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Sample records for arterial pressure increases

  1. Pulse pressure variation and volume responsiveness during acutely increased pulmonary artery pressure: an experimental study

    OpenAIRE

    Daudel, Fritz; Tüller, David; Krähenbühl, Stefanie; Jakob, Stephan M; Takala, Jukka

    2010-01-01

    Introduction We found that pulse pressure variation (PPV) did not predict volume responsiveness in patients with increased pulmonary artery pressure. This study tests the hypothesis that PPV does not predict fluid responsiveness during an endotoxin-induced acute increase in pulmonary artery pressure and right ventricular loading. Methods Pigs were subjected to endotoxemia (0.4 μg/kg/hour lipopolysaccharide), followed by volume expansion, subsequent hemorrhage (20% of estimated blood volume), ...

  2. Acute lead exposure increases arterial pressure: role of the renin-angiotensin system.

    Directory of Open Access Journals (Sweden)

    Maylla Ronacher Simões

    Full Text Available BACKGROUND: Chronic lead exposure causes hypertension and cardiovascular disease. Our purpose was to evaluate the effects of acute exposure to lead on arterial pressure and elucidate the early mechanisms involved in the development of lead-induced hypertension. METHODOLOGY/PRINCIPAL FINDINGS: Wistar rats were treated with lead acetate (i.v. bolus dose of 320 µg/Kg, and systolic arterial pressure, diastolic arterial pressure and heart rate were measured during 120 min. An increase in arterial pressure was found, and potential roles of the renin-angiotensin system, Na(+,K(+-ATPase and the autonomic reflexes in this change in the increase of arterial pressure found were evaluated. In anesthetized rats, lead exposure: 1 produced blood lead levels of 37±1.7 µg/dL, which is below the reference blood concentration (60 µg/dL; 2 increased systolic arterial pressure (Ct: 109±3 mmHg vs Pb: 120±4 mmHg; 3 increased ACE activity (27% compared to Ct and Na(+,K(+-ATPase activity (125% compared to Ct; and 4 did not change the protein expression of the α1-subunit of Na(+,K(+-ATPase, AT(1 and AT(2. Pre-treatment with an AT(1 receptor blocker (losartan, 10 mg/Kg or an ACE inhibitor (enalapril, 5 mg/Kg blocked the lead-induced increase of arterial pressure. However, a ganglionic blockade (hexamethonium, 20 mg/Kg did not prevent lead's hypertensive effect. CONCLUSION: Acute exposure to lead below the reference blood concentration increases systolic arterial pressure by increasing angiotensin II levels due to ACE activation. These findings offer further evidence that acute exposure to lead can trigger early mechanisms of hypertension development and might be an environmental risk factor for cardiovascular disease.

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

    NARCIS (Netherlands)

    A. Dubin; M.O. Pozo; C.A. Casabella; F.,Jr Pálizas; G. Murias; M.C. Moseinco; V.S. Kanoore Edul; F. Pálizas; E. Estenssoro; C. Ince

    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 mecha

  4. Pulmonary artery pressure responses to increased cardiac output in chickens with raised metabolic rate

    OpenAIRE

    West, John B.; Fu, Zhenxing; Gu, Yusu; Wagner, Harrieth E.; Carr, J. Austin; Peterson, Kirk L.

    2010-01-01

    Previous work has shown remarkable differences in the pressure-flow relations of the pulmonary circulation between birds and mammals. For example several studies suggest that the avian pulmonary blood vessels behave like rigid tubes, very different from the situation in mammalian lung. We therefore speculated that birds would develop high pulmonary artery pressures when the cardiac output was substantially increased during heavy exercise, for example during flight. However because of the tech...

