifer L.); B.Z. Alizadeh (Behrooz); J.C. Chambers (John); X. Guo (Xiuqing); T. Lehtimäki (Terho); B. Kuhnel (Brigitte); L.M. Lopez; O. Polasek (Ozren); M. Boban (Mladen); C.P. Nelson (Christopher P.); A.C. Morrison (Alanna); V. Pihur (Vasyl); S.K. Ganesh (Santhi); A. Hofman (Albert); S. Kundu (Suman); F.U.S. Mattace Raso (Francesco); F. Rivadeneira Ramirez (Fernando); E.J.G. Sijbrands (Eric); A.G. Uitterlinden (André); S.J. Hwang; R.S. Vasan (Ramachandran Srini); Y.A. Wang (Ying); S.M. Bergmann (Sven); P. Vollenweider (Peter); G. Waeber (Gérard); J. Laitinen (Jaana); A. Pouta (Anneli); P. Zitting (Paavo); W.L. McArdle (Wendy); H.K. Kroemer (Heyo); U. Völker (Uwe); H. Völzke (Henry); N.L. Glazer (Nicole); K.D. Taylor (Kent); T.B. Harris (Tamara); H. Alavere (Helene); T. Haller (Toomas); A. Keis (Aime); M.L. Tammesoo; Y.S. Aulchenko (Yurii); K-T. Khaw (Kay-Tee); P. Galan (Pilar); S. Hercberg (Serge); G.M. Lathrop (Mark); S. Eyheramendy (Susana); E. Org (Elin); S. Sõber (Siim); X. Lu (Xiaowen); I.M. Nolte (Ilja); B.W.J.H. Penninx (Brenda); T. Corre (Tanguy); C. Masciullo (Corrado); C. Sala (Cinzia); L. Groop (Leif); B.F. Voight (Benjamin); O. Melander (Olle); C.J. O'Donnell (Christopher); V. Salomaa (Veikko); P. d' Adamo (Pio); A. Fabretto (Antonella); F. Faletra (Flavio); S. Ulivi (Shelia); F. Del Greco M (Fabiola); M.F. Facheris (Maurizio); F.S. Collins (Francis); R.N. Bergman (Richard); J.P. Beilby (John); J. Hung (Judy); A.W. Musk (Arthur); M. Mangino (Massimo); S.Y. Shin (So Youn); N. Soranzo (Nicole); H. Watkins (Hugh); A. Goel (Anuj); A. Hamsten (Anders); P. Gider (Pierre); M. Loitfelder (Marisa); M. Zeginigg (Marion); D.G. Hernandez (Dena); S.S. Najjar (Samer); P. Navarro (Pau); S.H. Wild (Sarah); A.M. Corsi (Anna Maria); A. Singleton (Andrew); E.J.C. de Geus (Eco); G.A.H.M. Willemsen (Gonneke); A.N. Parker (Alex); L.M. Rose (Lynda); B.M. Buckley (Brendan M.); D.J. Stott (David. J.); M. Orrù (Marco); M. Uda (Manuela); M.M. van der Klauw (Melanie); X. Li (Xiaohui); J. Scott (James); Y.D.I. Chen (Yii-Der Ida); G.L. Burke (Greg); M. Kähönen (Mika); J. Viikari (Jorma); A. Döring (Angela); T. Meitinger (Thomas); G.S. Davis; J.M. Starr (John); V. Emilsson (Valur); A.S. Plump (Andrew); J.H. Lindeman (Jan H.); P.A.C. 't Hoen (Peter); I.R. König (Inke); J.F. Felix (Janine); R. Clarke; J. Hopewell; H. Ongen (Halit); M.M.B. Breteler (Monique); S. Debette (Stéphanie); A.L. DeStefano (Anita); M. Fornage (Myriam); G.F. Mitchell (Gary); H. Holm (Hilma); K. Stefansson (Kari); G. Thorleifsson (Gudmar); U. Thorsteinsdottir (Unnur); N.J. Samani (Nilesh); M. Preuss (Michael); I. Rudan (Igor); C. Hayward (Caroline); I.J. Deary (Ian); H.E. Wichmann (Heinz Erich); O. Raitakari (Olli); W. Palmas (Walter); J.S. Kooner (Jaspal); R.P. Stolk (Ronald); J.W. Jukema (Jan Wouter); A.F. Wright (Alan); D.I. Boomsma (Dorret); S. Bandinelli (Stefania); U. Gyllensten (Ulf); J.F. Wilson (James); L. Ferrucci (Luigi); M. Farrall (Martin); T.D. Spector (Timothy); L.J. Palmer; J. Tuomilehto (Jaakko); A. Pfeufer (Arne); P. Gasparini (Paolo); D.S. Siscovick (David); D. Altshuler (David); R.J.F. Loos (Ruth); D. Toniolo (Daniela); H. Snieder (Harold); C. Gieger (Christian); P. Meneton (Pierre); N.J. Wareham (Nick); B.A. Oostra (Ben); A. Metspalu (Andres); L.J. Launer (Lenore); R. Rettig (Rainer); D.P. Strachan (David); J.S. Beckmann (Jacques); J.C.M. Witteman (Jacqueline); J.A.P. Willems van Dijk (Ko); E.A. Boerwinkle (Eric); M. Boehnke (Michael); P.M. Ridker (Paul); M.R. Järvelin; A. Chakravarti (Aravinda); J. Erdmann (Jeanette); V. Gudnason (Vilmundur); C. Newton-Cheh (Christopher); D. Levy (Daniel); P. Arora (Pankaj); P. Munroe (Patricia); B.M. Psaty (Bruce); M. Caulfield (Mark); D.C. Rao (Dabeeru C.); P. Elliott (Paul); P. Tikka-Kleemola (Päivi); G.R. Abecasis (Gonçalo); I.E. Barroso (Inês)

    2011-01-01

    textabstractNumerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N =

  8. Oscillometric blood pressure measurements: differences between measured and calculated mean arterial pressure.

    NARCIS (Netherlands)

    Kiers, H.D.; Hofstra, J.M.; Wetzels, J.F.M.

    2008-01-01

    Mean arterial pressure (MAP) is often used as an index of overall blood pressure. In recent years, the use of automated oscillometric blood pressure measurement devices is increasing. These devices directly measure and display MAP; however, MAP is often calculated from systolic blood pressure (SBP)

  9. Techniques for Non-Invasive Monitoring of Arterial Blood Pressure

    Directory of Open Access Journals (Sweden)

    Agnes S. Meidert

    2018-01-01

    Full Text Available Since both, hypotension and hypertension, can potentially impair the function of vital organs such as heart, brain, or kidneys, monitoring of arterial blood pressure (BP is a mainstay of hemodynamic monitoring in acutely or critically ill patients. Arterial BP can either be obtained invasively via an arterial catheter or non-invasively. Non-invasive BP measurement provides either intermittent or continuous readings. Most commonly, an occluding upper arm cuff is used for intermittent non-invasive monitoring. BP values are then obtained either manually (by auscultation of Korotkoff sounds or palpation or automatically (e.g., by oscillometry. For continuous non-invasive BP monitoring, the volume clamp method or arterial applanation tonometry can be used. Both techniques enable the arterial waveform and BP values to be obtained continuously. This article describes the different techniques for non-invasive BP measurement, their advantages and limitations, and their clinical applicability.

  10. Pressure Dependence of the Radial Breathing Mode of Carbon Nanotubes: The Effect of Fluid Adsorption

    Science.gov (United States)

    Longhurst, M. J.; Quirke, N.

    2007-04-01

    The pressure dependence of shifts in the vibrational modes of individual carbon nanotubes is strongly affected by the nature of the pressure transmitting medium as a result of adsorption at the nanotube surface. The adsorbate is treated as an elastic shell which couples with the radial breathing mode (RBM) of the nanotube via van der Waal interactions. Using analytical methods as well as molecular simulation, we observe a low frequency breathing mode for the adsorbed fluid at ˜50cm-1, as well as diameter dependent upshifts in the RBM frequency with pressure, suggesting metallic nanotubes may wet more than semiconducting ones.

  11. Minimum weight designs for reinforcement of spherical pressure vessels with flush radial nozzles

    International Nuclear Information System (INIS)

    Yeo, K.T.; Robinson, M.

    1978-01-01

    A cylinder-sphere pressure vessel, reinforced in the sphere by a section of constant thickness, has been analysed from the point of view of minimum weight. The reinforcement is allowed to be offset from the main sphere and the design has to be such that the test pressure of the vessel equals the limit pressure. It is shown that in most circumstances an economy of weight may be obtained by making the reinforcement thicker, but less extensive, than suggested in a previous proposal. Further benefit can be obtained by offsetting the reinforcement radially outwards so that the inside surfaces of main sphere and reinforcement are flush. (author)

  12. Radial energy transport by magnetospheric ULF waves: Effects of magnetic curvature and plasma pressure

    Science.gov (United States)

    Kouznetsov, Igor; Lotko, William

    1995-01-01

    The 'radial' transport of energy by internal ULF waves, stimulated by dayside magnetospheric boundary oscillations, is analyzed in the framework of one-fluid magnetohydrodynamics. (the term radial is used here to denote the direction orthogonal to geomagnetic flux surfaces.) The model for the inhomogeneous magnetospheric plasma and background magnetic field is axisymmetric and includes radial and parallel variations in the magnetic field, magnetic curvature, plasma density, and low but finite plasma pressure. The radial mode structure of the coupled fast and intermediate MHD waves is determined by numerical solution of the inhomogeneous wave equation; the parallel mode structure is characterized by a Wentzel-Kramer-Brillouin (WKB) approximation. Ionospheric dissipation is modeled by allowing the parallel wave number to be complex. For boudnary oscillations with frequencies in the range from 10 to 48 mHz, and using a dipole model for the background magnetic field, the combined effects of magnetic curvature and finite plasma pressure are shown to (1) enhance the amplitude of field line resonances by as much as a factor of 2 relative to values obtained in a cold plasma or box-model approximation for the dayside magnetosphere; (2) increase the energy flux delivered to a given resonance by a factor of 2-4; and (3) broaden the spectral width of the resonance by a factor of 2-3. The effects are attributed to the existence of an 'Alfven buoyancy oscillation,' which approaches the usual shear mode Alfven wave at resonance, but unlike the shear Alfven mode, it is dispersive at short perpendicular wavelengths. The form of dispersion is analogous to that of an internal atmospheric gravity wave, with the magnetic tension of the curved background field providing the restoring force and allowing radial propagation of the mode. For nominal dayside parameters, the propagation band of the Alfven buoyancy wave occurs between the location of its (field line) resonance and that of the

  13. Implantable blood pressure sensor for analyzing elasticity in arteries

    Science.gov (United States)

    Franco-Ayala, Marco; Martínez-Piñón, Fernando; Reyes-Barranca, Alfredo; Sánchez de la Peña, Salvador; Álvarez-Chavez, José A.

    2009-03-01

    MEMS technology could be an option for the development of a pressure sensor which allows the monitoring of several electronic signals in humans. In this work, a comparison is made between the typical elasticity curves of several arteries in the human body and the elasticity obtained for MEMS silicon microstructures such as membranes and cantilevers employing Finite Element analysis tools. The purpose is to identify which types of microstructures are mechanically compatible with human arteries. The goal is to integrate a blood pressure sensor which can be implanted in proximity with an artery. The expected benefits for this type of sensor are mainly to reduce the problems associated with the use of bulk devices through the day and during several days. Such a sensor could give precise blood pressure readings in a continuous or periodic form, i.e. information that is especially important for some critical cases of hypertension patients.

  14. Development of optoelectronic monitoring system for ear arterial pressure waveforms

    Science.gov (United States)

    Sasayama, Satoshi; Imachi, Yu; Yagi, Tamotsu; Imachi, Kou; Ono, Toshirou; Man-i, Masando

    1994-02-01

    Invasive intra-arterial blood pressure measurement is the most accurate method but not practical if the subject is in motion. The apparatus developed by Wesseling et al., based on a volume-clamp method of Penaz (Finapres), is able to monitor continuous finger arterial pressure waveforms noninvasively. The limitation of Finapres is the difficulty in measuring the pressure of a subject during work that involves finger or arm action. Because the Finapres detector is attached to subject's finger, the measurements are affected by inertia of blood and hydrostatic effect cause by arm or finger motion. To overcome this problem, the authors made a detector that is attached to subject's ear and developed and optoelectronic monitoring systems for ear arterial pressure waveform (Earpres). An IR LEDs, photodiode, and air cuff comprised the detector. The detector was attached to a subject's ear, and the space adjusted between the air cuff and the rubber plate on which the LED and photodiode were positioned. To evaluate the accuracy of Earpres, the following tests were conducted with participation of 10 healthy male volunteers. The subjects rested for about five minutes, then performed standing and squatting exercises to provide wide ranges of systolic and diastolic arterial pressure. Intra- and inter-individual standard errors were calculated according to the method of van Egmond et al. As a result, average, the averages of intra-individual standard errors for earpres appeared small (3.7 and 2.7 mmHg for systolic and diastolic pressure respectively). The inter-individual standard errors for Earpres were about the same was Finapres for both systolic and diastolic pressure. The results showed the ear monitor was reliable in measuring arterial blood pressure waveforms and might be applicable to various fields such as sports medicine and ergonomics.

  15. Noninvasive 24-hour ambulatory arterial blood pressure monitoring in cirrhosis

    DEFF Research Database (Denmark)

    Møller, Søren; Wiinberg, N; Henriksen, Jens Henrik

    1995-01-01

    Cirrhotic patients have disturbed systemic hemodynamics with reduced arterial blood pressure, but this has not been investigated during daily activity and sleep. Systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP), and heart rate (HR) were measured by an automatic ambulant...... device for monitoring blood pressure in 35 patients with cirrhosis and 35 healthy matched controls. During the daytime, SBP, DBP, and MAP were significantly lower in the patients than in the controls (median 118 vs. 127; 70 vs. 78; 86 vs. 94 mm Hg, P blood pressures...... were almost similar in the two groups (108 vs. 110; 65 vs. 67; 78 vs. 82 mm Hg, NS). Conversely, HR was significantly higher in the patients both in the daytime (86 vs. 72/min, P blood pressure and HR from daytime...

  16. Regression analysis of radial artery pulse palpation as a potential tool for traditional Chinese medicine training education.

    Science.gov (United States)

    Huang, Po-Yu; Lin, Wen-Chen; Chiu, Bill Yuan-Chi; Chang, Hen-Hong; Lin, Kang-Ping

    2013-12-01

    Pulse palpation was an important part of the traditional Chinese medicine (TCM) vascular examination. It is challenging for new physicians to learn to differentiate between palpations of various pulse types, due to limited comparative learning time with established masters, and so normally it takes many years to master the art. The purpose of this study was to introduce an offline TCM skill evaluation and comparison system that makes available learning of palpation without the master's presence. We record patient's radial artery pulse using an existing pressure-based pulse acquisition system, then annotate it with teachers' evaluation when palpating the same patient, assigned as likelihood of it being each pulse type, e.g. wiry, slippery, hesitant. These training data were separated into per-doctor and per-skill databases for evaluation and comparison purposes, using the following novel procedure: each database was used as training data to a panel of time-series data-mining algorithms, driven by two validation tests, with the created training models evaluated in mean-squared-error. Each validation of the panel and training data yielded an array of error terms, and we chose one to quantitatively evaluate palpation techniques, giving way to compute self consistency and mutual-similarity across different practitioners and techniques. Our experiment of two practitioners and 396 per-processing samples yielded the following: one of the physicians has much higher value of self-consistency for all tested pulse types. Also, the two physicians have high similarity in how they palpate the slipper pulse (P) type, but very dissimilar for hesitant (H) type. This system of skill comparisons may be more broadly applied in places where supervised learning algorithms can detect and use meaningful features in the data; we chose a panel of algorithms previously shown to be effective for many time-series types, but specialized algorithms may be added to improve feature-specific aspect

  17. Medial circumflex femoral artery flap for ischial pressure sore

    Directory of Open Access Journals (Sweden)

    Palanivelu S

    2009-01-01

    Full Text Available A new axial pattern flap based on the terminal branches of the medial circumflex femoral artery is described for coverage of ischial pressure sore. Based on the terminal branches of the transverse branch of medial circumflex femoral artery, which exit through the gap between the quadratus femoris muscle above and the upper border of adductor magnus muscle below, this fascio cutaneous flap is much smaller than the posterior thigh flap but extremely useful to cover ischeal pressure sores. The skin redundancy below the gluteal fold allows a primary closure of the donor defect. It can also be used in combination with biceps femoris muscle flap.

  18. Arterial pressure control for nursing military professionals

    Directory of Open Access Journals (Sweden)

    Jorge Luiz Lima da Silva

    2016-01-01

    Full Text Available Objetivo: Verificar quais os fatores de risco para a HAS que os profissionais militares da área de enfermagem identificam em seu estilo de vida; classificar os níveis pressóricos dos profissionais. Método: Quantitativo, embasado em pesquisa descritiva. Resultados: Participaram do estudo 40 profissionais militares da área de enfermagem. Foram identificados os seguintes fatores de risco para a HAS na população estudada: uso de contraceptivos hormonais (8,0%, tabagismo (7,0%, etilismo (2,0%, sedentarismo (21,0%, estresse (25,0%, consumo excessivo de sal (11,0%, obesidade (8,0% e dieta hipercalórica e hiperprotéica (18,0%.  A classificação da pressão arterial dos sujeitos revelou que 70,0% demonstraram valores pressóricos considerados normais ou ótimo, 12,5% valores considerados limítrofes e 17,5% comprovaram HAS. Conclusão: O estudo denota a necessidade de mudanças no estilo de vida dos profissionais, pois os fatores de risco associados aos níveis pressóricos podem contribuir para o aparecimento de HAS na população estudada. Descritores: Pressão arterial, hipertensão, enfermagem, enfermagem militar.

  19. Marginal artery stump pressure in left colic artery-preserving rectal cancer surgery: a clinical trial.

    Science.gov (United States)

    Guo, Yuchen; Wang, Daguang; He, Liang; Zhang, Yang; Zhao, Shishun; Zhang, Luyao; Sun, Xuan; Suo, Jian

    2017-07-01

    The aim of this clinical trial is to evaluate the influence of high and low ligation of the inferior mesenteric artery with apical lymph node dissection on the anastomotic blood supply, lymph node retrieval rate, operative time and anastomotic leakage rate in rectal cancer surgery. A total of 57 Chinese patients were randomly distributed into group A and group B and underwent radical resection of rectal cancer. Patients in group A underwent high ligation of the inferior mesenteric artery, and patients in group B underwent apical lymph node resection around the root of the inferior mesenteric artery with preservation of the left colic artery. The marginal artery stump pressure was measured after colon and artery reconstruction. Systemic pressure, distal colon length, operative time and lymph node retrieval rate were measured and recorded. The results were analysed and related to patient characteristics and post-operative complications. The anastomotic blood supply negatively and linearly correlated with age and distal colon length and showed a positive linear correlation with systemic pressure. Patients who received low ligation with apical lymph node dissection had a better anastomotic blood supply than those who received high ligation. No differences were found in lymph node retrieval rate, operative time and anastomotic leakage rate. Anastomotic leakage was associated with a worse anastomotic blood supply. Low ligation with apical lymph node dissection in rectal cancer treatment provides better anastomotic blood supply but is not associated with differences in node retrieval rate or operation time. © 2015 Royal Australasian College of Surgeons.

  20. Radial breathing vibration of double-walled carbon nanotubes subjected to pressure

    International Nuclear Information System (INIS)

    Lei, Xiao-Wen; Natsuki, Toshiaki; Shi, Jin-Xing; Ni, Qing-Qing

    2011-01-01

    A theoretical vibrational analysis of the radial breathing mode (RBM) of double-walled carbon nanotubes (DWCNTs) subjected to pressure is presented based on an elastic continuum model. The results agree with reported experimental results obtained under different conditions. Frequencies of the RBM in DWCNTs subjected to increasing pressure depend strongly on circumferential wave numbers, but weakly on the aspect ratio and axial half-wave numbers. For the inner and outer tubes of DWCNTs, the frequency of the RBM increases obviously as the pressure increases under different conditions. The range of variation is smaller for the inner tube than the outer tube. -- Highlights: → An elastic continuum model is used in the theoretical analysis of RBM of DWCNTs. → The RBM of DWCNTs subjected to pressure is analyzed. → Frequency of RBM depends on wave number and aspect ratio. → Frequencies of RBM in inner and outer tubes change in different trends and ranges.

  1. 2-Octyl Cyanoacrylate (Dermabond® skin adhesive versus polyglactin for skin closure in endoscopic radial artery harvesting

    Directory of Open Access Journals (Sweden)

    Ahmed Mostafa Omran

    2018-03-01

    Full Text Available Background: As the goal of endoscopic conduit harvesting is to decrease pain and better cosmetic appearance, and as the optimal choice of skin closure after endoscopic radial artery harvesting (ERAH has not yet been determined, we started this study with an aim to compare wound complications, patient satisfaction and scar healing between glue (Dermabond versus polyglactin intra-cuticular suture for skin closure after ERAH. Methods: This observational study was done at Al Dabbous Cardiac Center, Kuwait, from January 2017 till October 2017 enrolling 40 patients divided into two equal groups (Dermabond group and sutures group. Inclusion criterion was patients underwent coronary artery bypass grafting (CABG using ERAH, while open technique for radial artery harvesting and Negro race are considered as exclusion criteria. Demographic data were collected, (gender, age, race, body mass index (BMI, preoperative medication and albumin level, as well as diabetes or peripheral vascular disease. Operatively, wound closure time was calculated for all patients. Postoperatively: Cosmetic appearance was assessed using the Hollander scale. Patient satisfaction was recorded at week 6–8 weeks. Results: Demographic and preoperative data were comparable; Dermabond group showed shorter closure time, better scar pigmentation, shape and patient satisfaction. Pain, scar size, infection and hematoma showed no statistical difference. Conclusion: Dermabond can be used safely in closure of skin after ERAH. The excellent results in the small wound of ERAH encouraged us to use it in larger wounds. Keywords: Dermabond, Wound, ERAH, Skin adhesive, OCA

  2. Stress concentration factors for integral and pad reinforced nozzles in spherical pressure vessels subjected to radial load and moment

    International Nuclear Information System (INIS)

    Soliman, S.F.; Gill, S.S.

    1979-01-01

    Charts are presented giving the elastic stress concentration factors in spherical pressure vessels with pad and integral reinforcement for radial branches subjected to radial load and moment. The effect of all the geometrical parameters is discussed, including the limitations of thin shell theory on the validity of the results. (author)

  3. Using the adaptive SMA composite cylinder concept to reduce radial dilation in composite pressure vessels

    Science.gov (United States)

    Paine, Jeffrey S.; Rogers, Craig A.

    1995-05-01

    Composite materials are widely used in the design of pressurized gas and fluid vessels for applications ranging from underground gasoline storage tanks to rocket motors for the space shuttle. In the design of a high pressure composite vessel (Pi > 12 Ksi), thick-wall (R/h short term dilation and long term creep are not problematic for applications requiring only the containment of the pressurized fluid. In applications where metallic liners are required, however, substantial dilation and creep causes plastic yielding which leads to reduced fatigue life. To applications such as a hydraulic accumulator, where a piston is employed to fit and seal the fluid in the composite cylinder, the dilation and creep may allow leakage and pressure loss around the piston. A concept called the adaptive composite cylinder is experimentally presented. Shape memory alloy wire in epoxy resin is wrapped around or within polymer matrix composite cylinders to reduce radial dilation of the cylinder. Experimental results are presented that demonstrate the ability of the SMA wire layers to reduce radial dilation. Results from experimental testing of the recovery stress fatigue response of nitinol shape memory alloy wires is also presented.

  4. The conundrum of arterial stiffness, elevated blood pressure, and aging.

    Science.gov (United States)

    AlGhatrif, Majd; Lakatta, Edward G

    2015-02-01

    Isolated systolic hypertension is a major health burden that is expanding with the aging of our population. There is evidence that central arterial stiffness contributes to the rise in systolic blood pressure (SBP); at the same time, central arterial stiffening is accelerated in patients with increased SBP. This bidirectional relationship created a controversy in the field on whether arterial stiffness leads to hypertension or vice versa. Given the profound interdependency of arterial stiffness and blood pressure, this question seems intrinsically challenging, or probably naïve. The aorta's function of dampening the pulsatile flow generated by the left ventricle is optimal within a physiological range of distending pressure that secures the required distal flow, keeps the aorta in an optimal mechanical conformation, and minimizes cardiac work. This homeostasis is disturbed by age-associated, minute alterations in aortic hemodynamic and mechanical properties that induce short- and long-term alterations in each other. Hence, it is impossible to detect an "initial insult" at an epidemiological level. Earlier manifestations of these alterations are observed in young adulthood with a sharp decline in aortic strain and distensibility accompanied by an increase in diastolic blood pressure. Subsequently, aortic mechanical reserve is exhausted, and aortic remodeling with wall stiffening and dilatation ensue. These two phenomena affect pulse pressure in opposite directions and different magnitudes. With early remodeling, there is an increase in pulse pressure, due to the dominance of arterial wall stiffness, which in turn accelerates aortic wall stiffness and dilation. With advanced remodeling, which appears to be greater in men, the effect of diameter becomes more pronounced and partially offsets the effect of wall stiffness leading to plateauing in pulse pressure in men and slower increase in pulse pressure (PP) than that of wall stiffness in women. The complex nature of

  5. Radial artery anomalies in patients undergoing transradial coronary procedures – An Egyptian multicenter experience

    Directory of Open Access Journals (Sweden)

    Ayman K.M. Hassan

    2016-03-01

    Conclusion: There is a relatively significant presence of radial anomalies, with different degrees of impact on procedural failure rate, in our Egyptian population. Further collaborative studies are recommended to increase our success rates.

  6. Comparison of the feasibility and effectiveness of transradial coronary angiography via right versus left radial artery approaches (from the PREVAIL Study).

    Science.gov (United States)

    Pelliccia, Francesco; Trani, Carlo; Biondi-Zoccai, Giuseppe G L; Nazzaro, Marco; Berni, Andrea; Patti, Giuseppe; Patrizi, Roberto; Pironi, Bruno; Mazzarotto, Pietro; Gioffrè, Gaetano; Speciale, Giulio; Pristipino, Christian

    2012-09-15

    It remains undefined if transradial coronary angiography from a right or left radial arterial approach differs in real-world practice. To address this issue, we performed a subanalysis of the PREVAIL study. The PREVAIL study was a prospective, multicenter, observational survey of unselected consecutive patients undergoing invasive cardiovascular procedures over a 1-month observation period, specifically aimed at assessing the outcomes of radial approach in the contemporary real world. The choice of arterial approach was left to the discretion of the operator. Prespecified end points of this subanalysis were procedural characteristics. Of 1,052 patients consecutively enrolled, 509 patients underwent transradial catheterization, 304 with a right radial and 205 with a left radial approach. Procedural success rates were similar between the 2 groups. Compared to the left radial group, the right radial group had longer procedure duration (46 ± 29 vs 33 ± 24 minutes, p <0.0001) and fluoroscopy time (765 ± 787 vs 533 ± 502, p <0.0001). At multivariate analysis, including a parsimonious propensity score for the choice of left radial approach, duration of procedure (beta coefficient 11.38, p <0.001) and total dose-area product (beta coefficient 11.38, p <0.001) were independently associated with the choice of the left radial artery approach. The operator's proficiency in right/left radial approach did not influence study results. In conclusion, right and left radial approaches are feasible and effective to perform percutaneous procedures. In the contemporary real world, however, the left radial route is associated with shorter procedures and lower radiologic exposure than the right radial approach, independently of an operator's proficiency. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Features of energetic particle radial profiles inferred from geosynchronous responses to solar wind dynamic pressure enhancements

    Directory of Open Access Journals (Sweden)

    Y. Shi

    2009-02-01

    Full Text Available Determination of the radial profile of phase space density of relativistic electrons at constant adiabatic invariants is crucial for identifying the source for them within the outer radiation belt. The commonly used method is to convert flux observed at fixed energy to phase space density at constant first, second and third adiabatic invariants, which requires an empirical global magnetic field model and thus might produce some uncertainties in the final results. From a different perspective, in this paper we indirectly infer the shape of the radial profile of phase space density of relativistic electrons near the geosynchronous region by statistically examining the geosynchronous energetic flux response to 128 solar wind dynamic pressure enhancements during the years 2000 to 2003. We thus avoid the disadvantage of using empirical magnetic field models. Our results show that the flux response is species and energy dependent. For protons and low-energy electrons, the primary response to magnetospheric compression is an increase in flux at geosynchronous orbit. For relativistic electrons, the dominant response is a decrease in flux, which implies that the phase space density decreases toward increasing radial distance at geosynchronous orbit and leads to a local peak inside of geosynchronous orbit. The flux response of protons and non-relativistic electrons could result from a phase density that increases toward increasing radial distance, but this cannot be determined for sure due to the particle energization associated with pressure enhancements. Our results for relativistic electrons are consistent with previous results obtained using magnetic field models, thus providing additional confirmation that these results are correct and indicating that they are not the result of errors in their selected magnetic field model.

  8. Comparison between ultrasound guided technique and digital palpation technique for radial artery cannulation in adult patients: An updated meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Bhattacharjee, Sulagna; Maitra, Souvik; Baidya, Dalim K

    2018-03-22

    Possible advantages and risks associated with ultrasound guided radial artery cannulation in-comparison to digital palpation guided method in adult patients are not fully known. We have compared ultrasound guided radial artery cannulation with digital palpation technique in this meta-analysis. Meta-analysis of randomized controlled trials. Trials conducted in operating room, emergency department, cardiac catheterization laboratory. PubMed and Cochrane Central Register of Controlled Trials (CENTRAL) were searched (from 1946 to 20th November 2017) to identify prospective randomized controlled trials in adult patients. Two-dimensional ultrasound guided radial artery catheterization versus digital palpation guided radial artery cannulation. Overall cannulation success rate, first attempt success rate, time to cannulation and mean number of attempts to successful cannulation. Odds ratio (OR) and standardized mean difference (SMD) or mean difference (MD) with 95% confidence interval (CI) were calculated for categorical and continuous variables respectively. Data of 1895 patients from 10 studies have been included in this meta- analysis. Overall cannulation success rate was similar between ultrasound guided technique and digital palpation [OR (95% CI) 2.01 (1.00, 4.06); p = 0.05]. Ultrasound guided radial artery cannulation is associated with higher first attempt success rate of radial artery cannulation in comparison to digital palpation [OR (95% CI) 2.76 (186, 4.10); p guided technique with palpation technique. Radial artery cannulation by ultrasound guidance may increase the first attempt success rate but not the overall cannulation success when compared to digital palpation technique. However, results of this meta-analysis should be interpreted with caution due presence of heterogeneity. Copyright © 2018. Published by Elsevier Inc.

  9. [Arterial pressure curve and fluid status].

    Science.gov (United States)

    Pestel, G; Fukui, K

    2009-04-01

    Fluid optimization is a major contributor to improved outcome in patients. Unfortunately, anesthesiologists are often in doubt whether an additional fluid bolus will improve the hemodynamics of the patient or not as excess fluid may even jeopardize the condition. This article discusses physiological concepts of liberal versus restrictive fluid management followed by a discussion on the respective capabilities of various monitors to predict fluid responsiveness. The parameter difference in pulse pressure (dPP), derived from heart-lung interaction in mechanically ventilated patients is discussed in detail. The dPP cutoff value of 13% to predict fluid responsiveness is presented together with several assessment techniques of dPP. Finally, confounding variables on dPP measurements, such as ventilation parameters, pneumoperitoneum and use of norepinephrine are also mentioned.

  10. Predicting Electrocardiogram and Arterial Blood Pressure Waveforms with Different Echo State Network Architectures

    Science.gov (United States)

    2014-11-01

    Predicting Electrocardiogram and Arterial Blood Pressure Waveforms with Different Echo State Network Architectures Allan Fong, MS1,3, Ranjeev...the medical staff in Intensive Care Units. The ability to predict electrocardiogram and arterial blood pressure waveforms can potentially help the...type of neural network for mining, understanding, and predicting electrocardiogram and arterial blood pressure waveforms. Several network

  11. Pulmonary artery imaging under free-breathing using golden-angle radial bSSFP MRI: a proof of concept.

    Science.gov (United States)

    Fyrdahl, Alexander; Vargas Paris, Roberto; Nyrén, Sven; Holst, Karen; Ugander, Martin; Lindholm, Peter; Sigfridsson, Andreas

    2018-03-14

    To evaluate the feasibility of an improved motion and flow robust methodology for imaging the pulmonary vasculature using non-contrast-enhanced, free-breathing, golden-angle radial MRI. Healthy volunteers (n = 10, age 46 ± 11 years, 50% female) and patients (n = 2, ages 27 and 84, both female) were imaged at 1.5 T using a Cartesian and golden-angle radial 2D balanced SSFP pulse sequence. The acquisitions were made under free breathing without contrast agent enhancement. The radial acquisitions were reconstructed at 3 temporal footprints. All series were scored from 1 to 5 for perceived diagnostic quality, artifact level, and vessel sharpness in multiple anatomical locations. In addition, vessel sharpness and blood-to-blood clot contrast were measured. Quantitative measurements showed higher vessel sharpness for golden-angle radial (n = 76, 0.79 ± 0.11 versus 0.71 ± 0.16, p golden-angle radial in the 2 patients. At comparable temporal footprints, golden-angle radial was scored higher for diagnostic quality (mean ± SD, 2.3 ± 0.7 versus 2.2 ± 0.6, p < .01) and vessel sharpness (2.2 ± 0.8 versus 2.1 ± 0.5, p < .01), whereas the artifact level did not differ (3.0 ± 0.9 versus 3.0 ± 1.0, p = .80). The ability to retrospectively choose a temporal resolution and perform sliding-window reconstructions was demonstrated in patients. In pulmonary artery imaging, the motion and flow robustness of a radial trajectory does both improve image quality over Cartesian trajectory in healthy volunteers, and allows for flexible selection of temporal footprints and the ability to perform real-time sliding window reconstructions, which could potentially provide further diagnostic insight. © 2018 International Society for Magnetic Resonance in Medicine.

  12. Radial profile of pressure in a storm ring current as a function of D st

    Science.gov (United States)

    Kovtyukh, A. S.

    2010-06-01

    Using satellite data obtained near the equatorial plane during 12 magnetic storms with amplitudes from -61 down to -422 nT, the dependences of maximum in L-profile of pressure ( L m) of the ring current (RC) on the current value of D st are constructed, and their analytical approximations are derived. It is established that function L m( D st ) is steeper on the phase of recovery than during the storm’s main phase. The form of the outer edge of experimental radial profiles of RC pressure is studied, and it is demonstrated to correspond to exponential growth of the total energy of RC particles on a given L shell with decreasing L. It is shown that during the storms’ main phase the ratio of plasma and magnetic field pressures at the RC maximum does not practically depend on the storm strength and L m value. This fact reflects resistance of the Earth’s magnetic field to RC expansion, and testifies that during storms the possibilities of injection to small L are limited for RC particles. During the storms’ recovery phase this ratio quickly increases with increasing L m, which reflects an increased fraction of plasma in the total pressure balance. It is demonstrated that function L m( D st ) is derived for the main phase of storms from the equations of drift motion of RC ions in electrical and magnetic fields, reflecting the dipole character of magnetic field and scale invariance of the pattern of particle convection near the RC maximum. For the recovery phase it is obtained from the Dessler-Parker-Sckopke relationship. The obtained regularities allow one to judge about the radial profile of RC pressure from ground-based magnetic measurements (data on the D st variation).

  13. Human urotensin II in internal mammary and radial arteries of patients undergoing coronary surgery

    DEFF Research Database (Denmark)

    Chen, Zhi-Wu; Yang, Qin; Huang, Yu

    2009-01-01

    (max):20.4+/-4.8%, p7.1%). The relaxation was abolished by endothelium denudation...... and by indomethacin, oxadiazoloquinoxalinone or N(omega)-nitro-L-arginine, oxyhemoglobin, and Ca2+-activated K+ channel (K(Ca)) blockers. Urotensin receptor mRNA was detected in both arteries. CONCLUSIONS: hU-II is an important spasmogen in arterial grafts with receptors expressed in IMA and RA. hU-II elicits...

  14. Peripheral Chemoreception and Arterial Pressure Responses to Intermittent Hypoxia

    OpenAIRE

    Prabhakar, Nanduri R.; Peng, Ying-Jie; Kumar, Ganesh K.; Nanduri, Jayasri

    2015-01-01

    Carotid bodies are the principal peripheral chemoreceptors for detecting changes in arterial blood oxygen levels, and the resulting chemoreflex is a potent regulator of blood pressure. Recurrent apnea with intermittent hypoxia (IH) is a major clinical problem in adult humans and infants born preterm. Adult patients with recurrent apnea exhibit heightened sympathetic nerve activity and hypertension. Adults born preterm are predisposed to early onset of hypertension. Available evidence suggests...

  15. Neck length and mean arterial pressure in the sauropod dinosaurs.

    Science.gov (United States)

    Hughes, Stephen; Barry, John; Russell, Jeremy; Bell, Robert; Gurung, Som

    2016-04-15

    How blood was able to reach the heads of the long-necked sauropod dinosaurs has long been a matter of debate and several hypotheses have been presented. For example, it has been proposed that sauropods had exceptionally large hearts, multiple 'normal' sized hearts spaced at regular intervals up the neck or held their necks horizontal, or that the siphon effect was in operation. By means of an experimental model, we demonstrate that the siphon principle is able to explain how blood was able to adequately perfuse the sauropod brain. The return venous circulation may have been protected from complete collapse by a structure akin to the vertebral venous plexus. We derive an equation relating neck height and mean arterial pressure, which indicates that with a mean arterial pressure similar to that of the giraffe, the maximum safe vertical distance between heart and head would have been about 12 m. A hypothesis is presented that the maximum neck length in the fossil record is due to the siphon height limit. The equation indicates that to migrate over high ground, sauropods would have had to either significantly increase their mean arterial pressure or keep their necks below a certain height dependent on altitude. © 2016. Published by The Company of Biologists Ltd.

  16. [Invasive arterial blood pressure measurement using an aneroid pressure system in cattle].

    Science.gov (United States)

    Mosing, M; Franz, S; Iff, I; Schwendenwein, I

    2009-06-01

    The aim of this study was to compare the results of invasive arterial blood pressure measurement using an electronic pressure transducer (EPT) or an aneroid pressure system (APS) in cattle. A catheter was placed in the auricular artery of 11 adult cattle and connected to a pressure transducer via pressure line. The aneroid system was connected to the same catheter using a three-way stop-cock in the pressure line. On five occasions three consecutive measurements were performed with the APS. The mean blood pressure values of the EPT were recorded before each individual measurement. Values from each device were compared using Passing and Bablok regression of agreement and a Bland and Altman difference plot. One hundred and forty-seven paired measurements were analysed. The average bias between the two methods (EPT vs. APS) was -1.6 mmHg (95 % confidence interval [CI]: -3.0 to -0.2 mmHg). The coefficient of correlation was 1.0084. The aneroid system showed an almost perfect agreement with the EPT. This study shows that it can be used in a clinical setting as well as under field conditions to measure arterial blood pressure in cattle.

  17. Similar Outcomes in Diabetes Patients After Coronary Artery Bypass Grafting With Single Internal Thoracic Artery Plus Radial Artery Grafting and Bilateral Internal Thoracic Artery Grafting.

    Science.gov (United States)

    Raza, Sajjad; Blackstone, Eugene H; Houghtaling, Penny L; Koprivanac, Marijan; Ravichandren, Kirthi; Javadikasgari, Hoda; Bakaeen, Faisal G; Svensson, Lars G; Sabik, Joseph F

    2017-12-01

    The purpose of this study was to determine in patients with diabetes mellitus whether single internal thoracic artery (SITA) plus radial artery (RA) grafting yields outcomes similar to those of bilateral internal thoracic artery (BITA) grafting. From January 1994 to January 2011, 1,325 diabetic patients underwent primary isolated coronary artery bypass graft surgery with either (1) SITA plus RA with or without saphenous vein (SV) grafts (n = 965) or (2) BITA with or without SV grafts (n = 360); an internal thoracic artery was used in all patients to graft the left anterior descending coronary artery. Endpoints were in-hospital outcomes and time-related mortality. Median follow-up was 7.4 years, with a total follow-up of 9,162 patient-years. Propensity score matching was performed to identify 282 well-matched pairs for adjusted comparisons. Unadjusted in-hospital mortality was 0.52% for SITA plus RA with or without SV grafts and 0.28% for BITA with or without SV grafts, and prevalence of deep sternal wound infection was 3.2% and 1.7%, respectively. Unadjusted survival at 1, 5, 10, and 14 years was 97%, 88%, 68%, and 51% for SITA plus RA with or without SV grafts, and 97%, 95%, 80%, and 66% for BITA with or without SV grafts, respectively. Among propensity-matched patients, in-hospital mortality (0.35% versus 0.35%) and prevalence of deep sternal wound infection (1.4% versus 1.4%) were similar (p > 0.9) in the two groups, as was 1-, 5-, 10-, and 14-year survival: 97%, 90%, 70%, and 58% for SITA plus RA with or without SV grafting versus 97%, 93%, 79%, and 64% for BITA with or without SV grafting, respectively (early p = 0.8, late p = 0.2). For diabetic patients, SITA plus RA with or without SV grafting and BITA with or without SV grafting yield similar in-hospital outcomes and long-term survival after coronary artery bypass graft surgery. Therefore, both SITA plus RA and BITA plus SV grafting should be considered for these patients. Copyright © 2017 The Society

  18. Comparison of a priori versus provisional heparin therapy on radial artery occlusion after transradial coronary angiography and patent hemostasis (from the PHARAOH Study).

    Science.gov (United States)

    Pancholy, Samir B; Bertrand, Olivier F; Patel, Tejas

    2012-07-15

    Systemic anticoagulation decreases the risk of radial artery occlusion (RAO) after transradial catheterization and standard occlusive hemostasis. We compared the efficacy and safety of provisional heparin use only when the technique of patent hemostasis was not achievable to standard a priori heparin administration after radial sheath introduction. Patients referred for coronary angiography were randomized in 2 groups. In the a priori group, 200 patients received intravenous heparin (50 IU/kg) immediately after sheath insertion. In the provisional group, 200 patients did not receive heparin during the procedure. After sheath removal, hemostasis was obtained using a TR band (Terumo corporation, Tokyo, Japan) with a plethysmography-guided patent hemostasis technique. In the provisional group, no heparin was given if radial artery patency could be obtained and maintained. If radial patency was not achieved, a bolus of heparin (50 IU/kg) was given. Radial artery patency was evaluated at 24 hours (early RAO) and 30 days after the procedure (late RAO) by plethysmography. Patent hemostasis was obtained in 67% in the a priori group and 74% in the provisional group (p = 0.10). Incidence of RAO remained similar in the 2 groups at the early (7.5% vs 7.0%, p = 0.84) and late (4.5% vs 5.0%, p = 0.83) evaluations. Women, patients with diabetes, patients having not received heparin, and patients without radial artery patency during hemostasis had more RAO. By multivariate analysis, patent radial artery during hemostasis (odds ratio [OR] 0.03, 95% confidence interval [CI] 0.004 to 0.28, p = 0.002) and diabetes (OR 11, 95% CI 3 to 38,p patent hemostasis is maintained. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Perinatal taurine exposure affects adult arterial pressure control

    Science.gov (United States)

    Roysommuti, Sanya; Wyss, J. Michael

    2012-01-01

    Taurine is an abundant free amino acid found in mammalian cells that contributes to many physiologic functions from that of a simple cell osmolyte to a programmer of adult health and disease. Taurine’s contribution extends from conception throughout life, but its most critical exposure period is during perinatal life. In adults, taurine supplementation prevents or alleviates cardiovascular disease and related complications. In contrast, low taurine consumption coincides with increased risk of cardiovascular disease, obesity and type II diabetes. This review focuses on the effects that altered perinatal taurine exposure has on long-term mechanisms that control adult arterial blood pressure and could thereby contribute to arterial hypertension through its ability to program these cardiovascular regulatory mechanisms very early in life. The modifications of these mechanisms can last a lifetime and transfer to the next generation, suggesting that epigenetic mechanisms underlie the changes. The ability of perinatal taurine exposure to influence arterial pressure control mechanisms and hypertension in adult life appears to involve the regulation of growth and development, the central and autonomic nervous system, the renin-angiotensin system, glucose-insulin interaction and changes to heart, blood vessels and kidney function. PMID:23070226

  20. Relationship of daily arterial blood pressure monitoring readings and arterial stiffness profile in male patients with chronic obstructive pulmonary disease combined with arterial hypertension

    Directory of Open Access Journals (Sweden)

    Karoli N.A.

    2013-06-01

    Full Text Available The aim of the study was to determine correlation between arterial blood pressure daily rhythm and daily profile of arterial stiffness in male patients with chronic obstructive pulmonary disease (COPD and arterial hypertension. Materials et methods: Prospective investigation comprised 45 male patients with COPD and arterial hypertension. Individuals of 40 years younger and 80 years elder, patients with diabetes, stroke, angina pectoris, or heart infarction, vascular diseases, and exacerbation of chronic disease, bronchial and pulmonary diseases of other etiology were excluded from the analyses. Comparison group included 47 patients with essential arterial hypertension and without chronic respiratory diseases closely similar on general parameters with patients from main clinical series. Twenty-four-hour arterial blood pressure monitoring (ABPM and daily arterial stiffness monitoring were performed using BPLab® MnSDP-2 apparatus (Petr Telegin, Russian Federation. Results: Patients with COPD combined with arterial hypertension with raised arterial stiffness measures prevail over individuals in essential hypertension group. There is pathological alteration of the ABPM circadian rhythm and raised «Pressure load» values in raised arterial stiffness group. Conclusion: We found ABPM raised parameters in patients with COPD and arterial hypertension. It confirms necessity of ABPM in daily arterial stiffness assessment in patients with COPD.

  1. Large plasma pressure perturbations and radial convective transport in a tokamak

    International Nuclear Information System (INIS)

    Krasheninnikov, Sergei; Yu, Guanghui; Ryutov, Dmitri

    2004-01-01

    Strongly localized plasma structures with large pressure inhomogeneities (such as plasma blobs in the scrape-off-layer (SOL)/shadow regions, pellet clouds, Edge localized Modes (ELMs)) observed in the tokamaks, stellarators and linear plasma devices. Experimental studies of these phenomena reveal striking similarities including more convective rather than diffusive radial plasma transport. We suggest that rather simple models can describe many essentials of blobs, ELMs, and pellet clouds dynamics. The main ingredient of these models is the effective plasma gravity caused by magnetic curvature, centrifugal or friction forces effects. As a result, the equations governing plasma transport in such localized structures appear to be rather similar to that used to describe nonlinear evolution of thermal convection in the Boussinesq approximation (directly related to the Rayleigh-Taylor (RT) instability). (author)

  2. Radial Distribution of the Nanosecond Dielectric Barrier Discharge Current in Atmospheric-Pressure Air

    Science.gov (United States)

    Malashin, M. V.; Moshkunov, S. I.; Khomich, V. Yu.; Shershunova, E. A.

    2018-01-01

    Experimental results on the radial distribution of the nanosecond dielectric barrier discharge (DBD) current in flat millimeter air gaps under atmospheric pressure and natural humidity of 40-60% at a voltage rise rate at the electrodes of 250 V/ns are presented. The time delay of the appearance of discharge currents was observed to increase from the center to the periphery of the air gap at discharge gap heights above 3 mm, which correlated with the appearance of constricted channels against the background of the volume DBD plasma. Based on the criterion of the avalanche-streamer transition, it is found out that the development of a nanosecond DBD in air gaps of 1-3 mm occurs by the streamer mechanism.

  3. Reciprocal Influence of Slow Waves Extracted in Intracranial Pressure, Arterial Pressure and Cerebral Blood Velocity Signals

    National Research Council Canada - National Science Library

    Cervenansky, F

    2001-01-01

    ...), and arterial blood pressure (ABP). To clarify the links, we compared two frequency methods based on coherence function to estimate the influence of ICP, ABP, and CBV on couples, respectively CBV-ABP, ICP-CBV and ICP-ABP, of slow waves...

  4. Subchannel flow analysis in Candu and ACR pressure tubes with radial and axial diameter variation

    Energy Technology Data Exchange (ETDEWEB)

    Catana, A.; Prodea, L. [RAAN, Institute for Nuclear Research, Arges (Romania); Danila, N.; Prisecaru, I.; Dupleac, D. [Bucharest Univ. Politehnica(Romania)

    2007-07-01

    The Candu (Canada Deuterium Uranium) and ACR (Advanced Candu Reactor) are pressure tubes (PT) heavy water moderated reactors. Candu are heavy water and ACR are light water cooled reactors. The pressure tube is filled with 12 bundles, each consisting of 37 respectively 43 fuel rods. One Candu reactor is in operation at Cernavoda, Romania since 1996. ACR is a proposed advanced Candu. PT diameter variation has a significant impact on the thermal-hydraulic parameters. Almost all thermal-hydraulic parameters change, but some of them have a greater significance. In this work we have considered a set of radial and axial PT diameter variations both for Candu-600 and ACR-700 reactors using various types of fuel bundles. We can conclude the following: 1) some thermal-hydraulic parameters are significantly influenced: critical heat flux (CHF), pressure drop, or void fraction; 2) the most significant parameter CHF is worsening which reduces the safety margin; 3) some fuel types present a better thermal-hydraulic behavior; and 4) fuel bundles with fresh fuel or low burnup have a worse thermal-hydraulic behaviour than those at average burn-up.

  5. Subchannel flow analysis in Candu and ACR pressure tubes with radial and axial diameter variation

    International Nuclear Information System (INIS)

    Catana, A.; Prodea, L.; Danila, N.; Prisecaru, I.; Dupleac, D.

    2007-01-01

    The Candu (Canada Deuterium Uranium) and ACR (Advanced Candu Reactor) are pressure tubes (PT) heavy water moderated reactors. Candu are heavy water and ACR are light water cooled reactors. The pressure tube is filled with 12 bundles, each consisting of 37 respectively 43 fuel rods. One Candu reactor is in operation at Cernavoda, Romania since 1996. ACR is a proposed advanced Candu. PT diameter variation has a significant impact on the thermal-hydraulic parameters. Almost all thermal-hydraulic parameters change, but some of them have a greater significance. In this work we have considered a set of radial and axial PT diameter variations both for Candu-600 and ACR-700 reactors using various types of fuel bundles. We can conclude the following: 1) some thermal-hydraulic parameters are significantly influenced: critical heat flux (CHF), pressure drop, or void fraction; 2) the most significant parameter CHF is worsening which reduces the safety margin; 3) some fuel types present a better thermal-hydraulic behavior; and 4) fuel bundles with fresh fuel or low burnup have a worse thermal-hydraulic behaviour than those at average burn-up

  6. Evaluation of a new arterial pressure-based cardiac output device requiring no external calibration

    Directory of Open Access Journals (Sweden)

    Amann Matthias

    2007-11-01

    Full Text Available Abstract Background Several techniques have been discussed as alternatives to the intermittent bolus thermodilution cardiac output (COPAC measurement by the pulmonary artery catheter (PAC. However, these techniques usually require a central venous line, an additional catheter, or a special calibration procedure. A new arterial pressure-based cardiac output (COAP device (FloTrac™, Vigileo™; Edwards Lifesciences, Irvine, CA, USA only requires access to the radial or femoral artery using a standard arterial catheter and does not need an external calibration. We validated this technique in critically ill patients in the intensive care unit (ICU using COPAC as the method of reference. Methods We studied 20 critically ill patients, aged 16 to 74 years (mean, 55.5 ± 18.8 years, who required both arterial and pulmonary artery pressure monitoring. COPAC measurements were performed at least every 4 hours and calculated as the average of 3 measurements, while COAP values were taken immediately at the end of bolus determinations. Accuracy of measurements was assessed by calculating the bias and limits of agreement using the method described by Bland and Altman. Results A total of 164 coupled measurements were obtained. Absolute values of COPAC ranged from 2.80 to 10.80 l/min (mean 5.93 ± 1.55 l/min. The bias and limits of agreement between COPAC and COAP for unequal numbers of replicates was 0.02 ± 2.92 l/min. The percentage error between COPAC and COAP was 49.3%. The bias between percentage changes in COPAC (ΔCOPAC and percentage changes in COAP (ΔCOAP for consecutive measurements was -0.70% ± 32.28%. COPAC and COAP showed a Pearson correlation coefficient of 0.58 (p PAC and ΔCOAP was 0.46 (p Conclusion Although the COAP algorithm shows a minimal bias with COPAC over a wide range of values in an inhomogeneous group of critically ill patients, the scattering of the data remains relative wide. Therefore, the used algorithm (V 1.03 failed to

  7. Evaluation of a new arterial pressure-based cardiac output device requiring no external calibration

    Science.gov (United States)

    Prasser, Christopher; Bele, Sylvia; Keyl, Cornelius; Schweiger, Stefan; Trabold, Benedikt; Amann, Matthias; Welnhofer, Julia; Wiesenack, Christoph

    2007-01-01

    Background Several techniques have been discussed as alternatives to the intermittent bolus thermodilution cardiac output (COPAC) measurement by the pulmonary artery catheter (PAC). However, these techniques usually require a central venous line, an additional catheter, or a special calibration procedure. A new arterial pressure-based cardiac output (COAP) device (FloTrac™, Vigileo™; Edwards Lifesciences, Irvine, CA, USA) only requires access to the radial or femoral artery using a standard arterial catheter and does not need an external calibration. We validated this technique in critically ill patients in the intensive care unit (ICU) using COPAC as the method of reference. Methods We studied 20 critically ill patients, aged 16 to 74 years (mean, 55.5 ± 18.8 years), who required both arterial and pulmonary artery pressure monitoring. COPAC measurements were performed at least every 4 hours and calculated as the average of 3 measurements, while COAP values were taken immediately at the end of bolus determinations. Accuracy of measurements was assessed by calculating the bias and limits of agreement using the method described by Bland and Altman. Results A total of 164 coupled measurements were obtained. Absolute values of COPAC ranged from 2.80 to 10.80 l/min (mean 5.93 ± 1.55 l/min). The bias and limits of agreement between COPAC and COAP for unequal numbers of replicates was 0.02 ± 2.92 l/min. The percentage error between COPAC and COAP was 49.3%. The bias between percentage changes in COPAC (ΔCOPAC) and percentage changes in COAP (ΔCOAP) for consecutive measurements was -0.70% ± 32.28%. COPAC and COAP showed a Pearson correlation coefficient of 0.58 (p < 0.01), while the correlation coefficient between ΔCOPAC and ΔCOAP was 0.46 (p < 0.01). Conclusion Although the COAP algorithm shows a minimal bias with COPAC over a wide range of values in an inhomogeneous group of critically ill patients, the scattering of the data remains relative wide. Therefore

  8. Choice of marker for assessment of RV dysfunction in acute pulmonary embolism : NT-proBNP, pulmonary artery systolic pressure, mean arterial pressure, or blood pressure index.

    Science.gov (United States)

    Ates, H; Ates, I; Kundi, H; Yilmaz, F M

    2017-12-01

    We aimed to examine the value of NT-proBNP, pulmonary artery systolic pressure (PASP), blood pressure index (BPI), and mean arterial pressure (MAP) in the determination of right ventricular dysfunction (RVD) in patients with acute pulmonary embolism (APE). A total of 547 patients diagnosed with APE were included in the study. Demographic characteristics and comorbid conditions of patients were recorded in patient files. For blood pressure measurement, a calibrated digital blood pressure monitor was used at regular intervals. Blood samples were taken from patients at the time of admission for hemogram, biochemical, and hemostasis blood tests. Echocardiography was performed on all patients to detect RVD and evaluate pulmonary artery pressure. PASP (p blood pressure (p blood cell (p AUC ± SE = 0.975 ± 0.006; p < 0.001) was found to be the best predictor of RVD with a higher sensitivity (92.8%) and specificity (100%). We found that BPI had a better diagnostic discrimination for RVD compared with PASP and NT-proBNP.

  9. A comparison of direct technique with the liquid stylet technique of radial artery cannulation in patients presenting for coronary artery bypass grafting

    International Nuclear Information System (INIS)

    Younus, U.; Ahmed, I.

    2012-01-01

    To compare direct technique with the liquid stylet technique of radial artery cannulation in patients undergoing coronary artery byroms grouping. We hypothesized that liquid stylet technique would lead to fewer attempts and save vital time. Study Design: Randomized controlled Trial (RCT). Place and Duration of Study: Department of Anaesthesia and Intensive Care, Armed Forces Institute of Cardiology and National Institute of Heart Diseases, [AFIC-NIHD] Rawalpindi, between 1 July 2007 to 31 Dec 2007. Patients and Methods: One hundred patients of either sex scheduled for CABG were included and were randomized to 2 groups using random number table. Fifty patients in the direct technique group and 50 in the liquid stylet group. Results: These two groups comparable with respect to age, gender and weight were studied. The number of attempts in group 1 were 1.7+-0.5 vs 3.6+-1.6 in groups 2, (p=0.021). The time consumed in group was 3.3 +- 2.2 minutes while in groups 2 it was 8.0 +- 3.6 (p=0.022). Conclusion: We concluded that the liquid stylet technique is safe, quick and is associated with lesser number of attempts at cannulation. Secondly it can be done without fancy guide wires and other technology especially in a developing country like Pakistan. (author)

  10. Pulsatility Index of Blood Echogenicity of the Human Radial and Common Carotid Arteries: Relation with Age and Stroke

    International Nuclear Information System (INIS)

    Bok, Tae Hoon; Kong, Qi; Nam, Kweon Ho; Choi, Jay Chol; Paeng, Dong Guk

    2012-01-01

    In the present paper, the ultrasound blood images were measured at both the human radial artery(RA) and common carotid artery(CCA), depending on the age, and the pulsatility index of blood echogenicity(PIBE) was analyzed. In addition, the ultrasound blood images were measured at both RA and CCA of both the stroke patients and the control group, and PIBE was compared. PIBE of RA for the young group was similar with that for the old group (0.13±0.21 and 0.16±0.03). PIBE of CCA for the young group, however, was larger than that for the old group (0.70±0.21 and 0.32±0.01), and was more variable depending on the subject. Similarly, the fibrinogen concentrations of the patients (336±61 and 340±126 mg/dl) were more than that of the control group (264±38 and 43 mg/dl), for both RA and CCA. The results indicate the possibility of the ultrasonic test on the correlation between erythrocyte aggregation and stroke, and it is expected that the in-vivo EA measurement would be clinically useful.

  11. Variations in pulmonary artery occlusion pressure to estimate changes in pleural pressure.

    Science.gov (United States)

    Bellemare, Patrick; Goldberg, Peter; Magder, Sheldon A

    2007-11-01

    A readily available assessment of changes in pleural pressure would be useful for ventilator and fluid management in critically ill patients. We examined whether changes in pulmonary artery occlusion pressure (Ppao) adequately reflect respiratory changes in pleural pressure as assessed by changes in intraesophageal balloon pressure (Peso). We studied patients who had a pulmonary catheter and esophageal balloon surrounding a nasogastric tube as part of their care (n=24). We compared changes in Ppao (dPpao) to changes in Peso (dPeso) by Bland-Altman and regression analysis. Adequacy of balloon placement was assessed by performing Mueller maneuvers and adjusting the position to achieve a ratio of dPeso to change in tracheal pressure (dPtr) of 0.85 or higher. This was achieved in only 14 of the 24 subjects. We also compared dCVP to dPeso. The dPpao during spontaneous breaths and positive pressure breaths gave a good estimate of Peso but generally underestimated dPeso (bias=2.2 +8.2 and -3.9 cmH2O for the whole group). The dCVP was not as good a predictor (bias=2.9 +10.3 and -4.6). In patients who have a pulmonary artery catheter in place dPpao gives a lower estimate of changes in pleural pressure and may be more reliable than dPeso. The dCVP is a less reliable predictor than changes in pleural pressure.

  12. Understanding the Influence of Pressure and Radial Loads on Stress and Displacement Response of a Rotating Body: The Automobile Wheel

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available This paper highlights the use of the finite element technique for analyzing stress and displacement distributions in wheels of automotive vehicles when subject to the conjoint influence of inflation pressure and radial load. The most commonly used considerations in the design of the rotating body are elucidated. A potentially viable technique for finite element modeling of radial wheel, subjected to loading, is highlighted. The extrinsic influence of inflation pressure on performance of the rotating body, that is, the wheel, is rationalized.

  13. Harmonic scalpel versus electrocautery for harvest of radial artery conduits: Reduced risk of spasm and intimal injury on optical coherence tomography

    Science.gov (United States)

    Brazio, Philip S.; Laird, Patrick C.; Xu, Chenyang; Gu, Junyan; Burris, Nicholas S.; Brown, Emile N.; Kon, Zachary N.; Poston, Robert S.