  5. Selective Heart Rate Reduction With Ivabradine Increases Central Blood Pressure in Stable Coronary Artery Disease.

    Science.gov (United States)

    Rimoldi, Stefano F; Messerli, Franz H; Cerny, David; Gloekler, Steffen; Traupe, Tobias; Laurent, Stéphane; Seiler, Christian

    2016-06-01

    Heart rate (HR) lowering by β-blockade was shown to be beneficial after myocardial infarction. In contrast, HR lowering with ivabradine was found to confer no benefits in 2 prospective randomized trials in patients with coronary artery disease. We hypothesized that this inefficacy could be in part related to ivabradine's effect on central (aortic) pressure. Our study included 46 patients with chronic stable coronary artery disease who were randomly allocated to placebo (n=23) or ivabradine (n=23) in a single-blinded fashion for 6 months. Concomitant baseline medication was continued unchanged throughout the study except for β-blockers, which were stopped during the study period. Central blood pressure and stroke volume were measured directly by left heart catheterization at baseline and after 6 months. For the determination of resting HR at baseline and at follow-up, 24-hour ECG monitoring was performed. Patients on ivabradine showed an increase of 11 mm Hg in central systolic pressure from 129±22 mm Hg to 140±26 mm Hg (P=0.02) and in stroke volume by 86±21.8 to 107.2±30.0 mL (P=0.002). In the placebo group, central systolic pressure and stroke volume remained unchanged. Estimates of myocardial oxygen consumption (HR×systolic pressure and time-tension index) remained unchanged with ivabradine.The decrease in HR from baseline to follow-up correlated with the concomitant increase in central systolic pressure (r=-0.41, P=0.009) and in stroke volume (r=-0.61, P<0.001). In conclusion, the decrease in HR with ivabradine was associated with an increase in central systolic pressure, which may have antagonized possible benefits of HR lowering in coronary artery disease patients. CLINICAL TRIALSURL: http://www.clinicaltrials.gov. Unique identifier NCT01039389. PMID:27091900

  6. Lifelong Cyclic Mechanical Strain Promotes Large Elastic Artery Stiffening: Increased Pulse Pressure and Old Age-Related Organ Failure.

    Science.gov (United States)

    Thorin-Trescases, Nathalie; Thorin, Eric

    2016-05-01

    The arterial wall is under a huge mechanical constraint imposed by the cardiac cycle that is bound to generate damage with time. Each heartbeat indeed imposes a pulsatile pressure that generates a vascular stretch. Lifetime accumulation of pulsatile stretches will eventually induce fatigue of the elastic large arterial walls, such as aortic and carotid artery walls, promoting their stiffening that will gradually perturb the normal blood flow and local pressure within the organs, and lead to organ failure. The augmented pulse pressure induced by arterial stiffening favours left ventricular hypertrophy because of the repeated extra work against stiff high-pressure arteries, and tissue damage as a result of excessive pulsatile pressure transmitted into the microcirculation, especially in low resistance/high-flow organs such as the brain and kidneys. Vascular aging is therefore characterized by the stiffening of large elastic arteries leading to a gradual increase in pulse pressure with age. In this review we focus on the effect of age-related stiffening of large elastic arteries. We report the clinical evidence linking arterial stiffness and organ failure and discuss the molecular pathways that are activated by the increase of mechanical stress in the wall. We also discuss the possible interventions that could limit arterial stiffening with age, such as regular aerobic exercise training, and some pharmacological approaches. PMID:26961664

  7. 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

    A model was set up in order to evaluate the importance of hemispheric perfusion pressure when the middle cerebral artery (MCA) is occluded in anaesthetized rats. In 6 animals the internal carotid artery (ICA) was occluded prior to ipsilateral MCA occlusion; in 17 animals the MCA only was occluded......; 6 animals underwent the same preparation, but the vessels were left unoccluded. Four days after surgery the infarct volume was measured with a computerized image analyser. The infarcted areas were significantly larger in the ICA + MCA occluded group compared with the MCA occluded group (p less than...... occurs, as compared to patients with no, or only minor, reduction in hemispheric perfusion pressure....

  8. Soybean oil increases SERCA2a expression and left ventricular contractility in rats without change in arterial blood pressure

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    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.

  9. Estimated aortic blood pressure based on radial artery tonometry underestimates directly measured aortic blood pressure in patients with advancing chronic kidney disease staging and increasing arterial stiffness

    DEFF Research Database (Denmark)

    Carlsen, Rasmus K; Peters, Christian D; Khatir, Dinah S;

    2016-01-01

    we compared invasive aortic systolic BP (SBP) with estimated central SBP obtained by radial artery tonometry and examined the influence of renal function and arterial stiffness on this relationship. We evaluated 83 patients with stage 3 to 5 CKD (mean estimated glomerular filtration rate [eGFR] 30 ml......% confidence interval -14.9 to -11.4) mm Hg. Arterial stiffness was evaluated by carotid-femoral pulse wave velocity (cf-PWV) and was significantly increased in CKD patients compared with (versus) control patients (mean 10.7 vs. 9.3 m/s). The difference in BP significantly increased 1.0 mm Hg for every 10 ml....../min decrease in eGFR and by 1.6 mm Hg per 1 m/s increase in cfPWV. Using multivariate regression analysis including both eGFR and cfPWV, the difference between estimated central and invasive aortic SBP was significantly increased by 0.7 mm Hg. For the entire cohort brachial SBP significantly better reflected...

  10. Preliminary study of abnormal increase of postexercise systolic blood pressure in the diagnosis of coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    于宗良; 杨向军; 王国强; 高美雯; 李勋; 惠杰; 蒋廷波; 宋建平; 刘志华; 蒋文平

    2003-01-01

    Objectives This study sought to evaluate the diagnostic value of abnormal increase of postexercise systolic blood pressure (SBP) for detecting coronary artery disease (CAD) in patients with or without hypertension. Methods Treadmill exercise testing (TET) was conducted in 88 patients (40 CAD patients, 48 control subjects)with or without hypertension, each of whom underwent selective coronary angiography (CAG). The abnormal increase of postexercise SBP was defined as 10mmHg higher than earlier periods during the recovery phase (6 minutes)of exercise testing. Results The abnormal increase of postexercise SBP had higher sensitivity, specificity,and accuracy for detecting CAD than those of ST - segment depression in patients with or without hypertension. Its accuracy increased with the severity of CAD while decreased in patients with hypertension, and the increase value of SBP had a positive correlation with the extent of coronary artery lesion. The combination of ST - segment depression and abnormal increase of postexercise SBP diagnosed CAD most accurately in patients with hypertension. Conclusions Abnormal increase of postexercise SBP may be a useful index for diagnosing CAD.

  11. Increasing mean arterial pressure in cardiogenic shock secondary to myocardial infarction: effects on hemodynamics and tissue oxygenation.

    Science.gov (United States)

    Perez, Pierre; Kimmoun, Antoine; Blime, Vincent; Levy, Bruno

    2014-04-01

    There are very few data regarding the effects of norepinephrine uptitration on global and regional hemodynamics in cardiogenic shock. We studied 25 patients with shock secondary to myocardial infarction successfully treated with percutaneous coronary intervention. Before the inclusion, 16 of 25 patients presented a cardiac arrest in the presence of medical staff. Norepinephrine was titrated to increase mean arterial pressure (MAP) from 65 to 85 mmHg during 1 h. Swan-Ganz variables, arterial and mixed venous blood gases, lactate, and thenar near-infrared spectroscopy variables (muscle tissue oxygen saturation [StO2] and its changes during a vascular occlusion test) were measured before, 1 h after norepinephrine uptitration, and 1 h after norepinephrine downtitration. To obtain a MAP at 85 mmHg, norepinephrine was increased from 0.6 (0.28-1.2) to 1.53 µg · kg · min (0.76-2.6 µg · kg · min) (P cardiogenic shock complicated by postreperfusion disease is associated with better cardiac performance and improved microcirculatory variables.