    2009-01-01

    Objective Vasospasm is the primary obstacle to widespread adoption of the radial artery as a conduit in coronary artery bypass grafting. We used optical coherence tomography, a catheter-based intravascular imaging modality, to measure the degree of radial artery spasm induced by means of harvest with electrocautery or a harmonic scalpel in patients undergoing coronary artery bypass grafting. Methods Radial arteries were harvested from 44 consecutive patients with a harmonic scalpel (n = 15) or electrocautery (n = 29). Vessels were imaged before harvesting and after removal from the arm, with saphenous vein tracts serving as internal controls. Optical coherence tomographic findings for the degree of harvesting-induced injury were validated against histologic measures. Results Optical coherence tomographic measures of endovascular dimensions and injury correlated strongly with histologic findings. Mean luminal volume, a measure of vasospasm, decreased significantly less after harvesting with a harmonic scalpel (9% ± 7%) than with electrocautery (35% ± 6%, P = .015). Completely intact intima was present in 11 (73%) of 15 radial arteries harvested with a harmonic scalpel (73%) compared with 9 of 29 arteries harvested by means of electrocautery (31%, P = .011). Intraoperative flow measurements and patency rates at 5 days postoperatively were not significantly different among groups. Conclusions Optical coherence tomography provides a level of speed and accuracy for quantifying endothelial injury and vasospasm that has not been described for any other modality, suggesting potential as an intraoperative quality assurance tool. Our optical coherence tomographic findings suggest that the harmonic scalpel induces less spasm and intimal injury compared with electrocautery. PMID:19026820

  14. Peripheral arterial volume distensibility: significant differences with age and blood pressure measured using an applied external pressure

    International Nuclear Information System (INIS)

    Zheng, Dingchang; Murray, Alan

    2011-01-01

    A new arterial distensibility measurement technique was assessed in 100 healthy normotensive subjects. Arterial transmural pressures on the whole right arm were reduced with a 50 cm long cuff inflated to 10, 20, 30 and 40 mmHg. The electrocardiogram, and finger and ear photoplethysmograms were recorded simultaneously. Arm pulse propagation time, pulse wave velocity (PWV) and arterial volume distensibility were determined. With a 40 mmHg reduction in transmural pressure, arm pulse propagation time increased from 61 to 83 ms, PWV decreased from 12 to 8 m s −1 and arterial distensibility increased from 0.102% to 0.232% per mmHg (all P < 0.0001). At all cuff pressures, arterial distensibility was significantly related to resting mean arterial pressure (MAP), diastolic blood pressure (DBP) and age, and for systolic blood pressure at 30 and 40 mmHg (all P < 0.05). At 40 mmHg cuff pressure, arterial distensibility fell by 54% for a MAP increase from 75 to 105 mmHg, 57% for a DBP increase from 60 to 90 mmHg and 47% for an age increase from 20 to 70 years. These changes were more than double than those without cuff pressure. Our technique showed that systemic volume distensibility of the peripheral arm artery reduced with age, with a greater effect at higher external and lower transmural pressures

  15. Machine Learning Techniques for Arterial Pressure Waveform Analysis

    Directory of Open Access Journals (Sweden)

    João Cardoso

    2013-05-01

    Full Text Available The Arterial Pressure Waveform (APW can provide essential information about arterial wall integrity and arterial stiffness. Most of APW analysis frameworks individually process each hemodynamic parameter and do not evaluate inter-dependencies in the overall pulse morphology. The key contribution of this work is the use of machine learning algorithms to deal with vectorized features extracted from APW. With this purpose, we follow a five-step evaluation methodology: (1 a custom-designed, non-invasive, electromechanical device was used in the data collection from 50 subjects; (2 the acquired position and amplitude of onset, Systolic Peak (SP, Point of Inflection (Pi and Dicrotic Wave (DW were used for the computation of some morphological attributes; (3 pre-processing work on the datasets was performed in order to reduce the number of input features and increase the model accuracy by selecting the most relevant ones; (4 classification of the dataset was carried out using four different machine learning algorithms: Random Forest, BayesNet (probabilistic, J48 (decision tree and RIPPER (rule-based induction; and (5 we evaluate the trained models, using the majority-voting system, comparatively to the respective calculated Augmentation Index (AIx. Classification algorithms have been proved to be efficient, in particular Random Forest has shown good accuracy (96.95% and high area under the curve (AUC of a Receiver Operating Characteristic (ROC curve (0.961. Finally, during validation tests, a correlation between high risk labels, retrieved from the multi-parametric approach, and positive AIx values was verified. This approach gives allowance for designing new hemodynamic morphology vectors and techniques for multiple APW analysis, thus improving the arterial pulse understanding, especially when compared to traditional single-parameter analysis, where the failure in one parameter measurement component, such as Pi, can jeopardize the whole evaluation.

  16. Radiation exposure and contrast agent use related to radial versus femoral arterial access during percutaneous coronary intervention (PCI)-Results of the FERARI study.

    Science.gov (United States)

    Becher, Tobias; Behnes, Michael; Ünsal, Melike; Baumann, Stefan; El-Battrawy, Ibrahim; Fastner, Christian; Kuschyk, Jürgen; Papavassiliu, Theano; Hoffmann, Ursula; Mashayekhi, Kambis; Borggrefe, Martin; Akin, Ibrahim

    2016-12-01

    Data regarding radiation exposure related to radial versus femoral arterial access in patients undergoing percutaneous coronary intervention (PCI) remain controversial. This study aims to evaluate patients enrolled in the FERARI study regarding radiation exposure, fluoroscopy time and contrast agent use. The Femoral Closure versus Radial Compression Devices Related to Percutaneous Coronary Interventions (FERARI) study evaluated prospectively 400 patients between February 2014 and May 2015 undergoing PCI either using the radial or femoral access. In these 400 patients, baseline characteristics, procedural data such as procedural duration, fluoroscopy time, dose-area product (DAP) as well as the amount of contrast agent used were documented and analyzed. Median fluoroscopy time was not significantly different in patients undergoing radial versus femoral access (12.2 vs. 9.8min, p=0.507). Furthermore, median DAP (54.5 vs. 52.0 Gycm2, p=0.826), procedural duration (46.0 vs. 45.0min, p=0.363) and contrast agent use (185.5 vs. 199.5ml, p=0.742) were also similar in radial and femoral PCI. There was no difference regarding median fluoroscopy time, procedural duration, radiation dose or contrast agent use between radial versus femoral arterial access in PCI. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. [Baroreflexes originated in vertebral artery zones upon peripheral vein tonus, systemic arterial blood pressure, and external respiration].

    Science.gov (United States)

    Agadzhanian, N A; Kupriianov, S V

    2008-06-01

    The investigation was intended to study the role ofbaroreceptors ofhemodynamically isolated zone of vertebral arteries in regulation of peripheral veins tonus, arterial pressure and external respiration. Pressure decrease in this vascular reflexogenic zone led to reflex responses of increase in femoral vein tonus, elevation of blood pressure level and stimulation of external respiration. The opposite reflex responses of cardio-respiratory functional system to initial pressure activation of vertebral arteries baroreceptors are observed. Basing on generalization of our own findings and similar physiological and morphological researches of other authors, it is established that afferentation from the vertebral artery zone is a reflexogenic factor of somatic muscles' veins tonus regulation. These reflexes of capacity vessels tonic activity changes are part of cardio-respiratory responses of maintaining the tissue gaseous exchange.

  18. Impact of age on pulmonary artery systolic pressures at rest and with exercise

    Directory of Open Access Journals (Sweden)

    Garvan C Kane

    2016-06-01

    Full Text Available Aim: It is not well known if advancing age influences normal rest or exercise pulmonary artery pressures. The purpose of the study was to evaluate the association of increasing age with measurements of pulmonary artery systolic pressure at rest and with exercise. Subjects and methods: A total of 467 adults without cardiopulmonary disease and normal exercise capacity (age range: 18–85 years underwent symptom-limited treadmill exercise testing with Doppler measurement of rest and exercise pulmonary artery systolic pressure. Results: There was a progressive increase in rest and exercise pulmonary artery pressures with increasing age. Pulmonary artery systolic pressures at rest and with exercise were 25 ± 5 mmHg and 33 ± 9 mmHg, respectively, in those <40 years, and 30 ± 5 mmHg and 41 ± 12 mmHg, respectively, in those ≥70 years. While elevated left-sided cardiac filling pressures were excluded by protocol design, markers of arterial stiffness associated with the age-dependent effects on pulmonary pressures. Conclusion: These data demonstrate that in echocardiographically normal adults, pulmonary artery systolic pressure increases with advancing age. This increase is seen at rest and with exercise. These increases in pulmonary pressure occur in association with decreasing transpulmonary flow and increases in systemic pulse pressure, suggesting that age-associated blood vessel stiffening may contribute to these differences in pulmonary artery systolic pressure.

  19. Contribution of the Arterial System and the Heart to Blood Pressure during Normal Aging - A Simulation Study

    NARCIS (Netherlands)

    Maksuti, Elira; Westerhof, Nico; Westerhof, Berend E.; Broomé, Michael; Stergiopulos, Nikos

    2016-01-01

    During aging, systolic blood pressure continuously increases over time, whereas diastolic pressure first increases and then slightly decreases after middle age. These pressure changes are usually explained by changes of the arterial system alone (increase in arterial stiffness and vascular

  20. Elevated arterial blood pressure after superior cavo-pulmonary anastomosis is associated with elevated pulmonary artery pressure and cerebrovascular dysautoregulation.

    Science.gov (United States)

    Cabrera, Antonio G; Kibler, Kathleen K; Blaine Easley, R; Goldsworthy, Michelle; Shekerdemian, Lara S; Andropoulos, Dean B; Heinle, Jeffrey; Gottlieb, Erin A; Vu, Eric; Brady, Ken M

    2018-04-18

    BackgroundElevated arterial blood pressure (ABP) is common after superior bidirectional cavopulmonary anastomosis (BCPA). The effects of elevated ABP after BCPA on cerebrovascular hemodynamics are unknown. We sought to determine the relationship between elevated ABP and cerebrovascular autoregulation after BCPA.MethodsProspective, observational study on infants with single-ventricle physiology after BCPA surgery. Continuous recordings of mean ABP, mean cavopulmonary artery pressure (PAP), near-infrared spectroscopy measures of cerebral oximetry (regional cerebral oxygen saturation (rSO 2 )), and relative cerebral blood volume index were obtained from admission to extubation. Autoregulation was measured as hemoglobin volume index (HVx). Physiologic variables, including the HVx, were tested for variance across ABP.ResultsSixteen subjects were included in the study. Elevated ABP post-BCPA was associated with both, elevated PAP (PABP and alterations in rSO 2 . Using piecewise regression, the relationship of PAP to ABP demonstrated a breakpoint at 68 mm Hg (interquartile range (IQR) 62-70 mm Hg). Curve fit of HVx as a function of ABP identified optimal ABP supporting robust autoregulation at a median ABP of 55 mm Hg (IQR 51-64 mm Hg).ConclusionsElevated ABP post-BCPA is associated with cerebrovascular dysautoregulation, and elevated PAP. The effects, of prolonged dysautoregulation within this population, require further study.Pediatric Research advance online publication, 18 April 2018; doi:10.1038/pr.2018.31.

  1. Radiation exposure and contrast agent use related to radial versus femoral arterial access during percutaneous coronary intervention (PCI)—Results of the FERARI study

    Energy Technology Data Exchange (ETDEWEB)

    Becher, Tobias, E-mail: Tobias.Becher@umm.de [First Department of Medicine, University Medical Centre Mannheim, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); Behnes, Michael; Ünsal, Melike; Baumann, Stefan; El-Battrawy, Ibrahim; Fastner, Christian; Kuschyk, Jürgen; Papavassiliu, Theano; Hoffmann, Ursula [First Department of Medicine, University Medical Centre Mannheim, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); Mashayekhi, Kambis [Division of Cardiology and Angiology II, University Heart Center Freiburg Bad Krozingen, Bad Krozingen (Germany); Borggrefe, Martin; Akin, Ibrahim [First Department of Medicine, University Medical Centre Mannheim, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany)

    2016-12-15

    Summary: Background: Data regarding radiation exposure related to radial versus femoral arterial access in patients undergoing percutaneous coronary intervention (PCI) remain controversial. This study aims to evaluate patients enrolled in the FERARI study regarding radiation exposure, fluoroscopy time and contrast agent use. Methods: The Femoral Closure versus Radial Compression Devices Related to Percutaneous Coronary Interventions (FERARI) study evaluated prospectively 400 patients between February 2014 and May 2015 undergoing PCI either using the radial or femoral access. In these 400 patients, baseline characteristics, procedural data such as procedural duration, fluoroscopy time, dose–area product (DAP) as well as the amount of contrast agent used were documented and analyzed. Results: Median fluoroscopy time was not significantly different in patients undergoing radial versus femoral access (12.2 vs. 9.8 min, p = 0.507). Furthermore, median DAP (54.5 vs. 52.0 Gycm2, p = 0.826), procedural duration (46.0 vs. 45.0 min, p = 0.363) and contrast agent use (185.5 vs. 199.5 ml, p = 0.742) were also similar in radial and femoral PCI. Conclusion: There was no difference regarding median fluoroscopy time, procedural duration, radiation dose or contrast agent use between radial versus femoral arterial access in PCI. - Highlights: • Data comparing radiation exposure in radial versus femoral PCI remain controversial. • 400 enrolled in the FERARI study were prospectively evaluated. • There was no difference regarding radiation exposure in radial versus femoral access. • Furthermore, there was no significant difference regarding contrast agent use.

  2. Radiation exposure and contrast agent use related to radial versus femoral arterial access during percutaneous coronary intervention (PCI)—Results of the FERARI study

    International Nuclear Information System (INIS)

    Becher, Tobias; Behnes, Michael; Ünsal, Melike; Baumann, Stefan; El-Battrawy, Ibrahim; Fastner, Christian; Kuschyk, Jürgen; Papavassiliu, Theano; Hoffmann, Ursula; Mashayekhi, Kambis; Borggrefe, Martin; Akin, Ibrahim

    2016-01-01

    Summary: Background: Data regarding radiation exposure related to radial versus femoral arterial access in patients undergoing percutaneous coronary intervention (PCI) remain controversial. This study aims to evaluate patients enrolled in the FERARI study regarding radiation exposure, fluoroscopy time and contrast agent use. Methods: The Femoral Closure versus Radial Compression Devices Related to Percutaneous Coronary Interventions (FERARI) study evaluated prospectively 400 patients between February 2014 and May 2015 undergoing PCI either using the radial or femoral access. In these 400 patients, baseline characteristics, procedural data such as procedural duration, fluoroscopy time, dose–area product (DAP) as well as the amount of contrast agent used were documented and analyzed. Results: Median fluoroscopy time was not significantly different in patients undergoing radial versus femoral access (12.2 vs. 9.8 min, p = 0.507). Furthermore, median DAP (54.5 vs. 52.0 Gycm2, p = 0.826), procedural duration (46.0 vs. 45.0 min, p = 0.363) and contrast agent use (185.5 vs. 199.5 ml, p = 0.742) were also similar in radial and femoral PCI. Conclusion: There was no difference regarding median fluoroscopy time, procedural duration, radiation dose or contrast agent use between radial versus femoral arterial access in PCI. - Highlights: • Data comparing radiation exposure in radial versus femoral PCI remain controversial. • 400 enrolled in the FERARI study were prospectively evaluated. • There was no difference regarding radiation exposure in radial versus femoral access. • Furthermore, there was no significant difference regarding contrast agent use

  3. Redundant Vasodilator Pathways Underlying Radial Artery Flow-Mediated Dilation Are Preserved in Healthy Aging

    Directory of Open Access Journals (Sweden)

    Kevin D. Ballard

    2014-01-01

    Full Text Available Background. Blocking nitric oxide (NO and vasodilator prostanoids (PN does not consistently reduce flow-mediated dilation (FMD in young adults. The impact of aging on the contribution of NO and PG to FMD is unknown. Methods. FMD was measured in older adults (n=10, 65±3 y after arterial infusion of saline, N(G-monomethyl-L-arginine (L-NMMA, and ketorolac + L-NMMA. Data were compared to published data in young adults. Results. L-NMMA reduced FMD in older adults (8.9±3.6 to 5.9±3.7% although this was not statistically significant (P=0.08 and did not differ (P=0.74 from the reduction observed in young adults (10.0±3.8 to 7.6±4.7%; P=0.03. Blocking PN did not affect FMD in young or older adults. In older adults, L-NMMA reduced (n=6; range = 36–123% decrease, augmented (n=3; 10–122% increase, or did not change FMD (n=1; 0.4% increase. After PN blockade, FMD responses were reduced (n=2, augmented (n=6, or unaffected (n=1. Conclusions. NO or PN blockade did not consistently reduce FMD in healthy older adults, suggesting the existence of redundant vasodilator phenotypes as observed previously in young adults.

  4. Arterial stiffness, cardiovagal baroreflex sensitivity and postural blood pressure changes in older adults: the Rotterdam Study

    NARCIS (Netherlands)

    Mattace-Raso, Francesco U. S.; van den Meiracker, Anton H.; Bos, Willem Jan; van der Cammen, Tischa J. M.; Westerhof, Berend E.; Elias-Smale, Suzette; Reneman, Robert S.; Hoeks, Arnold P. G.; Hofman, Albert; Witteman, Jacqueline C. M.

    2007-01-01

    Arterial stiffness may be involved in the impairment of the arterial baroreflex. In the present study the associations between arterial stiffness and cardiovagal baroreflex sensitivity (BRS) and between BRS and postural blood pressure (BP) changes were investigated within the framework of the

  5. Arterial compliance in patients with cirrhosis: stroke volume-pulse pressure ratio as simplified index

    DEFF Research Database (Denmark)

    Fuglsang, S; Bendtsen, F; Christensen, E

    2001-01-01

    Arterial function may be altered in patients with cirrhosis. We determined compliance of the arterial tree (C(1)) in relation to systemic and splanchnic hemodynamic derangement and clinical variables. C(1) and the stroke volume-pulse pressure index (SV/PP) were significantly higher (+62% and +40%...... predictors of SV/PP (P abnormalities in the arterial compliance of these patients....

  6. Stress concentration factors for an internally pressurized circular vessel containing a radial U-notch

    International Nuclear Information System (INIS)

    Carvalho, E.A. de

    2005-01-01

    This paper evaluates the stress concentration factors for an internally pressurized cylinder containing a radial U-notch along its length. This work studies the cases where the external to internal radius ratio (Ψ) is equal to 1.26, 1.52, 2.00, and 3.00 and the notch radius to internal radius ratio (Φ) is fixed and equal to 0.026. The U-notch depth varies from 0.1 to 0.6 of the wall thickness. Results are also presented for a fixed size semi-circular notch. Hoop stresses at the external wall are presented, showing regions where the stress matches the nominal one and the favourable places to install strain sensors. The finite element method is used to determine the stress concentration factors (K t ) for the above described situations and for a special case where a varying semi-circular notch is present with Ψ=3.00. This notch depth varies from 0.013 to 0.3 of the wall thickness. It is pointed out that even relatively small notches introduce large stress concentrations and disrupt the hoop stress distribution all over the cross section. Results are also compared to an example found in the literature for semi-circular notches and K t curves for both cases present the same shape

  7. Peripheral Chemoreception and Arterial Pressure Responses to Intermittent Hypoxia

    Science.gov (United States)

    Prabhakar, Nanduri R.; Peng, Ying-Jie; Kumar, Ganesh K.; Nanduri, Jayasri

    2015-01-01

    Carotid bodies are the principal peripheral chemoreceptors for detecting changes in arterial blood oxygen levels, and the resulting chemoreflex is a potent regulator of blood pressure. Recurrent apnea with intermittent hypoxia (IH) is a major clinical problem in adult humans and infants born preterm. Adult patients with recurrent apnea exhibit heightened sympathetic nerve activity and hypertension. Adults born preterm are predisposed to early onset of hypertension. Available evidence suggests that carotid body chemoreflex contributes to hypertension caused by IH in both adults and neonates. Experimental models of IH provided important insights into cellular and molecular mechanisms underlying carotid body chemoreflex-mediated hypertension. This article provides a comprehensive appraisal of how IH affects carotid body function, underlying cellular, molecular, and epigenetic mechanisms, and the contribution of chemoreflex to the hypertension. PMID:25880505

  8. Peripheral chemoreception and arterial pressure responses to intermittent hypoxia.

    Science.gov (United States)

    Prabhakar, Nanduri R; Peng, Ying-Jie; Kumar, Ganesh K; Nanduri, Jayasri

    2015-04-01

    Carotid bodies are the principal peripheral chemoreceptors for detecting changes in arterial blood oxygen levels, and the resulting chemoreflex is a potent regulator of blood pressure. Recurrent apnea with intermittent hypoxia (IH) is a major clinical problem in adult humans and infants born preterm. Adult patients with recurrent apnea exhibit heightened sympathetic nerve activity and hypertension. Adults born preterm are predisposed to early onset of hypertension. Available evidence suggests that carotid body chemoreflex contributes to hypertension caused by IH in both adults and neonates. Experimental models of IH provided important insights into cellular and molecular mechanisms underlying carotid body chemoreflex-mediated hypertension. This article provides a comprehensive appraisal of how IH affects carotid body function, underlying cellular, molecular, and epigenetic mechanisms, and the contribution of chemoreflex to the hypertension. © 2015 American Physiological Society.

  9. Intraspecific scaling of arterial blood pressure in the Burmese python.

    Science.gov (United States)

    Enok, Sanne; Slay, Christopher; Abe, Augusto S; Hicks, James W; Wang, Tobias

    2014-07-01

    Interspecific allometric analyses indicate that mean arterial blood pressure (MAP) increases with body mass of snakes and mammals. In snakes, MAP increases in proportion to the increased distance between the heart and the head, when the heart-head vertical distance is expressed as ρgh (where ρ is the density of blood, G: is acceleration due to gravity and h is the vertical distance above the heart), and the rise in MAP is associated with a larger heart to normalize wall stress in the ventricular wall. Based on measurements of MAP in Burmese pythons ranging from 0.9 to 3.7 m in length (0.20-27 kg), we demonstrate that although MAP increases with body mass, the rise in MAP is merely half of that predicted by heart-head distance. Scaling relationships within individual species, therefore, may not be accurately predicted by existing interspecific analyses. © 2014. Published by The Company of Biologists Ltd.

  10. Arterial blood pressure measurement and pulse wave analysis—their role in enhancing cardiovascular assessment

    International Nuclear Information System (INIS)

    Avolio, Alberto P; Butlin, Mark; Walsh, Andrew

    2010-01-01

    The most common method of clinical measurement of arterial blood pressure is by means of the cuff sphygmomanometer. This instrument has provided fundamental quantitative information on arterial pressure in individual subjects and in populations and facilitated estimation of cardiovascular risk related to levels of blood pressure obtained from the brachial cuff. Although the measurement is taken in a peripheral limb, the values are generally assumed to reflect the pressure throughout the arterial tree in large conduit arteries. Since the arterial pressure pulse becomes modified as it travels away from the heart towards the periphery, this is generally true for mean and diastolic pressure, but not for systolic pressure, and so pulse pressure. The relationship between central and peripheral pulse pressure depends on propagation characteristics of arteries. Hence, while the sphygmomanometer gives values of two single points on the pressure wave (systolic and diastolic pressure), there is additional information that can be obtained from the time-varying pulse waveform that enables an improved quantification of the systolic load on the heart and other central organs. This topical review will assess techniques of pressure measurement that relate to the use of the cuff sphygmomanometer and to the non-invasive registration and analysis of the peripheral and central arterial pressure waveform. Improved assessment of cardiovascular function in relation to treatment and management of high blood pressure will result from future developments in the indirect measurement of arterial blood pressure that involve the conventional cuff sphygmomanometer with the addition of information derived from the peripheral arterial pulse. (topical review)

  11. Aortic-Brachial Pulse Wave Velocity Ratio: A Measure of Arterial Stiffness Gradient Not Affected by Mean Arterial Pressure.

    Science.gov (United States)

    Fortier, Catherine; Desjardins, Marie-Pier; Agharazii, Mohsen

    2018-03-01

    Aortic stiffness, measured by carotid-femoral pulse wave velocity (cf-PWV), is used for the prediction of cardiovascular risk. This mini-review describes the nonlinear relationship between cf-PWV and operational blood pressure, presents the proposed methods to adjust for this relationship, and discusses a potential place for aortic-brachial PWV ratio (a measure of arterial stiffness gradient) as a blood pressure-independent measure of vascular aging. PWV is inherently dependent on the operational blood pressure. In cross-sectional studies, PWV adjustment for mean arterial pressure (MAP) is preferred, but still remains a nonoptimal approach, as the relationship between PWV and blood pressure is nonlinear and varies considerably among individuals due to heterogeneity in genetic background, vascular tone, and vascular remodeling. Extrapolations from the blood pressure-independent stiffness parameter β (β 0 ) have led to the creation of stiffness index β, which can be used for local stiffness. A similar approach has been used for cardio-ankle PWV to generate a blood pressure-independent cardio-ankle vascular index (CAVI). It was recently demonstrated that stiffness index β and CAVI remain slightly blood pressure-dependent, and a more appropriate formula has been proposed to make the proper adjustments. On the other hand, the negative impact of aortic stiffness on clinical outcomes is thought to be mediated through attenuation or reversal of the arterial stiffness gradient, which can also be influenced by a reduction in peripheral medium-sized muscular arteries in conditions that predispose to accelerate vascular aging. Arterial stiffness gradient, assessed by aortic-brachial PWV ratio, is emerging to be at least as good as cf-PWV for risk prediction, but has the advantage of not being affected by operating MAP. The negative impacts of aortic stiffness on clinical outcomes are proposed to be mediated through attenuation or reversal of arterial stiffness gradient

  12. Utilização da artéria radial como segundo enxerto arterial em pacientes acima de 70 anos The use of the radial artery as the second choice for arterial graft in patients over 70 years of age

    Directory of Open Access Journals (Sweden)

    Joseph Fredric Whitaker

    2005-03-01

    Full Text Available OBJETIVO: Estudo retrospectivo para avaliar a morbi-mortalidade e a evolução hospitalar em pacientes com idade superior a 70 anos, submetidos à operação de revascularização do miocárdio com utilização da artéria radial como segundo enxerto arterial. MÉTODO: No período de agosto de 1994 a dezembro de 2002, foram realizadas 2487 cirurgias de revascularização do miocárdio no Instituto do Coração de Juiz de Fora. Dentre os pacientes operados, 476 tinham idade superior a 70 anos, sendo que em 36 (Grupo II foi utilizada a artéria radial como 2º enxerto arterial. O mesmo tipo de cirurgia foi realizado em 142 pacientes com idade inferior a 70 anos (Grupo I. Não foram incluídas neste estudo reoperações, cirurgias sem CEC ou com procedimentos associados. RESULTADOS: A média de idade do Grupo II foi 72,5 anos, a mortalidade hospitalar neste grupo de pacientes foi 6,0%, a incidência de complicações também foi baixa, comparável à observada no mesmo tipo de operação realizada em pacientes com idade inferior a 70 anos. CONCLUSÃO: Diante destes resultados, os autores acreditam que a artéria radial possa ser usada com segurança como 2º enxerto arterial em pacientes acima de 70 anos, criteriosamente selecionados, apesar do maior risco de co-morbidades associadas nesta faixa etária.OBJECTIVE: Retrospective study eveluating the morbid-mortality and hospital behaviour in patients over 70-years -od patients submitted to myocardial revascularization involving the radial artery as the second arterial graft. METHOD: During the period of August 1994 to December 2002, 2487 cases of myocardial revascularization were performed by the group of the Juiz de Fora Heart Institute, 476 of whom were 70 years of age or older and 36 (Group II received the radial artery as the second arterial graft. The same type of surgery was performed in 142 patients under 70-year-old (Group I. Reoperations, off-pump operations (OPCAB or associated procedures

  13. Perfusion of veins at arterial pressure increases the expression of KLF5 and cell cycle genes in smooth muscle cells

    International Nuclear Information System (INIS)

    Amirak, Emre; Zakkar, Mustafa; Evans, Paul C.; Kemp, Paul R.

    2010-01-01

    Vascular smooth muscle cell (VSMC) proliferation remains a major cause of veno-arterial graft failure. We hypothesised that exposure of venous SMCs to arterial pressure would increase KLF5 expression and that of cell cycle genes. Porcine jugular veins were perfused at arterial or venous pressure in the absence of growth factors. The KLF5, c-myc, cyclin-D and cyclin-E expression were elevated within 24 h of perfusion at arterial pressure but not at venous pressure. Arterial pressure also reduced the decline in SM-myosin heavy chain expression. These data suggest a role for KLF5 in initiating venous SMCs proliferation in response to arterial pressure.

  14. Numerical modeling of dynamics of heart rate and arterial pressure during passive orthostatic test

    Science.gov (United States)

    Ishbulatov, Yu. M.; Kiselev, A. R.; Karavaev, A. S.

    2018-04-01

    A model of human cardiovascular system is proposed to describe the main heart rhythm, influence of autonomous regulation on frequency and strength of heart contractions and resistance of arterial vessels; process of formation of arterial pressure during systolic and diastolic phases; influence of respiration; synchronization between loops of autonomous regulation. The proposed model is used to simulate the dynamics of heart rate and arterial pressure during passive transition from supine to upright position. Results of mathematical modeling are compared to original experimental data.

  15. Classification of peripheral occlusive arterial diseases based on symptoms, signs and distal blood pressure measurements

    DEFF Research Database (Denmark)

    Tønnesen, K H; Noer, Ivan; Paaske, William

    1980-01-01

    Systolic blood pressures at toe and ankle were measured in 459 consecutive patients with occlusive arterial disease. Fifty-eight per cent had intermittent claudication with arterial disease of all degrees of severity. Seventeen per cent complained of rest pain having toe systolic pressures below 30...

  16. Fifteen years experience with finger arterial pressure monitoring : Assessment of the technology

    NARCIS (Netherlands)

    Imholz, B.P.M.; Wieling, W.; Montfrans, G.A. van; Wesseling, K.H.

    1998-01-01

    We review the Finapres technology, embodied in several TNO-prototypes and in the Ohmeda 2300 and 2300e Finapres NIBP. Finapres is an acronym for FINger Arterial PRESsure, the device delivers a continuous finger arterial pressure waveform. Many papers report on the accuracy of the device in

  17. Fifteen years experience with finger arterial pressure monitoring: assessment of the technology

    NARCIS (Netherlands)

    Imholz, B. P.; Wieling, W.; van Montfrans, G. A.; Wesseling, K. H.

    1998-01-01

    We review the Finapres technology, embodied in several TNO-prototypes and in the Ohmeda 2300 and 2300e Finapres NIBP. Finapres is an acronym for FINger Arterial PRESsure, the device delivers a continuous finger arterial pressure waveform. Many papers report on the accuracy of the device in

  18. Aneurisma sacular da artéria radial: a propósito de um caso clínico Sacular aneurysm of the radial artery: a case report

    Directory of Open Access Journals (Sweden)

    Nádia Duarte

    2011-06-01

    Full Text Available Os aneurismas da artéria radial são raros e esporádicos, sendo que os pseudoaneurismas são mais frequentes do que os aneurismas verdadeiros e maioritariamente de configuração sacular. A etiologia é variada e diferenciam-se de outros diagnósticos pela pulsação e frémito. Raramente se complicam de ruptura, sendo a trombose e embolização as principais complicações. Dos casos publicados sobre aneurismas verdadeiros da artéria radial, apenas um está descrito como sendo secundário a lesão ocupacional repetitiva, sendo a maioria de causa idiopática. Os autores descrevem um caso de uma mulher de 63 anos, referenciada à consulta de Cirurgia Vascular por crescimento de massa pulsátil na tabaqueira anatómica da mão esquerda. O estudo por eco-doppler e angiografia, confirmaram o diagnóstico de aneurisma sacular da artéria radial, com 20 mm de maior eixo, arcada palmar permeável e sem sinais de embolização distal. Foi submetida a aneurismectomia parcial com laqueação dupla proximal e distal e endoaneurismorrafia. A cirurgia e pós-operatório decorreram sem complicações, nomeadamente complicações isquémicas. A propósito desde caso clínico, discute-se a abordagem diagnóstica e opções terapêuticas.Radial artery aneurysms are sporadic and rare, pseudoaneurysms are more common than true aneurysms, mainly in saccular configuration. The etiology is varied and difference from other diagnostics is done by the presence of pulse and thrill. Thrombosis and embolization are the main complications, while rupture is rare. From the reported cases of true aneurysms of the radial artery, only one is described as being secondary to repetitive occupational injury, the majority being idiopathic. The authors describe the case of a 63 year old woman, referred to a Vascular Surgery consultation because of a growing pulsatile mass in the anatomical snuffbox of the left hand. The Doppler and Angiography studies confirmed the diagnosis of

  19. A common humoral background of intraocular and arterial blood pressure dysregulation.

    Science.gov (United States)

    Skrzypecki, Janusz; Grabska-Liberek, Iwona; Przybek, Joanna; Ufnal, Marcin

    2018-03-01

    It has been postulated that intraocular pressure, an important glaucoma risk factor, correlates positively with arterial blood pressure (blood pressure). However, results of experimental and clinical studies are often contradictory. It is hypothesized that, in some hypertensive patients, disturbances in intraocular pressure regulation may depend on biological effects of blood borne hormones underlying a particular type of hypertension, rather than on blood pressure level itself. This review compares the effects of hormones on blood pressure and intraocular pressure, in order to identify a hormonal profile of hypertensive patients with an increased risk of intraocular pressure surge. The PUBMED database was searched to identify pre-clinical and clinical studies investigating the role of angiotensin II, vasopressin, adrenaline, noradrenaline, prostaglandins, and gaseous transmitters in the regulation of blood pressure and intraocular pressure. Studies included in the review suggest that intraocular and blood pressures often follow a different pattern of response to the same hormone. For example, vasopressin increases blood pressure, but decreases intraocular pressure. In contrast, high level of nitric oxide decreases blood pressure, but increases intraocular pressure. Arterial hypertension is associated with altered levels of blood borne hormones. Contradicting results of studies on the relationship between arterial hypertension and intraocular pressure might be partially explained by diverse effects of hormones on arterial and intraocular pressures. Further studies are needed to evaluate if hormonal profiling may help to identify glaucoma-prone patients.

  20. Pressure Myography to Study the Function and Structure of isolated small arteries

    DEFF Research Database (Denmark)

    Schjørring, Olav; Carlsson, Rune; Simonsen, Ulf

    2015-01-01

    Small arteries play an important role in regulation of peripheral resistance and organ perfusion. Here we describe a series of the methods allowing measurements in pressurized segments of small arteries from the systemic and coronary circulation of mice as well as other species. The pressure...... myography techniques described include measurements of wall structure, wall stress, strain, and of myogenic tone. The pressurized perfused small arteries also allow evaluation of responses to increases in pressure, flow, and drugs, where the main readout is changes in vascular diameter....

  1. Blood pressure and arterial stiffness in obese children and adolescents.

    Science.gov (United States)

    Hvidt, Kristian Nebelin

    2015-03-01

    Obesity, elevated blood pressure (BP) and arterial stiffness are risk factors for cardiovascular disease. A strong relationship exists between obesity and elevated BP in both children and adults. Obesity and elevated BP in childhood track into adult life increasing the risk of cardiovascular disease in adulthood. Ambulatory BP is the most precise measure to evaluate the BP burden, whereas carotid-femoral pulse wave velocity (cfPWV) is regarded as the gold standard for evaluating arterial (i.e. aortic) stiffness. These measures might contribute to a better understanding of obesity's adverse impact on the cardiovascular system, and ultimately a better prevention and treatment of childhood obesity. The overall aim of the present PhD thesis is to investigate arterial stiffness and 24-hour BP in obese children and adolescents, and evaluate whether these measures are influenced by weight reduction. The present PhD thesis is based on four scientific papers.  In a cross-sectional design, 104 severe obese children and adolescents with an age of 10-18 years were recruited when newly referred to the Children's Obesity Clinic, Holbæk University Hospital, and compared to 50 normal weighted age and gender matched control individuals. Ambulatory BP was measured, and cfPWV was investigated in two ways in respect to the distance measure of aorta; the previously recommended length - the so called subtracted distance, and the currently recommended length - the direct distance. In a longitudinal design, the obese patients were re-investigated after one-year of lifestyle intervention at the Children's Obesity Clinic in purpose of reducing the degree of obesity. In the cross-sectional design, the obese group had higher measures of obesity, while matched for age, gender and height, when compared to the control group. In the longitudinal design, 74% of the 72 followed up obese patients experienced a significant weight reduction. CfPWV was dependent on the method used to measure the

  2. Morphological and functional consequences of transradial coronary angiography on the radial artery: implications for its use as a bypass conduit.

    Science.gov (United States)

    Gaudino, Mario; Leone, Alessandro; Lupascu, Andrea; Toesca, Amelia; Mazza, Andrea; Ponziani, Francesca Romana; Flore, Roberto; Tondi, Paolo; Massetti, Massimo

    2015-09-01

    To assess the degree of damage to the radial artery (RA) in coronary artery bypass grafting (CABG) patients who underwent preoperative transradial coronary angiography (RA-CA). From May 2012 to October 2013, 50 consecutive CABG patients who underwent RA-CA were prospectively enrolled in the study. All patients underwent echo-Doppler evaluation of the RA of the catheterized arm; the contralateral RA was used as control. The distal segment of the RA was submitted to immunohistochemical assessment of endothelial integrity. Patients were divided in three groups according to the time interval from angiography to evaluation: ≤24 h, >24 h to <7 days and ≥7 days. Baseline RA median diameters were 0.25 ± 0.04 cm in the cannulated arm and 0.22 ± 0.04 cm in the non-cannulated arm (P = 0.01). The flow-mediated dilatation (FMD) in the RA in the catheterized arm and in the control arm were 11.6 ± 7.9 and 14.2 ± 8.9 (P = 0.01), respectively. A statistically significant correlation was found between FMD of the catheterized RA and the time from RA-CA (Pearson's r = 0.348). Linear regression analysis confirmed that the FMD of the catheterized RA was dependent on days elapsed from the procedure (P = 0.032; OR 1.11, CI 0.009-0.203). Immunohistochemical evaluation showed extensive endothelial lesion in all examined RAs, with a trend towards reduction of the damage with time. Endothelial function and integrity of the cannulated arm did not reach those of the control arm in any of the study patients. RA-CA produces extensive damage to the RA. The lesions tend to heal with time but incomplete recovery of endothelial integrity and function is still present more than 30 days after the procedure. After RA-CA, the cannulated RA should not be used for CABG. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  3. Arterial Pressure Gradients during Upright Posture and 30 deg Head Down Tilt

    Science.gov (United States)

    Sanchez, E. R; William, J. M.; Ueno, T.; Ballard, R. E.; Hargens, A. R.; Holton, Emily M. (Technical Monitor)

    1997-01-01

    Gravity alters local blood pressure within the body so that arterial pressures in the head and foot are lower and higher, respectively, than that at heart level. Furthermore, vascular responses to local alterations of arterial pressure are probably important to maintain orthostatic tolerance upon return to the Earth after space flight. However, it has been difficult to evaluate the body's arterial pressure gradient due to the lack of noninvasive technology. This study was therefore designed to investigate whether finger arterial pressure (FAP), measured noninvasively, follows a normal hydrostatic pressure gradient above and below heart level during upright posture and 30 deg head down tilt (HDT). Seven healthy subjects gave informed consent and were 19 to 52 years old with a height range of 158 to 181 cm. A Finapres device measured arterial pressure at different levels of the body by moving the hand from 36 cm below heart level (BH) to 72 cm above heart level (AH) in upright posture and from 36 cm BH to 48 cm AH during HDT in increments of 12 cm. Mean FAP creased by 85 mmHg transitioning from BH to AH in upright posture, and the pressure gradient calculated from hydrostatic pressure difference (rho(gh)) was 84 mmHg. In HDT, mean FAP decreased by 65 mmHg from BH to AH, and the calculated pressure gradient was also 65 mmHg. There was no significant difference between the measured FAP gradient and the calculated pressure gradient, although a significant (p = 0.023) offset was seen for absolute arterial pressure in upright posture. These results indicate that arterial pressure at various levels can be obtained from the blood pressure at heart level by calculating rho(gh) + an offset. The offset equals the difference between heart level and the site of measurement. In summary, we conclude that local blood pressure gradients can be measured by noninvasive studies of FAP.

  4. Comparação da perviedade entre artéria radial e veia safena em pacientes em pós-operatório de cirurgia de revascularização miocárdica com retorno dos sintomas Comparison of patency between radial artery and saphenous vein in a coronary artery bypass grafting post operative with return of the symptoms

    Directory of Open Access Journals (Sweden)

    Herbert Coelho Hortmann

    2010-06-01

    Full Text Available OBJETIVO: Comparar a perviedade da artéria radial e veia safena em pacientes com retorno dos sintomas após cirurgia de revascularização do miocárdio (CRVM. MÉTODOS: Estudo retrospectivo. No período de janeiro de 1998 a dezembro de 2005, foram realizadas 469 CRVMs com o uso da artéria radial dentre os enxertos, no Hospital Vera Cruz, em Belo Horizonte/MG. Destes, 94 pacientes apresentaram alterações isquêmicas no pós-operatório recente ou tardio e foram reestudados com cineangiocoronariografia. Os enxertos foram divididos em três grupos: artéria torácica interna (ATI, artéria radial (AR e veia safena (VS, e foram estratificados segundo a gravidade das lesões: sem lesão grave (OBJECTIVE: To compare the radial artery and saphenous vein's patency in patients with recurrence of symptoms in a coronary artery bypass grafting (CABG. METHODS: Retrospective study. From January 1998 to December 2005, 469 CABGs were performed using the radial artery as a graft, in Vera Cruz Hospital in Belo Horizonte/ MG. Among the patients who underwent those surgeries, 94 presented ischemic changes in early or late postoperative period, which led them to be re-evaluated by coronary angiography. The grafts were divided in three groups: internal thoracic artery (ITA, radial artery (RA and saphenous vein (SV, and they were stratified according to the severity of injury: uninjured or patent (< 70%, severe obstruction (70 to 99% and occlusion. RESULTS: For the 94 patients in the study, 86 grafts of ITA, 94 of RA and 111 of SV were used. For the 86 ITA grafts, 73 (84.88% were found patent. For the 94 RA grafts, 55 (58.51% were found patent, and for the 111 SV grafts, 73 (65.76% were uninjured. A statistically significant difference (P= 0.001 was found between RA and SV grafts, with a higher patency found for VS graft. For the RA grafts, women presented a worse result concerning the RA patency (65.7% and 40.7%, with P = 0.006. Concerning coronary

  5. Pressure measurements in arterial feeders of brain arteriovenous malformations before and after endovascular embolization

    International Nuclear Information System (INIS)

    Henkes, H.; Gotwald, T.F.; Brew, S.; Kaemmerer, F.; Miloslavski, E.; Kuehne, D.

    2004-01-01

    Arteriovenous malformations (AVMs) are composed of abnormal arterial and venous vessels in the brain causing arteriovenous shunts of arterialized blood directly from pial arteries to draining veins. The hemodynamics of these lesions is not well-understood. Changes in blood flow and pressure are probably related to the natural history of AVMs and may also play a major role in AVM treatment. In this study intra-arterial pressure was measured in feeding arteries of AVMs using a microcatheter that had been placed for subsequent embolization treatment (201 measurements were performed in 95 patients before and after the embolization procedure). Results show a direct relationship between pressure changes and degree of embolization. Since pressure changes during the embolization procedure are relatively small, it seems unlikely that these changes are the direct cause of rupture and periprocedural bleedings. (orig.)

  6. Mean arterial pressure following prolonged exercise in the heat

    DEFF Research Database (Denmark)

    Gagnon, D; Lynn, A G; Binder, K

    2012-01-01

    benefit to its regulation. We examined MAP (Finometer) in eight trained (T) and eight untrained (UT) individuals prior to, and following, 120 min of cycling at 42 °C with (HYD) and without (DEHY) fluid replacement. Exercise during DEHY induced significant hyperthermia (T: 39.20 ± 0.52 °C vs UT: 38.70 ± 0......Prolonged exercise in the heat without fluid replacement represents a significant challenge to the regulation of mean arterial pressure (MAP). It is unknown, however, if MAP is equally challenged during the post-exercise period, and whether regular endurance exercise training can provide any.......36 °C, P = 0.941) and body weight losses (T: 3.4 ± 1.2% vs UT: 2.7 ± 0.9%, P = 0.332), which did not differ between groups. Although MAP was equally reduced 5 min into the post-exercise period of DEHY (T: -20 ± 11 mmHg vs UT: -22 ± 13 mmHg, P = 0.800), its subsequent recovery was significantly different...

  7. [Pulmonary artery pressure evaluation in adults by Doppler echocardiography].

    Science.gov (United States)

    Campos Filho, O; Andrade, J L; Carvalho, A C; Luna Filho, B; Pfeferman, A; Arroyo, J B; Leão, L E; Martinez Filho, E E

    1991-04-01

    To assess the role of pulsed Doppler echocardiography (PDE) in the indirect assessment of pulmonary artery (PA) pressure (P), analysing the pulmonary velocity blood flow curves (PVBFC) profile. Sixty-one adults with several kinds of heart disease were submitted to heart catheterization to obtain PAP (systolic, diastolic, mean), and other hemodynamic variables. A PDE examination was performed in all to obtain the PVBFC at the level of the pulmonic annulus. Qualitative features of the curve were analysed (morphological pattern, presence of pulmonic regurgitation) as well as quantitative data (acceleration time = AT, right ventricle ejection time = RVET index, AT/RVET index AT corrected for heart rate = ATC), which were compared to the invasive measurements. An abnormal rapid acceleration of the PVBFC, with triangular configuration, was noted in patient with pulmonary hypertension (PH), in contrast to the dome-like shape of the PVBFC in normal PAP. Pulmonary regurgitation was more frequent (p less than 0.05) in patients with severe PH (mean PAP greater than or equal to 40 mmHg), comparing with patients with PAP less than 40 mmHg. Inverse linear correlations were observed between AT and mean PAP, particularly when sinus rhythm was present (r = 0.89; p less than 0.05) excluding patients with atrial fibrilation (19 cases). PDE is an useful and noninvasive method for indirect evaluation of PAP in adults, especially during stable sinus rhythm, in heart rate range from 60 to 115 bpm.

  8. Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure

    Science.gov (United States)

    Wain, Louise V; Verwoert, Germaine C; O’Reilly, Paul F; Shi, Gang; Johnson, Toby; Johnson, Andrew D; Bochud, Murielle; Rice, Kenneth M; Henneman, Peter; Smith, Albert V; Ehret, Georg B; Amin, Najaf; Larson, Martin G; Mooser, Vincent; Hadley, David; Dörr, Marcus; Bis, Joshua C; Aspelund, Thor; Esko, Tõnu; Janssens, A Cecile JW; Zhao, Jing Hua; Heath, Simon; Laan, Maris; Fu, Jingyuan; Pistis, Giorgio; Luan, Jian’an; Arora, Pankaj; Lucas, Gavin; Pirastu, Nicola; Pichler, Irene; Jackson, Anne U; Webster, Rebecca J; Zhang, Feng; Peden, John F; Schmidt, Helena; Tanaka, Toshiko; Campbell, Harry; Igl, Wilmar; Milaneschi, Yuri; Hotteng, Jouke-Jan; Vitart, Veronique; Chasman, Daniel I; Trompet, Stella; Bragg-Gresham, Jennifer L; Alizadeh, Behrooz Z; Chambers, John C; Guo, Xiuqing; Lehtimäki, Terho; Kühnel, Brigitte; Lopez, Lorna M; Polašek, Ozren; Boban, Mladen; Nelson, Christopher P; Morrison, Alanna C; Pihur, Vasyl; Ganesh, Santhi K; Hofman, Albert; Kundu, Suman; Mattace-Raso, Francesco US; Rivadeneira, Fernando; Sijbrands, Eric JG; Uitterlinden, Andre G; Hwang, Shih-Jen; Vasan, Ramachandran S; Wang, Thomas J; Bergmann, Sven; Vollenweider, Peter; Waeber, Gérard; Laitinen, Jaana; Pouta, Anneli; Zitting, Paavo; McArdle, Wendy L; Kroemer, Heyo K; Völker, Uwe; Völzke, Henry; Glazer, Nicole L; Taylor, Kent D; Harris, Tamara B; Alavere, Helene; Haller, Toomas; Keis, Aime; Tammesoo, Mari-Liis; Aulchenko, Yurii; Barroso, Inês; Khaw, Kay-Tee; Galan, Pilar; Hercberg, Serge; Lathrop, Mark; Eyheramendy, Susana; Org, Elin; Sõber, Siim; Lu, Xiaowen; Nolte, Ilja M; Penninx, Brenda W; Corre, Tanguy; Masciullo, Corrado; Sala, Cinzia; Groop, Leif; Voight, Benjamin F; Melander, Olle; O’Donnell, Christopher J; Salomaa, Veikko; d’Adamo, Adamo Pio; Fabretto, Antonella; Faletra, Flavio; Ulivi, Sheila; Del Greco, M Fabiola; Facheris, Maurizio; Collins, Francis S; Bergman, Richard N; Beilby, John P; Hung, Joseph; Musk, A William; Mangino, Massimo; Shin, So-Youn; Soranzo, Nicole; Watkins, Hugh; Goel, Anuj; Hamsten, Anders; Gider, Pierre; Loitfelder, Marisa; Zeginigg, Marion; Hernandez, Dena; Najjar, Samer S; Navarro, Pau; Wild, Sarah H; Corsi, Anna Maria; Singleton, Andrew; de Geus, Eco JC; Willemsen, Gonneke; Parker, Alex N; Rose, Lynda M; Buckley, Brendan; Stott, David; Orru, Marco; Uda, Manuela; van der Klauw, Melanie M; Zhang, Weihua; Li, Xinzhong; Scott, James; Chen, Yii-Der Ida; Burke, Gregory L; Kähönen, Mika; Viikari, Jorma; Döring, Angela; Meitinger, Thomas; Davies, Gail; Starr, John M; Emilsson, Valur; Plump, Andrew; Lindeman, Jan H; ’t Hoen, Peter AC; König, Inke R; Felix, Janine F; Clarke, Robert; Hopewell, Jemma C; Ongen, Halit; Breteler, Monique; Debette, Stéphanie; DeStefano, Anita L; Fornage, Myriam; Mitchell, Gary F; Smith, Nicholas L; Holm, Hilma; Stefansson, Kari; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Samani, Nilesh J; Preuss, Michael; Rudan, Igor; Hayward, Caroline; Deary, Ian J; Wichmann, H-Erich; Raitakari, Olli T; Palmas, Walter; Kooner, Jaspal S; Stolk, Ronald P; Jukema, J Wouter; Wright, Alan F; Boomsma, Dorret I; Bandinelli, Stefania; Gyllensten, Ulf B; Wilson, James F; Ferrucci, Luigi; Schmidt, Reinhold; Farrall, Martin; Spector, Tim D; Palmer, Lyle J; Tuomilehto, Jaakko; Pfeufer, Arne; Gasparini, Paolo; Siscovick, David; Altshuler, David; Loos, Ruth JF; Toniolo, Daniela; Snieder, Harold; Gieger, Christian; Meneton, Pierre; Wareham, Nicholas J; Oostra, Ben A; Metspalu, Andres; Launer, Lenore; Rettig, Rainer; Strachan, David P; Beckmann, Jacques S; Witteman, Jacqueline CM; Erdmann, Jeanette; van Dijk, Ko Willems; Boerwinkle, Eric; Boehnke, Michael; Ridker, Paul M; Jarvelin, Marjo-Riitta; Chakravarti, Aravinda; Abecasis, Goncalo R; Gudnason, Vilmundur; Newton-Cheh, Christopher; Levy, Daniel; Munroe, Patricia B; Psaty, Bruce M; Caulfield, Mark J; Rao, Dabeeru C

    2012-01-01

    Numerous genetic loci influence systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans 1-3. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N=74,064) and follow-up studies (N=48,607), we identified at genome-wide significance (P= 2.7×10-8 to P=2.3×10-13) four novel PP loci (at 4q12 near CHIC2/PDGFRAI, 7q22.3 near PIK3CG, 8q24.12 in NOV, 11q24.3 near ADAMTS-8), two novel MAP loci (3p21.31 in MAP4, 10q25.3 near ADRB1) and one locus associated with both traits (2q24.3 near FIGN) which has recently been associated with SBP in east Asians. For three of the novel PP signals, the estimated effect for SBP was opposite to that for DBP, in contrast to the majority of common SBP- and DBP-associated variants which show concordant effects on both traits. These findings indicate novel genetic mechanisms underlying blood pressure variation, including pathways that may differentially influence SBP and DBP. PMID:21909110

  9. Evaluation of the cerebrovascular pressure reactivity index using non-invasive finapres arterial blood pressure

    International Nuclear Information System (INIS)

    Kasprowicz, M; Kim, D J; Haubrich, C; Czosnyka, Z; Smielewski, P; Czosnyka, M; Schmidt, E

    2010-01-01

    A pressure reactivity index (PRx) can be assessed in patients with continuous monitoring of arterial blood pressure (ABP) and intracranial pressure (ICP) as a moving correlation coefficient between slow fluctuations of these two signals within a low frequency bandwidth. The study aimed to investigate whether the invasive ABP monitoring can be replaced with non-invasive measurement of ABP using a Finapres plethysmograph (fABP) to calculate the fPRx. There is a well-defined group of patients, suffering from hydrocephalus and undergoing CSF pressure monitoring, which may benefit from such a measurement. 41 simultaneous day-by-day monitoring of ICP, ABP and fABP were performed for about 30 min in 10 head injury patients. A Bland–Altman assessment for agreement was used to compare PRx and fPRx calculations. Performance metrics and the McNemary test were used to determine whether fPRx is sensitive enough to distinguish between functioning and disturbed cerebrovascular pressure reactivity. The fPRx correlated with PRx (R Spearman = 0.92, p < 0.001; bias = −0.04; lower and upper limits of agreement: −0.26 and 0.17, respectively). The fPRx distinguished between active and passive reactivity in more than 89% cases. The fPRx can be used with care for assessment of cerebrovascular reactivity in patients for whom invasive ABP measurement is not feasible. The fPRx is sensitive enough to distinguish between functional and deranged reactivity

  10. Intravenous clonidine administration and its ability to reduce pulmonary arterial pressure in patients undergoing heart surgery

    Directory of Open Access Journals (Sweden)

    Benedito Barbosa João

    2014-01-01

    Full Text Available Objective: Evaluate the ability of clonidine to reduce pulmonary arterial pressure in patients with pulmonary hypertension undergoing heart surgery, either by reducing the pressure values from the direct measurement of pulmonary arterial pressure or by reducing or eliminating the need for intraoperative dobutamine and nitroprusside. Method: Randomized, double-blind, placebo-controlled, comparative study conducted in 30 patients with pulmonary arterial hypertension type 2 undergoing cardiac surgery. Mean pulmonary arterial pressure and dosage of dobutamine and sodium nitroprusside were assessed four times: before intravenous administration of clonidine (2 μg/kg or placebo (T0, 30 min after tested treatment and before cardiopulmonary bypass (T1, immediately after CPB (T2, 10 min after protamine injection (T3. Results: There were no significant differences regarding mean pulmonary arterial pressure at any time of evaluation. There was no significant difference between groups regarding other variables, such as mean systemic arterial pressure, heart rate, total dose of dobutamine, total dose of sodium nitroprusside, and need for fentanyl. Conclusion: Data analysis from patients included in this study allows us to conclude that intravenous clonidine (2 μg/kg was not able to reduce the mean pulmonary arterial pressure in patients with pulmonary hypertension in group 2 (pulmonary venous hypertension, undergoing heart surgery, or reduce or eliminate the need for intraoperative administration of dobutamine and sodium nitroprusside. Keywords: Clonidine, Pulmonary hypertension, Heart surgery

  11. Resistance training controls arterial blood pressure in rats with L-NAME- induced hypertension.

    Science.gov (United States)

    Araujo, Ayslan Jorge Santos de; Santos, Anne Carolline Veríssimo dos; Souza, Karine dos Santos; Aires, Marlúcia Bastos; Santana-Filho, Valter Joviniano; Fioretto, Emerson Ticona; Mota, Marcelo Mendonça; Santos, Márcio Roberto Viana

    2013-04-01

    Arterial hypertension is a multifactorial chronic condition caused by either congenital or acquired factors. To evaluate the effects of Resistance Training (RT) on arterial pressure, and on vascular reactivity and morphology, of L-NAME-treated hypertensive rats. Male Wistar rats (200 - 250 g) were allocated into Sedentary Normotensive (SN), Sedentary Hypertensive (SH) and Trained Hypertensive (TH) groups. Hypertension was induced by adding L-NAME (40 mg/Kg) to the drinking water for four weeks. Arterial pressure was evaluated before and after RT. RT was performed using 50% of 1RM, 3 sets of 10 repetitions, 3 times per week for four weeks. Vascular reactivity was measured in rat mesenteric artery rings by concentration-response curves to sodium nitroprusside (SNP); phenylephrine (PHE) was also used for histological and stereological analysis. Resistance training inhibited the increase in mean and diastolic arterial pressures. Significant reduction was observed in Rmax (maximal response) and pD2 (potency) of PHE between SH and TH groups. Arteries demonstrated normal intima, media and adventitia layers in all groups. Stereological analysis demonstrated no significant difference in luminal, tunica media, and total areas of arteries in the SH and TH groups when compared to the SN group. Wall-to-lumen ratio of SH arteries was significantly different compared to SN arteries (parteries. RT was able to prevent an increase in blood pressure under the conditions in this study. This appears to involve a vasoconstrictor regulation mechanism and maintenance of luminal diameter in L-NAME induced hypertensive rats.

  12. Radial Artery Catheterization

    Science.gov (United States)

    ... Circulation My alerts Sign In Join Sign out Facebook Twitter Home About this Journal Editorial Board General Statistics Circulation Doodle Information for Advertisers Author Reprints Commercial Reprints Customer Service and Ordering ...

  13. Straight versus tortuous retinal arteries in relation to blood pressure and genetics

    DEFF Research Database (Denmark)

    Taarnhøj, N C B B; Munch, I C; Sander, B

    2008-01-01

    dizygotic same-sex healthy twin pairs, aged 20 to 46 years, who were characterised by determination of retinal vessel diameters, arterial blood pressure, blood glucose, body mass index, smoking habits and retinal arterial tortuosity, using a three-level grading scale (straight, wavy, tortuous). Heritability......BACKGROUND/AIMS: To assess the relative influence of genetic and environmental factors on retinal arterial tortuosity and the association between tortuosity and various health indices in healthy young to middle-aged persons. METHODS: This cross-sectional study included 57 monozygotic and 52...... accounting for the remaining 18% (CI(95 )8, 36%). Increasing values of mean arterial blood pressure and body mass index were both associated with decreasing levels of retinal arterial tortuosity. CONCLUSION: There was a large variation in tortuosity of retinal arteries in these healthy subjects...

  14. Influence of geomagnetic activity and atmospheric pressure on human arterial pressure during the solar cycle 24

    Science.gov (United States)

    Azcárate, T.; Mendoza, B.; Levi, J. R.

    2016-11-01

    We performed a study of the systolic (SBP) and diastolic (DBP) arterial blood pressure behavior under natural variables such as the atmospheric pressure (AtmP) and the horizontal geomagnetic field component (H). We worked with a sample of 304 healthy normotense volunteers, 152 men and 152 women, with ages between 18 and 84 years in Mexico City during the period 2008-2014, corresponding to the minimum, ascending and maximum phases of the solar cycle 24. The data was divided by gender, age and day/night cycle. We studied the time series using three methods: Correlations, bivariate and superposed epochs (within a window of three days around the day of occurrence of a geomagnetic storm) analysis, between the SBP and DBP and the natural variables (AtmP and H). The correlation analysis indicated correlation between the SBP and DBP and AtmP and H, being the largest during the night. Furthermore, the correlation and bivariate analysis showed that the largest correlations are between the SBP and DBP and the AtmP. The superposed epoch analysis found that the largest number of significant SBP and DBP changes occurred for women. Finally, the blood pressure changes are larger during the solar minimum and ascending solar cycle phases than during the solar maximum; the storms of the minimum were more intense than those of the maximum and this could be the reason of behavior of the blood pressure changes along the solar cycle.

  15. Retinal vessel diameter and estimated cerebrospinal fluid pressure in arterial hypertension: the Beijing Eye Study.

    Science.gov (United States)

    Jonas, Jost B; Wang, Ningli; Wang, Shuang; Wang, Ya Xing; You, Qi Sheng; Yang, Diya; Wei, Wen Bin; Xu, Liang

    2014-09-01

    Hypertensive retinal microvascular abnormalities include an increased retinal vein-to-artery diameter ratio. Because central retinal vein pressure depends on cerebrospinal fluid pressure (CSFP), we examined whether the retinal vein-to-artery diameter ratio and other retinal hypertensive signs are associated with CSFP. Participants of the population-based Beijing Eye Study (n = 1,574 subjects) underwent measurement of the temporal inferior and superior retinal artery and vein diameter. CSFP was calculated as 0.44 × body mass index (kg/m(2)) + 0.16 × diastolic blood pressure (mm Hg) - 0.18 × age (years) - 1.91. Larger retinal vein diameters and higher vein-to-artery diameter ratios were significantly associated with higher estimated CSFP (P = 0.001) in multivariable analysis. In contrast, temporal inferior retinal arterial diameter was marginally associated (P = 0.03) with estimated CSFP, and temporal superior artery diameter was not significantly associated (P = 0.10) with estimated CSFP; other microvascular abnormalities, such as arteriovenous crossing signs, were also not significantly associated with estimated CSFP. In a reverse manner, higher estimated CSFP as a dependent variable in the multivariable analysis was associated with wider retinal veins and higher vein-to-artery diameter ratio. In the same model, estimated CSFP was not significantly correlated with retinal artery diameters or other retinal microvascular abnormalities. Correspondingly, arterial hypertension was associated with retinal microvascular abnormalities such as arteriovenous crossing signs (P = 0.003), thinner temporal retinal arteries (P arterial hypertension, an increased retinal vein-to-artery diameter ratio depends on elevated CSFP, which is correlated with blood pressure. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Healing of ulcers on the feet correlated with distal blood pressure measurements in occlusive arterial disease

    DEFF Research Database (Denmark)

    Holstein, P; Lassen, N A

    1980-01-01

    The frequency of healing in subchronic ulcers in 66 feet in 62 patients with arterial occlusive disease was correlated with the systolic digital blood pressure (SDBP) and the systolic ankle blood pressure (SABP), both measured with a strain gauge, and with the skin perfusion pressure on the heel...

  17. Respiratory sinus arrhythmia stabilizes mean arterial blood pressure at high-frequency interval in healthy humans.

    Science.gov (United States)

    Elstad, Maja; Walløe, Lars; Holme, Nathalie L A; Maes, Elke; Thoresen, Marianne

    2015-03-01

    Arterial blood pressure variations are an independent risk factor for end organ failure. Respiratory sinus arrhythmia (RSA) is a sign of a healthy cardiovascular system. However, whether RSA counteracts arterial blood pressure variations during the respiratory cycle remains controversial. We restricted normal RSA with non-invasive intermittent positive pressure ventilation (IPPV) to test the hypothesis that RSA normally functions to stabilize mean arterial blood pressure. Ten young volunteers were investigated during metronome-paced breathing and IPPV. Heart rate (ECG), mean arterial blood pressure and left stroke volume (finger arterial pressure curve) and right stroke volume (pulsed ultrasound Doppler) were recorded, while systemic and pulmonary blood flow were calculated beat-by-beat. Respiratory variations (high-frequency power, 0.15-0.40 Hz) in cardiovascular variables were estimated by spectral analysis. Phase angles and correlation were calculated by cross-spectral analysis. The magnitude of RSA was reduced from 4.9 bpm(2) (95% CI 3.0, 6.2) during metronome breathing to 2.8 bpm(2) (95% CI 1.1, 5.0) during IPPV (p = 0.03). Variations in mean arterial blood pressure were greater (2.3 mmHg(2) (95% CI 1.4, 3.9) during IPPV than during metronome breathing (1.0 mmHg(2) [95% CI 0.7, 1.3]) (p = 0.014). Respiratory variations in right and left stroke volumes were inversely related in the respiratory cycle during both metronome breathing and IPPV. RSA magnitude is lower and mean arterial blood pressure variability is greater during IPPV than during metronome breathing. We conclude that in healthy humans, RSA stabilizes mean arterial blood pressure at respiratory frequency.