  12. Exhaled and arterial levels of endothelin-1 are increased and correlate with pulmonary systolic pressure in COPD with pulmonary hypertension

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    Dragonieri Silvano

    2008-09-01

    Full Text Available Abstract Background Endothelin-1 (ET-1 and Nitric Oxide (NO are crucial mediators for establishing pulmonary artery hypertension (PAH. We tested the hypothesis that their imbalance might also occur in COPD patients with PAH. Methods The aims of the study were to measure exhaled breath condensate (EBC and circulating levels of ET-1, as well as exhaled NO (FENO levels by, respectively, a specific enzyme immunoassay kit, and by chemiluminescence analysis in 3 groups of subjects: COPD with PAH (12, COPD only (36, and healthy individuals (15. In order to evaluate pulmonary-artery systolic pressure (PaPs, all COPD patients underwent Echo-Doppler assessment. Results Significantly increased exhaled and circulating levels of ET-1 were found in COPD with PAH compared to both COPD (p 1%, (r = -0.59, p = 0.043, and PaPs negatively correlated to PaO2 (r = -0.618; p = 0.032. Significantly reduced levels of FENO were found in COPD associated with PAH, compared to COPD only (22.92 ± 11.38 vs.35.07 ± 17.53 ppb; p = 0.03. Thus, we observed an imbalanced output in the breath between ET-1 and NO, as expression of pulmonary endothelium and epithelium impairment, in COPD with PAH compared to COPD only. Whether this imbalance is an early cause or result of PAH due to COPD is still unknown and deserves further investigations.

  13. Estimated aortic blood pressure based on radial artery tonometry underestimates directly measured aortic blood pressure in patients with advancing chronic kidney disease staging and increasing arterial stiffness.

    Science.gov (United States)

    Carlsen, Rasmus K; Peters, Christian D; Khatir, Dinah S; Laugesen, Esben; Bøtker, Hans Erik; Winther, Simon; Buus, Niels H

    2016-10-01

    Central blood pressure (BP) can be assessed noninvasively based on radial tonometry and may potentially be a better predictor of clinical outcome than brachial BP. However, the validity of noninvasively obtained estimates has never been examined in patients with chronic kidney disease (CKD). Here we compared invasive aortic systolic BP (SBP) with estimated central SBP obtained by radial artery tonometry and examined the influence of renal function and arterial stiffness on this relationship. We evaluated 83 patients with stage 3 to 5 CKD (mean estimated glomerular filtration rate [eGFR] 30 ml/min/1.73 m(2)) and 41 controls without renal disease undergoing scheduled coronary angiography. BP in the ascending aorta was measured through the angiography catheter and simultaneously estimated using radial tonometry. The mean difference between estimated central and aortic SBP was -13.2 (95% confidence interval -14.9 to -11.4) mm Hg. Arterial stiffness was evaluated by carotid-femoral pulse wave velocity (cf-PWV) and was significantly increased in CKD patients compared with (versus) control patients (mean 10.7 vs. 9.3 m/s). The difference in BP significantly increased 1.0 mm Hg for every 10 ml/min decrease in eGFR and by 1.6 mm Hg per 1 m/s increase in cfPWV. Using multivariate regression analysis including both eGFR and cfPWV, the difference between estimated central and invasive aortic SBP was significantly increased by 0.7 mm Hg. For the entire cohort brachial SBP significantly better reflected invasive SBP than estimated SBP. Thus, tonometry-based estimates of central BP progressively underestimate invasive central SBP with decreasing renal function and increasing arterial stiffness in CKD patients.