  18. Association of clinical androgen excess with radial artery intima media thickness in women with polycystic ovary syndrome.

    Science.gov (United States)

    Yilmaz, S A; Kebapcilar, A; Koplay, M; Kerimoglu, O S; Pekin, A T; Gencoglu, B; Dogan, N U; Celik, C

    2015-06-01

    This study explores the relationship between clinical cardiovascular risk factors and clinical androgen excess, with direct comparison to radial artery intima media thickness (rIMT). rIMT of 91 patients with polycystic ovary syndrome (PCOS) were compared with 72 healthy women. Patients were divided into three groups with regard to body mass index (BMI). Group1 = 56 women (31 controls and 25 PCOS) with low BMI(18-22.49 kg/m(2)), Group2 = 36 women (15 controls and 21 PCOS) with normal BMI (22.5-24.99 kg/m(2)) and Group3 = 71 women (26 controls and 45 PCOS) with high BMI (25-30 kg/m(2)). rIMT was significantly higher in patients with PCOS (p = 0.007). rIMT was significantly higher group1 and group3 in patients with PCOS compared to controls (p = 0.007 and p = 0.042, respectively). There was a significant positive association between rIMT levels and fT in women with PCOS in group1 (r = 0.24, p = 0.04). rIMT levels correlated to fT levels in women with PCOS in group3 (r = 0.32, p = 0.03). Modified Ferriman-Gallwey (mFG) scores demonstrated a positive association with free testosterone, total testosterone, free androgen index, waist circumference (WC), LH levels, insulin levels, Homeostasis Model Assessment index(HOMA-IR), rIMT and a negative correlation with sex hormone binding globulin in group1 and group2. mFG scores demonstrated a positive association with free testosterone (r = 0.33, p = 0.029) in group3, but no association was found between mFG and WC, HOMA-IR in group3. Our findings indicate that clinical androgen excess may be associated with cardiovascular disease in patients with PCOS.

  19. Iron Deficiency in COPD Associates with Increased Pulmonary Artery Pressure Estimated by Echocardiography

    DEFF Research Database (Denmark)

    Plesner, Louis L; Schoos, Mikkel M; Dalsgaard, Morten

    2017-01-01

    OBJECTIVES: Iron deficiency (ID) might augment chronic pulmonary hypertension in chronic obstructive pulmonary disease (COPD). This observational study investigates the association between ID and systolic pulmonary artery pressure estimated by echocardiography in non-anaemic COPD outpatients...

  20. Evaluation of arterial blood gases and arterial blood pressures in brachycephalic dogs.

    Science.gov (United States)

    Hoareau, G L; Jourdan, G; Mellema, M; Verwaerde, P

    2012-01-01

    Brachycephalic dogs (BD) are prone to congenital upper airway obstruction (brachycephalic syndrome, BS). In humans suffering from sleep apnea, upper airway obstruction is known to cause hypertension. There is no information regarding the influence of BS in dogs on cardiorespiratory physiology. BD are prone to lower P(a) O(2), higher P(a) CO (2), and hypertension compared with meso- or dolicocephalic dogs (MDD). Eleven BD and 11 MDD. After a questionnaire was completed by the owner, a physical examination was performed. Height and thoracic circumferences were measured. Arterial blood gases, electrolyte concentrations, and packed cell volume (PCV) were measured. Systolic (SAP), mean (MAP), and diastolic (DAP) arterial blood pressure recordings were performed. A total of 7 French and 4 English bulldogs met the inclusion criteria. The control group consisted in 6 Beagles, 2 mixed breed dogs, 1 Staffordshire Bull Terrier, 1 Parson Russell Terrier, and 1 Australian Cattle Dog. Statistically, BD had lower P(a) O(2), higher P(a) CO2, and higher PCV when compared with controls (86.2 ± 15.9 versus 100.2 ± 12.6 mmHg, P = .017; 36.3 ± 4.6 versus 32.7 ± 2.6 mmHg, P = .019; 48.2 ± 3.5 versus 44.2 ± 5.4%, P = .026, respectively). Also, they had significantly higher SAP (177.6 ± 25.0 versus 153.5 ± 21.7 mmHg, P = .013), MAP (123.3 ± 17.1 versus 108.3 ± 12.2 mmHg, P = .014), and DAP (95.3 ± 19.2 versus 83.0 ± 11.5 mmHg, P = .042). BD with a P(a) CO (2) >35 mmHg were significantly older than those with a P(a) CO (2) ≤35 mmHg (58 ± 16 and 30 ± 11 months, P = .004). Results of this study suggest that some BD are prone to lower P(a) O(2), higher P(a) CO (2), and hypertension when compared with MDD. Age may be a contributing factor. Copyright © 2012 by the American College of Veterinary Internal Medicine.

  1. Identifying factors that predict the choice and success rate of radial artery catheterisation in contemporary real world cardiology practice: a sub-analysis of the PREVAIL study data.

    Science.gov (United States)

    Pristipino, Christian; Roncella, Adriana; Trani, Carlo; Nazzaro, Marco S; Berni, Andrea; Di Sciascio, Germano; Sciahbasi, Alessandro; Musarò, Salvatore Donato; Mazzarotto, Pietro; Gioffrè, Gaetano; Speciale, Giulio

    2010-06-01

    To assess: the reasons behind an operator choosing to perform radial artery catheterisation (RAC) as against femoral arterial catheterisation, and to explore why RAC may fail in the real world. A pre-determined analysis of PREVAIL study database was performed. Relevant data were collected in a prospective, observational survey of 1,052 consecutive patients undergoing invasive cardiovascular procedures at nine Italian hospitals over a one month observation period. By multivariate analysis, the independent predictors of RAC choice were having the procedure performed: (1) at a high procedural volume centre; and (2) by an operator who performs a high volume of radial procedures; clinical variables played no statistically significant role. RAC failure was predicted independently by (1) a lower operator propensity to use RAC; and (2) the presence of obstructive peripheral artery disease. A 10-fold lower rate of RAC failure was observed among operators who perform RAC for > 85% of their personal caseload than among those who use RAC < 25% of the time (3.8% vs. 33.0%, respectively); by receiver operator characteristic (ROC) analysis, no threshold value for operator RAC volume predicted RAC failure. A routine RAC in all-comers is superior to a selective strategy in terms of feasibility and success rate.

  2. Prediction of Axial and Radial Creep in CANDU 6 Pressure Tubes

    International Nuclear Information System (INIS)

    Radu, Vasile S.

    2013-01-01

    Status and proposals: 1. A review of literature concerning on the in-reactor deformation of PTs has been carried ouţ. 2. A model based on MFNN has been proposed to assess the radial and axial creep of CANDU 6 PTs. 3. Preliminary discussion with Cernavoda NPP (Romania) has been lunched, and now the preparation of official documents (collaboration in providing the inspection data from fuel channel in Unit 1 and 2) are in progress. 4. Further activities: • Improvement MFNN to accommodate complex data base (eventually with many variables) for radial and axial in-reactor deformation PT, and to satisfy the requirements from NPP Cernavoda and hopefully from present CRP database; • To build-up a database by running the creep equations (if the creep constants are provided by AECL); training of MFNN on them and to qualify it as a tool for PT in-reactor deformation prediction

  3. Arterial pressure during cardiopulmonary bypass is not associated with acute kidney injury

    DEFF Research Database (Denmark)

    Kandler, K; Jensen, M E; Nilsson, J C

    2015-01-01

    BACKGROUND: Acute kidney injury (AKI) after cardiac surgery is common and is associated with increased mortality. We wanted to investigate if the arterial pressure or the use of norepinephrine during cardiopulmonary bypass were associated with AKI. METHODS: A retrospective analysis of patients who...... underwent coronary artery bypass grafting with or without concomitant procedures was conducted. AKI was defined using the RIFLE criteria. Data on arterial pressure and use of norepinephrine during cardiopulmonary bypass were entered in a binary logistic regression model to control for possible perioperative...... and in higher amounts, during cardiopulmonary bypass, in patients who developed AKI. These differences in arterial pressures and use of norepinephrine between the groups were not found to be significant when entered in the binary logistic regression model. CONCLUSION: No independent relationship between...

  4. Strength training reduces arterial blood pressure but not sympathetic neural activity in young normotensive subjects

    Science.gov (United States)

    Carter, Jason R.; Ray, Chester A.; Downs, Emily M.; Cooke, William H.

    2003-01-01

    The effects of resistance training on arterial blood pressure and muscle sympathetic nerve activity (MSNA) at rest have not been established. Although endurance training is commonly recommended to lower arterial blood pressure, it is not known whether similar adaptations occur with resistance training. Therefore, we tested the hypothesis that whole body resistance training reduces arterial blood pressure at rest, with concomitant reductions in MSNA. Twelve young [21 +/- 0.3 (SE) yr] subjects underwent a program of whole body resistance training 3 days/wk for 8 wk. Resting arterial blood pressure (n = 12; automated sphygmomanometer) and MSNA (n = 8; peroneal nerve microneurography) were measured during a 5-min period of supine rest before and after exercise training. Thirteen additional young (21 +/- 0.8 yr) subjects served as controls. Resistance training significantly increased one-repetition maximum values in all trained muscle groups (P < 0.001), and it significantly decreased systolic (130 +/- 3 to 121 +/- 2 mmHg; P = 0.01), diastolic (69 +/- 3 to 61 +/- 2 mmHg; P = 0.04), and mean (89 +/- 2 to 81 +/- 2 mmHg; P = 0.01) arterial blood pressures at rest. Resistance training did not affect MSNA or heart rate. Arterial blood pressures and MSNA were unchanged, but heart rate increased after 8 wk of relative inactivity for subjects in the control group (61 +/- 2 to 67 +/- 3 beats/min; P = 0.01). These results indicate that whole body resistance exercise training might decrease the risk for development of cardiovascular disease by lowering arterial blood pressure but that reductions of pressure are not coupled to resistance exercise-induced decreases of sympathetic tone.

  5. Clinical observations on the effect of carotid artery occlusion on cerebral blood flow mapped by xenon computed tomography and its correlation with carotid artery back pressure

    International Nuclear Information System (INIS)

    Steed, D.L.; Webster, M.W.; DeVries, E.J.; Jungreis, C.A.; Horton, J.A.; Sehkar, L.; Yonas, H.

    1990-01-01

    Xenon computed tomographic cerebral blood flow mapping was correlated with internal carotid artery stump pressures and clinical neurologic assessment during temporary internal carotid artery occlusion. One hundred fourteen patients with skull base tumors or intracranial aneurysms potentially requiring carotid resection or ligation underwent angiography, xenon CT cerebral blood flow mapping, and internal carotid artery blood pressure monitoring. The internal carotid artery was then temporarily occluded with a balloon catheter, stump pressure was measured through the catheter, and the xenon CT cerebral blood flow mapping was repeated. Adequate xenon CT cerebral blood flow was defined as greater than 30 cc/100 gm/min. All patients had normal xenon CT cerebral blood flow before internal carotid artery occlusion. During internal carotid artery occlusion, xenon CT cerebral blood flow was found to be normal (group I, 40 patients), globally reduced but still within the normal range (group II, 50 patients), or low in the distribution of the ipsilateral middle cerebral artery (group III, 13 patients). With balloon occlusion, an immediate neurologic deficit developed in 11 patients (9%) requiring deflation of the balloon preceding xenon CT cerebral blood flow measurement (group IV). In group I internal carotid artery blood pressure was 128 mm Hg. (range 85 to 171 mm Hg) with stump pressure 86 mm Hg (range 46 to 125 mm Hg). In group II internal carotid artery blood pressure was 130 mm Hg. (range 78 to 199 mm Hg), with stump pressure 86 mm Hg (range 31 to 150 mm Hg)

  6. First Research Coordination Meeting on Prediction of Axial and Radial Creep in HWR Pressure Tubes. Presentations

    International Nuclear Information System (INIS)

    2013-01-01

    Pressure tube deformation is a critical aging issue in operating Heavy Water Reactors (HWRs). According to the service year, horizontal pressure tubes have three kinds of deformation: diametral creep leading to the flow bypass and the penalty to critical heat flux for fuel rods, longitudinal creep leading to the interference of feeder pipes and/or with fuelling machine, and sagging leading to the interference with in-core components and potential contact between the pressure tube and calandria tube. The CRP scope includes the establishment of a database for pressure tube deformation, microstructure characterization of pressure tube materials collected from HWRs currently operating in Member States and development of a prediction model for pressure tube deformation

  7. A Pulse Wave Velocity Based Method to Assess the Mean Arterial Blood Pressure Limits of Autoregulation in Peripheral Arteries

    Directory of Open Access Journals (Sweden)

    Ananya Tripathi

    2017-11-01

    Full Text Available Background: Constant blood flow despite changes in blood pressure, a phenomenon called autoregulation, has been demonstrated for various organ systems. We hypothesized that by changing hydrostatic pressures in peripheral arteries, we can establish these limits of autoregulation in peripheral arteries based on local pulse wave velocity (PWV.Methods: Electrocardiogram and plethysmograph waveforms were recorded at the left and right index fingers in 18 healthy volunteers. Each subject changed their left arm position, keeping the right arm stationary. Pulse arrival times (PAT at both fingers were measured and used to calculate PWV. We calculated ΔPAT (ΔPWV, the differences between the left and right PATs (PWVs, and compared them to the respective calculated blood pressure at the left index fingertip to derive the limits of autoregulation.Results: ΔPAT decreased and ΔPWV increased exponentially at low blood pressures in the fingertip up to a blood pressure of 70 mmHg, after which changes in ΔPAT and ΔPWV were minimal. The empirically chosen 20 mmHg window (75–95 mmHg was confirmed to be within the autoregulatory limit (slope = 0.097, p = 0.56. ΔPAT and ΔPWV within a 20 mmHg moving window were not significantly different from the respective data points within the control 75–95 mmHg window when the pressure at the fingertip was between 56 and 110 mmHg for ΔPAT and between 57 and 112 mmHg for ΔPWV.Conclusions: Changes in hydrostatic pressure due to changes in arm position significantly affect peripheral arterial stiffness as assessed by ΔPAT and ΔPWV, allowing us to estimate peripheral autoregulation limits based on PWV.

  8. Physiological Mechanisms Mediating the Coupling between Heart Period and Arterial Pressure in Response to Postural Changes in Humans

    NARCIS (Netherlands)

    Silvani, A.; Calandra-Buonaura, G.; Johnson, B.D.; Helmond, N. van; Barletta, G.; Cecere, A.G.; Joyner, M.J.; Cortelli, P.

    2017-01-01

    The upright posture strengthens the coupling between heart period (HP) and systolic arterial pressure (SAP) consistently with a greater contribution of the arterial baroreflex to cardiac control, while paradoxically decreasing cardiac baroreflex sensitivity (cBRS). To investigate the physiological

  9. Noninvasive arterial blood pressure waveforms in patients with continuous-flow left ventricular assist devices.

    Science.gov (United States)

    Martina, Jerson R; Westerhof, Berend E; de Jonge, Nicolaas; van Goudoever, Jeroen; Westers, Paul; Chamuleau, Steven; van Dijk, Diederik; Rodermans, Ben F M; de Mol, Bas A J M; Lahpor, Jaap R

    2014-01-01

    Arterial blood pressure and echocardiography may provide useful physiological information regarding cardiac support in patients with continuous-flow left ventricular assist devices (cf-LVADs). We investigated the accuracy and characteristics of noninvasive blood pressure during cf-LVAD support. Noninvasive arterial pressure waveforms were recorded with Nexfin (BMEYE, Amsterdam, The Netherlands). First, these measurements were validated simultaneously with invasive arterial pressures in 29 intensive care unit patients. Next, the association between blood pressure responses and measures derived by echocardiography, including left ventricular end-diastolic dimensions (LVEDDs), left ventricular end-systolic dimensions (LVESDs), and left ventricular shortening fraction (LVSF) were determined during pump speed change procedures in 30 outpatients. Noninvasive arterial blood pressure waveforms by the Nexfin monitor slightly underestimated invasive measures during cf-LVAD support. Differences between noninvasive and invasive measures (mean ± SD) of systolic, diastolic, mean, and pulse pressures were -7.6 ± 5.8, -7.0 ± 5.2, -6.9 ± 5.1, and -0.6 ± 4.5 mm Hg, respectively (all blood pressure responses did not correlate with LVEDD, LVESD, or LVSF, while LVSF correlated weakly with both pulse pressure (r = 0.24; p = 0.005) and (dP(art)/dt)max (r = 0.25; p = 0.004). The dicrotic notch in the pressure waveform was a better predictor of aortic valve opening (area under the curve [AUC] = 0.87) than pulse pressure (AUC = 0.64) and (dP(art)/dt)max (AUC = 0.61). Patients with partial support rather than full support at 9,000 rpm had a significant change in systolic pressure, pulse pressure, and (dP(art)/dt)max during ramp studies, while echocardiographic measures did not change. Blood pressure measurements by Nexfin were reliable and may thereby act as a compliment to the assessment of the cf-LVAD patient.

  10. Circadian rhythm of arterial blood pressure and albuminuria in diabetic nephropathy

    DEFF Research Database (Denmark)

    Hansen, H P; Rossing, P; Tarnow, L

    1996-01-01

    The aim of our study was to evaluate the diurnal relationship between arterial blood pressure and albuminuria, and some potential mechanisms responsible for impaired nocturnal blood pressure reduction (non-dippers, groups I and II) in diabetic nephropathy (DN). Twenty-four-hour ambulatory blood p...

  11. Noninvasive arterial blood pressure waveforms in patients with continuous-flow left ventricular assist devices

    NARCIS (Netherlands)

    Martina, Jerson R.; Westerhof, Berend E.; de Jonge, Nicolaas; van Goudoever, Jeroen; Westers, Paul; Chamuleau, Steven; van Dijk, Diederik; Rodermans, Ben F. M.; de Mol, Bas A. J. M.; Lahpor, Jaap R.

    2014-01-01

    Arterial blood pressure and echocardiography may provide useful physiological information regarding cardiac support in patients with continuous-flow left ventricular assist devices (cf-LVADs). We investigated the accuracy and characteristics of noninvasive blood pressure during cf-LVAD support.

  12. Variable day/night bias in 24-h non-invasive finger pressure against intrabrachial artery pressure is removed by waveform filtering and level correction

    NARCIS (Netherlands)

    Westerhof, Berend E.; Guelen, Ilja; Parati, Gianfranco; Groppelli, Antonella; van Montfrans, Gert A.; Wieling, Wouter; Wesseling, Karel H.; Bos, Willem Jan W.

    2002-01-01

    Background Twenty-four-hour finger arterial pressure (FAP) recordings show a negative bias against intrabrachial artery pressure (BAP) and the bias is greater during the night thereby overestimating the nocturnal blood pressure dip. We have available a methodology with which to reconstruct BAP from

  13. Comparison of noninvasive assessments of central blood pressure using general transfer function and late systolic shoulder of the radial pressure wave.

    Science.gov (United States)

    Wohlfahrt, Peter; Krajcoviechová, Alena; Seidlerová, Jitka; Mayer, Otto; Filipovsky, Jan; Cífková, Renata

    2014-02-01

    Central systolic blood pressure (cSBP) can be derived by the general transfer function of the radial pressure wave, as used in the SphygmoCor device, or by regression equation from directly measured late systolic shoulder of the radial pressure wave (pSBP2), as used in the Omron HEM-9000AI device. The aim of this study was to compare the SphygmoCor estimates of cSBP with 2 estimates of cSBP provided by the Omron HEM-9000AI (cSBP, pSBP2) in a large cohort of the white population. In 391 patients aged 52.3±13.5 years (46% men) from the Czech post-MONICA Study, cSBP was measured using the SphygmoCor and Omron HEM-9000AI devices in random order. Omron cSBP and pSBP2 were perfectly correlated (r = 1.0; P wave provides a comparable accuracy with the validated general transfer function. When comparing Omron HEM-9000AI and SphygmoCor estimates of cSBP, Omron pSBP2 should be used. The difference between both devices in cSBP may be explained by differences in calibration.

  14. A pitfall in the measurement of arterial blood pressure in the ischaemic limb during elevation

    DEFF Research Database (Denmark)

    Bülow, J; Jelnes, Rolf

    1987-01-01

    In order to evaluate if elevation of the ischaemic limb above heart level is an alternative to the conventionally applied method with external counterpressure for estimation of skin perfusion pressure, femoral and popliteal artery pressures were measured directly in eight patients with occlusion...... of the superficial femoral artery. The measurements were done in the horizontal position and during elevation of the calf above heart level. During elevation relative blood flow, measured by arterio-venous oxygen saturation differences, decreased compared with the horizontal position. In contrast the popliteal...... arterial pressure decreased only by 20% of the value expected from the degree of elevation of the calf above the level of the heart. Thus, it could be calculated that calf vascular resistance increased two- to three-fold on average during elevation. Four patients were reexamined with the venous pressure...

  15. Effects of hypoxia on the closing pressure of the canine systemic arterial circulation.

    Science.gov (United States)

    Sylvester, J T; Gilbert, R D; Traystman, R J; Permutt, S

    1981-10-01

    We studied the relationships among closing pressure (Pc) and indices of systemic arterial resistance (Ra) and compliance (Ca) during hypoxic hypoxia (HH) and carbon monoxide hypoxia (COH) in anesthetized dogs with cardiac bypass and constant ventilation. Closing pressure was measured as the lowest level to which arterial pressure (Pa) fell after inflow to the arterial bed was reduced suddenly to zero. Since the fall of Pa to Pc could be well-described as a single exponential function of time and since Pc was always greater than outflow (venous) pressure. Ra and CA were determined by applying a "vascular waterfall" model to the arterial bed. During HH, Pc increased while Ra and Ca decreased. During COH, Pc and Ra decreased, but Ca did not change. The Pc results indicate that during HH, but not COH, a large portion of the systemic arterial bed experienced a marked increase in vasomotor tone, a qualitative difference that would have been missed if Pc had not been measured. The relationship among Pc, Ra, and Ca during hypoxia suggest these indices may have been determined largely by different portions of the arterial bed in which tone changed independently.

  16. Proposal for a Coordinated Research Project: Prediction of Axial and Radial Creep in Pressure Tubes

    International Nuclear Information System (INIS)

    Bozzano, Patricia B.

    2013-01-01

    Participation of Argentina: • hydrogen charge of 90 samples for hydrogen determination: IGF, HVEMS, DSC, Resistivity, DTA; • 17 samples for non destructive techniques; • 6 blisters in CANDU pressure tube sections for NDT evaluation

  17. A computational analysis of the long-term regulation of arterial pressure.

    Science.gov (United States)

    Beard, Daniel A; Pettersen, Klas H; Carlson, Brian E; Omholt, Stig W; Bugenhagen, Scott M

    2013-01-01

    The asserted dominant role of the kidneys in the chronic regulation of blood pressure and in the etiology of hypertension has been debated since the 1970s. At the center of the theory is the observation that the acute relationships between arterial pressure and urine production-the acute pressure-diuresis and pressure-natriuresis curves-physiologically adapt to perturbations in pressure and/or changes in the rate of salt and volume intake. These adaptations, modulated by various interacting neurohumoral mechanisms, result in chronic relationships between water and salt excretion and pressure that are much steeper than the acute relationships. While the view that renal function is the dominant controller of arterial pressure has been supported by computer models of the cardiovascular system known as the "Guyton-Coleman model", no unambiguous description of a computer model capturing chronic adaptation of acute renal function in blood pressure control has been presented. Here, such a model is developed with the goals of: 1. representing the relevant mechanisms in an identifiable mathematical model; 2. identifying model parameters using appropriate data; 3. validating model predictions in comparison to data; and 4. probing hypotheses regarding the long-term control of arterial pressure and the etiology of primary hypertension. The developed model reveals: long-term control of arterial blood pressure is primarily through the baroreflex arc and the renin-angiotensin system; and arterial stiffening provides a sufficient explanation for the etiology of primary hypertension associated with ageing. Furthermore, the model provides the first consistent explanation of the physiological response to chronic stimulation of the baroreflex.

  18. Effect of Citrus paradisi extract and juice on arterial pressure both in vitro and in vivo.

    Science.gov (United States)

    Díaz-Juárez, J A; Tenorio-López, F A; Zarco-Olvera, G; Valle-Mondragón, L Del; Torres-Narváez, J C; Pastelín-Hernández, G

    2009-07-01

    Citrus paradisi (grapefruit) consumption is considered as beneficial and it is popularly used for the treatment of a vast array of diseases, including hypertension. In the present study, the coronary vasodilator and hypotensive effects of Citrus paradisi peel extract were assessed in the Langendorff isolated and perfused heart model and in the heart and lung dog preparation. In both models, Citrus paradisi peel extract decreased coronary vascular resistance and mean arterial pressure when compared with control values (60 +/- 15 x 10(7) dyn s cm(-5) vs 100 +/- 10 x 10(7) dyn s cm(-5) and 90 mmHg vs 130 +/- 15 mmHg, respectively). These decreases in coronary vascular resistance and mean arterial pressure were blocked when isolated and perfused hearts and mongrel dogs were pre-treated with L-NAME. In humans, Citrus paradisi juice decreased diastolic arterial pressure and systolic arterial pressure both in normotensive and hypertensive subjects. Citrus paradisi juice produced a greater decrease in mean arterial pressure when compared with Citrus sinensis juice, cow milk and a vitamin C-supplemented beverage. However, more detailed studies are required to isolate, purify and evaluate the chemical compounds responsible for this pharmacological effect and to clarify its possible role for treating hypertension. Copyright 2009 John Wiley & Sons, Ltd.

  19. Off-Design Considerations through the Properties of Some Pressure-Ratio Line of Radial Inflow Turbines

    Directory of Open Access Journals (Sweden)

    N. Binder

    2008-01-01

    Full Text Available Radial turbines are commonly used in applications involving operation through severe off-design conditions. The emergence of variable-geometry systems leads to the distinction between two off-design concepts: operational and geometric off-designs. Both of these operating constraints should be integrated in the design procedure. Recent developments in prediction and optimization methods allowed such an integration, but involving complex algorithms is coupled with semiempiric loss models. This paper provides a basis to obtain simple information from an existing or predesigned machine, for both operational and geometric off-design conditions. An alternative turbine map is defined using loading and flow coefficients. A one-dimensional analysis shows that the constant pressure-ratio lines are straight lines whose slope is remarkably correlated with the pressure-ratio value and geometrical characteristics. This theoretical approach is validated against the experimentation of two machines, the linearity is observed in both cases. The direct influence of the stator configuration on the pressure-ratio lines confirms the applicability of this work to variable-geometry stages. A dimensionless cross-section of the stator is thus defined. However, the unexpected displacement of the intercept of the pressure-ratio lines limits the application field of this method. Nevertheless, a simple performance prediction analysis is proposed for blocked mass flow operation.

  20. Effect of telmisartan on arterial distensibility and central blood pressure in patients with mild to moderate hypertension and Type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Roland Asmar

    2001-06-01

    Full Text Available Arterial wall stiffness is an important independent risk factor for cardiovascular disease in hypertensive patients, which is further exacerbated by co-existent diabetes mellitus. Increased arterial stiffness is directly associated with an increase in pulse wave velocity (PWV and indirectly with increased central and peripheral blood pressure. Following a two-week placebo run-in period, 27 patients with mild to moderate essential hypertension and Type 2 diabetes mellitus, were randomised to once daily treatment with either telmisartan 40 mg or placebo for three weeks, and after a two-week washout period, crossed-over to the alternative treatment for a further three weeks. Carotid/femoral and carotid/radial PWV were measured non-invasively using the automatic Complior® device, and central parameters (central blood pressure, pulse contour analysis, and augmentation index were measured using the SphygmoCor® system, at the start and end of each treatment period. Compared with placebo, treatment with telmisartan significantly reduced carotid/femoral PWV (mean adjusted treatment difference -0.95 m/s, 95% confidence intervals: -1.67, -0.23 m/s, p=0.013, as well as peripheral and central diastolic, systolic and pulse pressure. In conclusion, the results of this study show that telmisartan is effective in reducing arterial stiffness in hypertensive patients with Type 2 diabetes mellitus, and may potentially have beneficial effects on cardiovascular outcomes, beyond blood-pressure lowering effects, in this patient group.

  1. Behavior of a hollow core photonic crystal fiber under high radial pressure for downhole application

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, J., E-mail: j-sadeghi@sbu.ac.ir; Chenari, Z.; Ziaee, F. [Laser and Plasma Research Institute, Shahid Beheshti University, 1983963113 Tehran (Iran, Islamic Republic of); Latifi, H., E-mail: latifi@sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, 1983963113 Tehran (Iran, Islamic Republic of); Department of Physics, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Santos, J. L., E-mail: josantos@fc.up.pt [INESC Porto—Instituto de Engenharia de Sistemas e Computadores do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Departamento de Física, da Faculdade de Ciências, da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal)

    2014-02-17

    Pressure fiber sensors play an important role in downhole high pressure measurements to withstand long term operation. The purpose of this paper is to present an application of hollow core photonic crystal fiber (HC-PCF) as a high pressure sensor head for downhole application based on dispersion variation. We used a high pressure stainless steel unit to exert pressure on the sensor. The experimental results show that different wavelengths based on sagnac loop interferometer have additive sensitivities from 5 × 10{sup −5} nm/psi at 1480 nm to 1.3 × 10{sup −3} nm/psi at 1680 nm. We developed a simulation to understand the reason for difference in sensitivity of wavelengths and also the relationship between deformation of HC-PCF and dispersion variation under pressure. For this purpose, by using the finite element method, we investigated the effect of structural variation of HC-PCF on spectral transformation of two linear polarizations under 1000 psi pressure. The simulation and experimental results show exponential decay behavior of dispersion variation from −3.4 × 10{sup −6} 1/psi to −1.3 × 10{sup −6} 1/psi and from −5 × 10{sup −6} 1/psi to −1.8 × 10{sup −6} 1/psi, respectively, which were in a good accordance with each other.

  2. Modelling of pressurized water reactor fuel, rod time dependent radial heat flow with boundary element method; Modeliranje spremenljivega radijalnega toplotnega toka tlacnovodne gorivne palice z metodo robnih elementov

    Energy Technology Data Exchange (ETDEWEB)

    Sarler, B [Institut Jozef Stefan, Ljubljana (Yugoslavia)

    1987-07-01

    The basic principles of the boundary element method numerical treatment of the radial flow heat diffusion equation are presented. The algorithm copes the time dependent Dirichlet and Neumann boundary conditions, temperature dependent material properties and regions from different materials in thermal contact. It is verified on the several analytically obtained test cases. The developed method is used for the modelling of unsteady radial heat flow in pressurized water reactor fuel rod. (author)

  3. Effect of upper body position on arterial stiffness: influence of hydrostatic pressure and autonomic function.

    Science.gov (United States)

    Schroeder, Elizabeth C; Rosenberg, Alexander J; Hilgenkamp, Thessa I M; White, Daniel W; Baynard, Tracy; Fernhall, Bo

    2017-12-01

    To evaluate changes in arterial stiffness with positional change and whether the stiffness changes are due to hydrostatic pressure alone or if physiological changes in vasoconstriction of the conduit arteries play a role in the modulation of arterial stiffness. Thirty participants' (male = 15, 24 ± 4 years) upper bodies were positioned at 0, 45, and 72° angles. Pulse wave velocity (PWV), cardio-ankle vascular index, carotid beta-stiffness index, carotid blood pressure (cBP), and carotid diameters were measured at each position. A gravitational height correction was determined using the vertical fluid column distance (mmHg) between the heart and carotid artery. Carotid beta-stiffness was calibrated using three methods: nonheight corrected cBP of each position, height corrected cBP of each position, and height corrected cBP of the supine position (theoretical model). Low frequency systolic blood pressure variability (LFSAP) was analyzed as a marker of sympathetic activity. PWV and cardio-ankle vascular index increased with position (P hydrostatic pressure. Arterial stiffness indices based on Method 2 were not different from Method 3 (P = 0.65). LFSAP increased in more upright positions (P pressure did not (P > 0.05). Arterial stiffness increases with a more upright body position. Carotid beta-stiffness needs to be calibrated accounting for hydrostatic effects of gravity if measured in a seated position. It is unclear why PWV increased as this increase was independent of blood pressure. No difference between Methods 2 and 3 presumably indicates that the beta-stiffness increases are only pressure dependent, despite the increase in vascular sympathetic modulation.

  4. The multi-layered ring under parabolic distribution of radial stresses combined with uniform internal and external pressure

    Directory of Open Access Journals (Sweden)

    Christos F. Markides

    2017-04-01

    Full Text Available A recently introduced solution for the stress- and displacement-fields, developed in a multi-layered circular ring, composed of a finite number of linearly elastic concentric layers, subjected to a parabolic distribution of ra-dial stresses, is here extended to encompass a more general loading scheme, closer to actual conditions. The loading scheme includes, besides the para¬-bolic radial stresses, a combination of uniform pressures acting along the outer- and inner- most boundaries of the layered ring. The analytic solution of the problem is achieved by adopting Savin’s pioneering approach for an infinite plate with a hole strengthened by rings. Taking advantage of the results provided by the ana¬lytic solution, a numerical model, simulating the configuration of a three-layered ring (quite commonly encountered in practic¬al applications is validated. The numerical model is then used for a parametric analysis enlightening some crucial aspects of the overall response of the ring.

  5. A novel multi-wavelength procedure for blood pressure estimation using opto-physiological sensor at peripheral arteries and capillaries

    Science.gov (United States)

    Scardulla, Francesco; Hu, Sijung; D'Acquisto, Leonardo; Pasta, Salvatore; Barrett, Laura; Blanos, Panagiotis; Yan, Liangwen

    2018-02-01

    In this study, the Carelight multi-wavelength opto-electronic patch sensor (OEPS) was adopted to assess the effectiveness of a new approach for estimating the systolic blood pressure (SBP) through the changes in the morphology of the OEPS signal. Specifically, the SBP was estimated by changing the pressure exerted on an inflatable cuff placed around the left upper arm. Pressure acquisitions were performed both with gold standard (i.e. electronic sphygmomanometer), and Carelight sensor (experimental procedure), on subjects from a multiethnic cohort (aged 28 +/- 7). The OEPS sensor was applied together with a manual inflatable cuff, going slightly above the level of the SBP with increases of +10mmHg and subsequently deflated by 10mmHg until reaching full deflation. The OEPS signals were captured using four wavelength illumination sources (i.e., green 525 nm, orange 595 nm, red 650 nm and IR 870 nm) on three different measuring sites, namely forefinger, radial artery and wrist. The implemented algorithm provides information on the instant when the SBP was reached and the signal is lost since the vessel is completely blocked. Similarly, it detected the signal resumption when the external pressure dropped below the SBP. The findings demonstrated a good correlation between the variation of the pressure and the corresponding OEPS signal with the most accurate result achieved in the fingertip among all wavelengths, with a temporal identification error of 8.07 %. Further studies will improve the clinical relevance on a cohort of patients diagnosed with hyper- or hypotension, in order to develop a wearable blood-pressure device.

  6. Renal artery anatomy affects the blood pressure response to renal denervation in patients with resistant hypertension.

    Science.gov (United States)

    Hering, Dagmara; Marusic, Petra; Walton, Antony S; Duval, Jacqueline; Lee, Rebecca; Sata, Yusuke; Krum, Henry; Lambert, Elisabeth; Peter, Karlheinz; Head, Geoff; Lambert, Gavin; Esler, Murray D; Schlaich, Markus P

    2016-01-01

    Renal denervation (RDN) has been shown to reduce blood pressure (BP), muscle sympathetic nerve activity (MSNA) and target organ damage in patients with resistant hypertension (RH) and bilateral single renal arteries. The safety and efficacy of RDN in patients with multiple renal arteries remains unclear. We measured office and 24-hour BP at baseline, 3 and 6 months following RDN in 91 patients with RH, including 65 patients with single renal arteries bilaterally (group 1), 16 patients with dual renal arteries on either one or both sides (group 2) and 10 patients with other anatomical constellations or structural abnormalities (group 3). Thirty nine out of 91 patients completed MSNA at baseline and follow-up. RDN significantly reduced office and daytime SBP in group 1 at both 3 and 6 months follow-up (Pkidney function in any group. While RDN can be performed safely irrespective of the underlying renal anatomy, the presence of single renal arteries with or without structural abnormalities is associated with a more pronounced BP and MSNA lowering effect than the presence of dual renal arteries in patients with RH. However, when patients with dual renal arteries received renal nerve ablation in all arteries there was trend towards a greater BP reduction. Insufficient renal sympathetic nerve ablation may account for these differences. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. [The predictive value of dynamic arterial elastance in arterial pressure response after norepinephrine dosage reduction in patients with septic shock].

    Science.gov (United States)

    Liang, F M; Yang, T; Dong, L; Hui, J J; Yan, J

    2017-05-01

    Objective: To assess whether dynamic arterial elastance(Ea(dyn))can be used to predict the reduction of arterial pressure after decreasing norepinephrine (NE) dosage in patients with septic shock. Methods: A prospective observational cohort study was conducted. Thirty-two patients with septic shock and mechanical ventilationwere enrolledfrom January 2014 to December 2015 in ICU of Wuxi People's Hospital of Nanjing Medical University. Hemodynamic parameters were recorded by pulse contour cardiac output(PiCCO)monitoring technology before and after decreasing norepinephrine dosage. Ea(dyn) was defined as the ratio of pulse pressure variation (PPV) to stroke volume variation (SVV). Mean arterial pressure(MAP) variation was calculated after decreasing the dose of NE. Response was defined as a ≥15% decrease of MAP. AUC was plotted to assess the value of Ea(dyn) in predicting MAP response. Results: A total of 32 patients were enrolled in our study, with 13 responding to NE dose decrease where as the other 19 did not. Ea(dyn) was lower in responders than in nonresponders (0.77±0.13 vs 1.09±0.31, P blood pressure variation, diastolic blood pressure variation, systemic vascular resistance variation and MAP variation( r =0.621, P =0.000; r =0.735, P =0.000; r =0.756, P =0.000; r =0.568, P =0.000 respectively). However, stoke volume variation, baseline level of systemic vascular resistance and NE baseline dose were not correlated with Ea(dyn) baseline value( r =0.264, P =0.076; r =0.078, P =0.545; r =0.002, P =0.987 respectively). Ea(dyn)≤0.97 predicted a decrease of MAP when decreasing NE dose, with an area under the receiver-operating characteristic curve of 0.85.The sensitivity was 100.0% and specificity was 73.7%. Conclusions: In septic shock patients treated with NE, Ea(dyn) is an index to predict the decrease of arterial pressure in response to NE dose reduction.

  8. Autologous Transfusion of Stored Red Blood Cells Increases Pulmonary Artery Pressure

    Science.gov (United States)

    Pinciroli, Riccardo; Stowell, Christopher P.; Wang, Lin; Yu, Binglan; Fernandez, Bernadette O.; Feelisch, Martin; Mietto, Cristina; Hod, Eldad A.; Chipman, Daniel; Scherrer-Crosbie, Marielle; Bloch, Kenneth D.; Zapol, Warren M.

    2014-01-01

    Rationale: Transfusion of erythrocytes stored for prolonged periods is associated with increased mortality. Erythrocytes undergo hemolysis during storage and after transfusion. Plasma hemoglobin scavenges endogenous nitric oxide leading to systemic and pulmonary vasoconstriction. Objectives: We hypothesized that transfusion of autologous blood stored for 40 days would increase the pulmonary artery pressure in volunteers with endothelial dysfunction (impaired endothelial production of nitric oxide). We also tested whether breathing nitric oxide before and during transfusion could prevent the increase of pulmonary artery pressure. Methods: Fourteen obese adults with endothelial dysfunction were enrolled in a randomized crossover study of transfusing autologous, leukoreduced blood stored for either 3 or 40 days. Volunteers were transfused with 3-day blood, 40-day blood, and 40-day blood while breathing 80 ppm nitric oxide. Measurements and Main Results: The age of volunteers was 41 ± 4 years (mean ± SEM), and their body mass index was 33.4 ± 1.3 kg/m2. Plasma hemoglobin concentrations increased after transfusion with 40-day and 40-day plus nitric oxide blood but not after transfusing 3-day blood. Mean pulmonary artery pressure, estimated by transthoracic echocardiography, increased after transfusing 40-day blood (18 ± 2 to 23 ± 2 mm Hg; P transfusing 3-day blood (17 ± 2 to 18 ± 2 mm Hg; P = 0.5). Breathing nitric oxide decreased pulmonary artery pressure in volunteers transfused with 40-day blood (17 ± 2 to 12 ± 1 mm Hg; P Transfusion of autologous leukoreduced blood stored for 40 days was associated with increased plasma hemoglobin levels and increased pulmonary artery pressure. Breathing nitric oxide prevents the increase of pulmonary artery pressure produced by transfusing stored blood. Clinical trial registered with www.clinicaltrials.gov (NCT 01529502). PMID:25162920

  9. Radial oxygen gradients over rat cortex arterioles

    OpenAIRE

    Galler, Michael

    2011-01-01

    Purpose: We present the results of the visualisation of radial oxygen gradients in rats’ cortices and their use in neurocritical management. Methods: PO2 maps of the cortex of 10 wistar rats were obtained with a camera (SensiMOD, PCO, Kehlheim, Germany). Those pictures were analyzed and edited by a custom-made software. We chose a vessel for examination. A matrix, designed to evaluate the cortical O2 partial pressure, was placed vertically to the artery and afterwards multiple regio...

  10. Body height and arterial pressure in seated and supine young males during +2 G centrifugation

    DEFF Research Database (Denmark)

    Arvedsen, Sine K.; Eiken, Ola; Kölegård, Roger

    2015-01-01

    by the use of a human centrifuge would increase mean arterial pressure (MAP) more in tall than in short males in the seated position. In short (162-171cm, n=8) and tall (194-203cm, n=10) healthy males (18-41yr), brachial arterial pressure, heart rate (HR) and cardiac output were measured during +2G...... centrifugation, while they were seated upright with the legs kept horizontal (+2Gz). In a separate experiment, the same measurements were done with the subjects supine (+2Gx). During +2Gz MAP increased in the short (22±2 mmHg, P 

  11. Radial profiles of velocity and pressure for condensation-induced hurricanes

    International Nuclear Information System (INIS)

    Makarieva, A.M.; Gorshkov, V.G.

    2011-01-01

    The Bernoulli integral in the form of an algebraic equation is obtained for the hurricane air flow as the sum of the kinetic energy of wind and the condensational potential energy. With an account for the eye rotation energy and the decrease of angular momentum towards the hurricane center it is shown that the theoretical profiles of pressure and velocity agree well with observations for intense hurricanes. The previous order of magnitude estimates obtained in pole approximation are confirmed.

  12. Radial profiles of velocity and pressure for condensation-induced hurricanes

    Science.gov (United States)

    Makarieva, A. M.; Gorshkov, V. G.

    2011-02-01

    The Bernoulli integral in the form of an algebraic equation is obtained for the hurricane air flow as the sum of the kinetic energy of wind and the condensational potential energy. With an account for the eye rotation energy and the decrease of angular momentum towards the hurricane center it is shown that the theoretical profiles of pressure and velocity agree well with observations for intense hurricanes. The previous order of magnitude estimates obtained in pole approximation are confirmed.

  13. Radial profiles of velocity and pressure for condensation-induced hurricanes

    Energy Technology Data Exchange (ETDEWEB)

    Makarieva, A.M., E-mail: ammakarieva@gmail.co [Theoretical Physics Division, Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg (Russian Federation); Gorshkov, V.G. [Theoretical Physics Division, Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg (Russian Federation)

    2011-02-14

    The Bernoulli integral in the form of an algebraic equation is obtained for the hurricane air flow as the sum of the kinetic energy of wind and the condensational potential energy. With an account for the eye rotation energy and the decrease of angular momentum towards the hurricane center it is shown that the theoretical profiles of pressure and velocity agree well with observations for intense hurricanes. The previous order of magnitude estimates obtained in pole approximation are confirmed.

  14. Correlation Between Doppler Echocardiography and Right Heart Catheterization Derived Pulmonary Artery Pressures: Impact of Right Atrial Pressures

    International Nuclear Information System (INIS)

    Ahmed, I.; Nuri, M. M. H.; Zakariyya, A. N.; Ahmad, S. M.; Ahmed, M.

    2016-01-01

    Objective: To evaluate the correlation between Doppler echocardiography (DE) and right heart catheterization (RHC) derived pulmonary artery pressures and to assess the impact of right atrial (RA) pressures on this correlation. Study Design: Cross-sectional analytical study. Place and Duration of Study: Cardiology Department, Tahir Heart Institute, Chenab Nagar, from June 2013 to December 2014. Methodology: All patients undergoing RHC were included. Relevant data were collected from hospital database. Continuous variables were expressed as the mean and SD or as the median and interquartile range where the distributions were skewed. Pearson correlation coefficient and Bland-Altman method were used to correlate DE derived right ventricular systolic pressure (RVSP) and RHC derived systolic pulmonary artery pressures (sPAP). Adjusted RVSP was calculated by replacing default value of RA pressure (10 mmHg) with RHC derived mean RA pressure. Receiver operating characteristic curve (ROC) was used to identify the best cut-off value of RVSP in predicting pulmonary hypertension. Results: Fifty-one patients completed the study protocol. Mean age of study population was 45.22 ± 15.25 years with male to female ratio of 1.47:1. Median error was 13 mmHg (7 to 20). Pearson correlation coefficient (r) between RVSP and sPAP was 0.72. Bland-Altman method of correlation showed bias of +4.43 mmHg with 95% limits of agreement ranging from -34.61 to +43.47. Using ROC curve, the best cut-off value of RVSP was greater than 52 mmHg with accuracy of 75% (sensitivity: 81%, specificity: 69%) in predicting pulmonary hypertension. Adjusted RVSP showed only little improvement in correlation (r = 0.75), adjusted error (13.65 ± 13.05) and diagnostic accuracy (79%). Conclusion: Doppler echocardiography can frequently overestimate pulmonary artery pressures. Though correctly estimated RA pressure may improve this correlation, yet its contribution is only minimal. (author)

  15. Use of paravascular admittance waveforms to monitor relative change in arterial blood pressure

    Science.gov (United States)

    Zielinski, Todd M.; Hettrick, Doug; Cho, Yong

    2010-04-01

    Non-invasive methods to monitor ambulatory blood pressure often have limitations that can affect measurement accuracy and patient adherence [1]. Minimally invasive measurement of a relative blood pressure surrogate with an implantable device may provide a useful chronic diagnostic and monitoring tool. We assessed a technique that uses electrocardiogram and paravascular admittance waveform morphology analysis to one, measure a time duration (vascular tone index, VTI in milliseconds) change from the electrocardiogram R-wave to admittance waveform peak and two, measure the admittance waveform minimum, maximum and magnitude as indicators of change in arterial compliance/distensibility or pulse pressure secondary to change in afterload. Methods: Five anesthetized domestic pigs (32 ± 4.2 kg) were used to study the effects of phenylephrine (1-5 ug/kg/min) on femoral artery pressure and admittance waveform morphology measured with a quadrapolar electrode array catheter placed next to the femoral artery to assess the relative change in arterial compliance due to change in peripheral vascular tone. Results: Statistical difference was observed (p blood pressure may be suitable for implantable devices to detect progression of cardiovascular disease such as hypertension.

  16. Cantilever arrayed blood pressure sensor for arterial applanation tonometry.

    Science.gov (United States)

    Lee, Byeungleul; Jeong, Jinwoo; Kim, Jinseok; Kim, Bonghwan; Chun, Kukjin

    2014-03-01

    The authors developed a cantilever-arrayed blood pressure sensor array fabricated by (111) silicon bulk-micromachining for the non-invasive and continuous measurement of blood pressure. The blood pressure sensor measures the blood pressure based on the change in the resistance of the piezoresistor on a 5-microm-thick-arrayed perforated membrane and 20-microm-thick metal pads. The length and the width of the unit membrane are 210 and 310 microm, respectively. The width of the insensible zone between the adjacent units is only 10 microm. The resistance change over contact force was measured to verify the performance. The good linearity of the result confirmed that the polydimethylsiloxane package transfers the forces appropriately. The measured sensitivity was about 4.5%/N. The maximum measurement range and the resolution of the fabricated blood pressure sensor were greater than 900 mmHg (= 120 kPa) and less than 1 mmHg (= 133.3 Pa), respectively.

  17. Relationship between pulmonary artery volumes at computed tomography and pulmonary artery pressures in patients with- and without pulmonary hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Froelich, Jens J. [Department of Radiology, Philipps-University Hospital, Baldingerstrasse, 35043 Marburg (Germany)], E-mail: jens.froelich@klinikum-hef.de; Koenig, Helmut [Department of Radiology, Philipps-University Hospital, Baldingerstrasse, 35043 Marburg (Germany)], E-mail: helmut.koenig@siemens.com; Knaak, Lennard [Department of Medicine, Philipps-University Hospital, Baldingerstrasse, 35043 Marburg (Germany)], E-mail: froehlic@staff.uni-marburg.de; Krass, Stefan [MeVis Research, Universitaetsallee 29, 28359 Bremen (Germany)], E-mail: krass@mevis.de; Klose, Klaus J. [Department of Radiology, Philipps-University Hospital, Baldingerstrasse, 35043 Marburg (Germany)], E-mail: klose@med.uni-marburg.de

    2008-09-15

    Objectives: This study was designed to determine the relationship between pulmonary artery (PA) volumes at computed tomography (CT) and PA pressures at right-sided heart catheterization in patients with and without pulmonary hypertension (PAH) to develop a noninvasive CT method of PA pressure quantification. Materials and methods: Sixteen patients with chronic sleep apnea syndrome underwent contrast enhanced helical CT (slice thickness 3 mm; pitch 2; increment 2 mm) at inspiration. Eight patients had PAH while cardiopulmonary disease has been excluded in eight other patients. Vascular volumes were determined using a 3D technique (threshold seeded vascular tracing algorithm; thresholds -600 H [lower] and 3000 H [upper]). Right-sided heart catheterization measurements were available for linear regression analysis of PA volumes and pressures. Results: Correlation between PA pressures and volumes (normalized for BMI), was high in both groups (without PAH: r = .85; with PAH .90, Pearson). Compared to elevated PA pressures in patients with pulmonary hypertension (p < .005), PA volumes also were significantly increased (p < .05) among the groups. Conclusions: High correlation was found between PA volumes and mean PA pressures in patients with- and without PAH. Significant differences in PA volumes at CT-volumetry may admit non-invasive determination of pulmonary hypertension.

  18. Relationship between pulmonary artery volumes at computed tomography and pulmonary artery pressures in patients with- and without pulmonary hypertension

    International Nuclear Information System (INIS)

    Froelich, Jens J.; Koenig, Helmut; Knaak, Lennard; Krass, Stefan; Klose, Klaus J.

    2008-01-01

    Objectives: This study was designed to determine the relationship between pulmonary artery (PA) volumes at computed tomography (CT) and PA pressures at right-sided heart catheterization in patients with and without pulmonary hypertension (PAH) to develop a noninvasive CT method of PA pressure quantification. Materials and methods: Sixteen patients with chronic sleep apnea syndrome underwent contrast enhanced helical CT (slice thickness 3 mm; pitch 2; increment 2 mm) at inspiration. Eight patients had PAH while cardiopulmonary disease has been excluded in eight other patients. Vascular volumes were determined using a 3D technique (threshold seeded vascular tracing algorithm; thresholds -600 H [lower] and 3000 H [upper]). Right-sided heart catheterization measurements were available for linear regression analysis of PA volumes and pressures. Results: Correlation between PA pressures and volumes (normalized for BMI), was high in both groups (without PAH: r = .85; with PAH .90, Pearson). Compared to elevated PA pressures in patients with pulmonary hypertension (p < .005), PA volumes also were significantly increased (p < .05) among the groups. Conclusions: High correlation was found between PA volumes and mean PA pressures in patients with- and without PAH. Significant differences in PA volumes at CT-volumetry may admit non-invasive determination of pulmonary hypertension

  19. Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Theodore W.; Sultan, Laith R.; Sehgal, Chandra M., E-mail: sehgalc@uphs.upenn.edu [Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Reamer, Courtney B.; Mohler, Emile R. [Department of Medicine, Division of Cardiovascular Medicine, Section of Vascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2014-02-15

    Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.

  20. [Fasciocutaneous flap reliable by deep femoral artery perforator for the treatment of ischial pressure ulcers].

    Science.gov (United States)

    Gebert, L; Boucher, F; Lari, A; Braye, F; Mojallal, A; Ismaïl, M

    2018-04-01

    The surgical management of pressure ulcers in the paraplegic or quadriplegic population is marked by the high risk of recurrence in the long-term. In the current era of perforator flaps, newer reconstructive options are available for the management of pressure ulcers, decreasing the need to use the classically described muscular or musculocutaneous locoregional flaps. The coverage of ischial sores described in this article by a pedicled flap based on a deep femoral artery perforator, appears to be an effective first-line reconstructive option for the management of limited size pressure ulcers. A number of fifteen paraplegic or quadriplegic patients having at least one ischial bed sore with underlying osteomyelitis were included in this series. The approximate location of the deep femoral artery perforator was initially identified using the "The Atlas of the perforator arteries of the skin, the trunk and limbs", which was confirmed, with the use of a Doppler device. A fasciocutaneous transposition flap was elevated, with the pivot point based on the cutaneous bridge centered on the perforator, and then transposed to cover the area of tissue loss. The donor site was closed primarily. A total of fifteen patients were operated from November 2015 to November 2016. The series comprised of 16 first presentations of a stage 4 pressure ulcers associated with underlying osteomyelitis that were subsequently reconstructed by the pedicled deep femoral artery perforator flap. The healing rate and functional results were both satisfactory. Fasciocutaneous flap reliable by deep femoral artery perforator appears to have a promising role in the treatment of ischial pressure sores. It is an attractive option to spare the use of musculocutaneous flaps in the area. Thus this flap could be used as a first-line option to cover ischial pressure ulcers of limited size. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. The mechanical properties of the systemic and pulmonary arteries of Python regius correlate with blood pressures.

    Science.gov (United States)

    van Soldt, Benjamin J; Danielsen, Carl Christian; Wang, Tobias

    2015-12-01

    Pythons are unique amongst snakes in having different pressures in the aortas and pulmonary arteries because of intraventricular pressure separation. In this study, we investigate whether this correlates with different blood vessel strength in the ball python Python regius. We excised segments from the left, right, and dorsal aortas, and from the two pulmonary arteries. These were subjected to tensile testing. We show that the aortic vessel wall is significantly stronger than the pulmonary artery wall in P. regius. Gross morphological characteristics (vessel wall thickness and correlated absolute amount of collagen content) are likely the most influential factors. Collagen fiber thickness and orientation are likely to have an effect, though the effect of collagen fiber type and cross-links between fibers will need further study. © 2015 Wiley Periodicals, Inc.

  2. A micromechanical device that monitors arterial pressure during general anesthesia and in intensive care units

    Science.gov (United States)

    Andreeva, A. V.; Luchinin, V. V.; Kuzmina, K. A.; Klyavinek, A. S.; Karelov, A. E.

    2015-12-01

    A vibroacoustic fiber optic system that consists of micromechanical components designated for use in medicine and biology is reviewed. A theoretical analysis of a fiber optic microphone is done and its optimal construction parameters are determined. The possibility of using the developed system with magnetic resonance tomography to noninvasively measure man's arterial pressure is specified.

  3. Arterial blood pressure changes in acute T. brucei infection of dogs ...

    African Journals Online (AJOL)

    The aim of this study is to find out the usefulness of serial arterial blood pressure measurements in predicting severity and outcome of acute Trypanosoma brucei infection in dogs. Twenty adult dogs of mixed sexes and aged between 2 and 5 years were used for this study. The dogs were of good cardiac health and were ...

  4. [Doppler ultrasound evaluation of aortic insufficiency using half-pressure time. Absence of arterial rigidity influence].

    Science.gov (United States)

    Kalotka-Bratek, H; Drobinski, G; Klimczak, K; Busquet, P; Fraysse, J B; Bejean-Lebuisson, A; Grosgogeat, Y

    1989-02-01

    In 20 patients with pure aortic regurgitation we studied the relationship between the severity of regurgitation, as assessed haemodynamically by the percentage of leakage (%L), and the half-pressure (T 1/2 P) and half-velocity (T 1/2 V) times, as obtained from doppler aortic blood velocity curves, taking into account the rigidity of the systemic vascular circuit characterized by the pressure wave propagation velocity (PWPV). The systemic arterial circuit was supple in 14 patients (PWPV less than 7.5 m/sec) and rigid in 6 patients (PWPV greater than 7.5 m/sec). The regression slopes between %L and T 1/2 P and between %L and T 1/2 V were calculated with their confidence limits in the 14 patients with supple arteries. The 6 patients with rigid arteries fitted into this nomogram, thus demonstrating that systemic arterial rigidity makes no difference in the relationship between %L and doppler indices. The half-velocity and half-pressure times measured by doppler ultrasound were acquired from a velocity signal directly determined by the aortic regurgitation, without any detectable effect of vascular circuit rigidity. Being equivalent by nature to the signal decrease time constant, they are independent of the absolute protodiastolic value of diastolic pressure gradient or blood flow velocity. For this reason these two doppler parameters are reliable to evaluate the severity of aortic regurgitation.

  5. Unilateral renal artery stenosis and hypertension. II. Angiographic findings correlated with blood pressure response after surgery

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, I; Bergentz, S E; Ericsson, B F; Dymling, J F; Hansson, B G; Hoekfelt, B [Department of Diagnostic Radiography, Surgery and Endocrinology, Malmoe Allmaenna Sjukhus, Malmoe, Sweden

    1979-01-01

    The findings at preoperative nephroanigiography of 42 hypertensive patients with unilateral renal artery stenosis or occlusion were correlated with the blood pressure response following surgery and also with the preoperative renal vein renin activity ratio. A stenosis reducing luminal area by at least 90 per cent (or occlusion) and the presence of collateral circulation are considered to be highly suggestive of renovascular hypertension.

  6. Increasing arterial blood pressure with norepinephrine does not improve microcirculatory blood flow: a prospective study

    NARCIS (Netherlands)

    Dubin, Arnaldo; Pozo, Mario O.; Casabella, Christian A.; Palizas, Fernando; Murias, Gaston; Moseinco, Miriam C.; Kanoore Edul, Vanina S.; Estenssoro, Elisa; Ince, Can

    2009-01-01

    Introduction Our goal was to assess the effects of titration of a norepinephrine infusion to increasing levels of mean arterial pressure (MAP) on sublingual microcirculation. Methods Twenty septic shock patients were prospectively studied in two teaching intensive care units. The patients were

  7. Functional role of diverse changes in sympathetic nerve activity in regulating arterial pressure during REM sleep.

    Science.gov (United States)

    Yoshimoto, Misa; Yoshida, Ikue; Miki, Kenju

    2011-08-01

    This study aimed to investigate whether REM sleep evoked diverse changes in sympathetic outflows and, if so, to elucidate why REM sleep evokes diverse changes in sympathetic outflows. Male Wistar rats were chronically implanted with electrodes to measure renal (RSNA) and lumbar sympathetic nerve activity (LSNA), electroencephalogram, electromyogram, and electrocardiogram, and catheters to measure systemic arterial and central venous pressure; these parameters were measured simultaneously and continuously during the sleep-awake cycle in the same rat. REM sleep resulted in a step reduction in RNSA by 36.1% ± 2.7% (P sleep. In contrast to REM sleep, RSNA, LSNA, systemic arterial pressure, and heart rate increased in a unidirectional manner associated with increases in physical activity levels in the order from NREM sleep, quiet awake, moving, and grooming state. Thus, the relationship between RSNA vs. LSNA and systemic arterial pressure vs. heart rate observed during REM sleep was dissociated compared with that obtained during the other behavioral states. It is suggested that the diverse changes in sympathetic outflows during REM sleep may be needed to increase systemic arterial pressure by balancing vascular resistance between muscles and vegetative organs without depending on the heart.

  8. Chronic binge alcohol consumption during pregnancy alters rat maternal uterine artery pressure response.

    Science.gov (United States)

    Naik, Vishal D; Lunde-Young, Emilie R; Davis-Anderson, Katie L; Orzabal, Marcus; Ivanov, Ivan; Ramadoss, Jayanth

    2016-11-01

    We aimed to investigate pressure-dependent maternal uterine artery responses and vessel remodeling following gestational binge alcohol exposure. Two groups of pregnant rats were used: the alcohol group (28.5% wt/v, 6.0 g/kg, once-daily orogastric gavage in a binge paradigm between gestational day (GD) 5-19) and pair-fed controls (isocalorically matched). On GD20, excised, pressurized primary uterine arteries were studied following equilibration (60 mm Hg) using dual chamber arteriograph. The uterine artery diameter stabilized at 20 mm Hg, showed passive distension at 40 mm Hg, and redeveloped tone at 60 mm Hg. An alcohol effect (P = 0.0025) was observed on the percent constriction of vessel diameter with greater pressure-dependent myogenic constriction. Similar alcohol effect was noted with lumen diameter response (P = 0.0020). The percent change in media:lumen ratio was higher in the alcohol group (P alcohol affects pressure-induced uterine artery reactivity, inward-hypotrophic remodeling, and adaptations critical for nutrient delivery to the fetus. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Continuous stroke volume monitoring by modelling flow from non-invasive measurement of arterial pressure in humans under orthostatic stress

    NARCIS (Netherlands)

    Harms, M.P.M.; Wesseling, K.H.; Pott, F.; Jenstrup, M.; Goudoever, J. van; Secher, N.H.; Lieshout, J.J. van

    1999-01-01

    The relationship between aortic flow and pressure is described by a three-element model of the arterial input impedance, including continuous correction for variations in the diameter and the compliance of the aorta (Modelflow). We computed the aortic flow from arterial pressure by this model, and

  10. Phylloquinone (vitamin K₁) intake and pulse pressure as a measure of arterial stiffness in older adults.

    Science.gov (United States)

    Vaccaro, Joan A; Huffman, Fatma G

    2013-01-01

    This study examined the relationships among ethnicity/race, lifestyle factors, phylloquinone (vitamin K₁) intake, and arterial pulse pressure in a nationally representative sample of older adults from four ethnic/racial groups: non-Hispanic Whites, non-Hispanic Blacks, Mexican Americans, and other Hispanics. This was a cross-sectional study of U.S. representative sample with data from the National Health and Nutrition Examination Surveys, 2007-2008 and 2009-2010 of adults aged 50 years and older (N = 5296). Vitamin K intake was determined by 24-hour recall. Pulse pressure was calculated as the difference between the averages of systolic blood pressure and diastolic blood pressure. Compared to White non-Hispanics, the other ethnic/racial groups were more likely to have inadequate vitamin K₁ intake. Inadequate vitamin K₁ intake was an independent predictor of high arterial pulse pressure. This was the first study that compared vitamin K₁ inadequacy with arterial pulse pressure across ethnicities/races in U.S. older adults. These findings suggest that vitamin K screening may be a beneficial marker for the health of older adults.