  14. Abnormal shortened diastolic time length at increasing heart rates in patients with abnormal exercise-induced increase in pulmonary artery pressure

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    Bombardini Tonino

    2011-11-01

    Full Text Available Abstract Background The degree of pulmonary hypertension is not independently related to the severity of left ventricular systolic dysfunction but is frequently associated with diastolic filling abnormalities. The aim of this study was to assess diastolic times at increasing heart rates in normal and in patients with and without abnormal exercise-induced increase in pulmonary artery pressure (PASP. Methods. We enrolled 109 patients (78 males, age 62 ± 13 years referred for exercise stress echocardiography and 16 controls. The PASP was derived from the tricuspid Doppler tracing. A cut-off value of PASP ≥ 50 mmHg at peak stress was considered as indicative of abnormal increase in PASP. Diastolic times and the diastolic/systolic time ratio were recorded by a precordial cutaneous force sensor based on a linear accelerometer. Results At baseline, PASP was 30 ± 5 mmHg in patients and 25 ± 4 in controls. At peak stress the PASP was normal in 95 patients (Group 1; 14 patients (Group 2 showed an abnormal increase in PASP (from 35 ± 4 to 62 ± 12 mmHg; P Conclusion The first and second heart sound vibrations non-invasively monitored by a force sensor are useful for continuously assessing diastolic time during exercise. Exercise-induced abnormal PASP was associated with reduced diastolic time at heart rates beyond 100 beats per minute.

  15. Heterozygous disruption of activin receptor-like kinase 1 is associated with increased arterial pressure in mice

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    María González-Núñez

    2015-11-01

    Full Text Available The activin receptor-like kinase 1 (ALK-1 is a type I cell-surface receptor for the transforming growth factor-β (TGF-β family of proteins. Hypertension is related to TGF-β1, because increased TGF-β1 expression is correlated with an elevation in arterial pressure (AP and TGF-β expression is upregulated by the renin-angiotensin-aldosterone system. The purpose of this study was to assess the role of ALK-1 in regulation of AP using Alk1 haploinsufficient mice (Alk1+/−. We observed that systolic and diastolic AP were significantly higher in Alk1+/− than in Alk1+/+ mice, and all functional and structural cardiac parameters (echocardiography and electrocardiography were similar in both groups. Alk1+/− mice showed alterations in the circadian rhythm of AP, with higher AP than Alk1+/+ mice during most of the light period. Higher AP in Alk1+/− mice is not a result of a reduction in the NO-dependent vasodilator response or of overactivation of the peripheral renin-angiotensin system. However, intracerebroventricular administration of losartan had a hypotensive effect in Alk1+/− and not in Alk1+/+ mice. Alk1+/− mice showed a greater hypotensive response to the β-adrenergic antagonist atenolol and higher concentrations of epinephrine and norepinephrine in plasma than Alk1+/+ mice. The number of brain cholinergic neurons in the anterior basal forebrain was reduced in Alk1+/− mice. Thus, we concluded that the ALK-1 receptor is involved in the control of AP, and the high AP of Alk1+/− mice is explained mainly by the sympathetic overactivation shown by these animals, which is probably related to the decreased number of cholinergic neurons.

  16. Heterozygous disruption of activin receptor-like kinase 1 is associated with increased arterial pressure in mice

    Science.gov (United States)

    González-Núñez, María; Riolobos, Adela S.; Castellano, Orlando; Fuentes-Calvo, Isabel; de los Ángeles Sevilla, María; Oujo, Bárbara; Pericacho, Miguel; Cruz-Gonzalez, Ignacio; Pérez-Barriocanal, Fernando; ten Dijke, Peter; López-Novoa, Jose M.