  11. Neonatal oxidative stress depends on oxygen blood pressure in umbilical artery.

    Science.gov (United States)

    Proietti, F; De Bernardo, G; Longini, M; Sordino, D; Scaramuzzini, G; Tataranno, M L; Belvisi, E; Bazzini, F; Perrone, S; Buonocore, G

    2016-01-01

    With advancing gestation, partial pressure of oxygen (pO2) and pH fall significantly. Hypoxia is a main factor inducing free radical generation and thereby oxidative stress (OS). Placental and fetal tissue response when oxygen becomes restricted is complex and partially known. We tested the hypothesis that changes in umbilical artery and vein blood gas concentrations modulate OS occurrence in the newborn. Seventy umbilical artery and vein plasma samples were collected from healthy term newborns immediately after delivery. F2 Isoprostanes (F2-Isop) were measured in all samples as reliable markers of lipid peroxidation. Significantly lower pCO2 and higher pO2 and pH were found in umbilical vein than in artery, as expected. A positive correlation was detected between pH and pO2 only in umbilical artery (p=0.019). F2-Isop levels were no different between artery and vein in cord blood. Significant correlations were found between F2-Isop and pCO2 (p=0.025) as well as between F2-Isop and pH in umbilical vein (p=0.027). F2-Isop correlated with pCO2 (p=0.007) as well as with pO2 values (p=0.005) in umbilical artery blood. Oxidative stress (OS) in newborns depends on oxygen concentrations in umbilical artery. OS biomarkers significantly correlate with pO2 and in umbilical artery but not in umbilical vein. In normoxic conditions fetal-maternal gas exchanges occurring in placenta re-establish normal higher oxygen levels in umbilical vein than artery, with a normal production of free radicals without any deleterious effects.

  12. Elevated plasma endothelin-1 and pulmonary arterial pressure in children exposed to air pollution.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Vincent, Renaud; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Henríquez-Roldán, Carlos; Barragán-Mejía, Gerardo; Garrido-García, Luis; Camacho-Reyes, Laura; Valencia-Salazar, Gildardo; Paredes, Rogelio; Romero, Lina; Osnaya, Hector; Villarreal-Calderón, Rafael; Torres-Jardón, Ricardo; Hazucha, Milan J; Reed, William

    2007-08-01

    Controlled exposures of animals and humans to particulate matter (PM) or ozone air pollution cause an increase in plasma levels of endothelin-1, a potent vasoconstrictor that regulates pulmonary arterial pressure. The primary objective of this field study was to determine whether Mexico City children, who are chronically exposed to levels of PM and O(3) that exceed the United States air quality standards, have elevated plasma endothelin-1 levels and pulmonary arterial pressures. We conducted a study of 81 children, 7.9 +/- 1.3 years of age, lifelong residents of either northeast (n = 19) or southwest (n = 40) Mexico City or Polotitlán (n = 22), a control city with PM and O(3) levels below the U.S. air quality standards. Clinical histories, physical examinations, and complete blood counts were done. Plasma endothelin-1 concentrations were determined by immunoassay, and pulmonary arterial pressures were measured by Doppler echocardiography. Mexico City children had higher plasma endothelin-1 concentrations compared with controls (p < 0.001). Mean pulmonary arterial pressure was elevated in children from both northeast (p < 0.001) and southwest (p < 0.05) Mexico City compared with controls. Endothelin-1 levels in Mexico City children were positively correlated with daily outdoor hours (p = 0.012), and 7-day cumulative levels of PM air pollution < 2.5 mum in aerodynamic diameter (PM(2.5)) before endothelin-1 measurement (p = 0.03). Chronic exposure of children to PM(2.5) is associated with increased levels of circulating endothelin-1 and elevated mean pulmonary arterial pressure.

  13. Elevated Plasma Endothelin-1 and Pulmonary Arterial Pressure in Children Exposed to Air Pollution

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Vincent, Renaud; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Henríquez-Roldán, Carlos; Barragán-Mejía, Gerardo; Garrido-García, Luis; Camacho-Reyes, Laura; Valencia-Salazar, Gildardo; Paredes, Rogelio; Romero, Lina; Osnaya, Hector; Villarreal-Calderón, Rafael; Torres-Jardón, Ricardo; Hazucha, Milan J.; Reed, William

    2007-01-01

    Background Controlled exposures of animals and humans to particulate matter (PM) or ozone air pollution cause an increase in plasma levels of endothelin-1, a potent vasoconstrictor that regulates pulmonary arterial pressure. Objectives The primary objective of this field study was to determine whether Mexico City children, who are chronically exposed to levels of PM and O3 that exceed the United States air quality standards, have elevated plasma endothelin-1 levels and pulmonary arterial pressures. Methods We conducted a study of 81 children, 7.9 ± 1.3 years of age, lifelong residents of either northeast (n = 19) or southwest (n = 40) Mexico City or Polotitlán (n = 22), a control city with PM and O3 levels below the U.S. air quality standards. Clinical histories, physical examinations, and complete blood counts were done. Plasma endothelin-1 concentrations were determined by immunoassay, and pulmonary arterial pressures were measured by Doppler echocardiography. Results Mexico City children had higher plasma endothelin-1 concentrations compared with controls (p < 0.001). Mean pulmonary arterial pressure was elevated in children from both northeast (p < 0.001) and southwest (p < 0.05) Mexico City compared with controls. Endothelin-1 levels in Mexico City children were positively correlated with daily outdoor hours (p = 0.012), and 7-day cumulative levels of PM air pollution < 2.5 μm in aerodynamic diameter (PM2.5) before endothelin-1 measurement (p = 0.03). Conclusions Chronic exposure of children to PM2.5 is associated with increased levels of circulating endothelin-1 and elevated mean pulmonary arterial pressure. PMID:17687455

  14. Blood Pressure and Arterial Load After Transcatheter Aortic Valve Replacement for Aortic Stenosis.

    Science.gov (United States)

    Lindman, Brian R; Otto, Catherine M; Douglas, Pamela S; Hahn, Rebecca T; Elmariah, Sammy; Weissman, Neil J; Stewart, William J; Ayele, Girma M; Zhang, Feifan; Zajarias, Alan; Maniar, Hersh S; Jilaihawi, Hasan; Blackstone, Eugene; Chinnakondepalli, Khaja M; Tuzcu, E Murat; Leon, Martin B; Pibarot, Philippe

    2017-07-01

    After aortic valve replacement, left ventricular afterload is often characterized by the residual valve obstruction. Our objective was to determine whether higher systemic arterial afterload-as reflected in blood pressure, pulsatile and resistive load-is associated with adverse clinical outcomes after transcatheter aortic valve replacement (TAVR). Total, pulsatile, and resistive arterial load were measured in 2141 patients with severe aortic stenosis treated with TAVR in the PARTNER I trial (Placement of Aortic Transcatheter Valve) who had systolic blood pressure (SBP) and an echocardiogram obtained 30 days after TAVR. The primary end point was 30-day to 1-year all-cause mortality. Lower SBP at 30 days after TAVR was associated with higher mortality (20.0% for SBP 100-129 mm Hg versus 12.0% for SBP 130-170 mm Hg; P <0.001). This association remained significant after adjustment, was consistent across subgroups, and confirmed in sensitivity analyses. In adjusted models that included SBP, higher total and pulsatile arterial load were associated with increased mortality ( P <0.001 for all), but resistive load was not. Patients with low 30-day SBP and high pulsatile load had a 3-fold higher mortality than those with high 30-day SBP and low pulsatile load (26.1% versus 8.1%; hazard ratio, 3.62; 95% confidence interval, 2.36-5.55). Even after relief of valve obstruction in patients with aortic stenosis, there is an independent association between post-TAVR blood pressure, systemic arterial load, and mortality. Blood pressure goals in patients with a history of aortic stenosis may need to be redefined. Increased pulsatile arterial load, rather than blood pressure, may be a target for adjunctive medical therapy to improve outcomes after TAVR. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00530894. © 2017 American Heart Association, Inc.

  15. Roles of Arterial Stiffness and Blood Pressure in Hypertension-Associated Cognitive Decline in Healthy Adults.

    Science.gov (United States)

    Hajjar, Ihab; Goldstein, Felicia C; Martin, Greg S; Quyyumi, Arshed A

    2016-01-01

    Although there is strong evidence that hypertension leads to cognitive decline, especially in the executive domain, the relationship between blood pressure and cognition has been conflicted. Hypertension is characterized by blood pressure elevation and increased arterial stiffness. We aimed at investigating whether arterial stiffness would be superior to blood pressure in predicting cognitive decline and explaining the hypertension-executive decline association. A randomly selected asymptomatic population (n=591, age=49.2 years, 70% women, 27% black, and education=18 years) underwent annual vascular and cognitive assessments. Cognition was assessed using computerized versions commonly used cognitive tests, and principal component analysis was used for deriving cognitive scores for executive function, memory, and working memory. Arterial stiffness was measured by carotid-femoral pulse wave velocity (PWV). Higher PWV, but not blood pressure, was associated with a steeper decline in executive (P=0.0002), memory (P=0.05), and working memory (P=0.02) scores after adjusting for demographics, education, and baseline cognitive performance. This remained true after adjusting for hypertension. Hypertension was associated with greater decline in executive score (P=0.0029) and those with combined hypertension and elevated PWV (>7 m/s) had the greatest decline in executive score (P value hypertension×PWV=0.02). PWV explained the association between hypertension and executive function (P value for hypertension=0.0029 versus 0.24 when adjusting for PWV). In healthy adults, increased arterial stiffness is superior to blood pressure in predicting cognitive decline in all domains and in explaining the hypertension-executive function association. Arterial stiffness, especially in hypertension, may be a target in the prevention of cognitive decline. © 2015 American Heart Association, Inc.

  16. Effects of Acupuncture Stimulation on the Radial artery’s Pressure Pulse Wave in Healthy Young Participants: Protocol for a prospective, single-Arm, Exploratory, Clinical Study

    Directory of Open Access Journals (Sweden)

    Jae-Young Shin

    2016-09-01

    Full Text Available Introduction: This study aims to investigate the effects of acupuncture stimulation on the radial artery’s pressure pulse wave, along with various hemodynamic parameters, and to explore the possible underlying mechanism of pulse diagnosis in healthy participants in their twenties. Methods and analysis: This study is a prospective, si

  17. Allergic rhinitis and arterial blood pressure: a population-based study.

    Science.gov (United States)

    Sakallioglu, O; Polat, C; Akyigit, A; Cetiner, H; Duzer, S

    2018-05-01

    To investigate the likelihood of allergic rhinitis and potential co-morbidities, and to assess whether allergic rhinitis is associated with arterial blood pressure and hypertension. In this population-based study, 369 adults with allergic rhinitis and asthma were assessed via a questionnaire and immunoglobulin E levels. There were four groups: control (n = 90), allergic rhinitis (n = 99), asthma (n = 87) and hypertension (n = 93). Arterial blood pressure was measured in all groups. There were no significant differences in systolic or diastolic blood pressure between males and females in any group. Pairwise comparisons revealed no significant differences between: the control and allergic rhinitis groups, the control and asthma groups, or the allergic rhinitis and asthma groups. The systolic and diastolic blood pressure values of males and females were significantly higher in the hypertension group than the allergic rhinitis group. There were no significant differences in systolic blood pressure or diastolic blood pressure for seasonal and perennial allergic rhinitis patients. Rhinitis was not associated with increased blood pressure. Allergic rhinitis can coincide with asthma and hypertension. The findings do not support the need for blood pressure follow up in allergic rhinitis patients.

  18. Dorsalis pedis arterial pressure is lower than noninvasive arm blood pressure in normotensive patients under sevoflurane anesthesia.

    Science.gov (United States)

    Chen, Yan; Wang, Enqin; Zhu, Yuan; Li, Yongshuai; Lu, Kaizhi

    2016-02-01

    It is widely known that blood pressure (BP) in the lower extremity is higher than in the upper extremity. However, whether this phenomenon remains the same during general anesthesia is still unclear. This study aims to investigate the difference between invasive dorsalis pedis artery (DPA) pressure and the most commonly used noninvasive arm pressure during sevoflurane anesthesia. A total of 50 normotensive Chinese patients were enrolled in this observational study. Invasive DPA pressure, noninvasive arm pressure, and systemic vascular resistance index were assessed simultaneously. BP data during the entire surgery were analyzed through a Bland-Altman plot for repeated measures. The concordance of BP variation in the DPA and the arm was analyzed using four-quadrant plots and linear regression. The time-dependent changes in BP and the systemic vascular resistance index were also evaluated. Data from 46 effective cases were analyzed. Bias (95% limits of agreement) was -7.40 mmHg (-20.36 to +5.57 mmHg) for mean blood pressure, +3.54 mmHg (-20.32 to +27.41 mmHg) for systolic blood pressure, and -10.20 mmHg (-23.66 to +3.26 mmHg) for diastolic blood pressure, respectively. The concordance of BP variation at the two measurement sites was clinically acceptable. DPA pressure and vascular resistance in the lower limb decreased gradually during surgery. DPA pressure tends to be lower than arm pressure under sevoflurane anesthesia, especially the mean blood pressure and the diastolic blood pressure. Hence, noninvasive arm BP monitoring is recommend to be retained when invasive BP is measured at the DPA, so as to allow clinicians to comprehensively evaluate the BP condition of the patients and make appropriate therapeutic decisions.

  19. [Pedicled superior gluteal artery perforator bilateral quadrilobed flaps for repair of large sacrococcygeal pressure sores].

    Science.gov (United States)

    Hai, Henglin; Li, Huatao; Chen, Yang; Li, Qiang; Wu, Shenggang; Lili, Wang; Yan, Lei; Xiaoying, Zhou

    2013-03-01

    To investigate the effectiveness of pedicled superior gluteal artery perforator bilateral quadrilobed flaps for repairing large sacrococcygeal pressure sores. Between June 2003 and August 2011, 6 paraplegia patients with large sacrococcygeal pressure sores were repaired with the pedicled superior gluteal artery perforator bilateral quadrilobed flaps. There were 2 males and 4 females with an average age of 45.6 years (range, 37-62 years). The mean disease duration was 8.4 months (range, 3-26 months). According to National Pressure Ulcer Advisory Panel (NPUAP) standard, 6 cases rated as degree IV. The size of pressure sores ranged from 15 cm x 13 cm to 18 cm x 16 cm. The size of flaps ranged from 18 cm x 14 cm to 21 cm x 15 cm. After operation, all flaps survived successfully. The wounds healed by first intention in 5 cases; partial dehiscence of incision occurred in 1 case, which was cured after dressing change for 26 days. Six patients were followed up 6-24 months (mean, 12.5 months). The appearance and texture of the flaps were smooth and soft with good elasticity and no ulceration. Pedicled superior gluteal artery perforator bilateral quadrilobed flaps can repair large sacrococcygeal pressure sores. The appearance of flaps is smooth and has good compression-resistance effect.

  20. Treatment of ischial pressure sores with both profunda femoris artery perforator flaps and muscle flaps.

    Science.gov (United States)

    Kim, Chae Min; Yun, In Sik; Lee, Dong Won; Lew, Dae Hyun; Rah, Dong Kyun; Lee, Won Jai

    2014-07-01

    Reconstruction of ischial pressure sore defects is challenging due to extensive bursas and high recurrence rates. In this study, we simultaneously applied a muscle flap that covered the exposed ischium and large bursa with sufficient muscular volume and a profunda femoris artery perforator fasciocutaneous flap for the management of ischial pressure sores. We retrospectively analyzed data from 14 patients (16 ischial sores) whose ischial defects had been reconstructed using both a profunda femoris artery perforator flap and a muscle flap between January 2006 and February 2014. We compared patient characteristics, operative procedure, and clinical course. All flaps survived the entire follow-up period. Seven patients (50%) had a history of surgery at the site of the ischial pressure sore. The mean age of the patients included was 52.8 years (range, 18-85 years). The mean follow-up period was 27.9 months (range, 3-57 months). In two patients, a biceps femoris muscle flap was used, while a gracilis muscle flap was used in the remaining patients. In four cases (25%), wound dehiscence occurred, but healed without further complication after resuturing. Additionally, congestion occurred in one case (6%), but resolved with conservative treatment. Among 16 cases, there was only one (6%) recurrence at 34 months. The combination of a profunda femoris artery perforator fasciocutaneous flap and muscle flap for the treatment of ischial pressure sores provided pliability, adequate bulkiness and few long-term complications. Therefore, this may be used as an alternative treatment method for ischial pressure sores.

  1. Investigation Of Arterial Blood Pressure Level And Metabolic Indices In Patients With Arterial Hypertension At Pharmacotherapy With Antihypertensive Medicines Of Various Chemical Structure

    Directory of Open Access Journals (Sweden)

    G.Kh. Glybochko

    2009-12-01

    Full Text Available The research goal is to carry on the comparative analysis of medicines of various chemical structure, Telmisar-tan and Bisoprolol, and to reveal their effect on the arterial blood pressure level and the indices of various metabolic processes in patients with arterial hypertension. 60 out-patients with arterial hypertension (stage II risk III both males and females aged 33-55 have been under study taking Telmisartan and Bisoprolol for 3 months. While treating the patients the arterial blood pressure level control and biochemical investigations for determination the indices of metabolic processes have been carried out. The investigated medications have provided the decrease of systolic and diastolic arterial pressure parameters, the increase of concentration of total and ionized calcium, chlorine ions, urea and total bilirubin in blood plasma. Therapy with Telmisartan has shown more significant increase of potassium level in erythro-cytes, decrease of levels of natrium, glucose, glycolized hemoglobin and triglycerides and increased contents of alani-naminotransferase and aspartataminotransferase. The course of therapy with Bisoprolol has restored the normal level of magnesium in blood plasma, has not have any influence on carbohydrate and lipid metabolism, increased the level of alaninaminotransferase and significantly increased the contents of total and ionized calcium, urea and creatinine. 3-months therapy with Telmisartan and Bisoprolol has proved the decrease of systolic and diastolic arterial pressure in patients with arterial hypertension. The medications under study have had active and variable effects on metabolic indices

  2. PX-18 Protects Human Saphenous Vein Endothelial Cells under Arterial Blood Pressure.

    Science.gov (United States)

    Kupreishvili, Koba; Stooker, Wim; Emmens, Reindert W; Vonk, Alexander B A; Sipkens, Jessica A; van Dijk, Annemieke; Eijsman, Leon; Quax, Paul H; van Hinsbergh, Victor W M; Krijnen, Paul A J; Niessen, Hans W M

    2017-07-01

    Arterial blood pressure-induced shear stress causes endothelial cell apoptosis and inflammation in vein grafts after coronary artery bypass grafting. As the inflammatory protein type IIA secretory phospholipase A 2 (sPLA 2 -IIA) has been shown to progress atherosclerosis, we hypothesized a role for sPLA 2 -IIA herein. The effects of PX-18, an inhibitor of both sPLA 2 -IIA and apoptosis, on residual endothelium and the presence of sPLA 2 -IIA were studied in human saphenous vein segments (n = 6) perfused at arterial blood pressure with autologous blood for 6 hrs. The presence of PX-18 in the perfusion blood induced a significant 20% reduction in endothelial cell loss compared to veins perfused without PX18, coinciding with significantly reduced sPLA 2 -IIA levels in the media of the vein graft wall. In addition, PX-18 significantly attenuated caspase-3 activation in human umbilical vein endothelial cells subjected to shear stress via mechanical stretch independent of sPLA 2 -IIA. In conclusion, PX-18 protects saphenous vein endothelial cells from arterial blood pressure-induced death, possibly also independent of sPLA 2 -IIA inhibition. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Pressure profile and morphology of the arteries along the giraffe limb

    DEFF Research Database (Denmark)

    Østergaard, Kristine Hovkjær; Bertelsen, Mads Frost; Brøndum, Emil Toft

    2011-01-01

    Giraffes are the tallest animals on earth and the effects of gravity on their cardiovascular system have puzzled physiologists for centuries. The authors measured arterial and venous pressure in the foreleg of anesthetized giraffes, suspended in upright standing position, and determined the ratio......-fold higher innervation density than the immediate distal and proximal regions. The sudden narrowing was also observed in the hind legs of neonates, indicating that it does not develop as an adaptation to the high transmural pressure in the standing giraffe. More likely it represents a preadaptation...... to the high pressures experienced by adult giraffes....

  4. Arterial Blood Pressure Induces Transient C4b-Binding Protein in Human Saphenous Vein Grafts.

    Science.gov (United States)

    Kupreishvili, Koba; Meischl, Christof; Vonk, Alexander B A; Stooker, Wim; Eijsman, Leon; Blom, Anna M; Quax, Paul H A; van Hinsbergh, Victor W M; Niessen, Hans W M; Krijnen, Paul A J

    2017-05-01

    Complement is an important mediator in arterial blood pressure-induced vein graft failure. Previously, we noted activation of cell protective mechanisms in human saphenous veins too. Here we have analyzed whether C4b-binding protein (C4bp), an endogenous complement inhibitor, is present in the vein wall. Human saphenous vein segments obtained from patients undergoing coronary artery bypass grafting (n = 55) were perfused in vitro at arterial blood pressure with either autologous blood for 1, 2, 4, or 6 hr or with autologous blood supplemented with reactive oxygen species scavenger N-acetylcysteine. The segments were subsequently analyzed quantitatively for presence of C4bp and complement activation product C3d using immunohistochemistry. Perfusion induced deposition of C3d and C4bp within the media of the vessel wall, which increased reproducibly and significantly over a period of 4 hr up to 3.8% for C3d and 81% for C4bp of the total vessel area. Remarkably after 6 hr of perfusion, the C3d-positive area decreased significantly to 1.3% and the C4bp-positive area to 19% of the total area of the vein. The areas positive for both C4bp and C3d were increased in the presence of N-acetylcysteine. Exposure to arterial blood pressure leads to a transient presence of C4bp in the vein wall. This may be part of a cell-protective mechanism to counteract arterial blood pressure-induced cellular stress and inflammation in grafted veins. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Non-dipping blood pressure patterns and arterial stiffness parameters in patients with Behcet's disease.

    Science.gov (United States)

    Celik, Gulperi; Yilmaz, Sema; Ergulu Esmen, Serpil

    2015-12-01

    Behcet's disease is a multisystemic vasculitis involving veins and arteries of various sizes. Non-dipping status, augmentation index and pulse wave velocity are important determinants of cardiovascular mortality and morbidity. We investigated the non-dipping status and arterial stiffness in patients with Behcet's disease. In this cross-sectional study, we examined the vascular parameters of 96 patients with Behcet's disease (53% female) and 60 age- and sex-matched control subjects. The non-dipping status and arterial distensibility were assessed using a Mobil-O-Graph Arteriograph, an automatic oscillometric device. In total, 65.6% of 96 patients were systolic non-dippers, and 34.4% exhibited high augmentation indices. Ten percent of the control subjects were systolic non-dippers, and 11.7% exhibited high augmentation indices. Nocturnal decreases in systolic blood pressure correlated with central systolic blood pressure and diastolic blood pressure, as well as nocturnal decreases in diastolic blood pressure. Furthermore, non-dipper patients with Behcet's disease exhibited higher nocturnal cardiac outputs than did dipper patients with Behcet's disease. Augmentation index correlated negatively with C-reactive protein and correlated positively with both 24 h and nocturnal peripheral resistance, as well as 24 h pulse wave velocity. The patients with high augmentation indices exhibited lower creatinine clearance, as well as lower nocturnal cardiac outputs, higher 24 h peripheral resistance and higher 24 h pulse wave velocities. Non-dipping status and arterial stiffness may exacerbate the harmful cardiovascular effects of the other. In addition to conventional risk factors, non-dipping status and arterial stiffness should be examined during the follow-up evaluations of patients with Behcet's disease.

  6. Diagnostics of an AC driven atmospheric pressure non-thermal plasma jet and its use for radially directed jet array

    Science.gov (United States)

    Zhu, W.; Wang, R.

    2017-08-01

    An alternating current atmospheric pressure plasma jet is generated with noble gas or noble gas/oxygen admixture as working gas. A "core plasma filament" is observed at the center of the dielectric tube and extends to the plasma jet at higher peak-to-peak voltages. This type of plasma jet is believed to be of the same nature with the reported plasma bullet driven by pulsed DC power sources. Double current probes are used to assess the speed of the plasma bullet and show that the speed is around 104-105 m/s. The time dependence of the downstream bullet speed is attributed to the gas heating and in turn the increase of the reduced electric field E/N. Optical emission spectra show the dependence of helium and oxygen emission intensities on the concentration of oxygen additive in the carrier gas, with peak values found at 0.5% O2. Multiple radial jets are realized on dielectric tubes of different sizes. As a case study, one of these multi-jet devices is used to treat B. aureus on the inner surface of a plastic beaker and is shown to be more effective than a single jet.

  7. Pulmonary artery pulse pressure and wave reflection in chronic pulmonary thromboembolism and primary pulmonary hypertension.

    Science.gov (United States)

    Castelain, V; Hervé, P; Lecarpentier, Y; Duroux, P; Simonneau, G; Chemla, D

    2001-03-15

    The purpose of this time-domain study was to compare pulmonary artery (PA) pulse pressure and wave reflection in chronic pulmonary thromboembolism (CPTE) and primary pulmonary hypertension (PPH). Pulmonary artery pressure waveform analysis provides a simple and accurate estimation of right ventricular afterload in the time-domain. Chronic pulmonary thromboembolism and PPH are both responsible for severe pulmonary hypertension. Chronic pulmonary thromboembolism and PPH predominantly involve proximal and distal arteries, respectively, and may lead to differences in PA pressure waveform. High-fidelity PA pressure was recorded in 14 patients (7 men/7 women, 46 +/- 14 years) with CPTE (n = 7) and PPH (n = 7). We measured thermodilution cardiac output, mean PA pressure (MPAP), PA pulse pressure (PAPP = systolic - diastolic PAP) and normalized PAPP (nPAPP = PPAP/MPAP). Wave reflection was quantified by measuring Ti, that is, the time between pressure upstroke and the systolic inflection point (Pi), deltaP, that is, the systolic PAP minus Pi difference, and the augmentation index (deltaP/PPAP). At baseline, CPTE and PPH had similar cardiac index (2.4 +/- 0.4 vs. 2.5 +/- 0.5 l/min/m2), mean PAP (59 +/- 9 vs. 59 +/- 10 mm Hg), PPAP (57 +/- 13 vs. 53 +/- 13 mm Hg) and nPPAP (0.97 +/- 0.16 vs. 0.89 +/- 0.13). Chronic pulmonary thromboembolism had shorter Ti (90 +/- 17 vs. 126 +/- 16 ms, p PPAP (0.26 +/- 0.01 vs. 0.09 +/- 0.07, p < 0.01). Our study indicated that: 1) CPTE and PPH with severe pulmonary hypertension had similar PA pulse pressure, and 2) wave reflection is elevated in both groups, and CPTE had increased and anticipated wave reflection as compared with PPH, thus suggesting differences in the pulsatile component of right ventricular afterload.

  8. Evaluation of the monitor cursor-line method for measuring pulmonary artery and central venous pressures.

    Science.gov (United States)

    Pasion, Editha; Good, Levell; Tizon, Jisebelle; Krieger, Staci; O'Kier, Catherine; Taylor, Nicole; Johnson, Jennifer; Horton, Carrie M; Peterson, Mary

    2010-11-01

    To determine if the monitor cursor-line feature on bedside monitors is accurate for measuring central venous and pulmonary artery pressures in cardiac surgery patients. Central venous and pulmonary artery pressures were measured via 3 methods (end-expiratory graphic recording, monitor cursor-line display, and monitor digital display) in a convenience sample of postoperative cardiac surgery patients. Pressures were measured twice during both mechanical ventilation and spontaneous breathing. Analysis of variance was used to determine differences between measurement methods and the percentage of monitor pressures that differed by 4 mm Hg or more from the measurement obtained from the graphic recording. Significance level was set at P less than .05. Twenty-five patients were studied during mechanical ventilation (50 measurements) and 21 patients during spontaneous breathing (42 measurements). Measurements obtained via the 3 methods did not differ significantly for either type of pressure (P > .05). Graphically recorded pressures and measurements obtained via the monitor cursor-line or digital display methods differed by 4 mm Hg or more in 4% and 6% of measurements, respectively, during mechanical ventilation and 4% and 11%, respectively, during spontaneous breathing. The monitor cursor-line method for measuring central venous and pulmonary artery pressures may be a reasonable alternative to the end-expiratory graphic recording method in hemodynamically stable, postoperative cardiac surgery patients. Use of the digital display on the bedside monitor may result in larger discrepancies from the graphically recorded pressures than when the cursor-line method is used, particularly in spontaneously breathing patients.

  9. LB03.04: SPHYGMOMANOMETER CUFF CONSTRUCTION AND MATERIALS AFFECT TRANSMISSION OF PRESSURE FROM CUFF TO ARTERIAL WALL. FINITE ELEMENT ANALYSIS OF HUMAN PRESSURE MEASUREMENTS AND DICOM DATA.

    Science.gov (United States)

    Lewis, P; Naqvi, S; Mandal, P; Potluri, P

    2015-06-01

    Sphygmomanometer cuff pressure during deflation is assumed to equal systolic arterial pressure at the point of resumption of flow. Previous studies demonstrated that pressure decreases with increasing depth of soft tissues whilst visco-elastic characteristics of the arm tissue cause spatial and temporal variation in pressure magnitude. These generally used non-anatomical axisymmetrical arm simulations without incorporating arterial pressure variation. We used data from a volunteer's Magnetic Resonance (MR) arm scan and investigated the effect of variations in cuff materials and construction on the simulated transmission of pressure from under the cuff to the arterial wall under sinusoidal flow conditions. Pressure was measured under 8 different cuffs using Oxford Pressure Monitor Sensors placed at 90 degrees around the mid upper arm of a healthy male. Each cuff was inflated 3 times to 155 mmHg and then deflated to zero with 90 seconds between inflations. Young's modulus, flexural rigidity and thickness of each cuff was measured.Using DICOM data from the MR scan of the arm, a 3D model was derived using ScanIP and imported into Abaqus for Finite Element Analysis (FEA). Published mechanical properties of arm tissues and geometric non-linearity were assumed. The measured sub-cuff pressures were applied to the simulated arm and pressure was calculated around the brachial arterial wall. which was loaded with a sinusoidal pressure of 125/85 mmHg. FEA estimates of pressure around the brachial artery cuffs varied by up to 27 mmHg SBP and 17 mmHg DBP with different cuffs. Pressures within the cuffs varied up to 27 mmHg. Pressure transmission from the cuff to the arterial surface achieved a 95% transmission ratio with one rubber-bladdered cuff but varied between 76 and 88% for the others. Non-uniform pressure distribution around the arterial wall was strongly related to cuff fabric elastic modulus. Identical size cuffs with a separate rubber bladder produced peri-arterial

  10. Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

    International Nuclear Information System (INIS)

    Kyriacou, P A; Shafqat, K; Pal, S K

    2007-01-01

    Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO 2 ) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO 2 ) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO 2 sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures. Both pulse

  11. Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

    Energy Technology Data Exchange (ETDEWEB)

    Kyriacou, P A [School of Engineering and Mathematical Sciences, City University, London EC1V 0HB (United Kingdom); Shafqat, K [School of Engineering and Mathematical Sciences, City University, London EC1V 0HB (United Kingdom); Pal, S K [St Andrew' s Centre for Plastic Surgery and Burns, Broomfield Hospital, Chelmsford, CM1 7ET (United Kingdom)

    2007-10-15

    Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO{sub 2}) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO{sub 2}) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO{sub 2} sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures

  12. Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

    Science.gov (United States)

    Kyriacou, P. A.; Shafqat, K.; Pal, S. K.

    2007-10-01

    Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO2) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO2) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO2 sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures. Both pulse

  13. Flow-related Right Ventricular - Pulmonary Arterial Pressure Gradients during Exercise.

    Science.gov (United States)

    Wright, Stephen P; Opotowsky, Alexander R; Buchan, Tayler A; Esfandiari, Sam; Granton, John T; Goodman, Jack M; Mak, Susanna

    2018-06-06

    The assumption of equivalence between right ventricular and pulmonary arterial systolic pressure is fundamental to several assessments of right ventricular or pulmonary vascular hemodynamic function. Our aims were to 1) determine whether systolic pressure gradients develop across the right ventricular outflow tract in healthy adults during exercise, 2) examine the potential correlates of such gradients, and 3) consider the effect of such gradients on calculated indices of right ventricular function. Healthy untrained and endurance-trained adult volunteers were studied using right-heart catheterization at rest and during submaximal cycle ergometry. Right ventricular and pulmonary artery pressures were simultaneously transduced, and cardiac output was determined by thermodilution. Systolic pressures, peak and mean gradients, and indices of chamber, vascular, and valve function were analyzed offline. Summary data are reported as mean ± standard deviation or median [interquartile range]. No significant right ventricular outflow tract gradients were observed at rest (mean gradient = 4 [3-5] mmHg), and calculated effective orifice area was 3.6±1.0 cm2. Right ventricular systolic pressure increases during exercise were greater than that of pulmonary artery systolic pressure. Accordingly, mean gradients developed during light exercise (8 [7-9] mmHg) and increased during moderate exercise (12 [9-14] mmHg, p < 0.001). The magnitude of the mean gradient was linearly related to cardiac output (r2 = 0.70, p < 0.001). In healthy adults without pulmonic stenosis, systolic pressure gradients develop during exercise, and the magnitude is related to blood flow rate.

  14. Relationship between pre-extubation positive endexpiratory pressure and oxygenation after coronary artery bypass grafting

    Directory of Open Access Journals (Sweden)

    Reijane Oliveira Lima

    2015-08-01

    Full Text Available Abstract Introduction After removal of endotracheal tube and artificial ventilation, ventilatory support should be continued, offering oxygen supply to ensure an arterial oxygen saturation close to physiological. Objective: The aim of this study was to investigate the effects of positive-end expiratory pressure before extubation on the oxygenation indices of patients undergoing coronary artery bypass grafting. Methods: A randomized clinical trial with seventy-eight patients undergoing coronary artery bypass grafting divided into three groups and ventilated with different positive-end expiratory pressure levels prior to extubation: Group A, 5 cmH2O (n=32; Group B, 8 cmH2O (n=26; and Group C, 10 cmH2O (n=20. Oxygenation index data were obtained from arterial blood gas samples collected at 1, 3, and 6 h after extubation. Patients with chronic pulmonary disease and those who underwent off-pump, emergency, or combined surgeries were excluded. For statistical analysis, we used Shapiro-Wilk, G, Kruskal-Wallis, and analysis of variance tests and set the level of significance at P<0.05. Results Groups were homogenous with regard to demographic, clinical, and surgical variables. There were no statistically significant differences between groups in the first 6 h after extubation with regard to oxygenation indices and oxygen therapy utilization. Conclusion: In this sample of patients undergoing coronary artery bypass grafting, the use of different positive-end expiratory pressure levels before extubation did not affect gas exchange or oxygen therapy utilization in the first 6 h after endotracheal tube removal.

  15. Diastolic coronary artery pressure-flow velocity relationships in conscious man.

    Science.gov (United States)

    Dole, W P; Richards, K L; Hartley, C J; Alexander, G M; Campbell, A B; Bishop, V S

    1984-09-01

    We characterised the diastolic pressure-flow velocity relationship in the normal left coronary artery of conscious man before and after vasodilatation with angiographic contrast medium. Phasic coronary artery pressure and flow velocity were measured in ten patients during individual diastoles (0.5 to 1.0 s) using a 20 MHz catheter-tipped, pulsed Doppler transducer. All pressure-flow velocity curves were linear over the diastolic pressure range of 110 +/- 15 (SD) mmHg to 71 +/- 7 mmHg (r = 0.97 +/- 0.01). In the basal state, values for slope and extrapolated zero flow pressure intercept averaged 0.35 +/- 0.12 cm X s-1 X mmHg-1 and 51.7 +/- 8.6 mmHg, respectively. Vasodilatation resulted in a 2.5 +/- 0.5 fold increase in mean flow velocity. The diastolic pressure-flow velocity relationship obtained during peak vasodilatation compared to that during basal conditions was characterised by a steeper slope (0.80 +/- 0.48 cm X s-1 X mmHg-1, p less than 0.001) and lower extrapolated zero flow pressure intercept (37.9 +/- 9.8 mmHg, p less than 0.05). Mean right atrial pressure for the group averaged 4.4 +/- 1.7 mmHg, while left ventricular end-diastolic pressure averaged 8.7 +/- 2.8 mmHg. These observations in man are similar to data reported in the canine coronary circulation which are consistent with a vascular waterfall model of diastolic flow regulation. In this model, coronary blood flow may be regulated by changes in diastolic zero flow pressure as well as in coronary resistance.

  16. Computational study to investigate effect of tonometer geometry and patient-specific variability on radial artery tonometry.

    Science.gov (United States)

    Singh, Pranjal; Choudhury, Mohammed Ikbal; Roy, Sitikantha; Prasad, Anamika

    2017-06-14

    Tonometry-based devices are valuable method for vascular function assessment and for measurement of blood pressure. However current design and calibration methods rely on simple models, neglecting key geometrical features, and anthropometric and property variability among patients. Understanding impact of these influences on tonometer measurement is thus essential for improving outcomes of current devices, and for proposing improved design. Towards this goal, we present a realistic computational model for tissue-device interaction using complete wrist section with hyperelastic material and frictional contact. Three different tonometry geometries were considered including a new design, and patient-specific influences incorporated via anthropometric and age-dependent tissue stiffness variations. The results indicated that the new design showed stable surface contact stress with minimum influence of the parameters analyzed. The computational predictions were validated with experimental data from a prototype based on the new design. Finally, we showed that the underlying mechanics of vascular unloading in tonometry to be fundamentally different from that of oscillatory method. Due to directional loading in tonometry, pulse amplitude maxima was observed to occur at a significantly lower compression level (around 31%) than previously reported, which can impact blood pressure calibration approaches based on maximum pulse pressure recordings. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Noninvasive estimation of pulmonary arterial pressure by analysis of pulmonary blood-flow distribution

    International Nuclear Information System (INIS)

    Konstam, M.A.; Strauss, H.W.; Alpert, N.M.; Miller, S.W.; Murphy, R.X.; Greene, R.E.; McKusick, K.A.

    1979-01-01

    To determine whether a correlation exists between pulmonary arterial (PA) pressure (P/sub a/) and the distribution of pulmonary blood flow, this distribution was measured in four upright dogs in the control state and during intravenous infusions of epinephrine or prostaglandin F/sub 2α/. During suspension of respiration, 15 mCi of Xe-133 were injected intravenously, and perfusion and equilibration lung images were recorded with a scintillation camera. The procedure was performed several times on each dog, with and without pharmacological elevation of PA pressure by 5 to 50 cm H 2 O. For each scintigram, the relative blood flow per unit ventilated lung volume (F) was plotted against centimeters above the hilum (h). Pulmonary arterial pressure was derived from each curve, assuming the relation F = B(P/sub a/ - hD) 2 , where B = constant and D = specific gravity of blood. Calculated PA pressure correlated strongly (r = 0.83) with measured PA pressure, suggesting a possible means of noninvasive estimation of PA pressure

  18. Contribution of the Arterial System and the Heart to Blood Pressure during Normal Aging - A Simulation Study.

    Science.gov (United States)

    Maksuti, Elira; Westerhof, Nico; Westerhof, Berend E; Broomé, Michael; Stergiopulos, Nikos

    2016-01-01

    During aging, systolic blood pressure continuously increases over time, whereas diastolic pressure first increases and then slightly decreases after middle age. These pressure changes are usually explained by changes of the arterial system alone (increase in arterial stiffness and vascular resistance). However, we hypothesise that the heart contributes to the age-related blood pressure progression as well. In the present study we quantified the blood pressure changes in normal aging by using a Windkessel model for the arterial system and the time-varying elastance model for the heart, and compared the simulation results with data from the Framingham Heart Study. Parameters representing arterial changes (resistance and stiffness) during aging were based on literature values, whereas parameters representing cardiac changes were computed through physiological rules (compensated hypertrophy and preservation of end-diastolic volume). When taking into account arterial changes only, the systolic and diastolic pressure did not agree well with the population data. Between 20 and 80 years, systolic pressure increased from 100 to 122 mmHg, and diastolic pressure decreased from 76 to 55 mmHg. When taking cardiac adaptations into account as well, systolic and diastolic pressure increased from 100 to 151 mmHg and decreased from 76 to 69 mmHg, respectively. Our results show that not only the arterial system, but also the heart, contributes to the changes in blood pressure during aging. The changes in arterial properties initiate a systolic pressure increase, which in turn initiates a cardiac remodelling process that further augments systolic pressure and mitigates the decrease in diastolic pressure.

  19. COMPARISON OF HIGH-DEFINITION OSCILLOMETRIC AND DIRECT ARTERIAL BLOOD PRESSURE MEASUREMENT IN ANESTHETIZED CHEETAHS (ACINONYX JUBATUS).

    Science.gov (United States)

    Sant Cassia, Emma V; Boswood, Adrian; Tordiffe, Adrian S W

    2015-09-01

    Blood pressure measurement reveals important insights into the health of conscious and anesthetized individuals. This is of particular interest in cheetahs (Acinonyx jubatus), which in captivity are known to suffer from chronic diseases that may be associated with hypertension and which often require immobilization for transport or veterinary treatment. Invasive testing methods are considered the gold standard but are not practical in many settings. Consequently, it is important to evaluate the use of noninvasive methods in this species. Measurements for systolic, diastolic, and mean arterial pressure obtained using high-definition oscillometry (HDO) at the coccygeal artery were compared to simultaneous direct measurements obtained via catheterization of the femoral or dorsal pedal artery in eight anesthetized captive cheetahs during nine anesthetic events. Overall, HDO and direct measurements agreed most closely for mean arterial pressure, and the poorest agreement was observed for systolic pressure. There was a tendency for low diastolic pressures to be underestimated and for high diastolic pressures to be overestimated. Across all three parameters, HDO measurements from the tail overestimated directly measured pressures in the femoral artery and underestimated those in the dorsal pedal artery. HDO agreed most closely with directly measured dorsal pedal pressures. Mean arterial pressure showed the greatest precision (standard deviation of 10.2 mm Hg) and lowest bias (-1.2 mm Hg), with 75.9% of readings within 10 mm Hg of the direct dorsal pedal pressure. Agreement with systolic pressure was hindered by a high bias (-10.4 mm Hg), but if a correction factor of +10 mm Hg was applied to all systolic measurements, agreement was improved and 65.7% of readings were within 10 mm Hg of the direct pressure. When compared to criteria defined by the American College of Veterinary Internal Medicine for validation of blood pressure devices, results were favorable, but a

  20. A theoretical description of arterial pressure-flow relationships with verification in the isolated hindlimb of the dog.

    Science.gov (United States)

    Jackman, A P; Green, J F

    1990-01-01

    We developed and tested a new two-compartment serial model of the arterial vasculature which unifies the capacitance (downstream arterial compliance) and waterfall (constant downstream pressure load) theories of blood flow through the arteries. In this model, blood drains from an upstream compliance through a resistance into a downstream compliance which empties into the veins through a downstream resistance which terminates in a constant pressure load. Using transient arterial pressure data obtained from an isolated canine hindlimb preparation, we tested this model, using a stop-flow technique. Numerical parameter estimation techniques were used to estimate the physiologic parameters of the model. The downstream compliance was found to be more than ten times larger than the upstream compliance and the constant pressure load was significantly above venous pressures but decreased in response to vasodilation. Our results support the applicability of both the capacitance and waterfall theories.

  1. [The heart catheter table is not the operating table : Intraindividual comparison of pulmonary artery pressures].

    Science.gov (United States)

    Ziegler, M U; Reinelt, H

    2018-05-01

    Patients undergoing cardiac surgery need extensive and invasive monitoring, which needs to be individually adapted for each patient and requires a diligent risk-benefit analysis. The use of a pulmonary artery catheter (PAC) seems to be justifiable in certain cases; therefore, the preoperative diagnosis of pulmonary hypertension represents an indication for perioperative monitoring with PAC in the S3 guidelines of the German Society for Anesthesiology and Intensive Care Medicine (DGAI). In many cases, however, this preoperative diagnosis cannot be confirmed intraoperatively. We wanted to find out whether this is just an impression or whether there actually are significant differences between preoperative, intraoperative and postoperative pulmonary artery pressures. After obtaining ethical approval, we retrospectively compared the pulmonary pressures of cardiac surgery patients with an elevated pulmonary pressure during preoperative right heart catheterization with those obtained intraoperatively and postoperatively by means of a PAC. All patients with a preoperatively documented pulmonary artery pressure of 40 mmHg or above and an intraoperative use of a PAC during a 4-year period were included. Exclusion criteria were intracardiac shunts, cardiogenic shock, emergency procedures, pulmonary hypertension of non-cardiac origin and a time span of more than 1 year between right heart catheterization and surgery. We included 90 patients. In the whole group and in the subgroups (according to diagnosis, time elapsed between heart catheterization and operation and pulmonary pressure), there were significant differences between preoperative and intraoperative pulmonary and systemic pressures. Systemic and pulmonary artery pressures were significantly higher during preoperative catheterization than intraoperatively. The systemic systolic pressure/systolic pulmonary pressure ratio, however, remained constant. The intraoperative and postoperative systemic and pulmonary

  2. Coronary artery assessment using self-navigated free-breathing radial whole-heart magnetic resonance angiography in patients with congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, Moritz H. [Medical University of South Carolina, Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Varga-Szemes, Akos; Schoepf, U.J.; Xu, Jiaqian; Jin, Kwang-Nam; Hlavacek, Anthony M.; Chowdhury, Shahryar M.; Suranyi, Pal; Tesche, Christian; De Cecco, Carlo N.; Nutting, Arni [Medical University of South Carolina, Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Charleston, SC (United States); Apfaltrer, Georg [Medical University of South Carolina, Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Charleston, SC (United States); University Hospital Graz, Department of Radiology, Graz (Austria); Piccini, Davide [University Hospital of Lausanne (CHUV), Department of Radiology, Centre for Biomedical Imaging (CIBM), Lausanne (Switzerland); Siemens Healthcare, IM BM PI, Advanced Clinical Imaging Technology, Lausanne (Switzerland); Stuber, Matthias; Ginami, Giulia [University Hospital of Lausanne (CHUV), Department of Radiology, Centre for Biomedical Imaging (CIBM), Lausanne (Switzerland); Vogl, Thomas J. [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany)

    2018-03-15

    To evaluate a self-navigated free-breathing three-dimensional (SNFB3D) radial whole-heart MRA technique for assessment of main coronary arteries (CAs) and side branches in patients with congenital heart disease (CHD). SNFB3D-MRA datasets of 109 patients (20.1±11.8 years) were included. Three readers assessed the depiction of CA segments, diagnostic confidence in determining CA dominance, overall image quality and the ability to freeze cardiac and respiratory motion. Vessel sharpness was quantitatively measured. The percentages of cases with excellent CA depiction were as follows (mean score): left main, 92.6 % (1.92); left anterior descending (LAD), 88.3 % (1.88); right (RCA), 87.8 % (1.85); left circumflex, 82.8 % (1.82); posterior descending, 50.2 % (1.50) and first diagonal, 39.8 % (1.39). High diagnostic confidence for the assessment of CA dominance was achieved in 56.2 % of MRA examinations (mean score, 1.56). Cardiac motion freezing (mean score, 2.18; Pearson's r=0.73, P<0.029) affected image quality more than respiratory motion freezing (mean score, 2.20; r=0.58, P<0.029). Mean quantitative vessel sharpness of the internal thoracic artery, RCA and LAD were 53.1, 52.5 and 48.7 %, respectively. Most SNFB3D-MRA examinations allow for excellent depiction of the main CAs in young CHD patients; visualisation of side branches remains limited. (orig.)

  3. Pulmonary artery occlusion pressure estimation by transesophageal echocardiography: is simpler better?

    Science.gov (United States)

    Voga, Gorazd

    2008-01-01

    The measurement of pulmonary artery occlusion pressure (PAOP) is important for estimation of left ventricular filling pressure and for distinction between cardiac and non-cardiac etiology of pulmonary edema. Clinical assessment of PAOP, which relies on physical signs of pulmonary congestion, is uncertain. Reliable PAOP measurement can be performed by pulmonary artery catheter, but it is possible also by the use of echocardiography. Several Doppler variables show acceptable correlation with PAOP and can be used for its estimation in cardiac and critically ill patients. Noninvasive PAOP estimation should probably become an integral part of transthoracic and transesophageal echocardiographic evaluation in critically ill patients. However, the limitations of both methods should be taken into consideration, and in specific patients invasive PAOP measurement is still unavoidable, if the exact value of PAOP is needed.

  4. Does mean arterial blood pressure scale with body mass in mammals?

    DEFF Research Database (Denmark)

    Poulsen, C B; Wang, T; Assersen, K

    2018-01-01

    For at least the last 30 years, it has been discussed whether mean arterial blood pressure (MAP) is independent of body mass or whether it increases in accordance with the vertical height between the heart and the brain. The debate has centred on the most appropriate mathematical models for analy......For at least the last 30 years, it has been discussed whether mean arterial blood pressure (MAP) is independent of body mass or whether it increases in accordance with the vertical height between the heart and the brain. The debate has centred on the most appropriate mathematical models......-Altman analysis showed a bias of 1 mm Hg with 95% confidence interval (from -35 to 36 mm Hg); that is, the limits of agreement between radiotelemetric studies and studies in restrained animals were double the supposed difference in the MAP between the mouse and elephant. In conclusion, the existing literature...

  5. Fourier Analysis of Peripheral Blood Pressure and Flow in Intraoperative Assessment of Infrainguinal Arterial Reconstructions

    Directory of Open Access Journals (Sweden)

    Cheshmedzhiev Mihail V.

    2014-08-01

    Full Text Available AIM: To assess infrainguinal arterial reconstructions by intraoperative flowmetry under the distal anastomosis using a fast Fourier transformation; calculate and compare the amplitude ratios of peripheral arterial blood pressure and volume flow before and after drug-induced vasodilation of occluded bypass grafts and bypass grafts that have been patent at least for 1 year. To find what magnitude of the change of these ratios indicate a long-term patency of the bypass grafting. PATIENTS AND METHODS: We compared the results of the intraoperative flowmetry tests of 97 patients with infrainguinal arterial reconstructions. The patients were divided into two groups based on the graft status: the grafts in 49 patients were patent for at least a year, and 48 patients had failed bypass. We used a fast Fourier transform (FFT of the pressure and blood flow waves and compared the ratios of their amplitudes before and after administration of a vasodilator drug into the graft. Comparing the ratios obtained before and those after administration of the drug we quantified their change in each group and analysed them. RESULTS: After a drug-induced vasodilation, the blood pressure and flow amplitude ratios for the group with compromised reconstructions were less than 1.9 times smaller than those before drug infusion, while for the group with bypass grafts that had been functional for at least 12 months the ratios declined by more than 1.9≈2 times. CONCLUSION: The magnitude of the change of amplitude ratios of the peripheral pressure and volume flow after drug-induced vasodilation can be used to make an assessment of the bypass graft and the distal arterial segment.

  6. Cardiac index and pulmonary arterial blood pressure during exercise in cases of suspected latent heart failure

    International Nuclear Information System (INIS)

    Agapov, A.A.; Berzak, N.V.; Vladimirov, S.S.

    1987-01-01

    The results studying hemodynamics during maximum physical load (veloeriometry when sitting) for 24 patients examined to avoid heart failure are presented. 19 patients were subjected to coronaroangiography and contrast ventriculography, and 12 patients - to myocardium scintigraphy with 99m Tc-pyrophosphate. It is shown that registration of diaslotic pressure in a pulmonary artery and in a cardiac index permits to diagnose failure in the miocardic function of patients with different heart diseases

  7. Determining the Arterial Blood Pressure of People Living in Yesilyurt Local Healthcare Office

    Directory of Open Access Journals (Sweden)

    Feyza Dereli

    2009-02-01

    Full Text Available AIM: Whereas the prevalance of arterial blood pressure which was a chronical health problem was 20%-25% among 30 year-old people, them showing an increase in aging, the percentage went as high as 50% in 60’s and later ages. What was that worrisome was that despite the high prevalance, only half of these received treathment. This is study was descriptively and cross-sectionally planned to determine whether the people asking their tensions to be measured in and around the Yesilyurt local healthcare office region. METHODS: The environment of the research consisted of 1400 people over 35 age and registered Yesilyurt Local healthcare Office and the whole of the environment were included in this sample. The study was conducted over 340 voluntaries. The data was collected by a questionnaire of 14 questions containing socio-demografic features and by measuring the arterial blood pressure, height and weight of the individuals. In the evaluation of the data, chi-square test was used and the level of significantly was accepted as 0.05. RESULTS: In this study, the rate of high sistolic blood pressure was found to be 21.47% and the rate of high diastolic blood pressure to be 8.23%. It was determined that age and body mass index varrieties were effective on sistolic hipertension. It was also found that in their behaviors of the use of hypertensive medicine, of regular arterial pressure controls and of having the hypertesion diagnosis significant differnces varied statistically on both sistolic and diastolic blood pressure people having. CONCLUSION: In order to improve the health, informative information abouth hypertension was provided for the participants for too days consisting of 4 sessions. [TAF Prev Med Bull 2009; 8(1.000: 53-58

  8. EFFECT OF LISINOPRIL ON 24-HOUR BLOOD PRESSURE AND ARTERIAL STIFFNESS IN PATIENTS WITH ARTERIAL HYPERTENSION AND RHEUMATOID ARTHRITIS

    Directory of Open Access Journals (Sweden)

    O. L. Sarkisova

    2017-01-01

    Full Text Available Aim. To study effect of 24-week treatment with lisinopril on blood pressure (BP and arterial stiffness in patients with arterial hypertension (HT and rheumatoid arthritis (RA.Material and methods. Twenty patients with essential HT grade  1-2 and RA (mean age 60.2±7.9 years were treated with lisinoprilin 24 weeks in open controlled study. Office blood pressure (BP was 147.2±9.4/87.5±8.6 mm Hg; 24-h mean  BP – 141.8±9.3/82.2±9.6 mm Hg; HT duration was 14.5±9.4 years, and RA duration – 12.3±2.6 years. A high incidence of traditional cardiovascular risk factors was identified: 95% of patients had dyslipidaemia, 45% – obesity, 35% – impaired glucose tolerance. Atherosclerosis of carotid arteries with stenosis less than 25% was diagnosed in 65% of patients. Most patients had a positive rheumatoid factor and cyclic citrullinated peptide antibodies, as well as moderate RA activity and III-IV radiologic stage of RA. All patients received methotrexate as the basic anti-inflammatory drug, 12 (60% patients – selective cyclooxygenase-2 inhibitors, 6 (30% patients took corticosteroids equivalent to prednisolone 7.5±5.5 mg per day. Mean  dose  of lisinopril was 12.2±9.8 mg/day. Office BP measurements, 24-hour ambulatory BP monitoring (ABPM, and  arterial stiffness evaluation were  performed initially and  at the end of the study. Arterial stiffness was assessed by cardio-ankle vascular index on the right (R-CAVI and on the left (L-CAVI.Results. After 24-week therapy with lisinopril office systolic and diastolic BP significantly decreased by 16.0±7.2/11.6±9.1 mm Hg (p<0.0001 and 11.6±9.1 mm Hg (p<0.0001, respectively. The target BP was achieved in 16 (83% patients. According to the ABPM 24-week therapy with lisino pril led to a significant (p<0.002 decrease in BP for all referable periods: by 12.4±9.1/7.6±3.9 mm Hg within 24 hours;  by 13.4±10.1/8.0±6.1 mm Hg for daytime; by 10.1±9.3/7.3±6.3 mm Hg for night-time. After

  9. Ischemic preconditioning of the lower extremity attenuates the normal hypoxic increase in pulmonary artery systolic pressure.

    Science.gov (United States)

    Foster, Gary P; Westerdahl, Daniel E; Foster, Laura A; Hsu, Jeffrey V; Anholm, James D

    2011-12-15

    Ischemic pre-condition of an extremity (IPC) induces effects on local and remote tissues that are protective against ischemic injury. To test the effects of IPC on the normal hypoxic increase in pulmonary pressures and exercise performance, 8 amateur cyclists were evaluated under normoxia and hypoxia (13% F(I)O(2)) in a randomized cross-over trial. IPC was induced using an arterial occlusive cuff to one thigh for 5 min followed by deflation for 5 min for 4 cycles. In the control condition, the resting pulmonary artery systolic pressure (PASP) increased from a normoxic value of 25.6±2.3 mmHg to 41.8±7.2 mmHg following 90 min of hypoxia. In the IPC condition, the PASP increased to only 32.4±3.1 mmHg following hypoxia, representing a 72.8% attenuation (p=0.003). No significant difference was detected in cycle ergometer time trial duration between control and IPC conditions with either normoxia or hypoxia. IPC administered prior to hypoxic exposure was associated with profound attenuation of the normal hypoxic increase of pulmonary artery systolic pressure. Published by Elsevier B.V.

  10. Heel ulcers - Pressure ulcers or symptoms of peripheral arterial disease? An exploratory matched case control study.

    Science.gov (United States)

    Twilley, Heidi; Jones, Sarahjane

    2016-05-01

    To investigate the relationship between pressure ulcers of the heel and peripheral arterial disease (PAD) and determine the feasibility of conducting a statistically powered matched case control study. Evidence indicates a relationship between chronic leg ulcers and vascular disease. The relationship between pressure ulcers of the heel and vascular disease is less well established. A matched case control study. Data were collected between March 2014 and January 2015. 15 patients identified as having a grade 2, 3 or 4 pressure ulcer of the heel were compared with 15 matched controls without pressure ulcers of the heel. The primary clinical outcome measure was the ankle brachial pressure index (ABPI), where an ABPI 1.3 was considered clinically indicative of PAD. The primary feasibility outcome measure was the rate of recruitment. Eighty seven patients were reported as having foot and heel ulcers; 36 of whom were identified as having pressure ulcers of the heel, 15 (42%) of whom were recruited to the study. Patients presenting with pressure ulcers of the heel were significantly more likely to simultaneously have previously undiagnosed PAD compared with age, gender and ethnicity matched controls without pressure ulcers of the heel (odds ratio: 11, 95% confidence interval 1.99-60.57). The formation of pressure ulcers of the heel could, in some patients, be related to the presence of PAD rather than a consequence of poor quality care. Healthcare professionals should assess the patient to exclude or confirm PAD. Copyright © 2016 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

  11. Oscillometric blood pressure measurement: a simple method in screening for peripheral arterial disease

    DEFF Research Database (Denmark)

    Mehlsen, Jesper; Wiinberg, Niels; Bruce, Christopher

    2008-01-01

    Blood pressure at the ankle level is a reliable indicator of peripheral arterial disease (PAD) and the ankle brachial index (ABI) is a useful non-invasive screening tool for the early detection of atherosclerosis. In the first part of the study, systolic blood pressures obtained by oscillometry...... of PAD was sufficiently high in subjects over the age of 60 years to warrant screening. The ankle brachial index based on measurements with an oscillometric device was shown reliable in the exclusion of PAD, thereby fulfilling an important criterion for the use in screening....

  12. Effects of two newly synthesized analogues of lidocaine on rat arterial blood pressure and heart rate.

    Science.gov (United States)

    Al Rasheed, N M; Al Sayed, M I; Al Zuhair, H H; Al Obaid, A R; Fatani, A J

    2001-04-01

    Two new analogues of lidocaine were synthesized at the College of Pharmacy, King Saud University: compound I (Methyl-2-[2-(N,N-diethylamino) acetamido]-3-cyano-4,5-dimethylbenzoate) and compound II (Methyl-2-[2-(piperidino) acetamido]-3-cyano-4,5-dimethylbenzoate). Their influence on the arterial blood pressure and the heart rate of urethane-anaesthetized rats was studied and compared with the actions of lidocaine. Compounds I, II and lidocaine induced significant dose-dependent decreases in the arterial blood pressure and heart rate, which usually returned to basal values within 3-5 min. There were significant differences in the potency of the three compounds in producing their effects on blood pressure and heart rate (Plidocaine and compound I, respectively. The results of this study also indicated the ineffectiveness of antagonists of autonomic, histaminergic and 5-HT receptor, and various vasodilators in blocking the actions of the three compounds on blood pressure and heart rate. Pretreatment with CaCl(2)significantly reduced the hypotension and bradycardia induced by the three compounds, suggesting the involvement of calcium channels, probably of the L type. Several possible mechanisms are postulated. In conclusion, the results direct attention to the capability of the two new compounds to decrease blood pressure and heart rate; affects that may have clinical potential. Copyright 2001 Academic Press.

  13. Radial nerve dysfunction (image)

    Science.gov (United States)

    The radial nerve travels down the arm and supplies movement to the triceps muscle at the back of the upper arm. ... the wrist and hand. The usual causes of nerve dysfunction are direct trauma, prolonged pressure on the ...

  14. Value of duplex scanning compared with angiography and pressure measurement in the assessment of aortoiliac arterial lesions

    NARCIS (Netherlands)

    Legemate, D. A.; Teeuwen, C.; Hoeneveld, H.; Eikelboom, B. C.

    1991-01-01

    To detect haemodynamically significant lesions in the aortoiliac arteries, invasive tests such as angiography and intra-arterial pressure measurement (IAPM) are considered valuable diagnostic tools. The value of duplex scanning as a direct non-invasive examination technique was prospectively

  15. C1-esterase inhibitor protects against early vein graft remodeling under arterial blood pressure.

    Science.gov (United States)

    Krijnen, Paul A J; Kupreishvili, Koba; de Vries, Margreet R; Schepers, Abbey; Stooker, Wim; Vonk, Alexander B A; Eijsman, Leon; Van Hinsbergh, Victor W M; Zeerleder, Sacha; Wouters, Diana; van Ham, Marieke; Quax, Paul H A; Niessen, Hans W M

    2012-01-01

    Arterial pressure induced vein graft injury can result in endothelial loss, accelerated atherosclerosis and vein graft failure. Inflammation, including complement activation, is assumed to play a pivotal role herein. Here, we analyzed the effects of C1-esterase inhibitor (C1inh) on early vein graft remodeling. Human saphenous vein graft segments (n=8) were perfused in vitro with autologous blood either supplemented or not with purified human C1inh at arterial pressure for 6h. The vein segments and perfusion blood were analyzed for cell damage and complement activation. In addition, the effect of purified C1inh on vein graft remodeling was analyzed in vivo in atherosclerotic C57Bl6/ApoE3 Leiden mice, wherein donor caval veins were interpositioned in the common carotid artery. Application of C1inh in the in vitro perfusion model resulted in significantly higher blood levels and significantly more depositions of C1inh in the vein wall. This coincided with a significant reduction in endothelial loss and deposition of C3d and C4d in the vein wall, especially in the circular layer, compared to vein segments perfused without supplemented C1inh. Administration of purified C1inh significantly inhibited vein graft intimal thickening in vivo in atherosclerotic C57Bl6/ApoE3 Leiden mice, wherein donor caval veins were interpositioned in the common carotid artery. C1inh significantly protects against early vein graft remodeling, including loss of endothelium and intimal thickening. These data suggest that it may be worth considering its use in patients undergoing coronary artery bypass grafting. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  16. Integration of a capacitive pressure sensing system into the outer catheter wall for coronary artery FFR measurements

    Science.gov (United States)

    Stam, Frank; Kuisma, Heikki; Gao, Feng; Saarilahti, Jaakko; Gomes Martins, David; Kärkkäinen, Anu; Marrinan, Brendan; Pintal, Sebastian

    2017-05-01

    The deadliest disease in the world is coronary artery disease (CAD), which is related to a narrowing (stenosis) of blood vessels due to fatty deposits, plaque, on the arterial walls. The level of stenosis in the coronary arteries can be assessed by Fractional Flow Reserve (FFR) measurements. This involves determining the ratio between the maximum achievable blood flow in a diseased coronary artery and the theoretical maximum flow in a normal coronary artery. The blood flow is represented by a pressure drop, thus a pressure wire or pressure sensor integrated in a catheter can be used to calculate the ratio between the coronary pressure distal to the stenosis and the normal coronary pressure. A 2 Fr (0.67mm) outer diameter catheter was used, which required a high level of microelectronics miniaturisation to fit a pressure sensing system into the outer wall. The catheter has an eccentric guidewire lumen with a diameter of 0.43mm, which implies that the thickest catheter wall section provides less than 210 microns height for flex assembly integration consisting of two dies, a capacitive MEMS pressure sensor and an ASIC. In order to achieve this a very thin circuit flex was used, and the two chips were thinned down to 75 microns and flip chip mounted face down on the flex. Many challenges were involved in obtaining a flex layout that could wrap into a small tube without getting the dies damaged, while still maintaining enough flexibility for the catheter to navigate the arterial system.

  17. Treatment of Ischial Pressure Sores with Both Profunda Femoris Artery Perforator Flaps and Muscle Flaps

    Directory of Open Access Journals (Sweden)

    Chae Min Kim

    2014-07-01

    Full Text Available Background Reconstruction of ischial pressure sore defects is challenging due to extensive bursas and high recurrence rates. In this study, we simultaneously applied a muscle flap that covered the exposed ischium and large bursa with sufficient muscular volume and a profunda femoris artery perforator fasciocutaneous flap for the management of ischial pressure sores. Methods We retrospectively analyzed data from 14 patients (16 ischial sores whose ischial defects had been reconstructed using both a profunda femoris artery perforator flap and a muscle flap between January 2006 and February 2014. We compared patient characteristics, operative procedure, and clinical course. Results All flaps survived the entire follow-up period. Seven patients (50% had a history of surgery at the site of the ischial pressure sore. The mean age of the patients included was 52.8 years (range, 18-85 years. The mean follow-up period was 27.9 months (range, 3-57 months. In two patients, a biceps femoris muscle flap was used, while a gracilis muscle flap was used in the remaining patients. In four cases (25%, wound dehiscence occurred, but healed without further complication after resuturing. Additionally, congestion occurred in one case (6%, but resolved with conservative treatment. Among 16 cases, there was only one (6% recurrence at 34 months. Conclusions The combination of a profunda femoris artery perforator fasciocutaneous flap and muscle flap for the treatment of ischial pressure sores provided pliability, adequate bulkiness and few long-term complications. Therefore, this may be used as an alternative treatment method for ischial pressure sores.

  18. [Influence of Sympathetic Denervation of the Renal Artery on the Level of Arterial Blood Pressure, Cerebral Blood Flow and Cognitive Function In Patients With Resistant Arterial Hypertension].

    Science.gov (United States)

    Efimova, Y N; Lichikaki, A V; Lishmanov, B Y

    2017-07-01

    To study the effect of radiofrequency ablation of renal arteries on regional cerebral blood flow and cognitive function in patients with resistant arterial hypertension (AH). Transcatheter renal denervation (TRD) was performed in 17 patients with resistant AH. Examination before and after TRD included SPECT with mTc-HMPAO, 24-hours blood pressure (BP) monitoring, and comprehensive neuropsychological testing. Fifteen patients without angiographic signs of carotid atherosclerosis, coronary artery disease and AH, neurological and psychiatric disorders were investigated as control group. Compared with control group patients with AH had decreases of regional cerebral blood flow (rCBF) in right (by 13.5%, p=0.00002) and left (by 15.5%, p=0.0006) inferior frontal lobes, in right temporal brain region (by 11.5%, p=0.008); in right and left occipital lobes (by 8.2%, p=0.04). In 6 months after TRD we observed significant improvement of cognitive function, parameters of 24-hour BP monitoring, and rCBF. We also noted definite close interdependence between changes of rCBF, indices of 24-hours BP monitoring, and dynamics of cognitive function. Improvement of long-term verbal memory correlated with increases of rCBF in left superior frontal and right occipital regions while dynamics of mentation and attention correlated positively with augmentation of rCBF in right posterior parietal region. Changes of perfusion in inferior parts of left frontal lobe and in right occipital region correlated with dynamics of index of diurnal diastolic hypertension time (R2=0.64, p=0.001, and R2=0.60, p=0.03, respectively). Our results suggest, that in patients with resistant AH positive effect of TRD on levels of 24-hour mean BP as well as on indices of BP load leads to in augmentation of rCBF and improvement of cognitive function.

  19. Impact of mean arterial pressure on sublingual microcirculation during cardiopulmonary bypass - secondary outcome from a randomised clinical trial

    DEFF Research Database (Denmark)

    Holmgaard, Frederik; Vedel, Anne G; Ravn, Hanne Berg

    2018-01-01

    . METHODS: Thirty-six cardiac surgery patients undergoing coronary artery bypass grafting were included and randomised to either low (40-50 mmHg) or high (70-80 mmHg) mean arterial pressure during cardiopulmonary bypass. Sidestream Dark Field video images were recorded from the sublingual mucosa. Recordings...... were analysed in a blinded fashion to quantify microcirculatory variables. RESULTS: Mean arterial pressure during cardiopulmonary bypass in the low target group was 45.0 mmHg (SD 5.3) vs. 67.2 mmHg (SD 8.9) in the high target group. We found no significant difference between the two groups......OBJECTIVE: In this substudy of a randomised, clinical trial, we explored the sublingual microcirculation during cardiac surgery at two different levels of blood pressure. We hypothesised that a higher mean arterial pressure during cardiopulmonary bypass would cause higher Microvascular Flow Index...

  20. Pulmonary artery pressure increases during commercial air travel in healthy passengers.

    Science.gov (United States)

    Smith, Thomas G; Talbot, Nick P; Chang, Rae W; Wilkinson, Elizabeth; Nickol, Annabel H; Newman, David G; Robbins, Peter A; Dorrington, Keith L

    2012-07-01

    It is not known whether the mild hypoxia experienced by passengers during commercial air travel triggers hypoxic pulmonary vasoconstriction and increases pulmonary artery pressure in flight. Insidious pulmonary hypertensive responses could endanger susceptible passengers who have cardiopulmonary disease or increased hypoxic pulmonary vascular sensitivity. Understanding these effects may improve pre-flight assessment of fitness-to-fly and reduce in-flight morbidity and mortality. Eight healthy volunteers were studied during a scheduled commercial airline flight from London, UK, to Denver, CO. The aircraft was a Boeing 777 and the duration of the flight was 9 h. Systolic pulmonary artery pressure (sPAP) was assessed by portable Doppler echocardiography during the flight and over the following week in Denver, where the altitude (5280 ft/1610 m) simulates a commercial airliner environment. Cruising cabin altitude ranged between 5840 and 7170 ft (1780 to 2185 m), and mean arterial oxygen saturation was 95 +/- 0.6% during the flight. Mean sPAP increased significantly in flight by 6 +/- 1 mmHg to 33 +/- 1 mmHg, an increase of approximately 20%. After landing in Denver, sPAP was still 3 +/- 1 mmHg higher than baseline and remained elevated at 30 +/- 1 mmHg for a further 12 h. Pulmonary artery pressure increases during commercial air travel in healthy passengers, raising the possibility that hypoxic pulmonary hypertension could develop in susceptible individuals. A hypoxia altitude simulation test with simultaneous echocardiography ('HAST-echo') may be beneficial in assessing fitness to fly in vulnerable patients.

  1. Effects of a nitrate-rich meal on arterial stiffness and blood pressure in healthy volunteers.

    Science.gov (United States)

    Liu, Alex H; Bondonno, Catherine P; Croft, Kevin D; Puddey, Ian B; Woodman, Richard J; Rich, Lisa; Ward, Natalie C; Vita, Joseph A; Hodgson, Jonathan M

    2013-11-30

    An increase in nitrate intake can augment circulating nitrite and nitric oxide. This may lead to lower blood pressure and improved vascular function. Green leafy vegetables, such as spinach, are rich sources of nitrate. We aimed to assess the acute effects of a nitrate-rich meal containing spinach on arterial stiffness and blood pressure in healthy men and women. Twenty-six participants aged 38-69years were recruited to a randomized controlled cross-over trial. The acute effects of two energy-matched (2000kJ) meals, administered in random order, were compared. The meals were either high nitrate (220mg of nitrate derived from spinach [spinach]) or low nitrate [control]. Outcome measurements were performed pre-meal and at specific time points up to 210min post meal. Spinach resulted in an eightfold increase in salivary nitrite and a sevenfold increase in salivary nitrate concentrations from pre-meal (Pnitrate-rich meal can lower systolic blood pressure and pulse pressure and increase large artery compliance acutely in healthy men and women. If sustained, these effects could contribute to better cardiovascular health. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Profunda Femoris Artery Perforator Propeller Flap: A Valid Method to Cover Complicated Ischiatic Pressure Sores.

    Science.gov (United States)

    Scalise, Alessandro; Tartaglione, Caterina; Bolletta, Elisa; Pierangeli, Marina; Di Benedetto, Giovanni

    2015-08-01

    We report the case of a 50-year-old paraplegic man with a complicated grade III/IV ischiatic pressure sore treated with a propeller flap based on the first perforator of the profunda femoris artery. Our aim was to surgically reconstruct an ischiatic pressure sore in a patient with ankylosis using a fasciocutaneous perforator propeller flap obtained from the posterior region of the thigh. Our decision to perform a profunda femoris artery perforator propeller flap reconstruction was mainly due to the anatomical contiguity of the flap with the site of the lesion and the good quality of the skin harvested from the posterior region of the thigh. The use of the perforator fasciocutaneous flap represents a muscle-sparing technique, providing a better long-term result in surgical reconstruction. The choice of the 180-degree propeller flap was due to its ability to provide a good repair of the pressure ulcer and to pass over the ischiatic prominence in the patient in the forced decubitus position. The operatory course did not present any kind of complication. Using this reconstructive treatment, we have obtained complete coverage of the ischiatic pressure sore.

  3. Increased serum urea to creatinine ratio and its negative correlation with arterial pressure in canine babesiosis.

    Science.gov (United States)

    Zygner, Wojciech; Gójska-Zygner, Olga

    2014-09-01

    The increase of the serum urea to creatinine ratio (UCR) was observed in dogs infected with Babesia canis. Previous studies have suggested that decrease of blood pressure can be one of the reasons for this phenomenon. In this work statistically significant increase of the UCR was observed in dogs with babesiosis. Comparison of the UCR between 23 azotaemic dogs and 25 non-azotaemic dogs infected with Babesia canis showed statistically significantly higher mean of the UCR in azotaemic dogs. Correlations between UCR and systolic, diastolic and mean arterial pressure (SAP, DAP and MAP) in 48 dogs infected with B. canis were negative (UCR and SAP: r = -0.3909; UCR and DAP: r = -0.3182; UCR and MAP: r = -0.3682) and statistically significant (p high, and there was no statistically significant correlation between UCR and arterial pressures in azotaemic dogs. Thus, it seems that decrease of blood pressure in dogs with babesiosis explains only partially the cause of increased UCR in infected dogs. The other authors suggested hyperureagenesis and myocardial injury as a potential reason for the increased UCR in canine babesiosis. Thus, further studies are needed to determine causes of increased UCR in dogs with babesiosis, especially on the connection between UCR changes and the concentrations of plasma cardiac troponins and ammonia, and the occurrence of occult blood on fecal examination.

  4. PREDICTION OF BLOOD PATTERN IN S-SHAPED MODEL OF ARTERY UNDER NORMAL BLOOD PRESSURE

    Directory of Open Access Journals (Sweden)

    Mohd Azrul Hisham Mohd Adib

    2013-06-01

    Full Text Available Athletes are susceptible to a wide variety of traumatic and non-traumatic vascular injuries to the lower limb. This paper aims to predict the three-dimensional flow pattern of blood through an S-shaped geometrical artery model. This model has created by using Fluid Structure Interaction (FSI software. The modeling of the geometrical S-shaped artery is suitable for understanding the pattern of blood flow under constant normal blood pressure. In this study, a numerical method is used that works on the assumption that the blood is incompressible and Newtonian; thus, a laminar type of flow can be considered. The authors have compared the results with a previous study with FSI validation simulation. The validation and verification of the simulation studies is performed by comparing the maximum velocity at t = 0.4 s, because at this time, the blood accelerates rapidly. In addition, the resulting blood flow at various times, under the same boundary conditions in the S-shaped geometrical artery model, is presented. The graph shows that velocity increases linearly with time. Thus, it can be concluded that the flow of blood increases with respect to the pressure inside the body.

  5. Increasing arterial oxygen partial pressure during cardiopulmonary resuscitation is associated with improved rates of hospital admission.

    Science.gov (United States)

    Spindelboeck, Walter; Schindler, Otmar; Moser, Adrian; Hausler, Florian; Wallner, Simon; Strasser, Christa; Haas, Josef; Gemes, Geza; Prause, Gerhard

    2013-06-01

    As recent clinical data suggest a harmful effect of arterial hyperoxia on patients after resuscitation from cardiac arrest (CA), we aimed to investigate this association during cardiopulmonary resuscitation (CPR), the earliest and one of the most crucial phases of recirculation. We analysed 1015 patients who from 2003 to 2010 underwent out-of-hospital CPR administered by emergency medical services serving 300,000 inhabitants. Inclusion criteria for further analysis were nontraumatic background of CA and patients >18 years of age. One hundred and forty-five arterial blood gas analyses including oxygen partial pressure (paO2) measurement were obtained during CPR. We observed a highly significant increase in hospital admission rates associated with increases in paO2 in steps of 100 mmHg (13.3 kPa). Subsequently, data were clustered according to previously described cutoffs (≤ 60 mmHg [8 kPa

  6. Axial- and radial-resolved electron density and excitation temperature of aluminum plasma induced by nanosecond laser: Effect of the ambient gas composition and pressure

    Directory of Open Access Journals (Sweden)

    Mahmoud S. Dawood

    2015-11-01

    Full Text Available The spatial variation of the characteristics of an aluminum plasma induced by a pulsed nanosecond XeCl laser is studied in this paper. The electron density and the excitation temperature are deduced from time- and space- resolved Stark broadening of an ion line and from a Boltzmann diagram, respectively. The influence of the gas pressure (from vacuum up to atmospheric pressure and compositions (argon, nitrogen and helium on these characteristics is investigated. It is observed that the highest electron density occurs near the laser spot and decreases by moving away both from the target surface and from the plume center to its edge. The electron density increases with the gas pressure, the highest values being occurred at atmospheric pressure when the ambient gas has the highest mass, i.e. in argon. The excitation temperature is determined from the Boltzmann plot of line intensities of iron impurities present in the aluminum target. The highest temperature is observed close to the laser spot location for argon at atmospheric pressure. It decreases by moving away from the target surface in the axial direction. However, no significant variation of temperature occurs along the radial direction. The differences observed between the axial and radial direction are mainly due to the different plasma kinetics in both directions.

  7. Opening wedge trapezial osteotomy as possible treatment for early trapeziometacarpal osteoarthritis: a biomechanical investigation of radial subluxation, contact area, and contact pressure.

    Science.gov (United States)

    Cheema, Tahseen; Salas, Christina; Morrell, Nathan; Lansing, Letitia; Reda Taha, Mahmoud M; Mercer, Deana

    2012-04-01

    Radial subluxation and cartilage thinning have been associated with initiation and accelerated development of osteoarthritis of the trapeziometacarpal joint. Few investigators have reported on the benefits of opening wedge trapezial osteotomy for altering the contact mechanics of the trapeziometacarpal joint as a possible deterrent to the initiation or progression of osteoarthritis. We used cadaveric specimens to determine whether opening wedge osteotomy of the trapezium was successful in reducing radial subluxation of the metacarpal base and to quantify the contact area and pressure on the trapezial surface during simulated lateral pinch. We used 8 fresh-frozen specimens in this study. The flexor pollicis longus, abductor pollicis longus, adductor pollicis, abductor pollicis brevis, and flexor pollicis brevis/opponens pollicis tendons were each loaded to simulate the thumb in lateral pinch position. We measured radial subluxation from anteroposterior radiographs before and after placement of a 15° wedge. We used real-time sensors to analyze contact pressure and contact area distribution on the trapezium. Center of force in the normal joint under lateral pinch loading was primarily located in the dorsal region of the trapezium. After wedge placement, contact pressure increased in the ulnar-dorsal region by 76%. Mean contact area increased in the ulnar-dorsal region from 0.05 to 0.07 cm(2), and in the ulnar-volar region from 0.003 to 0.024 cm(2). The average reduction in joint subluxation was 64%. The 15° opening wedge osteotomy of the trapezium reduced radial subluxation of the metacarpal on the trapezium and increased contact pressure and contact area away from the diseased compartments of the trapezial surface. Trapezial osteotomy addresses the 2 preeminent theories about the initiation and progression of osteoarthritis. By reducing radial subluxation and altering contact pressure and contact area, trapezial osteotomy may prove an alternative to first

  8. Closure of digital arteries in high vascular tone states as demonstrated by measurement of systolic blood pressure in the fingers

    DEFF Research Database (Denmark)

    Krähenbühl, B; Nielsen, S L; Lassen, N A

    1977-01-01

    by direct cooling or intra-arterial noradrenaline infusion caused a marked drop in FSP in the exposed fingers, but not in the non-exposed fingers of the same hand. The fact that the non-exposed fingers retained the normal (arm systolic) pressure level is taken to indicate that palmar arch blood pressure......Finger systolic blood pressure (FSP) was measured indirectly in normal subjects and patients with primary Raynaud phenomenon by applying a thin-walled plastic cuff around the finger and a strain gauge more distally to detect volume changes. Inducing a high vascular tone in one or more fingers...... also remained normal. In the high vascular tone state, a large transmural pressure difference must apparently be established before the digital arteries are forced open. The lowered opening pressure constitutes a manifestation of the closure phenomenon of the digital arteries described in patients...

  9. Prognostic value of renal fractional flow reserve in blood pressure response after renal artery stenting (PREFER study).

    Science.gov (United States)

    Kądziela, Jacek; Januszewicz, Andrzej; Prejbisz, Aleksander; Michałowska, Ilona; Januszewicz, Magdalena; Florczak, Elżbieta; Kalińczuk, Łukasz; Norwa-Otto, Bożena; Warchoł, Ewa; Witkowski, Adam

    2013-01-01

    The aim of our study was to determine a potential relationship between resting translesional pressures ratio (Pd/Pa ratio), renal fractional flow reserve (rFFR) and blood pressure response after renal artery stenting. Thirty five hypertensive patients (49% males, mean age 64 years) with at least 60% stenosis in angiography, underwent renal artery stenting. Translesional systolic pressure gradient (TSPG), Pd/Pa ratio (the ratio of mean distal to lesion and mean proximal pressures) and hyperemic rFFR - after intrarenal administration of papaverine - were measured before stent implantation. Ambulatory blood pressure measurements (ABPM) were recorded before the procedure and after 6 months. The ABPM results were presented as blood pressure changes in subgroups of patients with normal (≥ 0.9) vs. abnormal (renal artery stenting. Median changes of 24-h systolic/diastolic blood pressure were comparable in patients with abnormal vs. normal Pd/Pa ratio (-4/-3 vs. 0/2 mm Hg; p = NS) and with abnormal vs. normal rFFR (-2/-1 vs. -2/-0.5 mm Hg, respectively). Physiological assessment of renal artery stenosis using Pd/Pa ratio and papaverine- induced renal fractional fl ow reserve did not predict hypertension response after renal artery stenting.

  10. Downstream Hepatic Arterial Blood Pressure Changes Caused by Deployment of the Surefire AntiReflux Expandable Tip

    International Nuclear Information System (INIS)

    Rose, Steven C.; Kikolski, Steven G.; Chomas, James E.

    2013-01-01

    Purpose: The purpose of this work was to evaluate blood pressure changes caused by deployment of the Surefire antireflux expandable tip. The pressure measurements are relevant because they imply changes in hepatoenteric arterial blood flow within this liver compartment during hepatic artery delivery of cytotoxic agents. Methods: After positioning the Surefire antireflux system in the targeted hepatic artery, blood pressure was obtained initially with the tip collapsed (or through a femoral artery sheath), then again after the tip was expanded before chemoembolization or yttrium 90 ( 90 Y) radioembolization. Results: Eighteen patients with liver malignancy underwent 29 procedures in 29 hepatic arteries (3 common hepatic, 22 lobar, 4 segmental). Systolic, diastolic, and mean blood pressure were all decreased by a mean of 29 mm Hg (p = 0.000004), 14 mm Hg (p = 0.0000004), and 22 mm Hg (p = 0.00000001), respectively. Conclusion: When the Surefire expandable tip is deployed to prevent retrograde reflux of agents, it also results in a significant decrease in blood pressure in the antegrade distribution, potentially resulting in hepatopedal blood flow in vessels that are difficult to embolize, such as the supraduodenal arteries

  11. Aerobic exercise intensity can be controlled by palpation of the radial artery DOI:10.5007/1980-0037.2010v12n3p186

    Directory of Open Access Journals (Sweden)

    Anselmo José Perez

    2010-01-01

    Full Text Available Heart rate (HR during exercise has been used for the control of aerobic exercise intensity. Palpation is the most popular and accessible method for this purpose. The responses obtained in laboratory tests are used for field application and are suggested to be similar. The objective of this study was to correlate the HR measures obtained by palpation and with a heart rate monitor (HRM in four sessions of aerobic exercise, and to compare the results obtained in the laboratory and in the field. Fifteen healthy young women underwent four sessions of aerobic training of 40 min each at a continuous load, including two sessions on a treadmill and two in the field (50-60% and 80-85% HRmax. During the sessions, HR was recorded minute-by-minute with an HRM (Polar Accurex and measured at 10-minute intervals by pulse palpation. There were significant differences in ∆HR values obtained by palpation and with the HRM between exercise sessions performed on the track and in the laboratory. Strong correlations (r = 0.95 and moderate to strong (r = 0.73 correlations were observed between palpation and HRM in the four sessions. HR during exercise obtained by palpation was underestimated by no more than 5%, but there were no significant differences in mean absolute HR measured by HRM and palpation. For the same exercise intensity, similar results are obtained in the field and laboratory. In addition, HR obtained by palpation of the radial artery immediately after exercise can be used for the control of aerobic exercise intensity.

  12. [Features of daily rhythm of arterial pressure in patients with primary arterial hypertension and neurogenic syncope conditions].

    Science.gov (United States)

    Musaeva, Z A; Oknin, V Iu; Khapaev, B A; Fedotova, A V; Veĭn, A M

    2002-01-01

    A comparative analysis of parameters of systemic BP in patients with primary arterial hypotension (PAH) and in patients with neurogenic syncopes (NS) in the cycle sleep-awake. Blood pressure was investigated in 20 patients with PAH aged 16-44 years and 18 patients with NS aged 16-49 years. 24-h ambulatory monitoring of BP was made on the monitor ABPM-02/M (Meditech, Hungary). Rhythm indices of BP in NS patients corresponded to age normal criteria. 24-h arrhythmia of BP in PAH patients manifests with excessive drop of diastolic BP in sleep (55% patients were overdippers). PAH and NS patients differ maximally by hypotonic load in sleep: 1.0 +/- 0.7% in NS vs 15.4 +/- 3.2% in PAH. Hypotonia episodes in awake PAH patients were registered at each 4th-5th measurement of BP, in NS patients--at each 11th-13th. Heart rate in awake PAH patients is higher than in healthy subjects. Hypotonic load in sleep carries the highest differentially-diagnostic importance. This makes more perspective examinations of such patients in the cycle sleep-awake. The changes observed in PAH patients evidence for activation of cerebral sympathico-adrenal systems participating in baroreflex regulation.

  13. 3D Model Studies on the Effect of Bed and Powder Type Upon Radial Static Pressure and Powder Distribution in Metallurgical Shaft Furnaces

    Directory of Open Access Journals (Sweden)

    Panic B.

    2017-09-01

    Full Text Available The flow of gases in metallurgical shaft furnaces has a decisive influence on the course and process efficiency. Radial changes in porosity of the bed cause uneven flow of gas along the radius of the reactor, which sometimes is deliberate and intentional. However, holdup of solid particles in descending packed beds of metallurgical shaft furnaces can lead to unintentional changes in porosity of the bed along the radial reactor. Unintentional changes in porosity often disrupt the flow of gas causing poor performance of the furnace. Such disruptions of flow may occur in the blast furnace due to high level of powder content in gas caused by large amount of coal dust/powder insufflated as fuel substitute. The paper describes the model test results of radial distribution of static pressure and powder hold up within metallurgical reactor. The measurements were carried out with the use of 3D physical model of two-phase flow gas-powder in the moving (descending packed bed. Sinter or blast furnace pellets were used as packed bed while carbon powder or iron powder were used as the powder. Wide diversity within both static pressure distribution and powder distribution along the radius of the reactor were observed once the change in the type of powder occurred.

  14. The phosphodiesterase 3 inhibitor cilostazol dilates large cerebral arteries in humans without affecting regional cerebral blood flow

    DEFF Research Database (Denmark)

    Birk, Steffen; Kruuse, Christina Rostrup; Petersen, Kenneth A

    2004-01-01

    in the middle cerebral arteries (VMCA) was measured with transcranial Doppler, and the superficial temporal and radial arteries diameters were measured with ultrasonography. During the 4-hour observation period, there was no effect on systolic blood pressure (P = 0.28), but diastolic blood pressure decreased...

  15. Morning pressor surge, blood pressure variability, and arterial stiffness in essential hypertension.

    Science.gov (United States)

    Pucci, Giacomo; Battista, Francesca; Anastasio, Fabio; Schillaci, Giuseppe

    2017-02-01

    An excess morning blood pressure surge (MBPS) may portend an increased cardiovascular risk, but the mechanisms thereof have been little investigated. The link between MBPS, short-term blood pressure (BP) variability, and arterial stiffness has not been entirely defined. In 602 consecutive untreated hypertensive patients (48 ± 12 years, 61% men, office BP 149/93 ± 17/10 mmHg), we measured carotid-femoral pulse wave velocity (cf-PWV, SphygmoCor) and 24-h ambulatory BP. Using self-reported sleep and wake times, MBPS was defined as sleep-trough (ST-MBPS), prewaking, rising. Short-term BP variability was calculated as weighted 24-h SBP SD and average real variability of 24-h SBP (ARV), that is, average of absolute differences between consecutive SBP readings. ST-MBPS (r = 0.16, P < 0.001) and rising MBPS (r = 0.12, P = 0.003) showed a direct correlation with cf-PWV, whereas prewaking MBPS had no such relation (r = 0.06, P = 0.14). Only ST-MBPS was independently associated with cf-PWV (t = 1.96, P = 0.04) after adjustment for age, sex, height, office mean arterial pressure, heart rate, and renal function. This association was lost after further adjustment for weighted 24-h SBP SD (P = 0.13) or ARV (P = 0.24). ARV was a significant mediator of the relationship between ST-MBPS and cf-PWV (P = 0.003). In untreated hypertension, ST-MBPS has a direct relation with aortic stiffness, which is mediated by an increased ARV. The adverse effects of MBPS may be partly explained by its link with arterial stiffness, mediated by short-term SBP variability.

  16. Alterations of Blood Flow Through Arteries Following Atherectomy and the Impact on Pressure Variation and Velocity.

    Science.gov (United States)

    Plourde, Brian D; Vallez, Lauren J; Sun, Biyuan; Nelson-Cheeseman, Brittany B; Abraham, John P; Staniloae, Cezar S

    2016-09-01

    Simulations were made of the pressure and velocity fields throughout an artery before and after removal of plaque using orbital atherectomy plus adjunctive balloon angioplasty or stenting. The calculations were carried out with an unsteady computational fluid dynamic solver that allows the fluid to naturally transition to turbulence. The results of the atherectomy procedure leads to an increased flow through the stenotic zone with a coincident decrease in pressure drop across the stenosis. The measured effect of atherectomy and adjunctive treatment showed decrease the systolic pressure drop by a factor of 2.3. Waveforms obtained from a measurements were input into a numerical simulation of blood flow through geometry obtained from medical imaging. From the numerical simulations, a detailed investigation of the sources of pressure loss was obtained. It is found that the major sources of pressure drop are related to the acceleration of blood through heavily occluded cross sections and the imperfect flow recovery downstream. This finding suggests that targeting only the most occluded parts of a stenosis would benefit the hemodynamics. The calculated change in systolic pressure drop through the lesion was a factor of 2.4, in excellent agreement with the measured improvement. The systolic and cardiac-cycle-average pressure results were compared with measurements made in a multi-patient study treated with orbital atherectomy and adjunctive treatment. The agreements between the measured and calculated systolic pressure drop before and after the treatment were within 3%. This excellent agreement adds further confidence to the results. This research demonstrates the use of orbital atherectomy to facilitate balloon expansion to restore blood flow and how pressure measurements can be utilized to optimize revascularization of occluded peripheral vessels.

  17. Impact of statin therapy on central aortic pressures and hemodynamics: principal results of the Conduit Artery Function Evaluation-Lipid-Lowering Arm (CAFE-LLA) Study.

    Science.gov (United States)

    Williams, Bryan; Lacy, Peter S; Cruickshank, J Kennedy; Collier, David; Hughes, Alun D; Stanton, Alice; Thom, Simon; Thurston, Herbert

    2009-01-06

    Statins reduce the risk of cardiovascular events in people with hypertension. This benefit could arise from a beneficial effect of statins on central aortic pressures and hemodynamics. The Conduit Artery Function Evaluation-Lipid-Lowering Arm (CAFE-LLA) study, an Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) substudy, investigated this hypothesis in a prospective placebo-controlled study of treated patients with hypertension. CAFE-LLA recruited 891 patients randomized to atorvastatin 10 mg/d or placebo from 5 centers in the United Kingdom and Ireland. Radial artery applanation tonometry and pulse-wave analysis were used to derive central aortic pressures and hemodynamic indices at repeated visits over 3.5 years of follow-up. Atorvastatin lowered low-density lipoprotein cholesterol by 32.4 mg/dL (95% confidence interval [CI], 28.6 to 36.3) and total cholesterol by 35.1 mg/dL (95% confidence interval, 30.9 to 39.4) relative to placebo. Time-averaged brachial blood pressure was similar in CAFE-LLA patients randomized to atorvastatin or placebo (change in brachial systolic blood pressure, -0.1 mm Hg [95% CI, -1.8 to 1.6], P=0.9; change in brachial pulse pressure, -0.02 mm Hg [95% CI, -1.6 to 1.6], P=0.9). Atorvastatin did not influence central aortic pressures (change in aortic systolic blood pressure, -0.5 mm Hg [95% CI, -2.3 to 1.2], P=0.5; change in aortic pulse pressure, -0.4 mm Hg [95% CI, -1.9 to 1.0], P=0.6) and had no influence on augmentation index (change in augmentation index, -0.4%; 95% CI, -1.7 to 0.8; P=0.5) or heart rate (change in heart rate, 0.25 bpm; 95% CI, -1.3 to 1.8; P=0.7) compared with placebo. The effect of statin or placebo therapy was not modified by the blood pressure-lowering treatment strategy in the factorial design. Statin therapy sufficient to significantly reduce cardiovascular events in treated hypertensive patients in ASCOT did not influence central aortic blood pressure or hemodynamics in a large representative cohort of ASCOT

  18. Measuring systolic arterial blood pressure. Possible errors from extension tubes or disposable transducer domes.

    Science.gov (United States)

    Rothe, C F; Kim, K C

    1980-11-01

    The purpose of this study was to evaluate the magnitude of possible error in the measurement of systolic blood pressure if disposable, built-in diaphragm, transducer domes or long extension tubes between the patient and pressure transducer are used. Sinusoidal or arterial pressure patterns were generated with specially designed equipment. With a long extension tube or trapped air bubbles, the resonant frequency of the catheter system was reduced so that the arterial pulse was amplified as it acted on the transducer and, thus, gave an erroneously high systolic pressure measurement. The authors found this error to be as much as 20 mm Hg. Trapped air bubbles, not stopcocks or connections, per se, lead to poor fidelity. The utility of a continuous catheter flush system (Sorenson, Intraflow) to estimate the resonant frequency and degree of damping of a catheter-transducer system is described, as are possibly erroneous conclusions. Given a rough estimate of the resonant frequency of a catheter-transducer system and the magnitude of overshoot in response to a pulse, the authors present a table to predict the magnitude of probable error. These studies confirm the variability and unreliability of static calibration that may occur using some safety diaphragm domes and show that the system frequency response is decreased if air bubbles are trapped between the diaphragms. The authors conclude that regular procedures should be established to evaluate the accuracy of the pressure measuring systems in use, the transducer should be placed as close to the patient as possible, the air bubbles should be assiduously eliminated from the system.

  19. The giraffe kidney tolerates high arterial blood pressure by high renal interstitial pressure and low glomerular filtration rate

    DEFF Research Database (Denmark)

    Damkjær, Mads; Wang, T; Brøndum, E

    2015-01-01

    BACKGROUND: The tallest animal on earth, the giraffe (Giraffa camelopardalis) is endowed with a mean arterial blood pressure (MAP) twice that of other mammals. The kidneys reside at heart level and show no sign of hypertension-related damage. We hypothesized that a species-specific evolutionary...... cava generated a pressure drop of 12 ± 2 mmHg. RI was 0.27. The renal capsule was durable with a calculated burst pressure of 600 mmHg. Plasma renin and AngII were 2.6 ± 0.5 mIU L(-1) and 9.1 ± 1.5 pg mL(-1) respectively. CONCLUSION: In giraffes, GFR, ERPF and RI appear much lower than expected based...... adaption in the giraffe kidney allows normal for size renal haemodynamics and glomerular filtration rate (GFR) despite a MAP double that of other mammals. METHODS: Fourteen anaesthetized giraffes were instrumented with vascular and bladder catheters to measure glomerular filtration rate (GFR) and effective...

  20. The impact of renal artery stent revascularization on blood pressure: 1-year follow-up of 110 cases

    International Nuclear Information System (INIS)

    Wang Chao; Zou Yinghua; Yang Min; Wang Jian; Tong Xiaoqiang; Song Li

    2007-01-01

    Objective: To investigate the effect of renal artery revascularization through renal artery stenting(PTRAS)on blood pressure in patients with renal artery stenosis. Methods: During April 2000 through May 2005 110 cases of renal artery stenosis received PTRAS and followed up for at least 1 year with blood pressure measurements pre-and 1 year post-PTRAS. Results: The technical success rate was 100% for all 110 cases. The renal artery stenosis were decreased from 60%-100% before PTRAS to 0%-15% after the stent placement. There was significant difference between blood pressure pre-and 1 year post PTRAS. Systolic pressures decreased from(153 ± 32) mmHg to(131 ± 27) mmHg and diastolic pressures from(87 ± 19) mmHg to(75 ± 19) mmHg. The administration of antihypertensive diugs reduced from(2.6 ± 0.9 ) sorts to(1.9 ± 0.9) sorts. Conclusions: PTRAS revascularization is an effective procedure for blood pressure control in renal vascular hypertension during one year follow up. (authors)

  1. Obese children and adolescents have elevated nighttime blood pressure independent of insulin resistance and arterial stiffness

    DEFF Research Database (Denmark)

    Hvidt, Kristian N; Olsen, Michael H; Holm, Jens-Christian

    2014-01-01

    BACKGROUND: Insulin resistance has been related to elevated blood pressure (BP) in obese children and may adversely affect the vasculature by arterial stiffening. The objective was to investigate whether daytime and nighttime BP were elevated and related to insulin resistance and arterial stiffness...... in obese children and adolescents. METHODS: Ninety-two obese patients aged 10-18 years were compared with 49 healthy control individuals. Insulin resistance was measured as the homeostatic assessment model (HOMA), and arterial stiffness was measured as carotid-femoral pulse wave velocity (cfPWV). RESULTS......: Mean ± SD daytime systolic BP (SBP) (obese: 125±8.3mm Hg; control: 121±10.1mm Hg; P = 0.03) and nighttime SBP (obese: 108±10.7mm Hg; control: 102±8.2mm Hg; P = 0.0001) were higher in the obese group when compared with the control group. No difference was found in daytime diastolic BP (DBP), whereas...

  2. Tobacco smoking strengthens the association of elevated blood pressure with arterial stiffness: the Bogalusa Heart Study.

    Science.gov (United States)

    Yun, Miaoying; Li, Shengxu; Sun, Dianjianyi; Ge, Shaoqing; Lai, Chin-Chih; Fernandez, Camilo; Chen, Wei; Srinivasan, Sathanur R; Berenson, Gerald S

    2015-02-01

    The study assessed the hypothesis that smoking strengthens the association of adult arterial stiffness with long-term cumulative burden of blood pressure (BP) from childhood to adulthood. Tobacco smoking and elevated BPs are important risk factors of vascular stiffness. However, the synergistic effect of these two risk factors is not well established, especially for the long-term burden of elevated BP since childhood. The study cohort consisted of 945 adults (661 whites and 284 blacks, aged 24-43 years) who have BP measured 4-15 times since childhood (aged 4-17 years) in Bogalusa, Louisiana. The adult arterial stiffness was measured as aorta-femoral pulse wave velocity (afPWV); the total area under the curve (AUC) and incremental AUC were used as a measure of long-term burden and trends of BP, respectively. Increased adult afPWV was significantly associated with higher adulthood (P AUC (P AUC (P AUC (P = 0.007) were significantly greater among the current smokers than among the nonsmokers. DBP showed a similar pattern regarding the smoking-BP interaction on afPWV. These results, by showing the synergistic effect of tobacco smoking and long-term BP measures from childhood to adulthood on arterial stiffening process, underscore the importance of undertaking preventive strategies early in life and smoking behavior control.

  3. Blood pressure and calf muscle oxygen extraction during plantar flexion exercise in peripheral artery disease.

    Science.gov (United States)

    Luck, J Carter; Miller, Amanda J; Aziz, Faisal; Radtka, John F; Proctor, David N; Leuenberger, Urs A; Sinoway, Lawrence I; Muller, Matthew D

    2017-07-01

    Peripheral artery disease (PAD) is an atherosclerotic vascular disease that affects 200 million people worldwide. Although PAD primarily affects large arteries, it is also associated with microvascular dysfunction, an exaggerated blood pressure (BP) response to exercise, and high cardiovascular mortality. We hypothesized that fatiguing plantar flexion exercise that evokes claudication elicits a greater reduction in skeletal muscle oxygenation (SmO 2 ) and a higher rise in BP in PAD compared with age-matched healthy subjects, but low-intensity steady-state plantar flexion elicits similar responses between groups. In the first experiment, eight patients with PAD and eight healthy controls performed fatiguing plantar flexion exercise (from 0.5 to 7 kg for up to 14 min). In the second experiment, seven patients with PAD and seven healthy controls performed low-intensity plantar flexion exercise (2.0 kg for 14 min). BP, heart rate (HR), and SmO 2 were measured continuously using near-infrared spectroscopy (NIRS). SmO 2 is the ratio of oxygenated hemoglobin to total hemoglobin, expressed as a percent. At fatigue, patients with PAD had a greater increase in mean arterial BP (18 ± 2 vs. vs. 10 ± 2 mmHg, P = 0.029) and HR (14 ± 2 vs. 6 ± 2 beats/min, P = 0.033) and a greater reduction in SmO 2 (-54 ± 10 vs. -12 ± 4%, P = 0.001). However, both groups had similar physiological responses to low-intensity, nonpainful plantar flexion exercise. These data suggest that patients with PAD have altered oxygen uptake and/or utilization during fatiguing exercise coincident with an augmented BP response. NEW & NOTEWORTHY In this laboratory study, patients with peripheral artery disease performed plantar flexion exercise in the supine posture until symptoms of claudication occurred. Relative to age- and sex-matched healthy subjects we found that patients had a higher blood pressure response, a higher heart rate response, and a greater reduction in skeletal muscle oxygenation as

  4. Systemic arterial hypertension, blood pressure levels and associated factors in schoolchildren

    Directory of Open Access Journals (Sweden)

    Priscila Heleno

    Full Text Available Summary Introduction: Hypertension is a major public health problem in contemporary times and it has high prevalence throughout the world. Objective: To investigate the situation of Systemic Arterial Hypertension in schoolchildren aged 6 to 10 years in Divinópolis/MG-Brazil and associated factors. Method: This is a cross-sectional, epidemiological, descriptive and analytical study, whose population was children aged 6 to 10 years enrolled in public schools in Divinópolis-MG-Brazil. Data collection was conducted from October 2014 to May 2015. Multivariate linear regressions were used to test associations between blood pressure, socioeconomic, anthropometric, dietary and physical activity. Results: The prevalence of hypertension was 15.2% in a sample of 284 children and mean values of systolic blood pressure of 101.7 (±13.2 mmHg and diastolic blood pressure of 66.0 (±11.2 mmHg. The body fat percentage showed significant differences between the genders, with 24.2 and 26.2%, respectively for boys and girls. Significant associations were made between blood pressure levels, body weight, body mass index, waist circumference, body fat percentage, consumption of yogurt, beef /chicken, beans, pizza, sandwich and some behaviors variables. Conclusion: The presented data show important aspects of school profile in the age range 6-10 years, especially related to the behavior of blood pressure.

  5. Measurement of brachial artery endothelial function using a standard blood pressure cuff

    International Nuclear Information System (INIS)

    Maltz, Jonathan S; Budinger, Thomas F; Tison, Geoffrey H; Olgin, Jeffrey; Alley, Hugh F; Owens, Christopher D

    2015-01-01

    The integrity of endothelial function in major arteries (EFMA) is a powerful independent predictor of heart attack and stroke. Existing ultrasound-based non-invasive assessment methods are technically challenging and suitable only for laboratory settings. EFMA, like blood pressure (BP), is both acutely and chronically affected by factors such as lifestyle and medication. Consequently, laboratory-based measurements cannot fully gauge the effects of medical interventions on EFMA. EFMA and BP have, arguably, comparable (but complementary) value in the assessment of cardiovascular health. Widespread deployment of EFMA assessment is thus a desirable clinical goal. To this end, we propose a device based on modifying the measurement protocol of a standard electronic sphygmomanometer. The protocol involves inflating the cuff to sub-diastolic levels to enable recording of the pulse waveform before and after vasodilatory stimulus. The mechanical unloading of the arterial wall provided by the cuff amplifies the distension that occurs with each pulse, which is measured as a pressure variation in the cuff. We show that the height of the rising edge of each pulse is proportional to the change in lumen area between diastole and systole. This allows the effect of vasodilatory stimuli on the artery to be measured with high sensitivity. We compare the proposed cuff flow-mediated dilation (cFMD) method to ultrasound flow-mediated dilation (uFMD). We find significant correlation (r  =  0.55, p  =0.003, N  =  27) between cFMD- and uFMD-based metrics obtained when the release of a 5 min cuff occlusion is employed to induce endothelial stimulus via reactive hyperemia. cFMD is approximately proportional to the square of uFMD, representing a typical increase in sensitivity to vasodilation of 300–600%. This study illustrates the potential for an individual to conveniently measure his/her EFMA by using a low-cost reprogrammed home sphygmomanometer. (paper)

  6. Echocardiographic assessment of systolic pulmonary arterial pressure in HIV-positive patients.

    Directory of Open Access Journals (Sweden)

    Mehrnaz Rasoulinejad

    2014-11-01

    Full Text Available Pulmonary hypertension is rare but is one of the complications that occur due to HIV infection. Symptoms of HIV-associated pulmonary arterial hypertension are often non-specific but the main symptom of the disease is dyspnea. In this cross-sectional study, we measured systolic pulmonary arterial pressure (SPAP by echocardiographic methods among HIV-positive patients who received ART. This research is a descriptive, cross-sectional study of 170 HIV-positive patients that was conducted in Imam-Khomeini hospital, Tehran, Iran during 2011-2013. All patients regularly received antiretroviral therapy at least for recent 2 years. There were not any cardiopulmonary symptoms (cough, dyspnea, exertional fatigue and chest discomfort in these patients. All participants underwent echocardiography to estimate SPAP. The participants comprised 108 males (63.5% and 62 females (46.5%. The mean age of patients was 41 years old, and the mean duration of HIV infection was 5.5 years. The mean CD4 cell count was 401 cell/µl. The principal regimen of antiretroviral therapy included two nucleoside reverse transcriptase inhibitor (NRTI and one non-nucleoside reverse transcriptase inhibitor (NNRTI in the hospital. The mean of systolic pulmonary arterial pressure was 25 mmHg in the participants; 156 (93.4% of them had SPAP ≤ 30 mmHg (normal, six (3.6% had SPAP: 31-35 mmHg (borderline and five (3% had SPAP > 35 mmHg (pulmonary hypertension. Our results indicated a significant increase of pulmonary hypertension in asymptomatic HIV-positive patients that had no association with any other risk factor. Also, antiretroviral therapy was not a risk factor for pulmonary hypertension in this study.

  7. Comparison of Doppler and oscillometric ankle blood pressure measurement in patients with angiographically documented lower extremity arterial occlusive disease.

    Science.gov (United States)

    Nukumizu, Yoshihito; Matsushita, Masahiro; Sakurai, Tsunehisa; Kobayashi, Masayoshi; Nishikimi, Naomichi; Komori, Kimihiro

    2007-01-01

    To assess the reliability of the oscillometric method in patients with peripheral vascular disease, ankle blood pressure measurement by Doppler and oscillometry was compared. This study represents a prospective, non-blinded examination of pressure measurements in 168 patients. Twenty-two patients were included who had abdominal aortic aneurysms (AAA) and 146 had peripheral arterial occlusive disease (PAOD). Patients with PAOD were divided into 2 groups according to angiography results: a crural artery occlusion group (CAO, n = 32), and a no crural artery occlusion group (NCAO, n = 114). All subjects underwent pressure measurement by both Doppler and oscillometry. The correlation coefficient was 0.928 in AAA patients and 0.922 in PAOD patients. In CAO patients, there were significantly fewer patients whose oscillometric pressure was equivalent to the Doppler pressure (DP), as compared to NCAO patients, because the oscillometric pressure (OP) was 10% higher than DP in 44% of CAO patients. A high correlation exists between Doppler and oscillometric ankle pressure measurements irrespective of the type of vascular disease. However, the oscillometric method could not be substituted for the Doppler method completely, because there were several patients whose OP was greater than DP especially in those with crural artery occlusive disease.

  8. A pressão arterial está sendo medida? Is the blood pressure being measured?

    Directory of Open Access Journals (Sweden)

    Débora C. Alavarce

    2000-03-01

    Full Text Available A medida da pressão arterial faz parte do exame físico e deve ser realizada em toda consulta médica. Para avaliar se a pressão arterial é medida nas consultas médicas, foram consultados 500 prontuários de pacientes de primeira consulta ambulatorial, sendo 335 (67% provenientes de clínicas médicas e cirúrgicas e 165 (33% das clínicas ginecológica e obstétrica. A pressão arterial foi anotada em 39% das consultas realizadas (135±32/85±19 mm Hg, sendo que em 11% destas anotações a pressão diastólica estava acima de 90 mm Hg. Em relação ao diagnóstico prévio de hipertensão arterial verificou-se que: a em 62% dos prontuários não havia esta informação; b 20% referiram ter hipertensão, e em 79% destes a pressão arterial foi anotada; e c 18% referiram não ter hipertensão e 46% destes tiveram registro da pressão arterial. Portanto, a maior parte dos pacientes não teve sua pressão arterial anotada.The blood pressure measure is part of the physical exam and it should be accomplished in every medical consultation. To verify the blood pressure measured in the accomplished medical consultations record of first they were consulted it consults 500 patient's ambulatorial being 335 (67% coming of medical and surgical clinics and 165 (33% of the gynecological and obstetric clinics. The blood pressure was written down in 39% of the accomplished consultations (135+32 mm Hg 85+19 mm Hg, and 11% of this annotations the pressure diastólica was above 90 mm Hg. In relation to the previous diagnosis of hypertension it was verified that: a in 62% of the records there was not this information; b 20% referred to have hypertension, and in 79% of these the arterial pressure was scored; and c 18% referred not to have hypertension and 46% of these had registration of the arterial pressure. Therefore, most of the patients didn't have its logged arterial pressure.

  9. Association of sleep duration with arterial blood pressure profile of Gujarati Indian adolescents

    Directory of Open Access Journals (Sweden)

    Shaikh Wasim

    2010-01-01

    Full Text Available Background and Aim: Recently, National Health and Nutritional Examination Survey-1 data analysis found short sleep duration as a risk factor for hypertension in the U.S. population. However, since ethnic differences exist in the aetiopathogenesis of diseases, the current study was undertaken to study the effect of sleep duration on the blood pressure profile of Gujarati Indian adolescents. Materials and Methods: A cross-sectional study was conducted on 489 Gujarati Indian adolescents of age group 16-19 years studying in school and colleges in the local population. The participants were assessed for their sleep duration, physical activity status, body composition, blood pressure profile and cardiovascular reactivity. The sleep duration was reported by the subjects as the number of hours they slept on most of the nights in a week over the last one year. The observations of the study were then analyzed after grouping them into: 1 Adequate Sleep Duration at Night, ASDN (≥ 7 hrs and 2 Inadequate Sleep Duration at Night, ISDN (< 7 hrs groups. Student′s unpaired t-test was used to study if any significant difference (P< 0.05 existed between the groups. Results: No significant difference was found in Systolic blood pressure, Diastolic blood pressure, Pulse pressure and Mean arterial pressure between the ASDN group and the ISDN group. Physical activity status also did not differ between the two groups. However, adolescents of ISDN group showed a significantly higher level of adiposity and cardiovascular reactivity as compared to adolescents of ASDN group. Conclusion: Although short sleep duration is associated with a higher level of adiposity and cardiovascular reactivity in Gujarati Indian adolescents, it does not affect the resting blood pressure profile of these adolescents. However, longitudinal studies would be required to observe if the changes in adiposity and cardiovascular reactivity affect these adolescents in later life.

  10. Blood Pressure Response to Main Renal Artery and Combined Main Renal Artery Plus Branch Renal Denervation in Patients With Resistant Hypertension.

    Science.gov (United States)

    Fengler, Karl; Ewen, Sebastian; Höllriegel, Robert; Rommel, Karl-Philipp; Kulenthiran, Saaraaken; Lauder, Lucas; Cremers, Bodo; Schuler, Gerhard; Linke, Axel; Böhm, Michael; Mahfoud, Felix; Lurz, Philipp

    2017-08-10

    Single-electrode ablation of the main renal artery for renal sympathetic denervation showed mixed blood pressure (BP)-lowering effects. Further improvement of the technique seems crucial to optimize effectiveness of the procedure. Because sympathetic nerve fibers are closer to the lumen in the distal part of the renal artery, treatment of the distal main artery and its branches has been shown to reduce variability in treatment effects in preclinical studies and a recent randomized trial. Whether this optimized technique improves clinical outcomes remains uncertain. We report a 2-center experience of main renal artery and combined main renal artery plus branches renal denervation in patients with resistant hypertension using a multielectrode catheter. Twenty-five patients with therapy-resistant hypertension underwent renal sympathetic denervation with combined main renal artery and renal branch ablation and were compared to matched controls undergoing an ablation of the main renal artery only. BP change was assessed by ambulatory measurement at baseline and after 3 months. At baseline, BP was balanced between the groups. After 3 months, BP changed significantly in the combined ablation group (systolic/diastolic 24-hour mean and daytime mean BP -8.5±9.8/-7.0±10.7 and -9.4±9.8/-7.1±13.5 mm Hg, P renal artery and branches appears to improve BP-lowering efficacy and should be further investigated. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  11. Physiological Mechanisms Mediating the Coupling between Heart Period and Arterial Pressure in Response to Postural Changes in Humans

    OpenAIRE

    Silvani, Alessandro; Calandra-Buonaura, Giovanna; Johnson, Blair D.; van Helmond, Noud; Barletta, Giorgio; Cecere, Anna G.; Joyner, Michael J.; Cortelli, Pietro

    2017-01-01

    The upright posture strengthens the coupling between heart period (HP) and systolic arterial pressure (SAP) consistently with a greater contribution of the arterial baroreflex to cardiac control, while paradoxically decreasing cardiac baroreflex sensitivity (cBRS). To investigate the physiological mechanisms that mediate the coupling between HP and SAP in response to different postures, we analyzed the cross-correlation functions between low-frequency HP and SAP fluctuations and estimated cBR...

  12. Non-gated vessel wall imaging of the internal carotid artery using radial scanning and fast spin echo sequence. Evaluation of vessel signal intensity by flow rate at 3.0 tesla

    International Nuclear Information System (INIS)

    Nakamura, Manami; Makabe, Takeshi; Ichikawa, Masaki; Hatakeyama, Ryohei; Sugimori, Hiroyuki; Sakata, Motomichi

    2013-01-01

    Vessel wall imaging using radial scanning does not use a blood flow suppression pulse with gated acquisition. It has been proposed that there may not be a flow void effect if the flow rate is slow; however, this has yet to be empirically tested. To clarify the relationship between the signal intensity of the vessel lumen and the blood flow rate in a flow phantom, we investigated the usefulness of vessel wall imaging at 3.0 tesla (T). We measured the signal intensity while changing the flow rate in the flow phantom. Radial scanning at 1.5 T showed sufficient flow voids at above medium flow rates. There was no significant difference in lumen signal intensity at the carotid artery flow rate. The signal intensity of the vessel lumen decreased sufficiently using the radial scan method at 3.0 T. We thus obtained sufficient flow void effects at the carotid artery flow rate. We conclude this technique to be useful for evaluating plaque if high contrast can be maintained for fixed tissue (such as plaque) and the vessel lumen. (author)

  13. Passive heat therapy improves endothelial function, arterial stiffness and blood pressure in sedentary humans.

    Science.gov (United States)

    Brunt, Vienna E; Howard, Matthew J; Francisco, Michael A; Ely, Brett R; Minson, Christopher T

    2016-09-15

    A recent 30 year prospective study showed that lifelong sauna use reduces cardiovascular-related and all-cause mortality; however, the specific cardiovascular adaptations that cause this chronic protection are currently unknown. We investigated the effects of 8 weeks of repeated hot water immersion ('heat therapy') on various biomarkers of cardiovascular health in young, sedentary humans. We showed that, relative to a sham group which participated in thermoneutral water immersion, heat therapy increased flow-mediated dilatation, reduced arterial stiffness, reduced mean arterial and diastolic blood pressure, and reduced carotid intima media thickness, with changes all on par or greater than what is typically observed in sedentary subjects with exercise training. Our results show for the first time that heat therapy has widespread and robust effects on vascular function, and as such, could be a viable treatment option for improving cardiovascular health in a variety of patient populations, particularly those with limited exercise tolerance and/or capabilities. The majority of cardiovascular diseases are characterized by disorders of the arteries, predominantly caused by endothelial dysfunction and arterial stiffening. Intermittent hot water immersion ('heat therapy') results in elevations in core temperature and changes in cardiovascular haemodynamics, such as cardiac output and vascular shear stress, that are similar to exercise, and thus may provide an alternative means of improving health which could be utilized by patients with low exercise tolerance and/or capabilities. We sought to comprehensively assess the effects of 8 weeks of heat therapy on biomarkers of vascular function in young, sedentary subjects. Twenty young, sedentary subjects were assigned to participate in 8 weeks (4-5 times per week) of heat therapy (n = 10; immersion in a 40.5°C bath sufficient to maintain rectal temperature ≥ 38.5°C for 60 min per session) or thermoneutral water

  14. Double-Sided Laser Heating in Radial Diffraction Geometry for Diamond Anvil Cell Deformation Experiments at Simultaneous High Pressures and Temperatures

    Science.gov (United States)

    Miyagi, L. M.; Kunz, M.; Couper, S.; Lin, F.; Yan, J.; Doran, A.; MacDowell, A. A.

    2017-12-01

    The rheology of rocks and minerals in the Earth's deep interior plays a primary role in controlling large scale geodynamic processes such as mantle convection and slab subduction. Plastic deformation resulting from these processes can lead to texture development and associated seismic anisotropy. If a detailed understanding of the link between deformation and seismic anisotropy is established, observations of seismic anisotropy can be used to understand the dynamic state in the deep Earth. However, performing deformation experiments at lower mantle pressure and temperature conditions are extremely challenging. Thus most deformation studies have been performed either at room temperature and high pressure or at reduced pressures and high temperature. Only a few extraordinary efforts have attained pressures and temperatures relevant to lower mantle. Therefore our ability to interpret observations of lower mantle seismic anisotropy in terms of mantle flow models remains limited. In order to expand the pressure and temperature range available for deformation of deep Earth relevant mineral phases, we have developed a laser heating system for in-situ double-sided heating in radial diffraction geometry at beamline 12.2.2 of the Advanced Light Source of Lawrence Berkeley National Laboratory. This allows texture and lattice strain measurements to be recorded at simultaneous high pressures and temperatures in the diamond anvil cell. This new system is integrated into the newly built axial laser heating system to allow for rapid and reliable transitioning between double-sided laser heating in axial and radial geometries. Transitioning to radial geometry is accomplished by redirecting the laser and imaging paths from 0° and 180° to 90° and 270°. To redirect the 90° path, a motorized periscope mirror pair with an objective lens can be inserted into the downstream axial beam path. The 270° redirection is accomplished by removing the upstream axial objective lens and

  15. Effects of mercury on the arterial blood pressure of anesthetized rats

    Directory of Open Access Journals (Sweden)

    Rossoni L.V.

    1999-01-01

    Full Text Available The available data suggests that hypotension caused by Hg2+ administration may be produced by a reduction of cardiac contractility or by cholinergic mechanisms. The hemodynamic effects of an intravenous injection of HgCl2 (5 mg/kg were studied in anesthetized rats (N = 12 by monitoring left and right ventricular (LV and RV systolic and diastolic pressures for 120 min. After HgCl2 administration the LV systolic pressure decreased only after 40 min (99 ± 3.3 to 85 ± 8.8 mmHg at 80 min. However, RV systolic pressure increased, initially slowly but faster after 30 min (25 ± 1.8 to 42 ± 1.6 mmHg at 80 min. Both right and left diastolic pressures increased after HgCl2 treatment, suggesting the development of diastolic ventricular dysfunction. Since HgCl2 could be increasing pulmonary vascular resistance, isolated lungs (N = 10 were perfused for 80 min with Krebs solution (continuous flow of 10 ml/min containing or not 5 µM HgCl2. A continuous increase in pulmonary vascular resistance was observed, suggesting the direct effect of Hg2+ on the pulmonary vessels (12 ± 0.4 to 29 ± 3.2 mmHg at 30 min. To examine the interactions of Hg2+ and changes in cholinergic activity we analyzed the effects of acetylcholine (Ach on mean arterial blood pressure (ABP in anesthetized rats (N = 9 before and after Hg2+ treatment (5 mg/kg. Using the same amount and route used to study the hemodynamic effects we also examined the effects of Hg2+ administration on heart and plasma cholinesterase activity (N = 10. The in vivo hypotensive response to Ach (0.035 to 10.5 µg was reduced after Hg2+ treatment. Cholinesterase activity (µM h-1 mg protein-1 increased in heart and plasma (32 and 65%, respectively after Hg2+ treatment. In conclusion, the reduction in ABP produced by Hg2+ is not dependent on a putative increase in cholinergic activity. HgCl2 mainly affects cardiac function. The increased pulmonary vascular resistance and cardiac failure due to diastolic

  16. A prospective study of glomerular filtration rate and arterial blood pressure in insulin-dependent diabetics with diabetic nephropathy

    DEFF Research Database (Denmark)

    Parving, H H; Smidt, U M; Friisberg, B

    1981-01-01

    Glomerular filtration rate (GFR, single bolus 51Cr-EDTA technique), serum creatinine, proteinuria and arterial blood pressure have been measured prospectively in 14 young onset insulin-dependent diabetics selected by of persistent proteinuria (greater than 0.5 g/day) secondary to diabetic...... in arterial blood pressure to a hypertensive level is an early feature of diabetic nephropathy in young insulin-dependent diabetics....... and 112/mumol/l (NS), proteinuria increased from 1.8 to 3.3 g/day (p less than 0.001) and arterial blood pressure rose from 132/88 to 153/101 mmHg (p less than 0.001). Glomerular filtration rate decreased linearly with time (slope = -0.75, r = 0.99, p less than 0.001) by a mean of 0.75 ml/min/month (range...

  17. Effect of mechanical behaviour of the brachial artery on blood pressure measurement during both cuff inflation and cuff deflation.