    2015-01-01

    ABSTRACT The activin receptor-like kinase 1 (ALK-1) is a type I cell-surface receptor for the transforming growth factor-β (TGF-β) family of proteins. Hypertension is related to TGF-β1, because increased TGF-β1 expression is correlated with an elevation in arterial pressure (AP) and TGF-β expression is upregulated by the renin-angiotensin-aldosterone system. The purpose of this study was to assess the role of ALK-1 in regulation of AP using Alk1 haploinsufficient mice (Alk1+/−). We observed that systolic and diastolic AP were significantly higher in Alk1+/− than in Alk1+/+ mice, and all functional and structural cardiac parameters (echocardiography and electrocardiography) were similar in both groups. Alk1+/− mice showed alterations in the circadian rhythm of AP, with higher AP than Alk1+/+ mice during most of the light period. Higher AP in Alk1+/− mice is not a result of a reduction in the NO-dependent vasodilator response or of overactivation of the peripheral renin-angiotensin system. However, intracerebroventricular administration of losartan had a hypotensive effect in Alk1+/− and not in Alk1+/+ mice. Alk1+/− mice showed a greater hypotensive response to the β-adrenergic antagonist atenolol and higher concentrations of epinephrine and norepinephrine in plasma than Alk1+/+ mice. The number of brain cholinergic neurons in the anterior basal forebrain was reduced in Alk1+/− mice. Thus, we concluded that the ALK-1 receptor is involved in the control of AP, and the high AP of Alk1+/− mice is explained mainly by the sympathetic overactivation shown by these animals, which is probably related to the decreased number of cholinergic neurons. PMID:26398936

  17. Deletion of Cyclooxygenase-2 in the mouse increases arterial blood pressure with no impairment in renal NO production in response to chronic high salt intake

    DEFF Research Database (Denmark)

    Staehr, Mette; Hansen, Pernille B L; Madsen, Kirsten;

    2013-01-01

    Experiments were designed to test the hypothesis that COX-2 activity attenuates the blood pressure increase during high NaCl intake by stimulation of eNOS-mediated NO synthesis in the kidney medulla. COX-2(-/-) (C57BL6) and (+/+) mice were fed a diet with 0.004% (LS) or 4% (HS) NaCl for 18 days....... Arterial blood pressure was recorded continuously using indwelling catheters. Food and water intake and diuresis were measured in metabolic cages. Urine osmolality and excretion of electrolytes, cGMP, cAMP and NOx were determined, as well as plasma NOx and cGMP. There was a significant dependence of blood...... pressure during high salt intake and COX-2 activity is not necessary for increased renal NO formation during elevated NaCl intake....

  18. Correlation of invasive central arterial pressure with peripheral arterial pressure and coronary sclerosis

    Institute of Scientific and Technical Information of China (English)

    吴琪

    2013-01-01

    Objective To study the consistency among non-invasive and invasive brachial artery pressure,radial artery pressure and invasive central arterial pressure,and to explore the correlation between the severe degree of coronary artery disease and invasive central aortic pressure.

  19. Reconstruction of brachial pressure from finger arterial pressure during orthostasis

    DEFF Research Database (Denmark)

    Bogert, Lysander W J; Harms, Mark P M; Pott, Frank;

    2004-01-01

    In patients with recurrent syncope, monitoring of intra-arterial pressure during orthostatic stress testing is recommended because of the potentially sudden and rapid development of hypotension. Replacing brachial arterial pressure (BAP) by the non-invasively obtained finger arterial pressure (Fin...

  20. Rarefaction and blood pressure in systemic and pulmonary arteries.

    Science.gov (United States)

    Olufsen, Mette S; Hill, N A; Vaughan, Gareth D A; Sainsbury, Christopher; Johnson, Martin

    2012-08-01

    The effects of vascular rarefaction (the loss of small arteries) on the circulation of blood are studied using a multiscale mathematical model that can predict blood flow and pressure in the systemic and pulmonary arteries. We augmented a model originally developed for the systemic arteries (Olufsen et al. 1998, 1999, 2000, 2004) to (a) predict flow and pressure in the pulmonary arteries, and (b) predict pressure propagation along the small arteries in the vascular beds. The systemic and pulmonary arteries are modelled as separate, bifurcating trees of compliant and tapering vessels. Each tree is divided into two parts representing the `large' and `small' arteries. Blood flow and pressure in the large arteries are predicted using a nonlinear cross-sectional area-averaged model for a Newtonian fluid in an elastic tube with inflow obtained from magnetic resonance measurements. Each terminal vessel within the network of the large arteries is coupled to a vascular bed of small `resistance' arteries, which are modelled as asymmetric structured trees with specified area and asymmetry ratios between the parent and daughter arteries. For the systemic circulation, each structured tree represents a specific vascular bed corresponding to major organs and limbs. For the pulmonary circulation, there are four vascular beds supplied by the interlobar arteries. This manuscript presents the first theoretical calculations of the propagation of the pressure and flow waves along systemic and pulmonary large and small arteries. Results for all networks were in agreement with published observations. Two studies were done with this model. First, we showed how rarefaction can be modelled by pruning the tree of arteries in the microvascular system. This was done by modulating parameters used for designing the structured trees. Results showed that rarefaction leads to increased mean and decreased pulse pressure in the large arteries. Second, we investigated the impact of decreasing vessel