    Science.gov (United States)

    Zheng, Dingchang; Pan, Fan; Murray, Alan

    2013-10-01

    The aim of this study was to investigate the effect of different mechanical behaviour of the brachial artery on blood pressure (BP) measurements during cuff inflation and deflation. BP measurements were taken from each of 40 participants, with three repeat sessions under three randomized cuff deflation/inflation conditions. Cuff pressure was linearly deflated and inflated at a standard rate of 2-3 mmHg/s and also linearly inflated at a fast rate of 5-6 mmHg/s. Manual auscultatory systolic and diastolic BPs, and pulse pressure (SBP, DBP, PP) were measured. Automated BPs were determined from digitally recorded cuff pressures by fitting a polynomial model to the oscillometric pulse amplitudes. The BPs from cuff deflation and inflation were then compared. Repeatable measurements between sessions and between the sequential order of inflation/deflation conditions (all P > 0.1) indicated stability of arterial mechanical behaviour with repeat measurements. Comparing BPs obtained by standard inflation with those from standard deflation, manual SBP was 2.6 mmHg lower (P deflation suggest different arterial mechanical behaviour between arterial opening and closing during BP measurement. We have shown that the mechanical behaviour of the brachial artery during BP measurement differs between cuff deflation and cuff inflation.

  18. Double profunda brachii artery

    Directory of Open Access Journals (Sweden)

    Gavishiddappa A Hadimani

    2016-01-01

    Full Text Available Brachial artery (BA is a continuation of the axillary artery at the lower border of teres major. In the cubital fossa, BA divides into radial artery and ulnar artery as terminal branches. Large branch given from the BA in the upper part is profunda brachii artery. In the present case, we noticed double profunda brachii that arises from the BA. They are profunda brachii artery 1 and profunda brachii artery 2. Profunda brachii artery 1 arises in the proximal part of the BA and profunda brachii artery 2 arises distal to the profunda brachii artery 1. Both the arteries run inferolaterally in the spiral groove along with radial nerve. Variations of profunda brachii artery are important during harvesting of the lateral arm flaps and may lead to inadvertent injury during percutaneous arterial catheterization or injection of drugs.

  19. Effect of beta-1-blocker, nebivolol, on central aortic pressure and arterial stiffness in patients with essential hypertension.

    Science.gov (United States)

    Soanker, Radhika; Naidu, M U R; Raju, Sree Bhushan; Prasad, A Krishna; Rao, T Ramesh Kumar

    2012-05-01

    Blood pressure (BP) reduction is the major determinant of benefit provided by antihypertensive treatment. Although different drugs reduce peripheral BP to some extent, there may be a significant difference in their effect on central BP reduction. It has been shown that beta-blockers are efficient in reducing peripheral, but not central BP. This study was done to assess the effect of beta-1-blocker, nebivolol, in patients with essential hypertension on central aortic pressures and arterial stiffness. In this single arm, open-labeled study, 13 patients were given nebivolol, 5 mg orally once daily for 15 days. Primary outcome was change in central aortic pressure, and other measures of efficacy included changes in brachial BP, augmentation index (AIx%), AIx%@75 HR, augmentation pressure (AP), heart rate (HR), and carotid femoral pulse wave velocity (PWVcf). Nebivolol 5 mg significantly reduced central aortic pressures [systolic BP, 131.5-111.6 mmHg; diastolic BP, 96.3-81.7 mmHg; Mean Arterial Pressure (MAP), 111.3-94.0 mmHg (all PPressure (PP), 35.2-29.7 mmHg (Plost to followup. Nebivolol 5 mg demonstrated antihypertensive efficacy in patients with essential hypertension by reducing not only peripheral brachial pressures, but also significantly reducing central aortic pressures, augmentation index, and carotid femoral pulse wave velocity, which is the marker of arterial stiffness.

  20. Predictors of arterial blood pressure control during deliberate hypotension with sodium nitroprusside in children.

    Science.gov (United States)

    Spielberg, David R; Barrett, Jeffrey S; Hammer, Gregory B; Drover, David R; Reece, Tammy; Cohane, Carol A; Schulman, Scott R

    2014-10-01

    Sodium nitroprusside (SNP) is used to decrease arterial blood pressure (BP) during certain surgical procedures. There are limited data regarding efficacy of BP control with SNP. There are no data on patient and clinician factors that affect BP control. We evaluated the dose-response relationship of SNP in infants and children undergoing major surgery and performed a quantitative assessment of BP control. One hundred fifty-three subjects at 7 sites received a blinded infusion followed by open-label SNP during operative procedures requiring controlled hypotension. SNP was administered by continuous infusion and titrated to maintain BP control (mean arterial BP [MAP] within ±10% of clinician-defined target). BP was recorded using an arterial catheter. Statistical process control methodology was used to quantify BP control. A multivariable model assessed the effects of patient and procedural factors. BP was controlled an average 45.4% (SD 23.9%; 95% CI, 41.5%-49.18%) of the time. Larger changes in infusion rate were associated with worse BP control (7.99% less control for 1 μg·kg·min increase in average titration size, P = 0.0009). A larger difference between a patient's baseline and target MAP predicted worse BP control (0.93% worse control per 1-mm Hg increase in MAP difference, P = 0.0013). Both effects persisted in multivariable models. SNP was effective in reducing BP. However, BP was within the target range less than half of the time. No clinician or patient factors were predictive of BP control, although 2 inverse relationships were identified. These relationships require additional study and may be best coupled with exposure-response modeling to propose improved dosing strategies when using SNP for controlled hypotension in the pediatric population.

  1. Arterial oxygen partial pressures reduce the insulin-dependent induction of the perivenously located glucokinase in rat hepatocyte cultures: mimicry of arterial oxygen pressures by H2O2.

    OpenAIRE

    Kietzmann, T; Roth, U; Freimann, S; Jungermann, K

    1997-01-01

    Liver glucokinase (GK) is localized predominantly in the perivenous zone. GK mRNA was induced by insulin maximally under venous O2 partial pressure (pO2) and only half-maximally under arterial pO2. CoCl2 and desferrioxamine mimicked venous pO2 and enhanced the insulin-dependent induction of GK mRNA under arterial pO2. H2O2 mimicked arterial pO2 and reduced insulin-induced GK mRNA under venous pO2 to the lower arterial levels. Thus the zonal O2 gradient in liver seems to have a key role in the...

  2. Clinical significance of inter-arm pressure difference and ankle-brachial pressure index in patients with suspected coronary artery disease

    International Nuclear Information System (INIS)

    Igarashi, Yuko; Chikamori, Taishiro; Tomiyama, Hirofumi; Usui, Yasuhiro; Hida, Satoshi; Tanaka, Hirokazu; Nagao, Tadashi; Yamashina, Akira

    2007-01-01

    Although measuring blood pressure at the bilateral brachia is common in medical practice, its clinical significance in patients with suspected coronary artery disease (CAD) has not been fully clarified. The method of this study was to define the significance of inter-arm systolic blood pressure difference in patients with suspected CAD, and to assess the relationship between inter-arm pressure difference and CAD, simultaneous brachial and ankle blood pressure measurements and stress myocardial single-photon emission computed tomography (SPECT) were performed in 386 consecutive patients with suspected CAD, excluding those with previous myocardial infarction or coronary revascularization. Subclavian artery stenosis, defined as ≥15 mmHg inter-arm systolic blood pressure difference, was found in 27 patients (7%). Age (65±12 vs 65±11 years), male sex (21/27 vs 244/359), prevalence of hypertension (63% vs 56%), hypercholesterolemia (63% vs 62%), diabetes mellitus (33% vs 38%), cigarette smoking (44% vs 41%) and family history of CAD (15% vs 12%) were similar between patients with subclavian artery stenosis and those without. The incidence of decreased ankle-brachial pressure index (ABI) was higher (37% vs 12%, p=0.001), and percentage ischemic myocardium as assessed by SPECT was greater (9.0±8.5% vs 5.6±6.6%, p=0.05) in patients with subclavian artery stenosis than in those without. Furthermore, significant correlations were observed between inter-arm pressure difference and percentage ischemic myocardium (r=0.13; p=0.01), and ABI (r=-0.26, p<0.0001). Among 386 patients, 283 underwent coronary angiography, and 63% of those who had inter-arm blood pressure difference had CAD. Furthermore, 83% of those CAD patients had multi-vessel CAD, which is regarded as a high-risk subset for subsequent cardiac events. Inter-arm pressure difference is often found in patients with suspected CAD, and is associated with significant CAD and peripheral artery disease. Thus, inter

  3. Results of ambulatory arterial blood pressure monitoring in children with obesity

    Directory of Open Access Journals (Sweden)

    Faruk Öktem

    2010-12-01

    Full Text Available Objectives: The relationship between obesity and essential hypertension is well known. In this study, we aimed to evaluate ambulatory arterial blood pressure monitoring of obese and non-obese children who had similar demographic characteristics.Materials and methods: Seventy one children and adolescents (n=39 obesity, n=32 controls were studied. Blood pressure of the children were measured by 24 hour ambulatory blood pressure monitoring device.Results: Obese children had significantly higher mean blood pressure values (systolic 121.9±11.7 mmHg, diastolic 70.2±5.3 mmHg than control subjects (systolic 109.3±6.7 mmHg, diastolic 65.1±4.6 mmHg, p0.05. Blood pressure load was found to be increased in obese children compared to the controls (%13.6±12.9 and %2.6±3.4, respectively; p<0.05. Serum total cholesterol and LDL-cholesterol levels of obese children (181.1±33.4 and 131.1±23.1mg/dl were significantly higher than those of the controls (134.3±11.1 and 103.3±14.2 mg/dl, p<0.05.Conclusions: Obesity in children and adolescents should not be regarded as variations of normality, but as abnormality with an extremely high risk for the development of hypertension and hyperlipidemia in adulthood.

  4. Reproducibility of proximal and distal transcutaneous oxygen pressure measurements during exercise in stage 2 arterial claudication.

    Science.gov (United States)

    Bouyé, P; Picquet, J; Jaquinandi, V; Enon, B; Leftheriotis, G; Saumet, J-L; Abraham, P

    2004-06-01

    Although transcutaneous oxygen pressure measurements (tcpO2) are largely used in the investigation of vascular patients, its reproducibility is still debated. Indeed an unpredictable gradient exists between arterial and transcutaneous oxygen pressure. We hypothesised that indices taking into account changes over time and independent of absolute starting values would be more reproducible than other indices. comparative test-retest procedure (1 to 13 days between tests). institutional practice, ambulatory care. 15 subjects with stage 2 claudication. tcpO2 recordings at rest and at exercise during the 2 treadmill tests. calculation of the Delta-from-rest of oxygen pressure index (limb tcpO2 changes minus chest tcpO2 changes), of the resting - or minimal values attained during exercise - of absolute tcpO2 and of the regional perfusion index (regional perfusion index: ration of limb to chest). Both absolute tcpO2 and regional perfusion index at rest showed low reproducibility. During exercise the best reproducibility was attained through Delta-from-rest of oxygen pressure index calculation. Equations from the linear regression analysis (test 2 versus test 1) were 0.88 x -4.2 (r(2)=0.82) at the buttock level and 0.82 x -3.8 (r(2)=0.80) at the calf level. TcpO2 measurement on the calf or buttock during exercise, is a reproducible measurement in patients with vascular claudication, specifically when corrected for exercise-induced systemic pO2 changes trough Delta-from-rest of oxygen pressure calculation.

  5. Should mean arterial pressure be included in the definition of ambulatory hypertension in children?

    Science.gov (United States)

    Suláková, Terezie; Feber, Janusz

    2013-07-01

    The diagnosis of hypertension (HTN)/normotension (NT) on ambulatory blood pressure monitoring (ABPM) is usually based on systolic (SBP) or diastolic blood pressure (DBP). The goal of this study was to analyze whether inclusion of mean arterial pressure (MAP) improves the detection of HTN on ABPM. We retrospectively studied ABPM records in 229 children (116 boys, median age = 15.3 years) who were referred for evaluation of HTN. A diagnosis of HTN was made if: (A) MAP or SBP or DBP was ≥ 1.65 SDS (95th percentile); (B) SBP or DBP was ≥ 1.65 SDS (95th percentile), during 24-h or daytime or night-time in both definitions. Using definition A, 46/229 patients had HTN compared to definition B by which only 37/229 patients had HTN (p = 0.001). The level of agreement between the two definitions was very good (kappa = 0.86 ± 0.04), however nine patients (19.5 %) were missed by not using MAP in the definition of HTN. These nine patients had only mild HTN with a median Z score of 1.69. The inclusion of MAP in the definition of ambulatory HTN significantly increased the number of hypertensive patients. MAP may be very helpful in detecting mild HTN in patients with normal/borderline SBP and DBP.

  6. Association of vitamin D status with arterial blood pressure and hypertension risk

    DEFF Research Database (Denmark)

    Vimaleswaran, Karani S; Cavadino, Alana; Berry, Diane J

    2014-01-01

    BACKGROUND: Low plasma 25-hydroxyvitamin D (25[OH]D) concentration is associated with high arterial blood pressure and hypertension risk, but whether this association is causal is unknown. We used a mendelian randomisation approach to test whether 25(OH)D concentration is causally associated...... with blood pressure and hypertension risk. METHODS: In this mendelian randomisation study, we generated an allele score (25[OH]D synthesis score) based on variants of genes that affect 25(OH)D synthesis or substrate availability (CYP2R1 and DHCR7), which we used as a proxy for 25(OH)D concentration. We meta......, -0·12 mm Hg, 95% CI -0·20 to -0·04; p=0·003) and reduced odds of hypertension (odds ratio [OR] 0·98, 95% CI 0·97-0·99; p=0·0003), but not with decreased diastolic blood pressure (β per 10% increase, -0·02 mm Hg, -0·08 to 0·03; p=0·37). In meta-analyses in which we combined data from D...

  7. Robust motion artefact resistant circuit for calculation of Mean Arterial Pressure from pulse transit time.

    Science.gov (United States)

    Bhattacharya, Tinish; Gupta, Ankesh; Singh, Salam ThoiThoi; Roy, Sitikantha; Prasad, Anamika

    2017-07-01

    Cuff-less and non-invasive methods of Blood Pressure (BP) monitoring have faced a lot of challenges like stability, noise, motion artefact and requirement for calibration. These factors are the major reasons why such devices do not get approval from the medical community easily. One such method is calculating Blood Pressure indirectly from pulse transit time (PTT) obtained from electrocardiogram (ECG) and Photoplethysmogram (PPG). In this paper we have proposed two novel analog signal conditioning circuits for ECG and PPG that increase stability, remove motion artefacts, remove the sinusoidal wavering of the ECG baseline due to respiration and provide consistent digital pulses corresponding to blood pulses/heart-beat. We have combined these two systems to obtain the PTT and then correlated it with the Mean Arterial Pressure (MAP). The aim was to perform major part of the processing in analog domain to decrease processing load over microcontroller so as to reduce cost and make it simple and robust. We have found from our experiments that the proposed circuits can calculate the Heart Rate (HR) with a maximum error of ~3.0% and MAP with a maximum error of ~2.4% at rest and ~4.6% in motion.

  8. Serum Endoglin Levels in Patients Suffering from Systemic Sclerosis and Elevated Systolic Pulmonary Arterial Pressure

    Directory of Open Access Journals (Sweden)

    Paola Ximena Coral-Alvarado

    2010-01-01

    Full Text Available Background. Pulmonary arterial hypertension (PAH is the main cause of morbimortality in systemic sclerosis (SSc. Increased Eng expression has been demonstrated in SSc patients. Objective. Ascertaining serum levels of Eng in SSc patients with and without elevated systolic pulmonary arterial pressure (sPAP and comparing them with that of healthy volunteers. Methods. A cross-sectional study was carried out. A commercial ELISA kit was used for measuring serum concentrations of Eng in 60 subjects: 40 patients with SSc with and without elevated sPAP, compared to 20 healthy control subjects. Elevated sPAP was detected by echocardiogram. Results. No association between positive Eng and elevated sPAP was found when compared to the SSc without elevated sPAP group (OR=2.85; 0.65–12.88 95% CI; P=.11; however, an association was found between positive Eng and elevated sPAP compared to healthy controls (OR=23.22; 2.46–1050.33 95% CI; P=.001, and weak association was found between the positive Eng with SSc without elevated sPAP group compared to healthy controls (OR=8.14, 0.8–393.74 95% CI; P=.046. Conclusion. Raised serum levels of Eng in SSc patients compared to healthy controls were found, suggesting a role for Eng in SSc vasculopathy and not just in elevated sPAP. However, prospective studies are needed to verify such observations.

  9. Influence of isoflurane on the diastolic pressure-flow relationship and critical occlusion pressure during arterial CABG surgery: a randomized controlled trial

    OpenAIRE

    Hinz, Jos?; Mansur, Ashham; Hanekop, Gerd G.; Weyland, Andreas; Popov, Aron F.; Schmitto, Jan D.; Gr?ne, Frank F. G.; Bauer, Martin; Kazmaier, Stephan

    2016-01-01

    The effects of isoflurane on the determinants of blood flow during Coronary Artery Bypass Graft (CABG) surgery are not completely understood. This study characterized the influence of isoflurane on the diastolic Pressure-Flow (P-F) relationship and Critical Occlusion Pressure (COP) during CABG surgery. Twenty patients undergoing CABG surgery were studied. Patients were assigned to an isoflurane or control group. Hemodynamic and flow measurements during CABG surgery were perf...

  10. Trial occlusion to assess the risk of persistent pulmonary arterial hypertension after closure of a large patent ductus arteriosus in adolescents and adults with elevated pulmonary artery pressure.

    Science.gov (United States)

    Zhang, Duan-Zhen; Zhu, Xian-Yang; Lv, Bei; Cui, Chun-Sheng; Han, Xiu-Min; Sheng, Xiao-Tang; Wang, Qi-Guang; Zhang, Po

    2014-08-01

    No method is available to predict whether patients with patent ductus arteriosus (PDA) and severe pulmonary arterial hypertension (PAH) will show persistent postprocedural PAH (PP-PAH) after PDA closure. This study evaluated the usefulness of trial occlusion for predicting PP-PAH after transcatheter PDA closure in patients with severe PAH. Trial occlusion was performed in 137 patients (age ≥12 years) with PDA and severe PAH. All patients undergoing trial occlusion had a mean pulmonary artery pressure ≥45 mm Hg, pulmonary:systemic flow (Qp/Qs) ratio >1.5, and pulmonary:systemic resistance (Rp/Rs) ratio closure. Linear correlation analysis revealed weak or moderate relationships between the baseline and post-trial pulmonary artery pressures and pulmonary:systemic pressure (Pp/Ps) ratios. Patients were followed up for 1 to 10 years (median: 5 years). PP-PAH (systolic pulmonary artery pressure >50 mm Hg by Doppler echocardiography) was detected in 17 patients (13%), who displayed no significant differences in sex and age compared with patients without PP-PAH. According to discriminant analysis, the strongest discriminators between patients with and without PP-PAH were the baseline left ventricular end-diastolic volume and the baseline and post-trial systolic Pp/Ps ratios. In particular, a post-trial systolic Pp/Ps ratio >0.5 correctly classified 100% of the PP-PAH and non-PAH patients. Trial occlusion is a feasible method to predict PP-PAH in patients with PDA and severe PAH. A post-trial systolic Pp/Ps ratio >0.5 indicates a high risk of PP-PAH occurrence after device closure. © 2014 American Heart Association, Inc.

  11. Does Psychosocial Work Environment Factors Predict Stress and Mean Arterial Pressure in the Malaysian Industry Workers?

    Directory of Open Access Journals (Sweden)

    Muhammad Umair Javaid

    2018-01-01

    Full Text Available Psychosocial risks are considered as a burning issue in the Asia-Pacific region. The aim of this study was to investigate the impact of psychosocial work environment factors on health of petrochemical industry workers of Malaysia. In lieu to job demands-resources theory, significant positive associations were found between quantitative demands, work-family conflict, and job insecurity with stress, while a significant negative association of role clarity as a resource factor with stress was detected. We also found that quantitative demands were significantly associated with the mean arterial pressure (MAP. Multistage sampling procedure was used to collect study sample. Structural Equation Modeling was used to identify relationship between the endogenous and exogenous variables. Finally, the empirically tested psychosocial work environment model will further help in providing a better risk assessment in different industries and enterprises.

  12. Does Psychosocial Work Environment Factors Predict Stress and Mean Arterial Pressure in the Malaysian Industry Workers?

    Science.gov (United States)

    Javaid, Muhammad Umair; Isha, Ahmad Shahrul Nizam; Sabir, Asrar Ahmed; Ghazali, Zulkipli; Nübling, Matthias

    2018-01-01

    Psychosocial risks are considered as a burning issue in the Asia-Pacific region. The aim of this study was to investigate the impact of psychosocial work environment factors on health of petrochemical industry workers of Malaysia. In lieu to job demands-resources theory, significant positive associations were found between quantitative demands, work-family conflict, and job insecurity with stress, while a significant negative association of role clarity as a resource factor with stress was detected. We also found that quantitative demands were significantly associated with the mean arterial pressure (MAP). Multistage sampling procedure was used to collect study sample. Structural Equation Modeling was used to identify relationship between the endogenous and exogenous variables. Finally, the empirically tested psychosocial work environment model will further help in providing a better risk assessment in different industries and enterprises.

  13. Noninvasive pulmonary artery pressure monitoring by EIT: a model-based feasibility study.

    Science.gov (United States)

    Proença, Martin; Braun, Fabian; Solà, Josep; Thiran, Jean-Philippe; Lemay, Mathieu

    2017-06-01

    Current monitoring modalities for patients with pulmonary hypertension (PH) are limited to invasive solutions. A novel approach for the noninvasive and unsupervised monitoring of pulmonary artery pressure (PAP) in patients with PH was proposed and investigated. The approach was based on the use of electrical impedance tomography (EIT), a noninvasive and safe monitoring technique, and was tested through simulations on a realistic 4D bio-impedance model of the human thorax. Changes in PAP were induced in the model by simulating multiple types of hypertensive conditions. A timing parameter physiologically linked to the PAP via the so-called pulse wave velocity principle was automatically estimated from the EIT data. It was found that changes in PAP could indeed be reliably monitored by EIT, irrespective of the pathophysiological condition that caused them. If confirmed clinically, these findings could open the way for a new generation of noninvasive PAP monitoring solutions for the follow-up of patients with PH.

  14. Dependency of cerebral blood flow upon mean arterial pressure in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten; Larsen, Fin Stolze; Qvist, Jesper

    2000-01-01

    Diseases, Copenhagen University Hospital, Denmark. PATIENTS: Sixteen adult patients with acute bacterial meningitis. INTERVENTION: Infusion of norepinephrine to increase MAP. MEASUREMENTS: During a rise in MAP induced by norepinephrine infusion, we measured relative changes in CBF by transcranial Doppler......OBJECTIVE: Patients with acute bacterial meningitis are often treated with sympathomimetics to maintain an adequate mean arterial pressure (MAP). We studied the influence of such therapy on cerebral blood flow (CBF). DESIGN: Prospective physiologic trial. SETTING: The Department of Infectious....... Autoregulation was classified as impaired if Vmean increased by >10% per 30 mm Hg increase in MAP and if no lower limit of autoregulation was identified by the computer program; otherwise, autoregulation was classified as preserved. MAIN RESULTS: Initially, Vmean increased from a median value of 46 cm/sec (range...

  15. Treatment of hypertension and metabolic syndrome: lowering blood pressure is not enough for organ protection, new approach-arterial destiffening.

    Science.gov (United States)

    Zimlichman, Reuven

    2014-10-01

    Cardiovascular risk factors (CVRFs) have been shown to induce end organ damage. Until now, the main approach to reduce CVRF-induced end organ damage was by normalization of CVRFs; this approach was found effective to reduce damage and cardiovascular (CV) events. However, a residual risk always remained even when CVRFs were optimally balanced. An additional risk factor which has an immense effect on the progression of end organ damage is aging. Aging is accompanied by gradual stiffening of the arteries which finally leads to CV events. Until recently, the process of arterial aging was considered as unmodifiable, but this has changed. Arterial stiffening caused by the aging process is similar to the changes seen as a result of CVRF-induced arterial damage. Actually, the presence of CVRFs causes faster arterial stiffening, and the extent of damage is proportional to the severity of the CVRF, the length of its existence, the patient's genetic factors, etc. Conventional treatments of osteoporosis and of hormonal decline at menopause are potential additional approaches to positively affect progression of arterial stiffening. The new approach to further decrease progression of arteriosclerosis, thus preventing events, is the prevention of age-associated arterial structural changes. This approach should further decrease age-associated arterial stiffening. A totally new promising approach is to study the possibility of affecting collagen, elastin, and other components of connective tissue that participate in the process of arterial stiffening. Reduction of pulse pressure by intervention in arterial stiffening process by novel methods as breaking collagen cross-links or preventing their formation is an example of future directions in treatment. This field is of enormous potential that might be revolutionary in inducing further significant reduction of cardiovascular events.

  16. Threshold value of home pulse pressure predicting arterial stiffness in patients with type 2 diabetes: KAMOGAWA-HBP study.

    Science.gov (United States)

    Kitagawa, Noriyuki; Ushigome, Emi; Matsumoto, Shinobu; Oyabu, Chikako; Ushigome, Hidetaka; Yokota, Isao; Asano, Mai; Tanaka, Muhei; Yamazaki, Masahiro; Fukui, Michiaki

    2018-03-01

    This cross-sectional multicenter study was designed to evaluate the threshold value of home pulse pressure (PP) and home systolic blood pressure (SBP) predicting the arterial stiffness in 876 patients with type 2 diabetes. We measured the area under the receiver-operating characteristic curve (AUC) and estimated the ability of home PP to identify arterial stiffness using Youden-Index defined cut-off point. The arterial stiffness was measured using the brachial-ankle pulse wave velocity (baPWV). AUC for arterial stiffness in morning PP was significantly greater than that in morning SBP (P AUC for arterial stiffness in evening PP was also significantly greater than that in evening SBP (P < .001). The optimal cut-off points for morning PP and evening PP, which predicted arterial stiffness, were 54.6 and 56.9 mm Hg, respectively. Our findings indicate that we should pay more attention to increased home PP in patients with type 2 diabetes. ©2018 Wiley Periodicals, Inc.

  17. Effects of Weather and Heliophysical Conditions on Emergency Ambulance Calls for Elevated Arterial Blood Pressure

    Directory of Open Access Journals (Sweden)

    Jone Vencloviene

    2015-02-01

    Full Text Available We hypothesized that weather and space weather conditions were associated with the exacerbation of essential hypertension. The study was conducted during 2009–2010 in the city of Kaunas, Lithuania. We analyzed 13,475 cards from emergency ambulance calls (EACs, in which the conditions for the emergency calls were made coded I.10–I.15. The Kaunas Weather Station provided daily records of air temperature (T, wind speed (WS, relative humidity, and barometric pressure (BP. We evaluated the associations between daily weather variables and daily number of EACs by applying a multivariate Poisson regression. Unfavorable heliophysical conditions (two days after the active-stormy geomagnetic field or the days with solar WS > 600 km/s increased the daily number of elevated arterial blood pressure (EABP by 12% (RR = 1.12; 95% confidence interval (CI 1.04–1.21; and WS ≥ 3.5 knots during days of T < 1.5 °C and T ≥ 12.5 °C by 8% (RR = 1.08; CI 1.04–1.12. An increase of T by 10 °C and an elevation of BP two days after by 10 hPa were associated with a decrease in RR by 3%. An additional effect of T was detected during days of T ≥ 17.5 °C only in females. Women and patients with grade III arterial hypertension at the time of the ambulance call were more sensitive to weather conditions. These results may help in the understanding of the population’s sensitivity to different weather conditions.

  18. Location of the internal carotid artery and ophthalmic artery segments for non-invasive intracranial pressure measurement by multi-depth TCD.

    Science.gov (United States)

    Hamarat, Yasin; Deimantavicius, Mantas; Kalvaitis, Evaldas; Siaudvytyte, Lina; Januleviciene, Ingrida; Zakelis, Rolandas; Bartusis, Laimonas

    2017-12-01

    The aim of the present study was to locate the ophthalmic artery by using the edge of the internal carotid artery (ICA) as the reference depth to perform a reliable non-invasive intracranial pressure measurement via a multi-depth transcranial Doppler device and to then determine the positions and angles of an ultrasonic transducer (UT) on the closed eyelid in the case of located segments. High tension glaucoma (HTG) patients and healthy volunteers (HVs) undergoing non-invasive intracranial pressure measurement were selected for this prospective study. The depth of the edge of the ICA was identified, followed by a selection of the depths of the IOA and EOA segments. The positions and angles of the UT on the closed eyelid were measured. The mean depth of the identified ICA edge for HTG patients was 64.3 mm and was 63.0 mm for HVs (p = 0.21). The mean depth of the selected IOA segment for HTG patients was 59.2 mm and 59.3 mm for HVs (p = 0.91). The mean depth of the selected EOA segment for HTG patients was 48.5 mm and 49.8 mm for HVs (p = 0.14). The difference in the located depths of the segments between groups was not statistically significant. The results showed a significant difference in the measured UT angles in the case of the identified edge of the ICA and selected ophthalmic artery segments (p = 0.0002). We demonstrated that locating the IOA and EOA segments can be achieved using the edge of the ICA as a reference point. OA: ophthalmic artery; IOA: intracranial segments of the ophthalmic artery; EOA: extracranial segments of the ophthalmic artery; ICA: internal carotid artery; UT: ultrasonic transducer; HTG: high tension glaucoma; SD: standard deviation; ICP: intracranial pressure; TCD: transcranial Doppler.

  19. Dedicated radial ventriculography pigtail catheter

    Energy Technology Data Exchange (ETDEWEB)

    Vidovich, Mladen I., E-mail: miv@uic.edu

    2013-05-15

    A new dedicated cardiac ventriculography catheter was specifically designed for radial and upper arm arterial access approach. Two catheter configurations have been developed to facilitate retrograde crossing of the aortic valve and to conform to various subclavian, ascending aortic and left ventricular anatomies. The “short” dedicated radial ventriculography catheter is suited for horizontal ascending aortas, obese body habitus, short stature and small ventricular cavities. The “long” dedicated radial ventriculography catheter is suited for vertical ascending aortas, thin body habitus, tall stature and larger ventricular cavities. This new design allows for improved performance, faster and simpler insertion in the left ventricle which can reduce procedure time, radiation exposure and propensity for radial artery spasm due to excessive catheter manipulation. Two different catheter configurations allow for optimal catheter selection in a broad range of patient anatomies. The catheter is exceptionally stable during contrast power injection and provides equivalent cavity opacification to traditional femoral ventriculography catheter designs.

  20. Continuous estimates of dynamic cerebral autoregulation: influence of non-invasive arterial blood pressure measurements

    International Nuclear Information System (INIS)

    Panerai, R B; Smith, S M; Rathbone, W E; Samani, N J; Sammons, E L; Bentley, S; Potter, J F

    2008-01-01

    Temporal variability of parameters which describe dynamic cerebral autoregulation (CA), usually quantified by the short-term relationship between arterial blood pressure (BP) and cerebral blood flow velocity (CBFV), could result from continuous adjustments in physiological regulatory mechanisms or could be the result of artefacts in methods of measurement, such as the use of non-invasive measurements of BP in the finger. In 27 subjects (61 ± 11 years old) undergoing coronary artery angioplasty, BP was continuously recorded at rest with the Finapres device and in the ascending aorta (Millar catheter, BP AO ), together with bilateral transcranial Doppler ultrasound in the middle cerebral artery, surface ECG and transcutaneous CO 2 . Dynamic CA was expressed by the autoregulation index (ARI), ranging from 0 (absence of CA) to 9 (best CA). Time-varying, continuous estimates of ARI (ARI(t)) were obtained with an autoregressive moving-average (ARMA) model applied to a 60 s sliding data window. No significant differences were observed in the accuracy and precision of ARI(t) between estimates derived from the Finapres and BP AO . Highly significant correlations were obtained between ARI(t) estimates from the right and left middle cerebral artery (MCA) (Finapres r = 0.60 ± 0.20; BP AO r = 0.56 ± 0.22) and also between the ARI(t) estimates from the Finapres and BP AO (right MCA r = 0.70 ± 0.22; left MCA r = 0.74 ± 0.22). Surrogate data showed that ARI(t) was highly sensitive to the presence of noise in the CBFV signal, with both the bias and dispersion of estimates increasing for lower values of ARI(t). This effect could explain the sudden drops of ARI(t) to zero as reported previously. Simulated sudden changes in ARI(t) can be detected by the Finapres, but the bias and variability of estimates also increase for lower values of ARI. In summary, the Finapres does not distort time-varying estimates of dynamic CA obtained with a sliding window combined with an ARMA model

  1. Neural set point for the control of arterial pressure: role of the nucleus tractus solitarius

    Directory of Open Access Journals (Sweden)

    Valentinuzzi Max E

    2010-01-01

    Full Text Available Abstract Background Physiological experiments have shown that the mean arterial blood pressure (MAP can not be regulated after chemo and cardiopulmonary receptor denervation. Neuro-physiological information suggests that the nucleus tractus solitarius (NTS is the only structure that receives information from its rostral neural nuclei and from the cardiovascular receptors and projects to nuclei that regulate the circulatory variables. Methods From a control theory perspective, to answer if the cardiovascular regulation has a set point, we should find out whether in the cardiovascular control there is something equivalent to a comparator evaluating the error signal (between the rostral projections to the NTS and the feedback inputs. The NTS would function as a comparator if: a its lesion suppresses cardiovascular regulation; b the negative feedback loop still responds normally to perturbations (such as mechanical or electrical after cutting the rostral afferent fibers to the NTS; c perturbation of rostral neural structures (RNS to the NTS modifies the set point without changing the dynamics of the elicited response; and d cardiovascular responses to perturbations on neural structures within the negative feedback loop compensate for much faster than perturbations on the NTS rostral structures. Results From the control theory framework, experimental evidence found currently in the literature plus experimental results from our group was put together showing that the above-mentioned conditions (to show that the NTS functions as a comparator are satisfied. Conclusions Physiological experiments suggest that long-term blood pressure is regulated by the nervous system. The NTS functions as a comparator (evaluating the error signal between its RNS and the cardiovascular receptor afferents and projects to nuclei that regulate the circulatory variables. The mean arterial pressure (MAP is regulated by the feedback of chemo and cardiopulmonary receptors and

  2. Impact of lipopolysaccharide-induced acute inflammation on baroreflex-controlled sympathetic arterial pressure regulation.

    Directory of Open Access Journals (Sweden)

    Takeshi Tohyama

    Full Text Available Lipopolysaccharide (LPS induces acute inflammation, activates sympathetic nerve activity (SNA and alters hemodynamics. Since the arterial baroreflex is a negative feedback system to stabilize arterial pressure (AP, examining the arterial baroreflex function is a prerequisite to understanding complex hemodynamics under LPS challenge. We investigated the impact of LPS-induced acute inflammation on SNA and AP regulation by performing baroreflex open-loop analysis.Ten anesthetized Sprague-Dawley rats were used. Acute inflammation was induced by an intravenous injection of LPS (60 μg/kg. We isolated the carotid sinuses from the systemic circulation and controlled carotid sinus pressure (CSP by a servo-controlled piston pump. We matched CSP to AP to establish the baroreflex closed-loop condition, whereas we decoupled CSP from AP to establish the baroreflex open-loop condition and changed CSP stepwise to evaluate the baroreflex open-loop function. We recorded splanchnic SNA and hemodynamic parameters under baroreflex open- and closed-loop conditions at baseline and at 60 and 120 min after LPS injection.In the baroreflex closed-loop condition, SNA continued to increase after LPS injection, reaching three-fold the baseline value at 120 min (baseline: 94.7 ± 3.6 vs. 120 min: 283.9 ± 31.9 a.u.. In contrast, AP increased initially (until 75 min, then declined to the baseline level. In the baroreflex open-loop condition, LPS reset the neural arc (CSP-SNA relationship upward to higher SNA, while shifted the peripheral arc (SNA-AP relationship downward at 120 min after the injection. As a result, the operating point determined by the intersection between function curves of neural arc and peripheral arc showed marked sympatho-excitation without substantial changes in AP.LPS-induced acute inflammation markedly increased SNA via resetting of the baroreflex neural arc, and suppressed the peripheral arc. The balance between the augmented neural arc and

  3. Impact of lipopolysaccharide-induced acute inflammation on baroreflex-controlled sympathetic arterial pressure regulation.

    Science.gov (United States)

    Tohyama, Takeshi; Saku, Keita; Kawada, Toru; Kishi, Takuya; Yoshida, Keimei; Nishikawa, Takuya; Mannoji, Hiroshi; Kamada, Kazuhiro; Sunagawa, Kenji; Tsutsui, Hiroyuki

    2018-01-01

    Lipopolysaccharide (LPS) induces acute inflammation, activates sympathetic nerve activity (SNA) and alters hemodynamics. Since the arterial baroreflex is a negative feedback system to stabilize arterial pressure (AP), examining the arterial baroreflex function is a prerequisite to understanding complex hemodynamics under LPS challenge. We investigated the impact of LPS-induced acute inflammation on SNA and AP regulation by performing baroreflex open-loop analysis. Ten anesthetized Sprague-Dawley rats were used. Acute inflammation was induced by an intravenous injection of LPS (60 μg/kg). We isolated the carotid sinuses from the systemic circulation and controlled carotid sinus pressure (CSP) by a servo-controlled piston pump. We matched CSP to AP to establish the baroreflex closed-loop condition, whereas we decoupled CSP from AP to establish the baroreflex open-loop condition and changed CSP stepwise to evaluate the baroreflex open-loop function. We recorded splanchnic SNA and hemodynamic parameters under baroreflex open- and closed-loop conditions at baseline and at 60 and 120 min after LPS injection. In the baroreflex closed-loop condition, SNA continued to increase after LPS injection, reaching three-fold the baseline value at 120 min (baseline: 94.7 ± 3.6 vs. 120 min: 283.9 ± 31.9 a.u.). In contrast, AP increased initially (until 75 min), then declined to the baseline level. In the baroreflex open-loop condition, LPS reset the neural arc (CSP-SNA relationship) upward to higher SNA, while shifted the peripheral arc (SNA-AP relationship) downward at 120 min after the injection. As a result, the operating point determined by the intersection between function curves of neural arc and peripheral arc showed marked sympatho-excitation without substantial changes in AP. LPS-induced acute inflammation markedly increased SNA via resetting of the baroreflex neural arc, and suppressed the peripheral arc. The balance between the augmented neural arc and suppressed

  4. Ambulatory (24 h) blood pressure and arterial stiffness measurement in Marfan syndrome patients: a case control feasibility and pilot study.

    Science.gov (United States)

    Hillebrand, Matthias; Nouri, Ghazaleh; Hametner, Bernhard; Parragh, Stephanie; Köster, Jelena; Mortensen, Kai; Schwarz, Achim; von Kodolitsch, Yskert; Wassertheurer, Siegfried

    2016-05-06

    The aim of this work is the investigation of measures of ambulatory brachial and aortic blood pressure and indices of arterial stiffness and aortic wave reflection in Marfan patients. A case-control study was conducted including patients with diagnosed Marfan syndrome following Ghent2 nosology and healthy controls matched for sex, age and daytime brachial systolic blood pressure. For each subject a 24 h ambulatory blood pressure and 24 h pulse wave analysis measurement was performed. All parameters showed a circadian pattern whereby pressure dipping was more pronounced in Marfan patients. During daytime only Marfan patients with aortic root surgery showed increased pulse wave velocity. In contrast, various nighttime measurements, wave reflection determinants and circadian patterns showed a significant difference. The findings of our study provide evidence that ambulatory measurement of arterial stiffness parameters is feasible and that these determinants are significantly different in Marfan syndrome patients compared to controls in particular at nighttime. Further investigation is therefore indicated.

  5. Pressão arterial entre trabalhadores de curtume Blood pressure among tannery workers

    Directory of Open Access Journals (Sweden)

    Ricardo Cordeiro

    1998-10-01

    Full Text Available INTRODUÇÃO: O grupo das doenças cardiovasculares tem sido apontado como a principal causa de óbito no Brasil desde os anos 70, sendo a hipertensão arterial sistêmica (HAS o fator de risco mais importante para esse grupo. Entre os trabalhadores observa-se correlação negativa entre o status ocupacional e a pressão arterial. Tais fatos ressaltam a importância do conhecimento da distribuição da pressão arterial sistêmica entre os distintos grupos profissionais. Assim, foi realizado estudo para descrever o status pressórico de uma população homogênea e estável de trabalhadores do setor secundário da economia, pouco especializados e que ganham baixos salários, estabelecendo a prevalência da HAS nesse grupo específico, relacionando-a com algumas covariáveis biológicas e socioeconômicas, e comparando-a com a prevalência de HAS em outros grupos profissionais no Brasil. MÉTODO: Foram estudados 73 trabalhadores regularmente empregados em julho de 1993 em um curtume situado no Município de Botucatu, cidade de médio porte da região Centro-Oeste do Estado de São Paulo, os quais foram submetidos a exame antropométrico, aferição de pressão arterial, anamnese e exame clínico. Os resultados foram comparados com os obtidos em estudos semelhantes, controlando-se o confundimento da idade por intermédio de diferentes técnicas. RESULTADOS: A prevalência bruta da HAS encontrada foi de 56,1%, sendo 15,8% a prevalência de hipertensão sistólica isolada. Ambas se associaram ao etilismo e ao tabagismo na população estudada. DISCUSSÃO: A prevalência da hipertensão foi consideravelmente alta e significativamente maior do que a encontrada em outros grupos de trabalhadores estudados no Brasil. Tal achado ressalta a necessidade da continuidade da investigação, objetivando o isolamento dos fatores implicados na elevação pressórica do grupo estudado.INTRODUCTION: Cardiovascular diseases have been shown to be the leading cause of

  6. Effects of sodium and potassium supplementation on blood pressure and arterial stiffness: a fully controlled dietary intervention study

    NARCIS (Netherlands)

    Gijsbers, L.; Dower, J.I.; Mensink, M.R.; Siebelink, A.E.; Bakker, S.J.L.; Geleijnse, J.M.

    2015-01-01

    We performed a randomised, placebo-controlled, crossover study to examine the effects of sodium and potassium supplementation on blood pressure (BP) and arterial stiffness in untreated (pre)hypertensive individuals. During the study, subjects were on a fully controlled diet that was relatively low

  7. Classifying Acute Respiratory Distress Syndrome Severity: Correcting the Arterial Oxygen Partial Pressure to Fractional Inspired Oxygen at Altitude.

    Science.gov (United States)

    Pérez-Padilla, Rogelio; Hernández-Cárdenas, Carmen Margarita; Lugo-Goytia, Gustavo

    2016-01-01

    In the well-known Berlin definition of acute respiratory distress syndrome (ARDS), there is a recommended adjustment for arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FIO2) at altitude, but without a reference as to how it was derived.

  8. Association between administered oxygen, arterial partial oxygen pressure and mortality in mechanically ventilated intensive care unit patients

    NARCIS (Netherlands)

    de Jonge, Evert; Peelen, Linda; Keijzers, Peter J.; Joore, Hans; de Lange, Dylan; van der Voort, Peter Hj; Bosman, Robert J.; de Waal, Ruud Al; Wesselink, Ronald; de Keizer, Nicolette F.

    2008-01-01

    Introduction The aim of this study was to investigate whether in-hospital mortality was associated with the administered fraction of oxygen in inspired air (FiO(2)) and achieved arterial partial pressure of oxygen (PaO2). Methods This was a retrospective, observational study on data from the first

  9. Association between administered oxygen, arterial partial oxygen pressure and mortality in mechanically ventilated intensive care unit patients

    NARCIS (Netherlands)

    de Jonge, Evert; Peelen, Linda; Keijzers, Peter J.; Joore, Hans; de Lange, Dylan; van der Voort, Peter H. J.; Bosman, Robert J.; de Waal, Ruud A. L.; Wesselink, Ronald; de Keizer, Nicolette F.

    2008-01-01

    Introduction The aim of this study was to investigate whether in-hospital mortality was associated with the administered fraction of oxygen in inspired air (FiO(2)) and achieved arterial partial pressure of oxygen (PaO(2)). Methods This was a retrospective, observational study on data from the first

  10. Value of systolic pulmonary arterial pressure as a prognostic factor of death in the systemic sclerosis EUSTAR population

    DEFF Research Database (Denmark)

    Hachulla, Eric; Clerson, Pierre; Airò, Paolo

    2015-01-01

    OBJECTIVE: The aim of this study was to assess the prognostic value of systolic pulmonary artery pressure (sPAP) estimated by echocardiography in the multinational European League Against Rheumatism Scleroderma Trial and Research (EUSTAR) cohort. METHODS: Data for patients with echocardiography...

  11. Investigating complex patterns of blocked intestinal artery blood pressure signals by empirical mode decomposition and linguistic analysis

    International Nuclear Information System (INIS)

    Yeh, J-R; Lin, T-Y; Shieh, J-S; Chen, Y; Huang, N E; Wu, Z; Peng, C-K

    2008-01-01

    In this investigation, surgical operations of blocked intestinal artery have been conducted on pigs to simulate the condition of acute mesenteric arterial occlusion. The empirical mode decomposition method and the algorithm of linguistic analysis were applied to verify the blood pressure signals in simulated situation. We assumed that there was some information hidden in the high-frequency part of the blood pressure signal when an intestinal artery is blocked. The empirical mode decomposition method (EMD) has been applied to decompose the intrinsic mode functions (IMF) from a complex time series. But, the end effects and phenomenon of intermittence damage the consistence of each IMF. Thus, we proposed the complementary ensemble empirical mode decomposition method (CEEMD) to solve the problems of end effects and the phenomenon of intermittence. The main wave of blood pressure signals can be reconstructed by the main components, identified by Monte Carlo verification, and removed from the original signal to derive a riding wave. Furthermore, the concept of linguistic analysis was applied to design the blocking index to verify the pattern of riding wave of blood pressure using the measurements of dissimilarity. Blocking index works well to identify the situation in which the sampled time series of blood pressure signal was recorded. Here, these two totally different algorithms are successfully integrated and the existence of the existence of information hidden in high-frequency part of blood pressure signal has been proven

  12. Investigating complex patterns of blocked intestinal artery blood pressure signals by empirical mode decomposition and linguistic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, J-R; Lin, T-Y; Shieh, J-S [Department of Mechanical Engineering, Yuan Ze University, 135 Far-East Road, Chung-Li, Taoyuan, Taiwan (China); Chen, Y [Far Eastern Memorial Hospital, Taiwan (China); Huang, N E [Research Center for Adaptive Data Analysis, National Central University, Taiwan (China); Wu, Z [Center for Ocean-Land-Atmosphere Studies (United States); Peng, C-K [Beth Israel Deaconess Medical Center, Harvard Medical School (United States)], E-mail: s939205@ mail.yzu.edu.tw

    2008-02-15

    In this investigation, surgical operations of blocked intestinal artery have been conducted on pigs to simulate the condition of acute mesenteric arterial occlusion. The empirical mode decomposition method and the algorithm of linguistic analysis were applied to verify the blood pressure signals in simulated situation. We assumed that there was some information hidden in the high-frequency part of the blood pressure signal when an intestinal artery is blocked. The empirical mode decomposition method (EMD) has been applied to decompose the intrinsic mode functions (IMF) from a complex time series. But, the end effects and phenomenon of intermittence damage the consistence of each IMF. Thus, we proposed the complementary ensemble empirical mode decomposition method (CEEMD) to solve the problems of end effects and the phenomenon of intermittence. The main wave of blood pressure signals can be reconstructed by the main components, identified by Monte Carlo verification, and removed from the original signal to derive a riding wave. Furthermore, the concept of linguistic analysis was applied to design the blocking index to verify the pattern of riding wave of blood pressure using the measurements of dissimilarity. Blocking index works well to identify the situation in which the sampled time series of blood pressure signal was recorded. Here, these two totally different algorithms are successfully integrated and the existence of the existence of information hidden in high-frequency part of blood pressure signal has been proven.

  13. Agreement of high definition oscillometry with direct arterial blood pressure measurement at different blood pressure ranges in horses under general anaesthesia.

    Science.gov (United States)

    Tünsmeyer, Julia; Hopster, Klaus; Feige, Karsten; Kästner, Sabine Br

    2015-05-01

    To determine the agreement of high definition oscillometry (HDO) with direct arterial blood pressure measurements in normotensive, hypotensive and hypertensive horses during general anaesthesia. Experimental study. Seven healthy warmblood horses, aged 3-11 years, weighing 470-565 kg. Measurements from a HDO device with the cuff placed around the base of the tail were compared with pressures measured invasively from the facial artery. High blood pressures were induced by intravenous (IV) administration of dobutamine (5 μg kg(-1) minute(-1)) over ten minutes followed by norepinephrine (0.1 mg kg(-1) IV) and low pressures by increasing the inspired fraction of isoflurane and administration of nitroglycerine (0.05 mg kg(-1) IV). For analysis three pressure levels were determined: high (MAP>110 mmHg), normal (60 mmHgstandard deviation for SAP, MAP and DAP were 0.1 ± 19.4 mmHg, 0.5 ± 14.0, 4.7 ± 15.6, respectively. At high pressure levels bias and SD were 26.1 ± 37.3 (SAP), 4.2 ± 19.4 (MAP), 1.5 ± 16.8 (DAP) and at low pressures -20.0 ± 20.9 (SAP), -11.4 ± 19.6 (MAP), -4.7 ± 20.1 (DAP), with HDO measurements at a MAP <50 mmHg often failing. Good agreement with invasive arterial blood pressures was obtained with HDO at normotensive levels in horses. At high and low pressure ranges HDO was unreliable. Therefore, if haemodynamic instability is expected, invasive measurement remains preferable. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  14. Imaging and modeling of acute pressure-induced changes of collagen and elastin microarchitectures in pig and human resistance arteries.

    Science.gov (United States)

    Bloksgaard, Maria; Leurgans, Thomas M; Spronck, Bart; Heusinkveld, Maarten H G; Thorsted, Bjarne; Rosenstand, Kristoffer; Nissen, Inger; Hansen, Ulla M; Brewer, Jonathan R; Bagatolli, Luis A; Rasmussen, Lars M; Irmukhamedov, Akhmadjon; Reesink, Koen D; De Mey, Jo G R

    2017-07-01

    The impact of disease-related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared with frequently used rodent mesenteric arteries. We hypothesized that the biaxial mechanics of PRA mirror pressure-induced changes in the ECM microarchitecture. This was tested using isolated pig PRA as a model system, integrating vital imaging, pressure myography, and mathematical modeling. Collagenase and elastase digestions were applied to evaluate the load-bearing roles of collagen and elastin, respectively. The incremental elastic modulus linearly related to the straightness of adventitial collagen fibers circumferentially and longitudinally (both R 2 ≥ 0.99), whereas there was a nonlinear relationship to the internal elastic lamina elastin fiber branching angles. Mathematical modeling suggested a collagen recruitment strain (means ± SE) of 1.1 ± 0.2 circumferentially and 0.20 ± 0.01 longitudinally, corresponding to a pressure of ~40 mmHg, a finding supported by the vital imaging. The integrated method was tested on human PRA to confirm its validity. These showed limited circumferential distensibility and elongation and a collagen recruitment strain of 0.8 ± 0.1 circumferentially and 0.06 ± 0.02 longitudinally, reached at a distending pressure below 20 mmHg. This was confirmed by vital imaging showing negligible microarchitectural changes of elastin and collagen upon pressurization. In conclusion, we show here, for the first time in resistance arteries, a quantitative relationship between pressure-induced changes in the extracellular matrix and the arterial wall mechanics. The strength of the integrated methods invites for future detailed studies of microvascular pathologies. NEW & NOTEWORTHY This is the first study to quantitatively relate pressure

  15. Effects of weather and heliophysical conditions on emergency ambulance calls for elevated arterial blood pressure.

    Science.gov (United States)

    Vencloviene, Jone; Babarskiene, Ruta M; Dobozinskas, Paulius; Sakalyte, Gintare; Lopatiene, Kristina; Mikelionis, Nerijus

    2015-02-27

    We hypothesized that weather and space weather conditions were associated with the exacerbation of essential hypertension. The study was conducted during 2009-2010 in the city of Kaunas, Lithuania. We analyzed 13,475 cards from emergency ambulance calls (EACs), in which the conditions for the emergency calls were made coded I.10-I.15. The Kaunas Weather Station provided daily records of air temperature (T), wind speed (WS), relative humidity, and barometric pressure (BP). We evaluated the associations between daily weather variables and daily number of EACs by applying a multivariate Poisson regression. Unfavorable heliophysical conditions (two days after the active-stormy geomagnetic field or the days with solar WS>600 km/s) increased the daily number of elevated arterial blood pressure (EABP) by 12% (RR=1.12; 95% confidence interval (CI) 1.04-1.21); and WS≥3.5 knots during days of Tweather conditions. These results may help in the understanding of the population's sensitivity to different weather conditions.

  16. Prediction of blood pressure and blood flow in stenosed renal arteries using CFD

    Science.gov (United States)

    Jhunjhunwala, Pooja; Padole, P. M.; Thombre, S. B.; Sane, Atul

    2018-04-01

    In the present work an attempt is made to develop a diagnostive tool for renal artery stenosis (RAS) which is inexpensive and in-vitro. To analyse the effects of increase in the degree of severity of stenosis on hypertension and blood flow, haemodynamic parameters are studied by performing numerical simulations. A total of 16 stenosed models with varying degree of stenosis severity from 0-97.11% are assessed numerically. Blood is modelled as a shear-thinning, non-Newtonian fluid using the Carreau model. Computational Fluid Dynamics (CFD) analysis is carried out to compute the values of flow parameters like maximum velocity and maximum pressure attained by blood due to stenosis under pulsatile flow. These values are further used to compute the increase in blood pressure and decrease in available blood flow to kidney. The computed available blood flow and secondary hypertension for varying extent of stenosis are mapped by curve fitting technique using MATLAB and a mathematical model is developed. Based on these mathematical models, a quantification tool is developed for tentative prediction of probable availability of blood flow to the kidney and severity of stenosis if secondary hypertension is known.

  17. Evolution from electrophysiologic to hemodynamic monitoring: the story of left atrial and pulmonary artery pressure monitors

    Directory of Open Access Journals (Sweden)

    Deirdre M Mooney

    2015-10-01

    Full Text Available Heart failure (HF is a costly, challenging and highly prevalent medical condition. Hospitalization for acute decompensation is associated with high morbidity and mortality. Despite application of evidence-based medical therapies and technologies, HF remains a formidable challenge for virtually all healthcare systems. Repeat hospitalizations for acute decompensated HF (ADHF can have major financial impact on institutions and resources. Early and accurate identification of impending ADHF is of paramount importance yet there is limited high quality evidence or infrastructure to guide management in the outpatient setting. Historically, ADHF was identified by physical exam findings or invasive hemodynamic monitoring during a hospital admission; however, advances in medical microelectronics and the advent of device-based diagnostics have enabled long-term ambulatory monitoring of HF patients in the outpatient setting. These monitors have evolved from piggybacking on cardiac implantable electrophysiologic devices to standalone implantable hemodynamic monitors that transduce left atrial or pulmonary artery pressures as surrogate measures of left ventricular filling pressure. As technology evolves, devices will likely continue to miniaturize while their capabilities grow. An important, persistent challenge that remains is developing systems to translate the large volumes of real-time data, particularly data trends, into actionable information that leads to appropriate, safe and timely interventions without overwhelming outpatient cardiology and general medical practices. Future directions for implantable hemodynamic monitors beyond their utility in heart failure may include management of other major chronic diseases such as pulmonary hypertension, end stage renal disease and portal hypertension.

  18. Evolution from electrophysiologic to hemodynamic monitoring: the story of left atrial and pulmonary artery pressure monitors.

    Science.gov (United States)

    Mooney, Deirdre M; Fung, Erik; Doshi, Rahul N; Shavelle, David M

    2015-01-01

    Heart failure (HF) is a costly, challenging and highly prevalent medical condition. Hospitalization for acute decompensation is associated with high morbidity and mortality. Despite application of evidence-based medical therapies and technologies, HF remains a formidable challenge for virtually all healthcare systems. Repeat hospitalizations for acute decompensated HF (ADHF) can have major financial impact on institutions and resources. Early and accurate identification of impending ADHF is of paramount importance yet there is limited high quality evidence or infrastructure to guide management in the outpatient setting. Historically, ADHF was identified by physical exam findings or invasive hemodynamic monitoring during a hospital admission; however, advances in medical microelectronics and the advent of device-based diagnostics have enabled long-term ambulatory monitoring of HF patients in the outpatient setting. These monitors have evolved from piggybacking on cardiac implantable electrophysiologic devices to standalone implantable hemodynamic monitors that transduce left atrial or pulmonary artery pressures as surrogate measures of left ventricular filling pressure. As technology evolves, devices will likely continue to miniaturize while their capabilities grow. An important, persistent challenge that remains is developing systems to translate the large volumes of real-time data, particularly data trends, into actionable information that leads to appropriate, safe and timely interventions without overwhelming outpatient cardiology and general medical practices. Future directions for implantable hemodynamic monitors beyond their utility in heart failure may include management of other major chronic diseases such as pulmonary hypertension, end stage renal disease and portal hypertension.

  19. Random perturbations of arterial blood pressure for the assessment of dynamic cerebral autoregulation

    International Nuclear Information System (INIS)

    Katsogridakis, Emmanuel; Panerai, Ronney B; Bush, Glen; Fan, Lingke; Birch, Anthony A; Simpson, David M; Allen, Robert; Potter, John F

    2012-01-01

    The assessment of cerebral autoregulation (CA) relies mostly on methods that modulate arterial blood pressure (ABP). Despite advances, the gold standard of assessment remains elusive and clinical practicality is limited. We investigate a novel approach of assessing CA, consisting of the intermittent application of thigh cuffs using square wave sequences. Our aim was to increase ABP variability whilst minimizing volunteer discomfort, thus improving assessment acceptability. Two random square wave sequences and two maximum pressure settings (80 and 150 mmHg) were used, corresponding to four manoeuvres that were conducted in random order after a baseline recording. The intermittent application of thigh cuffs resulted in an amplitude dependent increase in ABP (p = 0.001) and cerebral blood flow velocity (CBFV) variability (p = 0.026) compared to baseline. No statistically significant differences in mean heart rate or heart rate variability were observed (p = 0.108 and p = 0.350, respectively), suggesting that no significant sympathetic response was elicited. No significant differences in the CBFV step response were observed, suggesting no distortion of autoregulatory parameters resulted from the use of thigh cuffs. We conclude that pseudorandom binary sequences are an effective and safe alternative for increasing ABP variability. This new approach shows great promise as a tool for the robust assessment of CA. (paper)

  20. Pulmonary Artery Wedge Pressure Relative to Exercise Work Rate in Older Men and Women.

    Science.gov (United States)

    Esfandiari, Sam; Wright, Stephen P; Goodman, Jack M; Sasson, Zion; Mak, Susanna

    2017-07-01

    An augmented pulmonary artery wedge pressure (PAWP) response may explain exercise intolerance in some humans. However, routine use of exercise hemodynamic testing is limited by a lack of data from normal older men and women. Our objective was to evaluate the exercise PAWP response and the potential for sexual dimorphism in healthy, nondyspneic older adults. Thirty-six healthy volunteers (18 men [54 ± 7 yr] and 18 women [58 ± 6 yr]) were studied at rest (control) and during two stages of semi-upright cycle ergometry, at heart rates of 100 bpm (light exercise) and 120 bpm (moderate exercise). Right heart catheterization was performed to measure pulmonary pressures. The PAWP response to exercise was assessed in context of exercise work rate and body size. At control, PAWP was similar between men and women. Work rates were significantly smaller in women at comparable HR (P exercise, with no further increase at moderate exercise. When indexed to work rate alone or work rate adjusted to body weight and height, the PAWP response at light and moderate exercise was significantly elevated in women compared with men (P exercise. The similar rise in the PAWP response to submaximal exercise occurs despite lower work rate in healthy older women compared with men, even when adjusted for smaller body size. It is important to consider sex in the development of normal reference ranges for exercise hemodynamic testing.

  1. Inferior gluteal artery perforator flap: a viable alternative for ischial pressure sores.

    Science.gov (United States)

    Kim, Young Seok; Lew, Dae Hyun; Roh, Tai Suk; Yoo, Won Min; Lee, Won Jai; Tark, Kwan Chul

    2009-10-01

    The ischial area is by far the most common site for pressure sores in wheelchair-bound paraplegic patients, because most of the pressure of the body is exerted on this area in the seated position. Even after a series of successful pressure sore treatments, the site is very prone to relapse from the simplest everyday tasks. Therefore, it is crucial to preserve the main pedicle during primary surgery. Several surgical procedures, such as myocutaneous flap and perforator flap, have been introduced for the treatment of pressure sores. During a 4-year time period at our institute, we found favourable clinical results using the inferior gluteal artery perforator (IGAP) procedure for ischial sore treatment. A total of 23 patients (20 males and three females) received IGAP flap surgery in our hospital from January 2003 to January 2007. Surgery was performed on the same site again in 10 (43%) patients who had originally relapsed after undergoing the conventional method of pressure sore surgery. The average age of patients was 47.4 years (range 26-71 years). Most of the patients were paraplegic (16 cases, 70%) and others were either quadriplegic (four cases, 17%) or ambulatory (three cases, 13%). Based on hospital records and clinical photographs, we attempted to assess the feasibility and practicability of the IGAP flap procedure through comparative analysis of several parameters including the size of the defective area, treatment modalities, relapses, complications, and postoperative treatments. The average follow-up duration for 23 subjects was 25.4 months (range 5-42 months). All flaps survived without major complications. Partial flap necrosis developed in one case but secondary healing was achieved and the final outcome was not impaired. Most of the cases healed well during the follow-up period. Postoperative complications such as wound dehiscence and fistula developed in some subjects, but all healed well with a secondary treatment. A total of five cases relapsed

  2. 1st RCM of IAEA CRP on Prediction of Axial and Radial Creep in HWR Pressure Tubes

    International Nuclear Information System (INIS)

    Choi, Jong-Ho

    2013-01-01

    Expected outcome: Improved understanding of pressure tube creep mechanism by studying the effect of intrinsic (material response) as well as extrinsic parameters (operating conditions). • Improvement of material characterization technology: many laboratories participating in this CRP will conduct the microstructure characterization for the first time. • Recommendation for manufacturing to achieve optimal PT performance: The database will enable the identification of best pressure tube performance by comparison of data. • Improvement in aging management procedure: (channel selection for PT deformation management, etc.). • Safety enhancement for operating HWRs by reducing the uncertainty in the prediction of PT deformation

  3. Low arterial pressure on admission as a predictor of mortality in operated patients with type A aortic dissection

    Directory of Open Access Journals (Sweden)

    Pavlović Katica

    2011-01-01

    Full Text Available Background/Aim. Hypertension is a known predictor of proximal aortic dissection, but it is not commonly present in these patients on presentation. The associations between ascending aorta with left ventricular hypertrophy, cardiovascular risk factors and coronary atherosclerosis, and outcome of these patients are not fully elucidated. Methods. This retrospective study included 55 consecutive patients with acute type A aortic dissection treated surgically in our institution during the last 2 years. The diagnosis was based on imaging studies. Diameter of ascending aorta was measured with echocardiography. Results. The mean age of the patients was 55.4 ± 12.19 years, and 72.7% were men. A history of arterial hypertension was present in 76.4% of the patients. Maximal ascending aorta diameter was 4.09 ± 0.59 cm, while patients with frank aneurysm accounted for 5.5%. Systolic blood pressure on admission was < 150 mmHg in 58.2% of the patients. Diastolic blood pressure on admission was < 90 mmHg in 54.5% of the patients. Mean arterial pressure on admission was 104.9 ± 24.6 mmHg. No correlations were demonstrated between maximal ascending aorta diameter and diameter of the left ventricular wall, any obtained risk factor and with coronary artery atherosclerosis (p > 0.05. After six months 11 (20% patients died, while intrahospital mortality was 72%. According to logistic regression analysis which included traditional risk factors, echo parameters, coronary artery disease and logistic euro scor, mean arterial blood pressure was the independent predictor of a six-month mortality [RR 0.956; CI (0.918-0.994 ; p = 0.024]. Conclusion. In our population the acute type A aortic dissection occurred rarely in the setting of frank ascending aortic aneurysms > 5.0 cm. The majority of patients had a history of arterial hypertension. A history of arterial hypertension was not associated with maximal ascending aorta diameter. Mean arterial blood pressure was the

  4. The Relationship Between Oxygen Reserve Index and Arterial Partial Pressure of Oxygen During Surgery.

    Science.gov (United States)

    Applegate, Richard L; Dorotta, Ihab L; Wells, Briana; Juma, David; Applegate, Patricia M

    2016-09-01

    The use of intraoperative pulse oximetry (SpO2) enhances hypoxia detection and is associated with fewer perioperative hypoxic events. However, SpO2 may be reported as 98% when arterial partial pressure of oxygen (PaO2) is as low as 70 mm Hg. Therefore, SpO2 may not provide advance warning of falling arterial oxygenation until PaO2 approaches this level. Multiwave pulse co-oximetry can provide a calculated oxygen reserve index (ORI) that may add to information from pulse oximetry when SpO2 is >98%. This study evaluates the ORI to PaO2 relationship during surgery. We studied patients undergoing scheduled surgery in which arterial catheterization and intraoperative arterial blood gas analysis were planned. Data from multiple pulse co-oximetry sensors on each patient were continuously collected and stored on a research computer. Regression analysis was used to compare ORI with PaO2 obtained from each arterial blood gas measurement and changes in ORI with changes in PaO2 from sequential measurements. Linear mixed-effects regression models for repeated measures were then used to account for within-subject correlation across the repeatedly measured PaO2 and ORI and for the unequal time intervals of PaO2 determination over elapsed surgical time. Regression plots were inspected for ORI values corresponding to PaO2 of 100 and 150 mm Hg. ORI and PaO2 were compared using mixed-effects models with a subject-specific random intercept. ORI values and PaO2 measurements were obtained from intraoperative data collected from 106 patients. Regression analysis showed that the ORI to PaO2 relationship was stronger for PaO2 to 240 mm Hg (r = 0.536) than for PaO2 over 240 mm Hg (r = 0.0016). Measured PaO2 was ≥100 mm Hg for all ORI over 0.24. Measured PaO2 was ≥150 mm Hg in 96.6% of samples when ORI was over 0.55. A random intercept variance component linear mixed-effects model for repeated measures indicated that PaO2 was significantly related to ORI (β[95% confidence interval] = 0

  5. Acoustic performance of low pressure axial fan rotors with different blade chord length and radial load distribution

    Science.gov (United States)

    Carolus, Thomas

    The paper examines the acoustic and aerodynamic performance of low-pressure axial fan rotors with a hub/tip ratio of 0.45. Six rotors were designed for the same working point by means of the well-known airfoil theory. The condition of an equilibrium between the static pressure gradient and the centrifugal forces is maintained. All rotors have unequally spaced blades to diminish tonal noise. The rotors are tested in a short cylindrical housing without guide vanes. All rotors show very similar flux-pressure difference characteristics. The peak efficiency and the noise performance is considerably influenced by the chosen blade design. The aerodynamically and acoustically optimal rotor is the one with the reduced load at the hub and increased load in the tip region under satisfied equilibrium conditions. It runs at the highest aerodynamic efficiency, and its noise spectrum is fairly smooth. The overall sound pressure level of this rotor is up to 8 dB (A) lower compared to the other rotors under consideration.

  6. Virtual arterial blood pressure feedback improves chest compression quality during simulated resuscitation.

    Science.gov (United States)

    Rieke, Horst; Rieke, Martin; Gado, Samkon K; Nietert, Paul J; Field, Larry C; Clark, Carlee A; Furse, Cory M; McEvoy, Matthew D

    2013-11-01

    Quality chest compressions (CC) are the most important factor in successful cardiopulmonary resuscitation. Adjustment of CC based upon an invasive arterial blood pressure (ABP) display would be theoretically beneficial. Additionally, having one compressor present for longer than a 2-min cycle with an ABP display may allow for a learning process to further maximize CC. Accordingly, we tested the hypothesis that CC can be improved with a real-time display of invasively measured blood pressure and with an unchanged, physically fit compressor. A manikin was attached to an ABP display derived from a hemodynamic model responding to parameters of CC rate, depth, and compression-decompression ratio. The area under the blood pressure curve over time (AUC) was used for data analysis. Each participant (N=20) performed 4 CPR sessions: (1) No ABP display, exchange of compressor every 2 min; (2) ABP display, exchange of compressor every 2 min; (3) no ABP display, no exchange of the compressor; (4) ABP display, no exchange of the compressor. Data were analyzed by ANOVA. Significance was set at a p-valueAUC for cycles without ABP display was 5201 mm Hgs (95% confidence interval (CI) of 4804-5597 mm Hgs), and for cycles with ABP display 6110 mm Hgs (95% CI of 5715-6507 mm Hgs) (pAUC increase with ABP display for each participant was 20.2±17.4% 95 CI (p<0.0001). Our study confirms the hypothesis that a real-time display of simulated ABP during CPR that responds to participant performance improves achieved and sustained ABP. However, without any real-time visual feedback, even fit compressors demonstrated degradation of CC quality. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. Increased augmentation index and central systolic arterial pressure are associated with lower school and motor performance in young adolescents.

    Science.gov (United States)

    Vogrin, Bernarda; Slak Rupnik, Marjan; Mičetić-Turk, Dušanka

    2017-12-01

    Objective In adults, improper arterial function has been linked to cognitive impairment. The pulse wave velocity (PWV), augmentation index (AIx) and other vascular parameters are useful indicators of arterial health. In our study, we monitored arterial properties, body constitution, school success, and motor skills in young adolescents. We hypothesize that reduced cognitive and motor abilities have a vascular origin in children. Methods We analysed 81 healthy school children aged 11-16 years. Anthropometry central systolic arterial pressure, body mass index (BMI), standard deviation scores (SDS) BMI, general school performance grade, and eight motor tests were assessed. PWV, AIx, and central systolic arterial pressure (SBPao) were measured. Results AIx and SBPao correlated negatively with school performance grades. Extremely high AIx, PWV and SBPao values were observed in 5% of children and these children had average to low school performance. PWV correlated significantly with weight, height, and waist and hip circumference. AIx, PWV, school success, and BMI correlated strongly with certain motor functions. Conclusions Increased AIx and SBPao are associated with lower school and motor performance in children. PWV is influenced by the body's constitution.

  8. Blood Pressure Control in Smokers with Arterial Hypertension Who Switched to Electronic Cigarettes

    Directory of Open Access Journals (Sweden)

    Riccardo Polosa

    2016-11-01

    Full Text Available Electronic cigarettes (ECs are battery-operated devices designed to vaporise nicotine, which may help smokers with quitting or reducing their tobacco consumption. No data is available regarding the health effects of ECs use among smokers with arterial hypertension and whether regular use results in blood pressure (BP changes. We investigated long-term changes in resting BP and level of BP control in hypertensive smokers who quit or reduced substantially their tobacco consumption by switching to ECs. A medical records review of patients with hypertension was conducted to identify patients reporting regular daily use of ECs on at least two consecutive follow-up visits. Regularly smoking hypertensive patients were included as a reference group. A marked reduction in cigarette consumption was observed in ECs users (n = 43 though consumption remained unchanged in the control group (n = 46. Compared to baseline, at 12 months (follow-up visit 2 decline in cigarette consumption was associated with significant reductions in median (25th-, 75th-centile systolic BP (140 (134.5, 144 to 130 (123.5, 138.5 mmHg; p < 0.001 and diastolic BP (86 (78, 90 to 80 (74.5, 90 mmHg; p = 0.006. No significant changes were observed in the control group. As expected, decline in cigarette consumption in the ECs users was also associated with improved BP control. The study concludes that regular ECs use may aid smokers with arterial hypertension reduce or abstain from cigarette smoking, with only trivial post-cessation weight gain. This resulted in improvements in systolic and diastolic BP as well as better BP control.

  9. Relationship between arterial partial oxygen pressure after resuscitation from cardiac arrest and mortality in children.

    Science.gov (United States)

    Ferguson, Lee P; Durward, Andrew; Tibby, Shane M

    2012-07-17

    Observational studies in adults have shown a worse outcome associated with hyperoxia after resuscitation from cardiac arrest. Extrapolating from adult data, current pediatric resuscitation guidelines recommend avoiding hyperoxia. We investigated the relationship between arterial partial oxygen pressure and survival in patients admitted to the pediatric intensive care unit (PICU) after cardiac arrest. We conducted a retrospective cohort study using the Pediatric Intensive Care Audit Network (PICANet) database between 2003 and 2010 (n=122,521). Patients aged oxygen status and outcome was modeled with logistic regression, with nonlinearities explored via multivariable fractional polynomials. Covariates included age, sex, ethnicity, congenital heart disease, out-of-hospital arrest, year, Pediatric Index of Mortality-2 (PIM2) mortality risk, and organ supportive therapies. Of 1875 patients, 735 (39%) died in PICU. Based on the first arterial gas, 207 patients (11%) had hyperoxia (Pa(O)(2) ≥300 mm Hg) and 448 (24%) had hypoxia (Pa(O)(2) <60 mm Hg). We found a significant nonlinear relationship between Pa(O)(2) and PICU mortality. After covariate adjustment, risk of death increased sharply with increasing hypoxia (odds ratio, 1.92; 95% confidence interval, 1.80-2.21 at Pa(O)(2) of 23 mm Hg). There was also an association with increasing hyperoxia, although not as dramatic as that for hypoxia (odds ratio, 1.25; 95% confidence interval, 1.17-1.37 at 600 mm Hg). We observed an increasing mortality risk with advancing age, which was more pronounced in the presence of congenital heart disease. Both severe hypoxia and, to a lesser extent, hyperoxia are associated with an increased risk of death after PICU admission after cardiac arrest.

  10. Opposing effects of particle pollution, ozone, and ambient temperature on arterial blood pressure.

    Science.gov (United States)

    Hoffmann, Barbara; Luttmann-Gibson, Heike; Cohen, Allison; Zanobetti, Antonella; de Souza, Celine; Foley, Christopher; Suh, Helen H; Coull, Brent A; Schwartz, Joel; Mittleman, Murray; Stone, Peter; Horton, Edward; Gold, Diane R

    2012-02-01

    Diabetes increases the risk of hypertension and orthostatic hypotension and raises the risk of cardiovascular death during heat waves and high pollution episodes. We examined whether short-term exposures to air pollution (fine particles, ozone) and heat resulted in perturbation of arterial blood pressure (BP) in persons with type 2 diabetes mellitus (T2DM). We conducted a panel study in 70 subjects with T2DM, measuring BP by automated oscillometric sphygmomanometer and pulse wave analysis every 2 weeks on up to five occasions (355 repeated measures). Hourly central site measurements of fine particles, ozone, and meteorology were conducted. We applied linear mixed models with random participant intercepts to investigate the association of fine particles, ozone, and ambient temperature with systolic, diastolic, and mean arterial BP in a multipollutant model, controlling for season, meteorological variables, and subject characteristics. An interquartile increase in ambient fine particle mass [particulate matter (PM) with an aerodynamic diameter of ≤ 2.5 μm (PM2.5)] and in the traffic component black carbon in the previous 5 days (3.54 and 0.25 μg/m3, respectively) predicted increases of 1.4 mmHg [95% confidence interval (CI): 0.0, 2.9 mmHg] and 2.2 mmHg (95% CI: 0.4, 4.0 mmHg) in systolic BP (SBP) at the population geometric mean, respectively. In contrast, an interquartile increase in the 5-day mean of ozone (13.3 ppb) was associated with a 5.2 mmHg (95% CI: -8.6, -1.8 mmHg) decrease in SBP. Higher temperatures were associated with a marginal decrease in BP. In subjects with T2DM, PM was associated with increased BP, and ozone was associated with decreased BP. These effects may be clinically important in patients with already compromised autoregulatory function.

  11. Prognostic role of alveolar-arterial oxygen pressure difference in acute pulmonary embolism

    International Nuclear Information System (INIS)

    Hsu Jente; Chang Shihtai; Cheng Huiwen; Chung Changmin; Chu, Chiming; Cheng Nyejan; Ho Wanching

    2006-01-01

    This study investigated the utility of the alveolar-arterial oxygen pressure difference (AaDO 2 ) in predicting the short-term prognosis of acute pulmonary embolism (PE). This study retrospectively enrolled 114 consecutive patients with acute PE, diagnosed by either spiral computed tomography or high probability ventilation-perfusion lung scans. During the first 24 h of admission, all patients had initial artery blood gas collected under room air. Patient exclusion criteria were chronic lung disease, septic emboli, and moderate and low probability lung scans. Patients were assigned to 2 groups based on either 30-day death or a 30-day composite event. Receiver operating characteristic analyses was used to determine the AaDO 2 cut-off value for predicting primary and composite endpoints. Statistical analysis demonstrated significant differences in AaDO 2 between the 30-day composite endpoint group and the 30-day composite event-free survival group (p=0.012). The AaDO 2 had a strong trend between the 30-day death group and the survival group (p=0.062). The best cut-off value for AaDO 2 was 53 mmHg and using this, the positive predictive value for 30-day death was 25% and the negative predictive value was 92%. For the 30-day composite endpoint, the positive predictive value for AaDO 2 was 35%, and the negative predictive value was 84%. In this study, thrombocytopenia was also an indicator of poor prognosis for patients with acute PE. The AaDO 2 measurement is a highly useful and simple measurement for predicting short-term prognosis in patients with acute PE. It has high negative predictive value and moderate positive predictive value for 30-day death and 30-day composite event. Aggressive thrombolytic treatment strategies should be considered for patients with an initial poor prognostic parameter (ie, AaDO 2 ≥53 mmHg). (author)

  12. Soybean oil increases SERCA2a expression and left ventricular contractility in rats without change in arterial blood pressure

    Directory of Open Access Journals (Sweden)

    Vassallo Dalton

    2010-05-01

    Full Text Available Abstract Background Our aim was to evaluate the effects of soybean oil treatment for 15 days on arterial and ventricular pressure, myocardial mechanics and proteins involved in calcium handling. Methods Wistar rats were divided in two groups receiving 100 μL of soybean oil (SB or saline (CT i.m. for 15 days. Ventricular performance was analyzed in male 12-weeks old Wistar rats by measuring left ventricle diastolic and systolic pressure in isolated perfused hearts according to the Langendorff technique. Protein expression was measured by Western blot analysis. Results Systolic and diastolic arterial pressures did not differ between CT and SB rats. However, heart rate was reduced in the SB group. In the perfused hearts, left ventricular isovolumetric systolic pressure was higher in the SB hearts. The inotropic response to extracellular Ca2+ and isoproterenol was higher in the soybean-treated animals than in the control group. Myosin ATPase and Na+-K+ATPase activities, the expression of sarcoplasmic reticulum calcium pump (SERCA2a and sodium calcium exchanger (NCX were increased in the SB group. Although the phosfolamban (PLB expression did not change, its phosphorylation at Ser16 was reduced while the SERCA2a/PLB ratio was increased. Conclusions In summary, soybean treatment for 15 days in rats increases the left ventricular performance without affecting arterial blood pressure. These changes might be associated with an increase in the myosin ATPase activity and SERCA2a expression.

  13. On the mechanisms of blunted nocturnal decline in arterial blood pressure in NIDDM patients with diabetic nephropathy

    DEFF Research Database (Denmark)

    Nielsen, Flemming Steen; Rossing, P; Bang, L E

    1995-01-01

    Nondiabetic hypertensive patients lacking the normal nocturnal decline in arterial blood pressure have enhanced cardiovascular complications. Since cardiovascular morbidity and mortality are increased in non-insulin-dependent diabetes mellitus (NIDDM), we performed a prospective cross......-sectional case-controlled study comparing the diurnal variation in arterial blood pressure, prevalence of dippers, cardiac autonomic nervous function (beat-to-beat variation during deep breathing), and extracellular fluid volume (51Cr-labeled EDTA) in 55 NIDDM patients with diabetic nephropathy (group 1), 55...... NIDDM patients with normoalbuminuria (group 2), and 22 nondiabetic control subjects (group 3). All antihypertensive treatments were withdrawn at least 2 weeks before the study. The nocturnal blood pressure reduction (daytime-to-nighttime)/daytime (mean +/- SE) was impaired in group 1 (6.6 +/- 1...

  14. Enhancement of Arterial Pressure Pulsatility by Controlling Continuous-Flow Left Ventricular Assist Device Flow Rate in Mock Circulatory System.

    Science.gov (United States)

    Bozkurt, Selim; van de Vosse, Frans N; Rutten, Marcel C M

    Continuous-flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which reduces pulsatility in the arteries and may lead to complications such as functional changes in the vascular system, gastrointestinal bleeding, or both. The purpose of this study is to increase the arterial pulse pressure and pulsatility by controlling the CF-LVAD flow rate. A MicroMed DeBakey pump was used as the CF-LVAD. A model simulating the flow rate through the aortic valve was used as a reference model to drive the pump. A mock circulation containing two synchronized servomotor-operated piston pumps acting as left and right ventricles was used as a circulatory system. Proportional-integral control was used as the control method. First, the CF-LVAD was operated at a constant speed. With pulsatile-speed CF-LVAD assistance, the pump was driven such that the same mean pump output was generated. Continuous and pulsatile-speed CF-LVAD assistance provided the same mean arterial pressure and flow rate, while the index of pulsatility increased significantly for both arterial pressure and pump flow rate signals under pulsatile speed pump support. This study shows the possibility of improving the pulsatility of CF-LVAD support by regulating pump speed over a cardiac cycle without reducing the overall level of support.

  15. Combined resistance and endurance exercise training improves arterial stiffness, blood pressure, and muscle strength in postmenopausal women.

    Science.gov (United States)

    Figueroa, Arturo; Park, Song Y; Seo, Dae Y; Sanchez-Gonzalez, Marcos A; Baek, Yeong H

    2011-09-01

    Menopause is associated with increased arterial stiffness and reduced muscle strength. Combined resistance (RE) and endurance (EE) exercise training can decrease brachial-ankle pulse wave velocity (baPWV), an index of arterial stiffness, in young men. We tested the hypothesis that combined circuit RE and EE training would improve baPWV, blood pressure (BP), and muscle strength in postmenopausal women. Twenty-four postmenopausal women (age 47-68 y) were randomly assigned to a "no exercise" control (n = 12) or to combined exercise training (EX; n = 12) group. The EX group performed concurrent circuit RE training followed by EE training at 60% of the predicted maximal heart rate (HR) 3 days per week. Brachial systolic BP, diastolic BP, mean arterial pressure, baPWV, HR, and dynamic and isometric muscle strength were measured before and after the 12-week study. Mean ± SE baPWV (-0.8 ± 0.2 meters/s), systolic BP (-6.0 ± 1.9 mm Hg), diastolic BP (-4.8 ± 1.7 mm Hg), HR (-4.0 ± 1.0 beats/min), and mean arterial pressure (-5.1 ± 1.6 mm Hg) decreased (P hypertension and frailty in postmenopausal women.

  16. Low pulmonary artery flush perfusion pressure combined with high positive end-expiratory pressure reduces oedema formation in isolated porcine lungs

    International Nuclear Information System (INIS)

    Schumann, Stefan; Schließmann, Stephan J; Wagner, Giskard; Goebel, Ulrich; Priebe, Hans-Joachim; Guttmann, Josef; Kirschbaum, Andreas

    2010-01-01

    Flush perfusion of the pulmonary artery with organ protection solution is a standard procedure before lung explantation. However, rapid flush perfusion may cause pulmonary oedema which is deleterious in the lung transplantation setting. In this study we tested the hypotheses that high pulmonary perfusion pressure contributes to the development of pulmonary oedema and positive end-expiratory pressure (PEEP) counteracts oedema formation. We expected oedema formation to increase weight and decrease compliance of the lungs on the basis of a decrease in alveolar volume as fluid replaces alveolar air spaces. The pulmonary artery of 28 isolated porcine lungs was perfused with a low-potassium dextrane solution at low (mean 27 mmHg) or high (mean 40 mmHg) pulmonary artery pressure (PAP) during mechanical ventilation at low (4 cmH 2 O) or high (8 cmH 2 O) PEEP, respectively. Following perfusion and storage, relative increases in lung weight were smaller (p < 0.05) during perfusion at low PAP (62 ± 32% and 42 ± 26%, respectively) compared to perfusion at high PAP (133 ± 54% and 87 ± 30%, respectively). Compared to all other PAP–PEEP combinations, increases in lung weight were smallest (44 ± 9% and 27 ± 12%, respectively), nonlinear intratidal lung compliance was largest (46% and 17% respectively, both p < 0.05) and lung histology showed least infiltration of mononuclear cells in the alveolar septa, and least alveolar destruction during the combination of low perfusion pressure and high PEEP. The findings suggest that oedema formation during pulmonary artery flush perfusion in isolated and ventilated lungs can be reduced by choosing low perfusion pressure and high PEEP. PAP–PEEP titration to minimize pulmonary oedema should be based on lung mechanics and PAP monitoring

  17. Algunas consideraciones sobre la hipertensión arterial en la diabetes mellitus tipo 2 Some considerations related to arterial high blood pressure in Type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Yanes Quesada

    2009-09-01

    Full Text Available Se realizó una revisión del tema relacionado con la hipertensión arterial en el paciente diabético tipo 2, con el objetivo de actualizar algunos elementos particulares en este grupo de pacientes. Se plantea que su prevalencia es considerablemente más alta que en la población no diabética, donde la hiperinsulinemia y la disfunción endotelial cobran un papel protagónico en su etiopatogenia. La hipertensión arterial en estos pacientes clínicamente se manifiesta como un patrón non dipper, lo que incrementa la morbimortalidad por esta entidad. El tratamiento medicamentoso es habitualmente necesario, y se usan como drogas de primera línea los inhibidores de la enzima convertidora, los antagonistas de los receptores de angiotensina ll y los calcioantagonistas, aunque se pueden utilizar también los diuréticos tiacídicos a dosis bajas.Authors made a review of the topic related to arterial high blood pressure in the patient presenting with Type 2 diabetes mellitus to update some particular elements in this group of patients. We propose that its prevalence is higher than that present in non-diabetic population, where the hyperinsulinism and the endothelial dysfunction have a leading role in its ethiopathogenesis. The arterial high blood pressure in these patients clinically is manifested as a non-dipper pattern increasing the morbidity and mortality. Drug therapy is commonly necessary and as first line-drugs are used the converting-enzyme inhibitors, the agiotensin-II receptors antagonists, and the antagonists-calcium, although the low-dose thiacidic diuretics.

  18. Comparison of Safety and Effectiveness Between Right Versus Left Radial Arterial Access in Primary Percutaneous Coronary Intervention for Acute ST Segment Elevation Myocardial Infarction.

    Science.gov (United States)

    Elmahdy, Mahmoud Farouk; ElMaghawry, Mohamed; Hassan, Mohamed; Kassem, Hussien Heshmat; Said, Karim; Elfaramawy, Amr AbdelAziz

    2017-01-01

    Transradial approach (TRA) is now considered the standard of care in many centres for elective and primary percutaneous intervention (PCI). The use of the radial approach in ST segment elevation myocardial infarction (STEMI) patients has been associated with a significant reduction in major adverse cardiac events. However, it is still unclear if the side of radial access (right vs. left) has impact on safety and effectiveness of TRA in primary PCI. So this study was conducted to compare the safety, feasibility, and outcomes of right radial access (RRA) vs. left radial access (LRA) in the setting of primary PCI. We retrospectively analysed the data of 400 consecutive patients presenting to our institution with STEMI for whom primary PCIs were performed via RRA and LRA. Mean age of the whole studied population was 57±12.8 years, with male predominance (77.2%). There were 202 cases in the RRA group and 198 in the LRA group, with no significant difference in demographics and clinical characteristics for patients included in both groups. There was no significant difference in procedure success rate (97.5% for RRA vs. 98.4% for LRA; P=0.77). In addition, no significant difference between both approaches was observed in the contrast volume, number of catheters, fluoroscopy time (FT), needle-to-balloon time, post-procedure vascular complications, in hospital reinfarction, stroke/transient ischaemic attack (TIA) or death. Right radial access and LRA are equally safe and effective in the setting of primary PCI. Both approaches have a high success rate and comparable needle-to-balloon time. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  19. Determining carotid artery pressure from scaled diameter waveforms: comparison and validation of calibration techniques in 2026 subjects

    International Nuclear Information System (INIS)

    Vermeersch, S J; Verdonck, P R; Segers, P; Rietzschel, E R; De Buyzere, M L; Gillebert, T C; De Bacquer, D; De Backer, G; Van Bortel, L M

    2008-01-01

    Calibrated diameter distension waveforms could provide an alternative for local arterial pressure assessment more widely applicable than applanation tonometry. We compared linearly and exponentially calibrated carotid diameter waveforms to tonometry readings. Local carotid pressures measured by tonometry and diameter waveforms measured by ultrasound were obtained in 2026 subjects participating in the Asklepios study protocol. Diameter waveforms were calibrated using a linear and an exponential calibration scheme and compared to measured tonometry waveforms by examining the mean root-mean-squared error (RMSE), carotid systolic blood pressure (SBP car ) and augmentation index (AIx) of calibrated and measured pressures. Mean RMSE was 5.2(3.3) mmHg (mean(stdev)) for linear and 4.6(3.6) mmHg for exponential calibration. Linear calibration yielded an underestimation of SBP car by 6.4(4.1) mmHg which was strongly correlated to values of brachial pulse pressure (PP bra ) (R = 0.4, P car by 1.9(3.9) mmHg, independent of PP bra . AIx was overestimated by linear calibration by 1.9(10.1)%, the difference significantly increasing with increasing AIx (R = 0.25, P < 0.001) and by exponential calibration by 5.4(10.6)%, independently of the value of AIx. Properly calibrated diameter waveforms offer a viable alternative for local pressure estimation at the carotid artery. Compared to linear calibration, exponential calibration significantly improves the pressure estimation

  20. Prevalence of elevated mean arterial pressure and how fitness moderates its association with BMI in youth.

    Science.gov (United States)

    Ogunleye, Ayodele A; Sandercock, Gavin R; Voss, Christine; Eisenmann, Joey C; Reed, Katharine

    2013-11-01

    Cardiorespiratory fitness is known to be cardioprotective and its association with the components of the metabolic syndrome in children is becoming clearer. The aim of the present study was to examine the extent to which cardiorespiratory fitness may offset the weight-related association with mean arterial pressure (MAP) in schoolchildren. Cross-sectional study. Schoolchildren from the East of England, U.K. A total of 5983 (48% females) schoolchildren, 10 to 16 years of age, had height, weight and blood pressure measured by standard procedures and cardiorespiratory fitness assessed by the 20 m shuttle-run test. Participants were classified as fit or unfit using internationally accepted fitness cut-off points; and as normal weight, overweight or obese based on BMI, again using international cut-off points. Age-adjusted ANCOVA was used to determine the main effects and interaction of fitness and BMI on MAP Z-score. Logistic regression models were used to estimate odds ratios of elevated MAP. Prevalence of elevated MAP in schoolchildren was 14.8% overall and 35.7% in those who were obese-unfit. Approximately 21% of participants were overweight and 5% obese, while 23% were classified as unfit. MAP generally increased across BMI categories and was higher in the aerobically unfit participants. Obese-fit males had lower MAP compared with obese-unfit males (P < 0.001); this trend was similar in females (P = 0.05). Increasing fitness level may have a positive impact on the weight-related elevations of MAP seen in obese and overweight schoolchildren.

  1. The association between arterial stiffness and left ventricular filling pressure in an apparently healthy Korean population

    Directory of Open Access Journals (Sweden)

    Kim Hack-Lyoung

    2013-01-01

    Full Text Available Abstract Background The aim of this study is to investigate the association between arterial stiffness and left ventricular filling pressure in an apparently healthy Korean population. Methods A total of 115 healthy subjects without known cardiovascular risk factors or overt heart disease who underwent both transthoracic echocardiography and brachial-ankle pulse wave velocity (baPWV measurement at the same day during their routine check-ups were analyzed. Results The mean age of study subjects was 52.8 ± 8.4 years, and 78 (67.8% were men. The mean baPWV value was 1,325 ± 185 cm/s. Study subjects were divided into 3 groups according to E/E’ value: subjects with E/E’ p β = 0.371, p after controlling confounders including age, sex and body mass index. In receiver-operating characteristic (ROC curve analysis, the sensitivity and specificity for detection of E/E’ ≥ 10 were 78.6% and 59.8%, respectively with mean baPWV of 1,282 cm/s as the cut off value. The discriminatory capacity for predicting E/E’ ≥ 10 was improved from an area under the ROC curve of 0.646 with age alone to 0.734 when baPWV was added (p Conclusions There is a significant association between baPWV and E/E’ in an apparently healthy Korean population. BaPWV is useful as a simple and non-invasive method for early detection of increased LV filling pressure among these people.

  2. Radial pseudoaneurysm following diagnostic coronary angiography

    Directory of Open Access Journals (Sweden)

    Shankar Laudari

    2015-06-01

    Full Text Available The radial artery access has gained popularity as a method of diagnostic coronary catheterization compared to femoral artery puncture in terms of vascular complications and early ambulation. However, very rare complication like radial artery pseudoaneurysm may occur following cardiac catheterization which may give rise to serious consequences. Here, we report a patient with radial pseudoaneurysm following diagnostic coronary angiography. Adequate and correct methodology of compression of radial artery following puncture for maintaining hemostasis is the key to prevention.DOI: http://dx.doi.org/10.3126/jcmsn.v10i3.12776 Journal of College of Medical Sciences-Nepal, 2014, Vol-10, No-3, 48-50

  3. Stresses from pressure, radial, and moment loads in cylinder-to-cylinder vessel by a finite plate method

    International Nuclear Information System (INIS)

    Brown, S.J.; Fox, M.E.

    1977-08-01

    A structural problem that has received continued interest and development over the last several decades is the determination of stresses in two normally intersecting cylindrical shells subjected to internal pressure and external loading. In nuclear pressure vessels the external loading of the vessel through the attachment is encountered in thermal interaction, seismic loading and various postulated rupture or failure mechanisms. A simple technique, the Finite Plate Method, (FPM) is presented to analyze stresses in cylinder-to-cylinder junctures. The approach uses shallow shell formulations and a three term series expansion plate formulation, which limits the range of applicability. It is felt that the value of the method is its accuracy, economy, and ease in modeling a structure which falls within the range of applicability. Another appealing feature of the method is that its simplistic approach of superposition of results permits an easy extension to include additional loads not treated. For those mechanical loadings not developed, it is felt that their effect can either be accounted for by the mechanisms discussed or by simple calculations. Generally, the stresses resulting from torsional or transverse shear are small compared to the loads discussed, however, these shear effects may be included. Finally, in the instance of thermal stress within the cylinder-to-cylinder structure, it has been shown in an unpublished study by Brown that the FPM yields very good results for the range of curvatures discussed

  4. Correlation between spirometry values and pulmonary artery pressure in young healthy subjects.

    Science.gov (United States)

    Grossman, Alon; Benderly, Michal; Prokupetz, Alex; Gordon, Barak; Kalter-Leibovici, Ofra

    2014-03-01

    Pulmonary hypertension is frequently associated with parenchymal lung disease. We evaluated the association between spirometry values and pulmonary artery systolic pressure (PASP) in young subjects without lung disease : We studied applicants to the Israeli Air Force, who undergo routine evaluation that includes resting spirometry and echocardiography. Applicants with overt lung disease were excluded. All echocardiographic studies performed in the years 1994 through 2010 (n = 6,598) were screened, and files that included PASP and spirometry values were analyzed for the association between PASP and FVC, FEV1, FEV1/FVC, peak expiratory flow, and forced expiratory flow during the middle half of the FVC maneuver. Of the 647 air force applicants who underwent echocardiography in which PASP was measurable and had spirometry data, 607 (94%) were male, and their average age was 18.16 ± 0.73 years. Mean PASP was 26.4 ± 5.2 mm Hg (range 10-41 mm Hg). None of the spirometry values significantly correlated with PASP. PASP in young healthy subjects is not significantly associated with spirometry values. Lung mechanics probably do not contribute significantly to PASP in this population.

  5. Determinants of abnormal blood pressure response to exercise in coronary artery disease

    International Nuclear Information System (INIS)

    Hakki, A.H.; Munley, B.M.; Hadjimiltiades, S.; Meissner, M.D.; Iskandrian, A.S.

    1986-01-01

    This study assessed the determinants of exercise-induced abnormal systolic blood pressure (BP) response in 127 patients with documented coronary artery disease (CAD) who underwent exercise thallium-201 scintigraphy. Three types of systolic BP response to exercise were identified: an increase by more than 20 mm Hg (group I, n = 74); an increase by 20 mm Hg or less (group II, n = 36); and a decrease of at least 10 mm Hg (group III, n = 17). The 3 groups were not significantly different in age, gender or medications. The number of segments with perfusion defects was significantly higher in groups II and III than group I (group III, 2.9 +/- 1.5; group II, 2.9 +/- 2.1; and group I, 1.8 +/- 1.4, p = 0.009). Prior myocardial infarction, abnormal left ventricular ejection fraction, and multivessel CAD were more common in group III than in groups I and II. Stepwise discriminant analysis of 15 relevant clinical, angiographic and exercise scintigraphic descriptors showed that the number of thallium perfusion defects, abnormal LV ejection fraction at rest and multivessel CAD to be important predictors of hypotensive BP response. Multivariate analysis, however, showed that the number of thallium perfusion defects was the only important predictor of the hypotensive response. Thus, it is the functional significance of CAD assessed by the extent of thallium perfusion abnormalities rather than the extent of CAD or left ventricular dysfunction at rest that determines the systolic BP response to exercise

  6. Arterial line pressure control enhanced extracorporeal blood flow prescription in hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Rosales Laura

    2008-11-01

    Full Text Available Abstract Background In hemodialysis, extracorporeal blood flow (Qb recommendation is 300–500 mL/min. To achieve the best Qb, we based our prescription on dynamic arterial line pressure (DALP. Methods This prospective study included 72 patients with catheter Group 1 (G1, 1877 treatments and 35 arterio-venous (AV fistulae Group 2 (G2, 1868 treatments. The dialysis staff was trained to prescribe Qb sufficient to obtain DALP between -200 to -250 mmHg. We measured ionic clearance (IK: mL/min, access recirculation, DALP (mmHg and Qb (mL/min. Six prescription zones were identified: from an optimal A zone (Qb > 400, DALP -200 to -250 to zones with lower Qb E (Qb -199. Results Treatments distribution in A was 695 (37% in G1 vs. 704 (37.7% in G2 (P = 0.7. In B 150 (8% in G1 vs. 458 (24.5% in G2 (P P = 0.62. IK in A was 214 ± 34 (G1 vs. 213 ± 35 (G2 (P = 0.65. IK Anova between G2 zones was: A vs. C and D (P P = 0.02. Conclusion In conclusion, an optimal Qb can de prescribed with DALP of -200 mmHg. Staff adherence to DLAP treatment prescription could be reached up to 81.3% in catheters and 84.1% in AV fistulae.

  7. Exercise training improves ambulatory blood pressure but not arterial stiffness in heart transplant recipients.

    Science.gov (United States)

    Pascoalino, Lucas Nóbilo; Ciolac, Emmanuel Gomes; Tavares, Aline Cristina; Castro, Rafael Ertner; Ayub-Ferreira, Silvia Moreira; Bacal, Fernando; Issa, Victor Sarli; Bocchi, Edimar Alcides; Guimarães, Guilherme Veiga

    2015-05-01

    Hypertension is the most prevalent comorbidity after heart transplantation (HT). Exercise training (ET) is widely recommended as a key non-pharmacologic intervention for the prevention and management of hypertension, but its effects on ambulatory blood pressure (ABP) and some mechanisms involved in the pathophysiology of hypertension have not been studied in this population. The primary purpose of this study was to investigate the effects of ET on ABP and arterial stiffness of HT recipients. 40 HT patients, randomized to ET (n = 31) or a control group (n = 9) underwent a maximal graded exercise test, 24-hour ABP monitoring, and carotid-femoral pulse wave velocity (PWV) assessment before the intervention and at a 12-week follow-up assessment. The ET program was performed thrice-weekly and consisted primarily of endurance exercise (40 minutes) at ~70% of maximum oxygen uptake (Vo2MAX). The ET group had reduced 24-hour (4.0 ± 1.4 mm Hg, p endurance ET may be a tool to counteract hypertension in this high-risk population. Copyright © 2015 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  8. Servo-controlled hind-limb electrical stimulation for short-term arterial pressure control.

    Science.gov (United States)

    Kawada, Toru; Shimizu, Shuji; Yamamoto, Hiromi; Shishido, Toshiaki; Kamiya, Atsunori; Miyamoto, Tadayoshi; Sunagawa, Kenji; Sugimachi, Masaru

    2009-05-01

    Autonomic neural intervention is a promising tool for modulating the circulatory system thereby treating some cardiovascular diseases. In 8 pentobarbital-anesthetized cats, it was examined whether the arterial pressure (AP) could be controlled by acupuncture-like hind-limb electrical stimulation (HES). With a 0.5-ms pulse width, HES monotonically reduced AP as the stimulus current increased from 1 to 5 mA, suggesting that the stimulus current could be a primary control variable. In contrast, the depressor effect of HES showed a nadir approximately 10 Hz in the frequency range between 1 and 100 Hz. Dynamic characteristics of the AP response to HES approximated a second-order low-pass filter with dead time (gain: -10.2 +/- 1.6 mmHg/mA, natural frequency: 0.040 +/- 0.004 Hz, damping ratio 1.80 +/- 0.24, dead time: 1.38 +/- 0.13 s, mean +/- SE). Based on these dynamic characteristics, a servo-controlled HES system was developed. When a target AP value was set at 20 mmHg below the baseline AP, the time required for the AP response to reach 90% of the target level was 38 +/- 10 s. The steady-state error between the measured and target AP values was 1.3 +/- 0.1 mmHg. Autonomic neural intervention by acupuncture-like HES might provide an additional modality to quantitatively control the circulatory system.

  9. Limitations and challenges of EIT-based monitoring of stroke volume and pulmonary artery pressure.

    Science.gov (United States)

    Braun, Fabian; Proença, Martin; Lemay, Mathieu; Bertschi, Mattia; Adler, Andy; Thiran, Jean-Philippe; Solà, Josep

    2018-01-30

    Electrical impedance tomography (EIT) shows potential for radiation-free and noninvasive hemodynamic monitoring. However, many factors degrade the accuracy and repeatability of these measurements. Our goal is to estimate the impact of this variability on the EIT-based monitoring of two important central hemodynamic parameters: stroke volume (SV) and pulmonary artery pressure (PAP). We performed simulations on a 4D ([Formula: see text]) bioimpedance model of a human volunteer to study the influence of four potential confounding factors (electrode belt displacement, electrode detachment, changes in hematocrit and lung air volume) on the performance of EIT-based SV and PAP estimation. Results were used to estimate how these factors affect the EIT measures of either absolute values or relative changes (i.e. trending). Our findings reveal that the absolute measurement of SV via EIT is very sensitive to electrode belt displacements and lung conductivity changes. Nonetheless, the trending ability of SV EIT might be a promising alternative. The timing-based measurement of PAP is more robust to lung conductivity changes but sensitive to longitudinal belt displacements at severe hypertensive levels and to rotational displacements (independent of the PAP level). We identify and quantify the challenges of EIT-based SV and PAP monitoring. Absolute SV via EIT is challenging, but trending is feasible, while both the absolute and trending of PAP via EIT are mostly impaired by belt displacements.

  10. Comparison of two methods of dental prophylaxis: evaluation of arterial pressure and patient comfort in a clinical randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Camila Lopes FERREIRA

    Full Text Available Abstract Introduction The number of hypertensive patients is increasing and prophylaxis with bicarbonate jet are widely performed in clinical practice using large amounts of this substance in a short period of time, which may lead to increased arterial pressure. In the literature there are several studies that analyze the effect of sodium bicarbonate jet on the biofilm and dental structures, but not report the effect on arterial pressure. Aim Evaluated the change in arterial pressure before and after two procedures of dental prophylaxis, jet baking soda application and conventional prophylaxis, and patient opinion of the comfort of each system was obtained. Material and method We selected 20 patients aged 18 to 30 in need of prophylaxis to remove biofilm. The patients were placed into three different treatment groups: sodium bicarbonate jet (G1, conventional prophylaxis (G2 and control (G3, with a one month interval between treatments. Patients were divided into groups randomly. Measurements were performed immediately before and after the procedure, 15 and 30 minutes after the end of treatment. Patient comfort was measured using a Visual Analog Scale (VAS at the end of each treatment. Data were analyzed by analysis of variance. Result There was a statistically significant difference in the comfort of the procedures, with G2 and G3 being better than G1. Additionally, an increase in the diastolic blood pressure was observed in sodium bicarbonate jet group evaluated just after the procedure. Conclusion The conventional prophylaxis is more comfortable from the patient stand point and does not alter arterial pressure.

  11. Effects of an alveolar recruitment maneuver on subdural pressure, brain swelling, and mean arterial pressure in patients undergoing supratentorial tumour resection: a randomized crossover study.

    Science.gov (United States)

    Flexman, Alana M; Gooderham, Peter A; Griesdale, Donald E; Argue, Ruth; Toyota, Brian

    2017-06-01

    Although recruitment maneuvers have been advocated as part of a lung protective ventilation strategy, their effects on cerebral physiology during elective neurosurgery are unknown. Our objectives were to determine the effects of an alveolar recruitment maneuver on subdural pressure (SDP), brain relaxation score (BRS), and cerebral perfusion pressure among patients undergoing supratentorial tumour resection. In this prospective crossover study, patients scheduled for resection of a supratentorial brain tumour were randomized to undergo either a recruitment maneuver (30 cm of water for 30 sec) or a "sham" maneuver (5 cm of water for 30 sec), followed by the alternative intervention after a 90-sec equilibration period. Subdural pressure was measured through a dural perforation following opening of the cranium. Subdural pressure and mean arterial pressure (MAP) were recorded continuously. The blinded neurosurgeon provided a BRS at baseline and at the end of each intervention. During each treatment, the changes in SDP, BRS, and MAP were compared. Twenty-one patients underwent the study procedure. The increase in SDP was higher during the recruitment maneuver than during the sham maneuver (difference, 3.9 mmHg; 95% confidence interval [CI], 2.2 to 5.6; P < 0.001). Mean arterial pressure decreased further in the recruitment maneuver than in the sham maneuver (difference, -9.0 mmHg; 95% CI, -12.5 to -5.6; P < 0.001). Cerebral perfusion pressure decreased 14 mmHg (95% CI, 4 to 24) during the recruitment maneuver. The BRS did not change with either maneuver. Our results suggest that recruitment maneuvers increase subdural pressure and reduce cerebral perfusion pressure, although the clinical importance of these findings is thus far unknown. This trial was registered with ClinicalTrials.gov, NCT02093117.

  12. The Effect of High Dose Cholecalciferol on Arterial Stiffness and Peripheral and Central Blood Pressure in Healthy Humans

    DEFF Research Database (Denmark)

    Bressendorff, Iain; Brandi, Lisbet; Schou, Morten

    2016-01-01

    and central blood pressure and 24-hour ambulatory blood pressure. RESULTS: 22 subjects in the cholecalciferol arm and 18 subjects in the placebo arm completed the 16 weeks of follow-up. There was no difference in changes in PWV, AIx corrected for heart rate or central or peripheral blood pressure between...... and blood pressure in healthy normotensive adults. METHODS: 40 healthy adults were randomised in this double-blinded study to either oral cholecalciferol 3000 IU/day or matching placebo and were followed for 16 weeks to examine any effects on pulse wave velocity (PWV), augmentation index (AIx), peripheral...... the two groups. There was no correlation between serum 25-hydroxy vitamin D and any of these parameters. CONCLUSIONS: Oral cholecalciferol 3000 IU/day does not affect arterial stiffness or blood pressure after 16 weeks of treatment in healthy normotensive adults. TRIAL REGISTRATION: ClinicalTrials.gov NCT...

  13. The acute effects of lower limb intermittent negative pressure on foot macro- and microcirculation in patients with peripheral arterial disease.

    Directory of Open Access Journals (Sweden)

    Øyvind Heiberg Sundby

    Full Text Available Intermittent negative pressure (INP applied to the lower leg and foot increases foot perfusion in healthy volunteers. The aim of the present study was to describe the effects of INP to the lower leg and foot on foot macro- and microcirculation in patients with lower extremity peripheral arterial disease (PAD.In this experimental study, we analyzed foot circulation during INP in 20 patients [median (range: 75 (63-84yrs] with PAD. One leg was placed inside an air-tight vacuum chamber connected to an INP-generator. During application of INP (alternating 10s of -40mmHg/7s of atmospheric pressure, we continuously recorded blood flow velocity in a distal foot artery (ultrasound Doppler, skin blood flow on the pulp of the first toes (laser Doppler, heart rate (ECG, and systemic blood pressure (Finometer. After a 5-min baseline sequence (no pressure, a 10-min INP sequence was applied, followed by 5-min post-INP (no pressure. To compare and quantify blood flow fluctuations between sequences, we calculated cumulative up-and-down fluctuations in arterial blood flow velocity per minute.Onset of INP induced an increase in arterial flow velocity and skin blood flow. Peak blood flow velocity was reached 3s after the onset of negative pressure, and increased 46% [(95% CI 36-57, P<0.001] above baseline. Peak skin blood flow was reached 2s after the onset of negative pressure, and increased 89% (95% CI 48-130, P<0.001 above baseline. Cumulative fluctuations per minute were significantly higher during INP-sequences compared to baseline [21 (95% CI 12-30cm/s/min to 41 (95% CI 32-51cm/s/min, P<0.001]. Mean INP blood flow velocity increased significantly ~12% above mean baseline blood flow velocity [(6.7 (95% CI 5.2-8.3cm/s to 7.5 (95% CI 5.9-9.1cm/s, P = 0.03].INP increases foot macro- and microcirculatory flow pulsatility in patients with PAD. Additionally, application of INP resulted in increased mean arterial blood flow velocity.

  14. Reduction of Blood Pressure Following After Renal Artery Adventitia Stripping During Total Nephroureterectomy: Potential Effect of Renal Sympathetic Denervation.

    Science.gov (United States)

    Okamura, Keisuke; Satou, Shunsuke; Setojima, Keita; Shono, Shinjiro; Miyajima, Shigero; Ishii, Tatsu; Shirai, Kazuyuki; Urata, Hidenori

    2018-05-16

    BACKGROUND Catheter-based renal sympathetic denervation has been reported to be effective for treatment resistance hypertension in Australia and Europe. However, in the blinded SYMPLICITY HTN-3 trial, renal denervation did not achieve a significant decrease in blood pressure (BP) in comparison to sham controls. There have been various discussions on the factors that influenced this result. CASE REPORT Two men on antihypertensive therapy underwent unilateral radical nephroureterectomy for cancer of the renal pelvis. When the renal artery adventitia was stripped and cauterized just before renal artery ligation, the measured BP of the 2 men increased after stripping adventitia and decreased gradually after cauterization of the renal artery. This was presumably due to removal of renal artery sympathetic nerves, similar to the mechanism of catheter-based renal sympathetic denervation, although anesthesia, fluid infusion, and/or mesenteric traction may have had an influence. CONCLUSIONS A similar strategy involving thoracolumbar sympathectomy was reported about 50 years ago. The clinically significant blood pressure reduction in these patients suggests renal denervation is effective.

  15. A novel photoplethysmography technique to derive normalized arterial stiffness as a blood pressure independent measure in the finger vascular bed

    International Nuclear Information System (INIS)

    Tanaka, Gohichi; Sawada, Yukihiro; Kato, Yuichi; Yamakoshi, Ken-ichi; Matsumura, Kenta; Maeda, Kimihito; Horiguchi, Masami; Ohguro, Hiroshi

    2011-01-01

    Stiffening of the small artery may be the earliest sign of arteriosclerosis. However, there is no adequate method for directly assessing small arterial stiffness. In this study, the finger arterial elasticity index (FEI) was defined as the parameter n which denotes the curvilinearity of an exponential model of pressure (P)–volume (V a ) relationship (V a = a − b exp (−nP)). For the original estimation, the FEI was calculated from a compliance index from the finger photoplethysmogram whilst occluding the finger. A simple estimation of the FEI was devised by utilizing normalized pulse volume instead of the compliance index. Both estimations yielded close agreement with the exponential model in healthy young participants (study 1: n = 19). Since the FEI was dependent on finger mean blood pressure, normalized finger arterial stiffness index (FSI) was defined as standardized residual from their relationship: mean and standard deviation (SD) of the FSI were 50 ± 10 (study 2: n = 174). The mean coefficient of variation of the FSI for four measurements was 5.72% (study 3: n = 6). The mean and SD of the FSI in seven arteriosclerotic patients were 100.0 ± 13.5. In conclusion, the FEI and FSI by simple estimation are valid and useful for arteriosclerosis research

  16. Association of thyroid function with arterial pressure in normotensive and hypertensive euthyroid individuals: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Saltiki Katerina

    2008-09-01

    Full Text Available Abstract Background Overt hypothyroidism has been associated with arterial hypertension and increased arterial stiffness. Results in euthyroid individuals have been conflicting. We investigated associations of thyroid function with systolic (SAP and diastolic (DAP arterial pressure in euthyroid subjects. Methods 311 euthyroid individuals (185 women, mean age 43.9 ± 9 without a history of diabetes attending a preventive medicine program were examined. Subjects receiving thyroxine (10.6% were excluded; 19.3% had hypertension, 43% had a family history for hypertension. TSH, fT4, thyroid autoantibodies, insulin, glucose were measured. The "fT4.TSH product", which has been suggested as a T4 resistance-index, was calculated. Results TSH range was 0.1–8, median 1.4 mU/L, fT4 range was 11.5–25.2 pmol/L, median 17.4. TSH and the "fT4.TSH product" were positively associated with DAP (p 2 mU/L (35.3% vs 21.3%, p = 0.045. Conclusion In euthyroid individuals the association of thyroid function with diastolic arterial pressure remains significant even when a stricter "normal range" for TSH levels is considered. The "freeT4.TSH" product appears to be an even stronger predictor of DAP, independently of HOMA insulin resistance index and obesity.

  17. Relationships Between Components of Blood Pressure and Cardiovascular Events in Patients with Stable Coronary Artery Disease and Hypertension.

    Science.gov (United States)

    Vidal-Petiot, Emmanuelle; Greenlaw, Nicola; Ford, Ian; Ferrari, Roberto; Fox, Kim M; Tardif, Jean-Claude; Tendera, Michal; Parkhomenko, Alexander; Bhatt, Deepak L; Steg, P Gabriel

    2018-01-01

    Observational studies have shown a J-shaped relationship between diastolic blood pressure (BP) and cardiovascular events in hypertensive patients with coronary artery disease. We investigated whether the increased risk associated with low diastolic BP reflects elevated pulse pressure (PP). In 22 672 hypertensive patients with coronary artery disease from the CLARIFY registry (Prospective Observational Longitudinal Registry of Patients With Stable Coronary Artery Disease), followed for a median of 5.0 years, BP was measured annually and averaged. The relationships between PP and diastolic BP, alone or combined, and the primary composite outcome (cardiovascular death or myocardial infarction) were analyzed using multivariable Cox proportional hazards models. Adjusted hazard ratios for the primary outcome were 1.62 (95% confidence interval [CI], 1.40-1.87), 1.00 (ref), 1.07 (95% CI, 0.94-1.21), 1.54 (95% CI, 1.32-1.79), and 2.34 (95% CI, 1.95-2.81) for PPhypertensive patients with coronary artery disease persists in patients within the lowest-risk PP range and is therefore unlikely to be solely the consequence of an increased PP reflecting advanced vascular disease. URL: http://www.clarify-registry.com. Unique identifier: ISRCTN43070564. © 2017 American Heart Association, Inc.

  18. High sodium intake during postnatal phases induces an increase in arterial blood pressure in adult rats.

    Science.gov (United States)

    Moreira, M C S; da Silva, E F; Silveira, L L; de Paiva, Y B; de Castro, C H; Freiria-Oliveira, A H; Rosa, D A; Ferreira, P M; Xavier, C H; Colombari, E; Pedrino, Gustavo R

    2014-12-28

    Epigenetic studies suggest that diseases that develop in adulthood are related to certain conditions to which the individual is exposed during the initial stages of life. Experimental evidence has demonstrated that offspring born to mothers maintained on high-Na diets during pregnancy have higher mean arterial pressure (MAP) in adulthood. Although these studies have demonstrated the importance of prenatal phases to hypertension development, no evidence regarding the role of high Na intake during postnatal phases in the development of this pathology has been reported. Therefore, in the present study, the effects of Na overload during childhood on induced water and Na intakes and on cardiovascular parameters in adulthood were evaluated. Experiments were carried out in two groups of 21-d-old rats: experimental group, maintained on hypertonic saline (0.3 m-NaCl) solution and food for 60 d, and control group, maintained on tap water and food. Later, both groups were given water and food for 15 d (recovery period). After the recovery period, chronic cannulation of the right femoral artery was performed in unanaesthetised rats to record baseline MAP and heart rate (HR). The experimental group was found to have increased basal MAP (98.6 (sem 2.6) v. 118.3 (sem 2.7) mmHg, P< 0.05) and HR (365.4 (sem 12.2) v. 398.2 (sem 7.5) beats per min, P< 0.05). There was a decrease in the baroreflex index in the experimental group when compared with that in the control group. A water and Na intake test was performed using furosemide. Na depletion was found to induce an increase in Na intake in both the control and experimental groups (12.1 (sem 0.6) ml and 7.8 (sem 1.1), respectively, P< 0.05); however, this increase was of lower magnitude in the experimental group. These results demonstrate that postnatal Na overload alters behavioural and cardiovascular regulation in adulthood.

  19. Intraoperative indocyanine green fluorescent angiography-assisted modified superior gluteal artery perforator flap for reconstruction of sacral pressure sores.

    Science.gov (United States)

    Chang, Chun-Kai; Wu, Chien-Ju; Chen, Chun-Yu; Wang, Chi-Yu; Chu, Tzi-Shiang; Hsu, Kuo-Feng; Chiu, Han-Ting; Liu, Hung-Hui; Chou, Chang-Yi; Wang, Chih-Hsin; Lin, Chin-Ta; Dai, Niann-Tzyy; Tzeng, Yuan-Sheng

    2017-12-01

    Pressure sores are often observed in patients who are bedridden. They can be a severe problem not only for patients and their caregivers but also for plastic surgeons. Here, we describe a new method of superior gluteal artery perforator flap harvesting and anchoring with the assistance of intraoperative indocyanine green fluorescent angiography. In this report, we describe the procedure and outcomes for 19 patients with grades III and IV sacral pressure sores who underwent the operation between September 2015 and November 2016. All flaps survived, and two experienced wound-edge partial dehiscence. With the assistance of this imaging device, we were able to acquire a reliable superior gluteal artery perforator flap and perform modified operations with it that are safe, easy to learn and associated with fewer complications than are traditional. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  20. Double profunda brachii artery

    OpenAIRE

    Gavishiddappa A Hadimani; Jyoti V Hadimani; Ishwar B Bagoji; Shardha Bai Rathod; Balappa M Bannur

    2016-01-01

    Brachial artery (BA) is a continuation of the axillary artery at the lower border of teres major. In the cubital fossa, BA divides into radial artery and ulnar artery as terminal branches. Large branch given from the BA in the upper part is profunda brachii artery. In the present case, we noticed double profunda brachii that arises from the BA. They are profunda brachii artery 1 and profunda brachii artery 2. Profunda brachii artery 1 arises in the proximal part of the BA and profunda brachii...

  1. Impact of the Absolute Difference in Diastolic Blood Pressure Between Arms in Patients With Coronary Artery Disease

    OpenAIRE

    Hitaka, Yuka; Miura, Shin-ichiro; Koyoshi, Rie; Shiga, Yuhei; Miyase, Yuiko; Norimatsu, Kenji; Nakamura, Ayumi; Adachi, Sen; Kuwano, Takashi; Sugihara, Makoto; Ike, Amane; Nishikawa, Hiroaki; Saku, Keijiro

    2015-01-01

    Background We investigated the relationship between the severity and presence of coronary artery disease (CAD) and a difference in systolic and diastolic blood pressure (SBP and DBP) between arms or between lower limbs. Methods We enrolled 277 patients who underwent coronary angiography. We calculated the absolute (|right BP (rt. BP) - left BP (lt. BP)|) and relative (rt. BP - lt. BP) differences in SBP or DBP between arms or between lower limbs, and assessed the severity of CAD in terms of t...

  2. Relationship between chronic intermittent hypoxia and intraoperative mean arterial pressure in obstructive sleep apnea patients having laparoscopic bariatric surgery.

    Science.gov (United States)

    Turan, Alparslan; You, Jing; Egan, Cameron; Fu, Alex; Gazmuri, Ignazia; Khanna, Ashish; Eshraghi, Yashar; Ghosh, Raktim; Bose, Somnath; Qavi, Shahbaz; Arora, Lovkesh; Sessler, Daniel I; Doufas, Anthony G

    2015-01-01

    Recurrent nocturnal hypoxemia in obstructive sleep apnea enhances sympathetic function, decreases baroreceptor sensitivity, and weakens peripheral vascular responses to adrenergic signals. The authors hypothesized that the percentage of total sleep time spent at oxyhemoglobin saturation (SaO2) less than 90% and minimum nocturnal SaO2 on preoperative polysomnography are associated with decreased intraoperative mean arterial pressure. The authors examined the records of all patients who had laparoscopic bariatric surgery at Cleveland Clinic between 2005 and 2009 and an available polysomnography study. The authors assessed the relationships between the percentage of total sleep time spent at SaO2 less than 90% and minimum nocturnal SaO2, and the time-weighted average of mean arterial pressure. The authors used multivariable regression models to adjust for prespecified clinical confounders. Two hundred eighty-one patients were included in the analysis. The average change in the time-weighted average of mean arterial pressure was -0.02 (97.5% CI, -0.08, 0.04) mmHg for each 1% absolute increase in the percentage of sleep time spent at SaO2 less than 90% (P = 0.50). The average change was -0.13 (97.5% CI, -0.27, 0.01) mmHg, for each 1% absolute decrease in the minimum SaO2 (P = 0.04 > significance criterion of 0.025, Bonferroni correction). An unplanned analysis estimated 1% absolute decrease in minimum SaO2 was associated with -0.22 (98.75% CI, -0.39, -0.04) mmHg, change in mean arterial pressure (P = 0.002) in the time period between endotracheal intubation and trocar insertion. Recurrent nocturnal hypoxemia in obstructive sleep apnea is not a risk marker for intraoperative hypotension.

  3. Beneficial effects of prolonged blood pressure control after carotid artery stenting

    Directory of Open Access Journals (Sweden)

    Chang A

    2017-01-01

    Full Text Available Anna Chang,1 Huei-Fong Hung,2 Fang-I Hsieh,3 Wei-Hung Chen,1,4 Hsu-Ling Yeh,1,5 Jiann-Horng Yeh,1,6 Hou-Chang Chiu,1,6 Li-Ming Lien1,4 1Department of Neurology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, 2Department of Cardiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, 3School of Public Health, College of Public Health, Taipei Medical University, Taipei, 4School of Medicine, College of Medicine, Taipei Medical University, Taipei, 5Institute of Public Health, National Yang-Ming University, Taipei, 6School of Medicine, College of Medicine, Fu Jen Catholic University, Taipei, Taiwan Objectives: The main purpose of this study was to investigate whether carotid artery stenting (CAS plus medicine in patients with severe carotid artery stenosis provide a better long-term blood pressure (BP control compared to other medical treatments alone. The other aim was to explore the correlation between post-CAS hypotension within 6 h and long-term BP reductions after CAS. Materials and methods: Patients with severe carotid stenosis were recruited either in the CAS group or in the medication group. BPs and the number of classes of antihypertensive agents were recorded at baseline, 6, and 12 months. Extra BP information was collected at 6 h, 3 days, and 1 month after CAS. Univariate and multivariate linear regressions were performed to test the relationship of BP changes among CAS and medication groups after 6 and 12 months of follow-up. Univariate linear regressions were also used to determine the correlations between the mean or maximal systolic BP (SBP reductions at 6 h and 1 year post-CAS. Results: In total, 72 members in the CAS group and 82 members in the medication group were recruited. Compared with the medication group, patients in the CAS group had greater BP reductions at 6 and 12 months of follow-up after adjusting for confounding factors (13.56 mmHg at 6 months, P=0.0002; 16.98 mmHg at 12 months, P<0.0001. This study also shows significant

  4. Does dairy food intake predict arterial stiffness and blood pressure in men?: Evidence from the Caerphilly Prospective Study.

    Science.gov (United States)

    Livingstone, Katherine M; Lovegrove, Julie A; Cockcroft, John R; Elwood, Peter C; Pickering, Janet E; Givens, D Ian

    2013-01-01

    Arterial stiffness is an independent predictor of cardiovascular disease events and mortality, and like blood pressure, may be influenced by dairy food intake. Few studies have investigated the effects of consumption of these foods on prospective measures of arterial stiffness. The present analysis aimed to investigate the prospective relationship between milk, cheese, cream, and butter consumption and aortic pulse wave velocity, augmentation index, systolic and diastolic blood pressure, as well as cross-sectional relationships between these foods and systolic and diastolic blood pressure and metabolic markers using data from the Caerphilly Prospective Study. Included in this cohort were 2512 men, aged 45 to 59 years, who were followed up at 5-year intervals for a mean of 22.8 years (number follow-up 787). Augmentation index was 1.8% lower in subjects in the highest quartiles of dairy product intake compared with the lowest (P trend=0.021), whereas in the highest group of milk consumption systolic blood pressure was 10.4 mm Hg lower (P trend=0.033) than in nonmilk consumers after a 22.8-year follow-up. Cross-sectional analyses indicated that across increasing quartiles of butter intake, insulin (P trend=0.011), triacylglycerol (P trend=0.023), total cholesterol (P trend=0.002), and diastolic blood pressure (P trend=0.027) were higher. Across increasing groups of milk intake and quartiles of dairy product intake, glucose (P trend=0.032) and triglyceride concentrations (P trend=0.031) were lower, respectively. The present results confirm that consumption of milk predicts prospective blood pressure, whereas dairy product consumption, excluding butter, is not detrimental to arterial stiffness and metabolic markers. Further research is needed to better understand the mechanisms that underpin these relationships.

  5. Blood pressure reactivity to psychological stress and coronary calcification in the Coronary Artery Risk Development in Young Adults Study.

    Science.gov (United States)

    Matthews, Karen A; Zhu, Sha; Tucker, Diane C; Whooley, Mary A

    2006-03-01

    A longstanding hypothesis is that individuals who exhibit large increases in blood pressure during psychological stress are at risk for atherosclerosis. We tested whether blood pressure changes during psychological stress predict subsequent coronary calcification (CaC) in young healthy adults. We evaluated 2816 healthy black and white women, 20 to 35 years of age, from the Coronary Artery Risk Development in Young Adults Study, who were not using medication for hypertension or diabetes in 1987-1988. Participants completed video game and star tracing tasks while their blood pressure was recorded. Thirteen years later (2000-2001), they completed computed tomography measures of CaC. Overall 9.3% (261 of 2816) had CaC present at follow-up. Each 10 mm Hg change in systolic blood pressure during the video game was associated with a 24% increased odds of having CaC at follow-up (unadjusted odds ratio, 1.24; 95% CI, 1.06 to 1.46; P=0.008). This association persisted after adjustment for age, race, sex, education, smoking, alcohol, family history of myocardial infarction, smoking, daily alcohol consumption, body mass index, and resting or baseline blood pressure (odds ratio, 1.31; 95% CI, 1.08 to 1.58; P=0.006). Blood pressure changes during the star tracing task were not associated with subsequent CaC. Blood pressure changes during a video game predicted the presence of CaC 13 years later. To our knowledge, this is the first study that reports blood pressure reactivity to a stressor being related to calcification in the coronary arteries. Blood pressure reactivity may provide useful prognostic information about future risk beyond standard risk factors.

  6. Evaluation of the impact of atmospheric pressure in different seasons on blood pressure in patients with arterial hypertension.

    Science.gov (United States)

    Kamiński, Marek; Cieślik-Guerra, Urszula I; Kotas, Rafał; Mazur, Piotr; Marańda, Witold; Piotrowicz, Maciej; Sakowicz, Bartosz; Napieralski, Andrzej; Trzos, Ewa; Uznańska-Loch, Barbara; Rechciński, Tomasz; Kurpesa, Małgorzata

    2016-01-01

    Atmospheric pressure is the most objective weather factor because regardless of if outdoors or indoors it affects all objects in the same way. The majority of previous studies have used the average daily values of atmospheric pressure in a bioclimatic analysis and have found no correlation with blood pressure changes. The main objective of our research was to assess the relationship between atmospheric pressure recorded with a frequency of 1 measurement per minute and the results of 24-h blood pressure monitoring in patients with treated hypertension in different seasons in the moderate climate of the City of Łódź (Poland). The study group consisted of 1662 patients, divided into 2 equal groups (due to a lower and higher average value of atmospheric pressure). Comparisons between blood pressure values in the 2 groups were performed using the Mann-Whitney U test. We observed a significant difference in blood pressure recorded during the lower and higher range of atmospheric pressure: on the days of the spring months systolic (p = 0.043) and diastolic (p = 0.005) blood pressure, and at nights of the winter months systolic blood pressure (p = 0.013). A significant inverse relationship between atmospheric pressure and blood pressure during the spring days and, only for systolic blood pressure, during winter nights was observed. Int J Occup Med Environ Health 2016;29(5):783-792. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  7. Ramadan fasting ameliorates arterial pulse pressure and lipid profile, and alleviates oxidative stress in hypertensive patients.

    Science.gov (United States)

    Al-Shafei, Ahmad I M

    2014-06-01

    Effects of Ramadan fasting on health are important. Its effects on arterial pulse pressure (PP), lipid profile and oxidative stress were characterized in hypertensives. PP, indices of lipid profile and oxidative stress were measured pre-, during and post-fasting in equal (40 each), sex- and age-matched groups (age 55 ± 5 years) of hypertensives (HT) and controls (C). Fasting reduced PP significantly by 17.2% and insignificantly by 9.3% in the HT and C groups, respectively. Total cholesterol (TC) was lowered insignificantly by 11.7% and 4.7% in the HT and C patients, respectively. Triglycerides (TG) and malondialdehyde (MDA) were significantly lowered by: TG: 24.5% and 22.8%; MDA: 45.6% and 54.3%; while glutathione (GSH) elevated by 56.8% and 52.6% in the HT and C groups, respectively. High-density lipoproteins (HDL) were raised significantly by 33.3% and insignificantly by 6.7%, whereas low-density lipoproteins (LDL) decreased significantly by 17.7% and insignificantly by 4.0% in the HT and C groups, respectively. At 6 weeks post-fasting, MDA remained significantly lower than the pre-fasting level by 24.3% and 25.7%, and GSH higher by 30.2% and 26.3% in the HT and C groups, respectively, while PP and TC returned to pre-fasting values in both groups. The post-fasting, HDL was significantly higher by 20.3% and LDL lower by 12.0% than the fasting levels in the HT patients. Fasting improves PP and lipids profile and ameliorates oxidative stress in hypertensives.

  8. 3D.07: CORRELATION BETWEEN THE ARTERIAL PRESSURE VARIABILITY ESTIMATED AT CLINICS, MAPA AND AMPA.

    Science.gov (United States)

    Abellan-Huerta, J; García-Escribano, I A; Soto, R M; Leal, M; Torres, A; Guerrero, B; Melgar, A C; Soto, M; Soria, F; Abellan-Aleman, J

    2015-06-01

    To measure the variability (VB) of the arterial pressure (AP) with the use of serial measurements at the clinics (VBCLIN), with 24 h ambulatory monitoring (MAPA) (VBMAPA) and home automonitoring -AMPA- (VBAMPA) and to estimate a relationship among each method. This is an observational, descriptive and transversal study assessed with 91 hypertensive patients in treatment and stable with AP MAPA was assessed to all the patients included in the study in order to obtain the VBMAPA and an AMPA in two non-consecutive weeks to obtain the VBAMPA (total of 54 measurements). 91 patients with 66 ± 7.7 years old and 58.2% males were recruited. AP values were 134 ± 14/82 ± 10 mmHg for systolic and diastolic APCLIN, respectively. AP values were 122 ± 17 / 68 ± 12 mmHg for systolic and diastolic APMAPA, respectively. AP values were 125 ± 13/75 ± 7 mmHg for systolic and diastolic APAMPA, respectively. The systolic VB for the three above methods was significantly correlated being maximal between VBCLIN and VBAMPA (r = 0.45; 0 MAPA methods is weak. This observation suggests that these are not interchangeable methodologies. Future studies focused on the relationship between VB -with different methods- and vascular target organ damage would be of great help in order to define the best analytical method.

  9. Favorable effect of aerobic exercise on arterial pressure and aortic pulse wave velocity during stress testing.

    Science.gov (United States)

    Milatz, Florian; Ketelhut, Sascha; Ketelhut, Sascha; Ketelhut, Reinhard G

    2015-07-01

    Increased central pulse wave velocity is a major risk factor for cardiovascular disease. The favorable influence of exercise on arterial stiffness (AS) and blood pressure (BP) has been reported exclusively at rest. The present study investigated the influence of a single bout of acute cycling on AS and BP during recovery and, moreover, during cold pressor stress testing. 32 healthy men (33.7 ± 8 years, BMI 24 ± 2.5 kg/m²) performed a 60 minute endurance exercise on a bicycle ergometer (45 % VO2max). Before and after exercise aortic pulse wave velocity (aPWV) as well as central and peripheral BP were measured non-invasively at rest and at the end of a 2 minute cold pressor test (CPT). Even after 60 minutes of recovery aPWV (- 0.22 ± 0.3 m / sec) was significantly reduced (p Exercise decreased peripheral (- 8 ± 7 mmHg) and central (- 7 ± 8 mmHg) systolic BP as well as peripheral (- 3 ± 5 mmHg) and central (- 4 ± 7 mmHg) diastolic BP (p exercise, there was a significant reduction in aPWV (- 0.19 ± 0.3 m / sec), peripheral (- 6 ± 10 mmHg) and central (- 5 ± 8 mmHg) systolic BP as well as peripheral (- 3 ± 6 mmHg) and central (- 3 ± 6 mmHg) diastolic BP during CPT after exercise (p exercise leads not only to decreased BP but even more reduces aPWV as a measure of AS even after 60 minutes of recovery. In particular, the investigation provides evidence that acute moderate-intensity exercise has a favorable effect on BP and aPWV during stress testing.

  10. Association between temporal mean arterial pressure and brachial noninvasive blood pressure during shoulder surgery in the beach chair position during general anesthesia.

    Science.gov (United States)

    Triplet, Jacob J; Lonetta, Christopher M; Everding, Nathan G; Moor, Molly A; Levy, Jonathan C

    2015-01-01

    Estimation of cerebral perfusion pressure during elective shoulder surgery in the beach chair position is regularly performed by noninvasive brachial blood pressure (NIBP) measurements. The relationship between brachial mean arterial pressure and estimated temporal mean arterial pressure (eTMAP) is not well established and may vary with patient positioning. Establishing a ratio between eTMAP and NIBP at varying positions may provide a more accurate estimation of cerebral perfusion using noninvasive measurements. This prospective study included 57 patients undergoing elective shoulder surgery in the beach chair position. All patients received an interscalene block and general anesthesia. After the induction of general anesthesia, values for eTMAP and NIBP were recorded at 0°, 30°, and 70° of incline. A statistically significant, strong, and direct correlation between NIBP and eTMAP was found at 0° (r = 0.909, P ≤ .001), 30° (r = 0.874, P Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  11. Physiological Mechanisms Mediating the Coupling between Heart Period and Arterial Pressure in Response to Postural Changes in Humans.

    Science.gov (United States)

    Silvani, Alessandro; Calandra-Buonaura, Giovanna; Johnson, Blair D; van Helmond, Noud; Barletta, Giorgio; Cecere, Anna G; Joyner, Michael J; Cortelli, Pietro

    2017-01-01

    The upright posture strengthens the coupling between heart period (HP) and systolic arterial pressure (SAP) consistently with a greater contribution of the arterial baroreflex to cardiac control, while paradoxically decreasing cardiac baroreflex sensitivity (cBRS). To investigate the physiological mechanisms that mediate the coupling between HP and SAP in response to different postures, we analyzed the cross-correlation functions between low-frequency HP and SAP fluctuations and estimated cBRS with the sequence technique in healthy male subjects during passive head-up tilt test (HUTT, n = 58), during supine wakefulness, supine slow-wave sleep (SWS), and in the seated and active standing positions ( n = 8), and during progressive loss of 1 L blood ( n = 8) to decrease central venous pressure in the supine position. HUTT, SWS, the seated, and the standing positions, but not blood loss, entailed significant increases in the positive correlation between HP and the previous SAP values, which is the expected result of arterial baroreflex control, compared with baseline recordings in the supine position during wakefulness. These increases were mirrored by increases in the low-frequency variability of SAP in each condition but SWS. cBRS decreased significantly during HUTT, in the seated and standing positions, and after blood loss compared with baseline during wakefulness. These decreases were mirrored by decreases in the RMSSD index, which reflects cardiac vagal modulation. These results support the view that the cBRS decrease associated with the upright posture is a byproduct of decreased cardiac vagal modulation, triggered by the arterial baroreflex in response to central hypovolemia. Conversely, the greater baroreflex contribution to cardiac control associated with upright posture may be explained, at least in part, by enhanced fluctuations of SAP, which elicit a more effective entrainment of HP fluctuations by the arterial baroreflex. These SAP fluctuations may result

  12. Cost-Effectiveness of Implantable Pulmonary Artery Pressure Monitoring in Chronic Heart Failure.

    Science.gov (United States)

    Sandhu, Alexander T; Goldhaber-Fiebert, Jeremy D; Owens, Douglas K; Turakhia, Mintu P; Kaiser, Daniel W; Heidenreich, Paul A

    2016-05-01

    This study aimed to evaluate the cost-effectiveness of the CardioMEMS (CardioMEMS Heart Failure System, St Jude Medical Inc, Atlanta, Georgia) device in patients with chronic heart failure. The CardioMEMS device, an implantable pulmonary artery pressure monitor, was shown to reduce hospitalizations for heart failure and improve quality of life in the CHAMPION (CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Heart Failure Patients) trial. We developed a Markov model to determine the hospitalization, survival, quality of life, cost, and incremental cost-effectiveness ratio of CardioMEMS implantation compared with usual care among a CHAMPION trial cohort of patients with heart failure. We obtained event rates and utilities from published trial data; we used costs from literature estimates and Medicare reimbursement data. We performed subgroup analyses of preserved and reduced ejection fraction and an exploratory analysis in a lower-risk cohort on the basis of the CHARM (Candesartan in Heart failure: Reduction in Mortality and Morbidity) trials. CardioMEMS reduced lifetime hospitalizations (2.18 vs. 3.12), increased quality-adjusted life-years (QALYs) (2.74 vs. 2.46), and increased costs ($176,648 vs. $156,569), thus yielding a cost of $71,462 per QALY gained and $48,054 per life-year gained. The cost per QALY gained was $82,301 in patients with reduced ejection fraction and $47,768 in those with preserved ejection fraction. In the lower-risk CHARM cohort, the device would need to reduce hospitalizations for heart failure by 41% to cost cost-effectiveness was most sensitive to the device's durability. In populations similar to that of the CHAMPION trial, the CardioMEMS device is cost-effective if the trial effectiveness is sustained over long periods. Post-marketing surveillance data on durability will further clarify its value. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights

  13. Non-invasive continuous finger blood pressure measurement during orthostatic stress compared to intra-arterial pressure

    NARCIS (Netherlands)

    Imholz, B. P.; Settels, J. J.; van der Meiracker, A. H.; Wesseling, K. H.; Wieling, W.

    1990-01-01

    The aim of the study was to evaluate whether invasive blood pressure responses to orthostatic stress can be replaced by non-invasive continuous finger blood pressure responses. DESIGN - Intrabrachial and Finapres blood pressures were simultaneously measured during passive head up tilt and during

  14. Increased pulmonary artery pressures during exercise are related to persistent tricuspid regurgitation after atrial septal defect closure.

    Science.gov (United States)

    De Meester, Pieter; Van De Bruaene, Alexander; Herijgers, Paul; Voigt, Jens-Uwe; Vanhees, Luc; Budts, Werner

    2013-08-01

    Although closure of an atrial septal defect type secundum often normalizes right heart dimensions and pressures, mild tricuspid insufficiency might persist. This study aimed at (1) identification of determinants explaining the persistence of tricuspid insufficiency after atrial septal defect closure, and (2) evaluation of functional capacity of patients with persistent mild tricuspid insufficiency. Twenty-five consecutive patients (age 42+17 y) were included from the outpatient clinic of congenital heart disease at the University Hospitals of Leuven. All underwent transthoracic echocardiography, semi-supine bicycle stress echocardiography and cardio-pulmonary exercise testing. Six patients (24%) had mild tricuspid insufficiency (2/4) compared to 19 patients (76%) with no or minimal tricuspid insufficiency ( 1/4) as assessed by semi-quantitative colour Doppler echocardiography. Mann-Whitney U and Fisher's exact tests were performed where applicable. Patients with persistent mild tricuspid insufficiency were significantly older than those with no or minimal tricuspid insufficiency (P = 0.042). At rest, no differences in right heart configuration, mean pulmonary artery pressure or right ventricular function were found. At peak exercise, mean pulmonary artery pressure was significantly higher in patients with mild persistent tricuspid insufficiency (P = 0.026). Peak oxygen uptake was significantly lower in patients with mild persistent tricuspid insufficiency (P = 0.019). Mild tricuspid insufficiency after atrial septal defect repair occurs more frequently in older patients and in patients with higher mean pulmonary artery pressure at peak exercise. In patients with mild tricuspid insufficiency, functional capacity was more reduced. Mild tricuspid insufficiency could be a marker of subclinical persistent pressure load on the right ventricle.

  15. Use of a pressure sensing sheath: comparison with standard means of blood pressure monitoring in catheterization procedures.

    Science.gov (United States)

    Purdy, Phillip D; South, Charles; Klucznik, Richard P; Liu, Kenneth C; Novakovic, Robin L; Puri, Ajit S; Pride, G Lee; Aagaard-Kienitz, Beverly; Ray, Abishek; Elliott, Alan C

    2017-08-01

    Monitoring of blood pressure (BP) during procedures is variable, depending on multiple factors. Common methods include sphygmomanometer (BP cuff), separate radial artery catheterization, and side port monitoring of an indwelling sheath. Each means of monitoring has disadvantages, including time consumption, added risk, and signal dampening due to multiple factors. We sought an alternative approach to monitoring during procedures in the catheterization laboratory. A new technology involving a 330 µm fiberoptic sensor embedded in the wall of a sheath structure was tested against both radial artery catheter and sphygmomanometer readings obtained simultaneous with readings recorded from the pressure sensing system (PSS). Correlations and Bland-Altman analysis were used to determine whether use of the PSS could substitute for these standard techniques. The results indicated highly significant correlations in systolic, diastolic, and mean arterial pressures (MAP) when compared against radial artery catheterization (p<0.0001), and MAP means differed by <4%. Bland-Altman analysis of the data suggested that the sheath measurements can replace a separate radial artery catheter. While less striking, significant correlations were seen when PSS readings were compared against BP cuff readings. The PSS has competitive functionality to that seen with a dedicated radial artery catheter for BP monitoring and is available immediately on sheath insertion without the added risk of radial catheterization. The sensor is structurally separated from the primary sheath lumen and readings are unaffected by device introduction through the primary lumen. Time delays and potential complications from radial artery catheterization are avoided. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  16. Central Hemodynamics and Arterial Stiffness in Systemic Sclerosis.

    Science.gov (United States)

    Bartoloni, Elena; Pucci, Giacomo; Cannarile, Francesca; Battista, Francesca; Alunno, Alessia; Giuliani, Marco; Cafaro, Giacomo; Gerli, Roberto; Schillaci, Giuseppe

    2016-12-01

    Although microvascular disease is a hallmark of systemic sclerosis (SSc), a higher prevalence of macrovascular disease and a poorer related prognosis have been reported in SSc than in the general population. The simultaneous assessment of prognostically relevant functional properties of larger and smaller arteries, and their effects on central hemodynamics, has never been performed in SSc using the state-of-the-art techniques. Thirty-four women with SSc (aged 61±15 years, disease duration 17±12 years, and blood pressure 123/70±18/11 mm Hg) and 34 healthy women individually matched by age and mean arterial pressure underwent the determination of carotid-femoral (aortic) and carotid-radial (upper limb) pulse wave velocity (a direct measure of arterial stiffness), aortic augmentation (a measure of the contribution of reflected wave to central pulse pressure), and aortobrachial pulse pressure amplification (brachial/aortic pulse pressure) through applanation tonometry (SphygmoCor). Patients and controls did not differ by carotid-femoral or carotid-radial pulse wave velocity. Aortic augmentation index corrected for a heart rate of 75 bpm (AIx@75) was higher in women with SSc (30.9±16% versus 22.2±12%; P=0.012). Patients also had a lower aortobrachial amplification of pulse pressure (1.22±0.18 versus 1.33±0.25; P=0.041). SSc was an independent predictor of AIx@75 (direct) and pulse pressure amplification (inverse). Among patients, age, mean arterial pressure, and C-reactive protein independently predicted carotid-femoral pulse wave velocity. Age and mean arterial pressure were the only predictors of AIx@75. Women with SSc have increased aortic augmentation and decreased pulse pressure amplification (both measures of the contribution of reflected wave to central waveform) but no changes in aortic or upper limb arterial stiffness. Microvascular involvement occurs earlier than large artery stiffening in SSc. © 2016 American Heart Association, Inc.

  17. Combined resistive and laser heating technique for in situ radial X-ray diffraction in the diamond anvil cell at high pressure and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Miyagi, Lowell [Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112 (United States); Department of Earth Sciences, Montana State University, Bozeman, Montana 59717 (United States); Kanitpanyacharoen, Waruntorn; Kaercher, Pamela; Wenk, Hans-Rudolf; Alarcon, Eloisa Zepeda [Department of Earth and Planetary Science, University of California, Berkeley, California 94720 (United States); Raju, Selva Vennila [Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); HiPSEC, Department of Physics, University of Nevada, Las Vegas, Nevada 89154 (United States); Knight, Jason; MacDowell, Alastair [Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); Williams, Quentin [Department of Earth and Planetary Science, University of California, Santa Cruz, California 95064 (United States)

    2013-02-15

    To extend the range of high-temperature, high-pressure studies within the diamond anvil cell, a Liermann-type diamond anvil cell with radial diffraction geometry (rDAC) was redesigned and developed for synchrotron X-ray diffraction experiments at beamline 12.2.2 of the Advanced Light Source. The rDAC, equipped with graphite heating arrays, allows simultaneous resistive and laser heating while the material is subjected to high pressure. The goals are both to extend the temperature range of external (resistive) heating and to produce environments with lower temperature gradients in a simultaneously resistive- and laser-heated rDAC. Three different geomaterials were used as pilot samples to calibrate and optimize conditions for combined resistive and laser heating. For example, in Run1, FeO was loaded in a boron-mica gasket and compressed to 11 GPa then gradually resistively heated to 1007 K (1073 K at the diamond side). The laser heating was further applied to FeO to raise temperature to 2273 K. In Run2, Fe-Ni alloy was compressed to 18 GPa and resistively heated to 1785 K (1973 K at the diamond side). The combined resistive and laser heating was successfully performed again on (Mg{sub 0.9}Fe{sub 0.1})O in Run3. In this instance, the sample was loaded in a boron-kapton gasket, compressed to 29 GPa, resistive-heated up to 1007 K (1073 K at the diamond side), and further simultaneously laser-heated to achieve a temperature in excess of 2273 K at the sample position. Diffraction patterns obtained from the experiments were deconvoluted using the Rietveld method and quantified for lattice preferred orientation of each material under extreme conditions and during phase transformation.

  18. A fluid-structure interaction model of the internal carotid and ophthalmic arteries for the noninvasive intracranial pressure measurement method.

    Science.gov (United States)

    Misiulis, Edgaras; Džiugys, Algis; Navakas, Robertas; Striūgas, Nerijus

    2017-05-01

    Accurate and clinically safe measurements of intracranial pressure (ICP) are crucial for secondary brain damage prevention. There are two methods of ICP measurement: invasive and noninvasive. Invasive methods are clinically unsafe; therefore, safer noninvasive methods are being developed. One of the noninvasive ICP measurement methods implements the balance principle, which assumes that if the velocity of blood flow in both ophthalmic artery segments - the intracranial (IOA) and extracranial (EOA) - is equal, then the acting ICP on the IOA and the external pressure (Pe) on the EOA are also equal. To investigate the assumption of the balance principle, a generalized computational model incorporating a fluid-structure interaction (FSI) module was created and used to simulate noninvasive ICP measurement by accounting for the time-dependent behavior of the elastic internal carotid (ICA) and ophthalmic (OA) arteries and their interaction with pulsatile blood flow. It was found that the extra balance pressure term, which incorporates the hydrodynamic pressure drop between measurement points, must be added into the balance equation, and the corrections on a difference between the velocity of blood flow in the IOA and EOA must be made, due to a difference in the blood flow rate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Effects of simulated microgravity on circadian rhythm of caudal arterial pressure and heart rate in rats and their underlying mechanism

    Directory of Open Access Journals (Sweden)

    Li CHEN

    2016-04-01

    Full Text Available Objective  To explore the effects of simulated microgravity on the circadian rhythm of rats' caudal arterial pressure and heart rate, and their underlying mechanism. Methods  Eighteen male SD rats (aged 8 weeks were randomly assigned to control (CON and tail suspension (SUS group (9 each. Rats with tail suspension for 28 days were adopted as the animal model to simulate microgravity. Caudal arterial pressure and heart rate of rats were measured every 3 hours. The circadian difference of abdominal aorta contraction was measured by aortic ring test. Western blotting was performed to determine and compare the protein expression level of clock genes such as Per2 (Period2, Bmal1 (Aryl hydrocarbon receptor nuclear translocatorlike and dbp (D element binding protein in suprachiasmatic nucleus (SCN and abdominal aorta of rats in CON and SUS group at different time points. Results  Compared with CON group, the caudal arterial pressure, both systolic and diastolic pressure, decreased significantly and the diurnal variability disappeared, meanwhile the heart rate increased obviously and also the diurnal variability disappeared in rats of SUS group. Compared with CON group, the contraction reactivity of abdominal aorta decreased with disappearence of the diurnal variability, and also the clock genes expression in SCN and abdominal aorta showed no diurnal variability in rats of SUS group. Conclusion  Simulated microgravity may lead to circadian rhythm disorders in rats' cardiovascular system, which may be associated with the changes of the clock genes expression. DOI: 10.11855/j.issn.0577-7402.2016.04.06

  20. Influence of isoflurane on the diastolic pressure-flow relationship and critical occlusion pressure during arterial CABG surgery: a randomized controlled trial.

    Science.gov (United States)

    Hinz, José; Mansur, Ashham; Hanekop, Gerd G; Weyland, Andreas; Popov, Aron F; Schmitto, Jan D; Grüne, Frank F G; Bauer, Martin; Kazmaier, Stephan

    2016-01-01

    The effects of isoflurane on the determinants of blood flow during Coronary Artery Bypass Graft (CABG) surgery are not completely understood. This study characterized the influence of isoflurane on the diastolic Pressure-Flow (P-F) relationship and Critical Occlusion Pressure (COP) during CABG surgery. Twenty patients undergoing CABG surgery were studied. Patients were assigned to an isoflurane or control group. Hemodynamic and flow measurements during CABG surgery were performed twice (15 minutes after the discontinuation of extracorporeal circulation (T15) and again 15 minutes later (T30)). The zero flow pressure intercept (a measure of COP) was extrapolated from a linear regression analysis of the instantaneous diastolic P-F relationship. In the isoflurane group, the application of isoflurane significantly increased the slope of the diastolic P-F relationship by 215% indicating a mean reduction of Coronary Vascular Resistance (CVR) by 46%. Simultaneously, the Mean Diastolic Aortic Pressure (MDAP) decreased by 19% mainly due to a decrease in the systemic vascular resistance index by 21%. The COP, cardiac index, heart rate, Left Ventricular End-Diastolic Pressure (LVEDP) and Coronary Sinus Pressure (CSP) did not change significantly. In the control group, the parameters remained unchanged. In both groups, COP significantly exceeded the CSP and LVEDP at both time points. We conclude that short-term application of isoflurane at a sedative concentration markedly increases the slope of the instantaneous diastolic P-F relationship during CABG surgery implying a distinct decrease with CVR in patients undergoing CABG surgery.

  1. Effects of spontaneously hypertensive rat plasma on blood pressure and tail artery calcium uptake in normotensive rats

    International Nuclear Information System (INIS)

    Lewanczuk, R.Z.; Wang, J.; Zhang, Z.R.; Pang, P.K.

    1989-01-01

    Previous studies have described the presence of humoral hypertensive factors in spontaneously hypertensive rats (SHR). Other studies have described factors that increase calcium uptake in vascular tissue. In this study, we attempted to confirm, and thereby correlate, the presence of both types of factors in SHR plasma. Intravenous infusion or bolus administration of dialyzed SHR plasma consistently induced an increase in blood pressure in normotensive rats. This hypertensive response was somewhat delayed, with peak blood pressures occurring 45 minutes after bolus administration and 90 minutes after infusion of SHR plasma. Spontaneously hypertensive rat plasma also increased 45 Ca uptake in isolated normotensive rat tail arteries in a dose-dependent manner, with a time course similar to that for the hypertensive response to bolus administration. These findings suggest, therefore, that a substance exists in SHR plasma that can increase intracellular calcium in vascular tissues and thereby increase blood pressure

  2. [Development of a continuous blood pressure monitoring and recording system].

    Science.gov (United States)

    Zhang, Yang; Li, Yong; Gao, Shumei; Song, Yilin

    2012-09-01

    A small experimental system is constructed with working principle of continuous blood pressure monitoring based on the volume compensation method. The preliminary experimental results show that the system can collect blood pressure signals at the radial artery effectively. The digital PID algorithm can track the variation of blood pressure. And the accuracy of continuous blood pressure detecting achieve the level of same kind of product.

  3. Correction ofvitamin D deficiency/insufficiency and assessment of 24-hour blood pressure parameters in perimenopausal women with arterial hypertension

    Directory of Open Access Journals (Sweden)

    Ludmiła Walerjewna Jankowska

    2014-09-01

    Full Text Available Both arterial hypertension and vitamin D deficiency are highly prevalent in the general population. Aim of the study was to assess blood pressure and its dynamics in 24-hour ambulatory blood pressure monitoring (ABPM while correcting the vitamin D deficiency/insufficiency in perimenopausal women, who have grade 2 arterial hypertension. Material and methods: The study group consisted of 50 premenopausal women [48 (45–50 years] and 52 women in early (up to 5 years postmenopausal period [52 (50–54 years]. Total 25-(OHD blood plasma levels were assessed by immunoenzyme assay using DRG kit (Marburg, Germany. The total 25-(OHD blood plasma levels below 20 ng/ml were considered as vitamin D insufficiency, the concentration of 20–30 ng/ml – as deficiency, and the levels 30–60 ng/ml were considered normal. In the group of women with 25-(OHD deficiency/insufficiency two subgroups were isolated: IB subgroup (n = 25 and IIB (n = 21, which were introduced with treatment algorithm, including cholecalciferol administration at a daily dose of 2000 IU for 3 months. Results: Cholecalciferol therapy at a dose of 2000 IU per day for a period of 3 months has allowed reaching the optimum concentration of vitamin D in 80% of premenopausal hypertensive women, and in 76.2% of women in the early postmenopausal period. Correction of plasma vitamin D deficiency achieved by taking cholecalciferol, while using combined antihypertensive therapy (ramipril + indapamide allows to improve the following parameters assessed in ambulatory blood pressure monitoring in premenopausal women: the mean daytime and nighttime systolic blood pressure, time index of 24-hour and daytime systolic blood pressure, nighttime blood pressure variability, systolic and diastolic blood pressure morning surge, and normalization of nighttime:daytime blood pressure ratio; in postmenopausal women the treatment allowed: the reduction of morning surge of

  4. Assessing Collagen and Elastin Pressure-dependent Microarchitectures in Live, Human Resistance Arteries by Label-free Fluorescence Microscopy

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Thorsted, Bjarne; Brewer, Jonathan R

    2018-01-01

    The pathogenic contribution of resistance artery remodeling is documented in essential hypertension, diabetes and the metabolic syndrome. Investigations and development of microstructurally motivated mathematical models for understanding the mechanical properties of human resistance arteries...... in health and disease have the potential to aid understanding how disease and medical treatments affect the human microcirculation. To develop these mathematical models, it is essential to decipher the relationship between the mechanical and microarchitectural properties of the microvascular wall...... of interest. Image analyses are described for quantifying i) pressure-induced changes in internal elastic lamina branching angles and adventitial collagen straightness using Fiji and ii) collagen and elastin volume densities determined using Ilastik software. Preferably all mechanical and imaging measurements...

  5. Chronic hypoxia increases arterial blood pressure and reduces adenosine and ATP induced vasodilatation in skeletal muscle in healthy humans

    DEFF Research Database (Denmark)

    Calbet, J A L; Boushel, Robert Christopher; Robach, P

    2014-01-01

    into the femoral artery at sea level and then after 8-12 days of residence at 4559 m above sea level. At sea level, the infusions were carried out while the subjects breathed room air, acute hypoxia (FI O2 = 0.11) and hyperoxia (FI O2 = 1); and at altitude (FI O2 = 0.21 and 1). Skeletal muscle P2Y2 receptor...... protein expression was determined in muscle biopsies after 4 weeks at 3454 m by Western blot. RESULTS: At altitude, mean arterial blood pressure was 13% higher (91 ± 2 vs. 102 ± 3 mmHg, P sea level and was unaltered by hyperoxic breathing. Baseline leg vascular conductance was 25% lower...... at altitude than at sea level (P sea level by 24 and 38%, during the low and high ATP doses...

  6. Mean pressure of pulmonary arteries in non-callous silicosis at states 1 to 2 as determined by radiology in comparison to parameters of pulmonary function

    Energy Technology Data Exchange (ETDEWEB)

    Jakob, M; Konrad, A; Adam, P; Scharf, R

    1984-11-19

    Fifty coal miners suffering from reticulonodular silicosis underwent catheterization of the right heart and showed latent or manifest pulmonary hypertension. It has been found that the statistical relationship between pulmonary arterial pressure and pulmonary function was only a loose one. Thirty percent of the studied subjects presented no alterations of the lung function but an increased pulmonary artery mean pressure at rest and under exercise, indicating that the Euler-Liljestrand-mechanism could hardly be responsible for these pressure changes. Subjects with silicosis who presented impaired lung function showed statistically significant higher pulmonary artery pressures than those without alteration of the lung function. It is likely that an additional pressure increase occurs secondary to Euler-Liljestrand-mechanism, when restrictive or obstructive impairments of ventilation emerge from the pneumoconiosis.

  7. Peripheral and central arterial pressure and its relationship to vascular target organ damage in carotid artery, retina and arterial stiffness. Development and validation of a tool. The Vaso risk study

    Directory of Open Access Journals (Sweden)

    Patino-Alonso Maria C

    2011-04-01

    Full Text Available Abstract Background Ambulatory blood pressure monitoring (ABPM shows a better correlation to target organ damage and cardiovascular morbidity-mortality than office blood pressure. A loss of arterial elasticity and an increase in carotid artery intima-media thickness (IMT has been associated with increased cardiovascular morbidity-mortality. Tools have been developed that allow estimation of the retinal arteriovenous index but not all studies coincide and there are contradictory results in relation to the evolution of the arteriosclerotic lesions and the caliber of the retinal vessels. The purpose of this study is to analyze the relationship between peripheral and central arterial pressure (clinic and ambulatory and vascular structure and function as evaluated by the carotid artery intima-media thickness, retina arteriovenous index, pulse wave velocity (PWV and ankle-brachial index in patients with and without type 2 diabetes. In turn, software is developed and validated for measuring retinal vessel thickness and automatically estimating the arteriovenous index. Methods/Design A cross-sectional study involving a control group will be made, with a posterior 4-year follow-up period in primary care. The study patients will be type 2 diabetics, with a control group of non-diabetic individuals. Consecutive sampling will be used to include 300 patients between 34-75 years of age and no previous cardiovascular disease, one-half being assigned to each group. Main measurements: age, gender, height, weight and abdominal circumference. Lipids, creatinine, microalbuminuria, blood glucose, HbA1c, blood insulin, high sensitivity C-reactive protein and endothelial dysfunction markers. Clinic and ambulatory blood pressure monitoring. Carotid ultrasound to evaluate IMT, and retinography to evaluate the arteriovenous index. ECG to assess left ventricle hypertrophy, ankle-brachial index, and pulse wave analysis (PWA and pulse wave velocity (PWV with the Sphigmocor

  8. Evaluation of an isotope washout technique to measure skin vascular resistance and skin perfusion pressure: influence of age, site and arterial surgery

    International Nuclear Information System (INIS)

    Duncan, H.J.; Faris, I.B.

    1986-01-01

    1. A simplified isotope (sup(99m)Tc) washout technique has been devised to calculate the skin perfusion pressure (SPP) and skin vascular resistance (SVR). This test is simple, requires inexpensive equipment and is well tolerated by patients. 2. SPP and SVR were calculated in 20 patients 30 years of age and in 15 patients with peripheral vascular disease (PVD). With increasing age the SPP and SVP were increased. The SPP was similar to the mean arterial pressure in normal individuals but was decreased in patients with PVD. The SPP is a useful indicator of the severity of the PVD. 3. The SPP and SVR were higher in the calf than in the foot. This is probably related to the decrease in pressure in the distal arterial tree. 4. SPP was increased by 110% and skin blood flow by 190% by arterial reconstructive surgery. This test may be of use in assessing the effectiveness of arterial surgery. (author)

  9. Minimal distal pressure rise after reconstructive arterial surgery in patients with multiple obstructive arteriosclerosis

    DEFF Research Database (Denmark)

    Noer, Ivan; Tønnesen, K H; Sager, P

    1980-01-01

    fifteen had ischemic ulcers. The preoperative median pressure index (per cent of arm systolic pressure) was 10% on the 1st toe. At the 10th postoperative day the median toe pressure rose to 25%. A further rise took place at the one month control to 30% which was unchanged throughout the study. All...... patients with a persistent postoperative toe pressure above 20% of arm systolic pressure were ultimately relieved from rest pain and chronic ulcers....

  10. Corpuls CPR Generates Higher Mean Arterial Pressure Than LUCAS II in a Pig Model of Cardiac Arrest

    Directory of Open Access Journals (Sweden)

    S. Eichhorn

    2017-01-01

    Full Text Available According to the European Resuscitation Council guidelines, the use of mechanical chest compression devices is a reasonable alternative in situations where manual chest compression is impractical or compromises provider safety. The aim of this study is to compare the performance of a recently developed chest compression device (Corpuls CPR with an established system (LUCAS II in a pig model. Methods. Pigs (n = 5/group in provoked ventricular fibrillation were left untreated for 5 minutes, after which 15 min of cardiopulmonary resuscitation was performed with chest compressions. After 15 min, defibrillation was performed every 2 min if necessary, and up to 3 doses of adrenaline were given. If there was no return of spontaneous circulation after 25 min, the experiment was terminated. Coronary perfusion pressure, carotid blood flow, end-expiratory CO2, regional oxygen saturation by near infrared spectroscopy, blood gas, and local organ perfusion with fluorescent labelled microspheres were measured at baseline and during resuscitation. Results. Animals treated with Corpuls CPR had significantly higher mean arterial pressures during resuscitation, along with a detectable trend of greater carotid blood flow and organ perfusion. Conclusion. Chest compressions with the Corpuls CPR device generated significantly higher mean arterial pressures than compressions performed with the LUCAS II device.

  11. Pressure drop variation as a function of axial and radial power distribution in CANDU fuel channel with standard and CANFLEX 43 bundles

    International Nuclear Information System (INIS)

    Catana, Alexandru; Department of Energy Danila, Nicolae; Prisecaru, Ilie; Dupleac, Daniel

    2007-01-01

    CANDU 600 nuclear reactors are usually fuelled with STANDARD (STD), 37 rods fuel bundles. Natural uranium (NU) dioxide (UO 2 ), is used as fuel composition. A new fuel bundle geometry called CANFLEX (CFX) with 43 rods is proposed and some new fuel composition are considered. Flexibility is the key word for the attempt to use some different fuel geometries and compositions for CANDU 600 nuclear reactors as well as for innovative ACR-700/1000 nuclear reactors. The fuel bundle considered in this paper is CFX-RU-0.90 that encodes the CANFLEX geometry, recycled dioxide uranium (RU) with 0.90% enrichment. The goal of this proposal is ambitious: a higher average discharge burn-up up to 14000 MWd/tU and, for the same amount of generated electric power, reduction in nuclear fuel fabrication, reduction of spent nuclear fuel radioactive waste and reduction of refueling operational work by using fewer bundles. An improved sub-channel approach for thermal-hydraulic analysis is used in this paper to compute some flow parameters, mainly the pressure drop along the CANDU 600 fuel channel when STD or CFX-RU-0.90 fuel bundles. Also an intermediate CFX-NU fuel bundle are used, for gradual comparison. For CFX-RU- 0.90 four fuel bundle shift refueling scheme is used instead of eight, that will determine different axial power distributions. At the same time radial power distribution is affected by the geometry and by the fuel composition of fuel bundle type used. Some other thermal-hydraulic flow parameters will be influenced, too. One of the most important parameter is pressure drop (PD) along the fuel channel because of its importance in drag force evaluation. We start with an axial power distribution, which is characteristic for a refueling scheme of eight or four fuel bundles on a shift. Comparative results are presented between STD37, CFX-NU CFX-RU-0.90 fuel bundles in a CANDU nuclear reactor operating conditions. Neutron flux distribution analysis shows that four bundle shift

  12. Middle cerebral artery occlusion in presence of low perfusion pressure increases infarct size in rats

    DEFF Research Database (Denmark)

    Sillesen, H; Nedergaard, Majken; Schroeder, T

    1988-01-01

    0.005), which in turn had larger infarcts than the sham-operated animals (p less than 0.001). These results indicate that patients with hypoperfusion, due to severe ICA stenosis and impaired collateral blood supply, are at higher risk of developing major stroke, when embolism into a cerebral artery...

  13. Vital Signs – Presión arterial alta (High Blood Pressure)

    Centers for Disease Control (CDC) Podcasts

    En los EE. UU. casi un tercio de la población adulta tiene presión arterial alta, el principal factor de riesgo de enfermedades cardiacas y accidentes cerebrovasculares, dos de las principales causas de muerte en el país.

  14. Oxidative stress mediated arterial dysfunction in patients with obstructive sleep apnoea and the effect of continuous positive airway pressure treatment

    Directory of Open Access Journals (Sweden)

    Del Ben Maria

    2012-07-01

    Full Text Available Abstract Background Several studies suggest an increase of oxidative stress and a reduction of endothelial function in obstructive sleep apnoea syndrome (OSAS. We assessed the association between OSAS, endothelial dysfunction and oxidative stress. Further aim was to evaluate the effect of nasal continuous positive airway pressure (nCPAP on oxidative stress and arterial dysfunction. Methods We studied 138 consecutive patients with heavy snoring and possible OSAS. Patients underwent unattended overnight home polysomnography. Ten patients with severe OSAS were revaluated after 6 months of nCPAP therapy. To assess oxidative stress in vivo, we measured urinary 8-iso-PGF2α and serum levels of soluble NOX2-derived peptide (sNOX2-dp. Serum levels of nitrite/nitrate (NOx were also determined. Flow-mediated brachial artery dilation (FMD was measured to asses endothelial function. Results Patients with severe OSAS had higher urinary 8-iso-PGF2α (p Conclusions The results of our study indicate that patients with OSAS and cardiometabolic comorbidities have increased oxidative stress and arterial dysfunction that are partially reversed by nCPAP treatment.

  15. The effects of stair climbing on arterial stiffness, blood pressure, and leg strength in postmenopausal women with stage 2 hypertension.

    Science.gov (United States)

    Wong, Alexei; Figueroa, Arturo; Son, Won-Mok; Chernykh, Oksana; Park, Song-Young

    2018-02-12

    Menopause is accompanied by a progressive arterial stiffening associated with increases in blood pressure (BP) and decline in muscular function. It is crucial to prevent or reduce the negative effects of menopause on vascular and muscular function by implementing appropriate lifestyle interventions, such as exercise training. We examined the effects of a stair climbing (SC) regimen on arterial stiffness (pulse wave velocity [PWV]), BP, and leg strength in postmenopausal women with stage 2 hypertension. Using a parallel experimental design, participants were randomly assigned to either SC (n = 21) or nonexercising control group (n = 20) for 12 weeks. Participants in the SC group trained 4 d/wk, climbing 192 steps 2 to 5 times/d. Participants' brachial-to-ankle PWV (baPWV), BP, and leg strength were measured at baseline and after 12 weeks of their assigned intervention. There was a significant group by time interaction (P hypertensive postmenopausal women. The decrease in arterial stiffness partially explained the improvements in SBP and leg strength. SC may be an effective intervention in the prevention and treatment of menopause/aging-related vascular complications and muscle weakness.

  16. Low-pressure balloon angioplasty with adjuvant pharmacological therapy in patients with acute ischemic stroke caused by intracranial arterial occlusions

    International Nuclear Information System (INIS)

    Nogueira, Raul G.; Schwamm, Lee H.; Buonanno, Ferdinando S.; Koroshetz, Walter J.; Yoo, Albert J.; Rabinov, James D.; Pryor, Johnny C.; Hirsch, Joshua A.

    2008-01-01

    The use of coronary balloons in the cerebral vasculature is limited due to their poor trackability and increased risk of vessel injury. We report our experience using more compliant elastomer balloons for thrombus resistant to intraarterial (IA) pharmacological and mechanical thrombolysis in acute stroke. We retrospectively analyzed 12 consecutive patients with an occluded intracranial artery treated with angioplasty using a low-pressure elastomer balloon. Angiograms were graded according to the Thrombolysis in Cerebral Infarction (TICI) and Qureshi grading systems. Outcomes were categorized as independent (modified Rankin scale, mRS, score ≤2), dependent (mRS score 3-5), or dead (mRS score 6). Included in the study were 12 patients (mean age 66±17 years, range 31-88 years; mean baseline National Institutes of Health stroke scale score 17±3, range 12-23). The occlusion sites were: internal carotid artery (ICA) terminus (five patients, including two concomitant cervical ICA occlusions), M1 segment (two patients), and basilar artery (two patients). Pharmacological treatment included intravenous (IV) t-PA only (two patients), IA urokinase only (nine patients), both IV t-PA and IA urokinase (one patient), and IV and/or IA eptifibatide (eight patients). Mean time to treatment was 5.9±3.9 h (anterior circulation) and 11.0±7.2 h (posterior circulation). Overall recanalization rate (TICI grade 2/3) was 91.6%. Procedure-related morbidity occurred in one patient (distal posterior inferior cerebellar artery embolus). There were no symptomatic hemorrhages. Outcomes at 90 days were independent (five patients), dependent (three patients) and dead (four patients, all due to progression of stroke with withdrawal of care). Angioplasty of acutely occluded intracranial arteries with low-pressure elastomer balloons results in high recanalization rates with an acceptable degree of safety. Prior use of thrombolytics may increase the chances of recanalization, and glycoprotein IIb

  17. The effect of siesta in parameters of cardiac structure and in interpretation of ambulatory arterial blood pressure monitoring

    Directory of Open Access Journals (Sweden)

    Marco A.M. Gomes

    2000-04-01

    Full Text Available OBJECTIVE: To evaluate the influence of the siesta in ambulatory blood pressure (BP monitoring and in cardiac structure parameters. METHODS: 1940 ambulatory arterial blood pressure monitoring tests were analyzed (Spacelabs 90207, 15/15 minutes from 7:00 to 22:00 hours and 20/20 minutes from 22:01 to 6.59hours and 21% of the records indicated that the person had taken a siesta (263 woman, 52±14 years. The average duration of the siesta was 118±58 minutes. RESULTS: (average ± standard deviation The average of systolic/diastolic pressures during wakefulness, including the napping period, was less than the average for the period not including the siesta (138±16/85±11 vs 139±16/86±11 mmHg, p5%. CONCLUSION: The siesta influenced the heart structure parameters and from a statistical point of view the average of systolic and diastolic pressures and the respective pressure loads of the wakeful period.

  18. Number of distal limb and brachial pressure measurements required when diagnosing peripheral arterial disease by laser Doppler flowmetry

    International Nuclear Information System (INIS)

    Høyer, C; Biurrun Manresa, J A; Petersen, L J

    2013-01-01

    We examine the reliability of single and repeated blood pressure measurements at ankle, toe, and arm levels for the diagnosis of peripheral arterial disease (PAD) by laser Doppler flowmetry. Segmental pressures were measured in 200 patients with known or suspected PAD. Segmental indices were calculated using (1) one measurement [M-1], two measurements [M-2], or by a predefined reproducibility criterion (RC) as well as (2) by using one brachial blood-pressure (BBP-one) or correspondent to each segmental pressure (BBP-all) as reference. The agreement in diagnosis of PAD by Cohen's Kappa was κ = 0.930 when comparing RC to M-1, and κ = 0.977 when comparing RC to M-2. The same comparison showed excellent relative reliability for segmental indices (all intra-class correlation coefficients (ICC) ≥ 0.980). Diagnostic classification agreement for BBP-all versus BBP-one were κ = 0.831 for RC, κ = 0.804 for M-1, and κ = 0.847 for M-2. The relative reliability analysis showed excellent correlation in segmental indices (all ICC ≥ 0.957). The study shows minimal difference in segmental indices and diagnostic classification when comparing calculations based on the listed strategies. However, the study indicated that it is important to measure BBPs correspondent to each segmental pressure. (paper)

  19. Quantitative angiography of the left anterior descending coronary artery: correlations with pressure gradient and results of exercise thallium scintigraphy

    International Nuclear Information System (INIS)

    Wijns, W.; Serruys, P.W.; Reiber, J.H.; van den Brand, M.; Simoons, M.L.; Kooijman, C.J.; Balakumaran, K.; Hugenholtz, P.G.

    1985-01-01

    To evaluate, during cardiac catheterization, what constitutes a physiologically significant obstruction to blood flow in the human coronary system, computer-based quantitative analysis of coronary angiograms was performed on the angiograms of 31 patients with isolated disease of the proximal left anterior descending coronary artery. The angiographic severity of stenosis was compared with the transstenotic pressure gradient measured with the dilation catheter during angioplasty and with the results of exercise thallium scintigraphy. A curvilinear relationship was found between the pressure gradient across the stenosis (normalized for the mean aortic pressure) and the residual minimal area of obstruction (after subtracting the area of the angioplasty catheter). This relationship was best fitted by the equation: normalized mean pressure gradient . a + b . log [obstruction area], r . .74. The measurements of the percent area of stenosis (cutoff 80%) and of the transstenotic pressure gradient (cutoff 0.30) obtained at rest correctly predicted the occurrence of thallium perfusion defects induced by exercise in 83% of the patients

  20. Quantitative angiography of the left anterior descending coronary artery: correlations with pressure gradient and exercise thallium scintigraphy

    International Nuclear Information System (INIS)

    Reiber, J.H.C.; Serruys, P.W.; Slager, C.J.; Erasmus Univ., Rotterdam

    1986-01-01

    In order to evaluate during cardiac catheterization what constitutes a physiologically significant obstruction to blood flow in the human coronary system, computer based quantitative analysis of coronary angiograms was performed in 31 patients with isolated proximal left anterior descending coronary artery disease. The angiographic severity of the stenosis was compared with the transstenotic pressure gradient measured with the dilatation catheter during angioplasty and the results of exercise thallium scintigraphy. A curvilinear relation was found between the pressure gradient across the stenosis (normalized for the mean aortic pressure) and the residual minimal obstruction area (after subtracting the area of the angioplasty catheter). This relation was best fitted by the equation: normalized mean pressure gradient = a + b · log [obstruction area], r = 0.74. The measurements of the percent area stenosis (cut-off 80%) and of the transstenotic pressure gradient (cut-off 0.30) obtained at rest, correctly predicted the occurrence of thallium perfusion defects induced by exercise in 83% of the patients. (Auth.)

  1. Variations in the usage and composition of a radial cocktail during radial access coronary angiography procedures.

    LENUS (Irish Health Repository)

    Pate, G

    2011-10-01

    A survey was conducted of medication administered during radial artery cannulation for coronary angiography in 2009 in Ireland; responses were obtained for 15 of 20 centres, in 5 of which no radial access procedures were undertaken. All 10 (100%) centres which provided data used heparin and one or more anti-spasmodics; verapamil in 9 (90%), nitrate in 1 (10%), both in 2 (20%). There were significant variations in the doses used. Further work needs to be done to determine the optimum cocktail to prevent radial artery injury following coronary angiography.

  2. Nicorandil prevents right ventricular remodeling by inhibiting apoptosis and lowering pressure overload in rats with pulmonary arterial hypertension.

    Directory of Open Access Journals (Sweden)

    Xiang-Rong Zuo

    Full Text Available BACKGROUND: Most of the deaths among patients with severe pulmonary arterial hypertension (PAH are caused by progressive right ventricular (RV pathological remodeling, dysfunction, and failure. Nicorandil can inhibit the development of PAH by reducing pulmonary artery pressure and RV hypertrophy. However, whether nicorandil can inhibit apoptosis in RV cardiomyocytes and prevent RV remodeling has been unclear. METHODOLOGY/PRINCIPAL FINDINGS: RV remodeling was induced in rats by intraperitoneal injection of monocrotaline (MCT. RV systolic pressure (RVSP was measured at the end of each week after MCT injection. Blood samples were drawn for brain natriuretic peptide (BNP ELISA analysis. The hearts were excised for histopathological, ultrastructural, immunohistochemical, and Western blotting analyses. The MCT-injected rats exhibited greater mortality and less weight gain and showed significantly increased RVSP and RV hypertrophy during the second week. These worsened during the third week. MCT injection for three weeks caused pathological RV remodeling, characterized by hypertrophy, fibrosis, dysfunction, and RV mitochondrial impairment, as indicated by increased levels of apoptosis. Nicorandil improved survival, weight gain, and RV function, ameliorated RV pressure overload, and prevented maladaptive RV remodeling in PAH rats. Nicorandil also reduced the number of apoptotic cardiomyocytes, with a concomitant increase in Bcl-2/Bax ratio. 5-hydroxydecanoate (5-HD reversed these beneficial effects of nicorandil in MCT-injected rats. CONCLUSIONS/SIGNIFICANCE: Nicorandil inhibits PAH-induced RV remodeling in rats not only by reducing RV pressure overload but also by inhibiting apoptosis in cardiomyocytes through the activation of mitochondrial ATP-sensitive K(+ (mitoK(ATP channels. The use of a mitoK(ATP channel opener such as nicorandil for PAH-associated RV remodeling and dysfunction may represent a new therapeutic strategy for the amelioration of RV

  3. Decline in arterial partial pressure of oxygen after exercise: a surrogate marker of pulmonary vascular obstructive disease in patients with atrial septal defect and severe pulmonary hypertension.

    Science.gov (United States)

    Laksmivenkateshiah, Srinivas; Singhi, Anil K; Vaidyanathan, Balu; Francis, Edwin; Karimassery, Sundaram R; Kumar, Raman K

    2011-06-01

    To examine the utility of decline in arterial partial pressure of oxygen after exercise as a marker of pulmonary vascular obstructive disease in patients with atrial septal defect and pulmonary hypertension. Treadmill exercise was performed in 18 patients with atrial septal defect and pulmonary hypertension. Arterial blood gas samples were obtained before and after peak exercise. A decline in the arterial pressure of oxygen of more than 10 millimetres of mercury after exercise was considered significant based on preliminary tests conducted on the controls. Cardiac catheterisation was performed in all patients and haemodynamic data sets were obtained on room air, oxygen, and a mixture of oxygen and nitric oxide (30-40 parts per million). There were 10 patients who had more than a 10 millimetres of mercury drop in arterial partial pressure of oxygen after exercise and who had a basal pulmonary vascular resistance index of more than 7 Wood units per square metre. Out of eight patients who had less than a 10 millimetres of mercury drop in arterial partial pressure of oxygen after exercise, seven had a basal pulmonary vascular resistance index of less than 7 Wood units per square metre, p equals 0.0001. A decline in arterial partial pressure of oxygen of more than 10 millimetres of mercury predicted a basal pulmonary vascular resistance index of more than 7 Wood units per square metre with a specificity of 100% and a sensitivity of 90%. A decline in arterial partial pressure of oxygen following exercise appears to predict a high pulmonary vascular resistance index in patients with atrial septal defect and pulmonary hypertension. This test is a useful non-invasive marker of pulmonary vascular obstructive disease in this subset.

  4. A computational analysis of the long-term regulation of arterial pressure [v1; ref status: indexed, http://f1000r.es/1xq

    Directory of Open Access Journals (Sweden)

    Daniel A. Beard

    2013-10-01

    Full Text Available The asserted dominant role of the kidneys in the chronic regulation of blood pressure and in the etiology of hypertension has been debated since the 1970s. At the center of the theory is the observation that the acute relationships between arterial pressure and urine production—the acute pressure-diuresis and pressure-natriuresis curves—physiologically adapt to perturbations in pressure and/or changes in the rate of salt and volume intake. These adaptations, modulated by various interacting neurohumoral mechanisms, result in chronic relationships between water and salt excretion and pressure that are much steeper than the acute relationships. While the view that renal function is the dominant controller of arterial pressure has been supported by computer models of the cardiovascular system known as the “Guyton-Coleman model”, no unambiguous description of a computer model capturing chronic adaptation of acute renal function in blood pressure control has been presented. Here, such a model is developed with the goals of: 1. capturing the relevant mechanisms in an identifiable mathematical model; 2. identifying model parameters using appropriate data; 3. validating model predictions in comparison to data; and 4. probing hypotheses regarding the long-term control of arterial pressure and the etiology of primary hypertension. The developed model reveals: long-term control of arterial blood pressure is primarily through the baroreflex arc and the renin-angiotensin system; and arterial stiffening provides a sufficient explanation for the etiology of primary hypertension associated with ageing. Furthermore, the model provides the first consistent explanation of the physiological response to chronic stimulation of the baroreflex.

  5. Investigating Cardiac MRI Based Right Ventricular Contractility As A Novel Non-Invasive Metric of Pulmonary Arterial Pressure

    Science.gov (United States)

    Menon, Prahlad G; Adhypak, Srilakshmi M; Williams, Ronald B; Doyle, Mark; Biederman, Robert WW

    2014-01-01

    BACKGROUND We test the hypothesis that cardiac magnetic resonance (CMR) imaging-based indices of four-dimensional (4D) (three dimensions (3D) + time) right ventricle (RV) function have predictive values in ascertaining invasive pulmonary arterial systolic pressure (PASP) measurements from right heart catheterization (RHC) in patients with pulmonary arterial hypertension (PAH). METHODS We studied five patients with idiopathic PAH and two age and sex-matched controls for RV function using a novel contractility index (CI) for amplitude and phase to peak contraction established from analysis of regional shape variation in the RV endocardium over 20 cardiac phases, segmented from CMR images in multiple orientations. RESULTS The amplitude of RV contractility correlated inversely with RV ejection fraction (RVEF; R2 = 0.64, P = 0.03) and PASP (R2 = 0.71, P = 0.02). Phase of peak RV contractility also correlated inversely to RVEF (R2 = 0.499, P = 0.12) and PASP (R2 = 0.66, P = 0.04). CONCLUSIONS RV contractility analyzed from CMR offers promising non-invasive metrics for classification of PAH, which are congruent with invasive pressure measurements. PMID:25624777

  6. Regulation of Arterial Pressure By The Paraventricular Nucleus in Conscious Rats: Interactions Among Glutamate, GABA, and Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Marli Cardoso Martins-Pinge

    2013-01-01

    Full Text Available The paraventricular nucleus (PVN of the hypothalamus is an important site for autonomic and neuroendocrine regulation. Experiments in anesthetized animals and in vitro indicate an interaction among gamma-aminobutyric acid (GABA, nitric oxide (NO and glutamate in the PVN. The cardiovascular role of the PVN and interactions of these neurotransmitters in conscious animals have not been evaluated fully. In chronically instrumented conscious rats, mean arterial pressure (MAP and heart rate (HR responses to microinjections (100 nl in the region of the PVN were tested. Bilateral blockade of ionotropic excitatory amino acid (EAA receptors (kynurenic acid, Kyn in the PVN produced small but significant decreases in MAP and HR. GABAA receptor blockade (bicuculline, Bic, and inhibition of NO synthase (N-(G-monomethyl-L-arginine, L-NMMA each increased MAP and HR. The NO donor sodium nitroprusside (SNP produced depressor responses that were attenuated by Bic. NO synthase inhibition potentiated both pressor responses to the selective EAA agonist, N-methyl-D-aspartic acid (NMDA, and depressor responses to Kyn. Increases in MAP and HR due to Bic were blunted by prior blockade of EAA receptors. Thus, pressor responses to GABA blockade require EAA receptors and GABA neurotransmission contributes to NO inhibition. Tonic excitatory effects of glutamate in the PVN are tonically attenuated by NO. These data demonstrate that, in the PVN of conscious rats, GABA, glutamate and NO interact in a complex fashion to regulate arterial pressure and heart rate under normal conditions.

  7. Noninvasive prediction of left ventricular end-diastolic pressure in patients with coronary artery disease and preserved ejection fraction.

    Science.gov (United States)

    Abd-El-Aziz, Tarek A

    2012-01-01

    The aim of this study was to compare 3 different available methods for estimating left ventricular end-diastolic pressure (LVEDP) noninvasively in patients with coronary artery disease and preserved left ventricular ejection fraction (EF). We used 3 equations for noninvasive estimation of LVEDP: The equation of Mulvagh et al., LVEDP(1) = 46 - 0.22 (IVRT) - 0.10 (AFF) - 0.03 (DT) - (2 ÷ E/A) + 0.05 MAR; the equation of Stork et al., LVEDP(2) = 1.06 + 15.15 × Ai/Ei; and the equation of Abd-El-Aziz, LVEDP(3) = [0.54 (MABP) × (1 - EF)] - 2.23. ( A, A-wave velocity; AFF, atrial filling fraction; Ai, time velocity integral of A wave; DT, deceleration time; E, E-wave velocity; Ei, time velocity integral of E wave; IVRT, isovolumic relaxation time; MABP, mean arterial blood pressure; MAR, time from termination of mitral flow to the electrocardiographic R wave; Ti, time velocity integral of total wave.) LVEDP measured by catheterization was correlated with LVEDP(1) (r = 0.52, P Aziz, LVEDP = [0.54 MABP × (1 - EF)] - 2.23, appears to be the most accurate, reliable, and easily applied method for estimating LVEDP noninvasively in patients with preserved left ventricular ejection fraction and an LVEDP < 20 mm Hg. Copyright © 2012 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  8. Antenatal hypoxia induces programming of reduced arterial blood pressure<