  1. Increased arterial compliance in decompensated cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik; Møller, Søren; Schifter, S;

    1999-01-01

    of the vasodilator, calcitonin gene-related peptide (CGRP) and mean arterial blood pressure (MAP). METHODS: Arterial compliance (COMPart=deltaV/deltaP) was determined as the stroke volume relative to pulse pressure (i.e. systolic minus diastolic blood pressure) during a haemodynamic evaluation of portal hypertension......BACKGROUND/AIMS: In patients with cirrhosis, the systemic circulation is hyperdynamic with low arterial blood pressure and reduced systemic vascular resistance. The present study was undertaken to estimate the compliance of the arterial tree in relation to severity of cirrhosis, circulating level.......1 x 10(-3) l/mmHg, respectively, p=0.03). The stroke volume did not change significantly with the severity of the disease, but pulse pressure decreased through class A, B, and C (79, 65, and 50 mmHg, respectively, p

  2. Management of high blood pressure in peripheral arterial disease

    OpenAIRE

    Krzesinski, Jean-Marie

    2005-01-01

    Arterial hypertension (HTA) is a promoter of peripheral arterial disease (PAD) in association with other atherosclerotic risk factors factors. Systolic HTA is the most frequently noted form in such disease, secondary to marked increase in large artery siffness. The existence of PAD confers on the hypertensive patient a very high cardiovascular (CV) risk, requiring an intensive global therapeutical approach. Treating HTA is one of such beneficial actions. The optimal blood pressure (BP) to...

  3. Increasing Inflationary Pressure

    Institute of Scientific and Technical Information of China (English)

    Guo Yan

    2008-01-01

    @@ China's CPI rose to 8.7 percent in February after hitting 7.1 percent in January,creating a 12-year high,the National Bureau of Statistics said.The figure exceeded market expectations,as the Bank of China,the country's secondlargest lender,had predicted a rise of only 8.3 percent.The Consumer Price Index (CPI)is the main gauge of inflation,andthe high CPI over the last two months has put pressure on the government to take action to curb the price increases,and added even more diffculty to the task of reining in this year's inflation rate.

  4. Experimental exposure to diesel exhaust increases arterial stiffness in man

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    Newby David E

    2009-03-01

    Full Text Available Abstract Introduction Exposure to air pollution is associated with increased cardiovascular morbidity, although the underlying mechanisms are unclear. Vascular dysfunction reduces arterial compliance and increases central arterial pressure and left ventricular after-load. We determined the effect of diesel exhaust exposure on arterial compliance using a validated non-invasive measure of arterial stiffness. Methods In a double-blind randomized fashion, 12 healthy volunteers were exposed to diesel exhaust (approximately 350 μg/m3 or filtered air for one hour during moderate exercise. Arterial stiffness was measured using applanation tonometry at the radial artery for pulse wave analysis (PWA, as well as at the femoral and carotid arteries for pulse wave velocity (PWV. PWA was performed 10, 20 and 30 min, and carotid-femoral PWV 40 min, post-exposure. Augmentation pressure (AP, augmentation index (AIx and time to wave reflection (Tr were calculated. Results Blood pressure, AP and AIx were generally low reflecting compliant arteries. In comparison to filtered air, diesel exhaust exposure induced an increase in AP of 2.5 mmHg (p = 0.02 and in AIx of 7.8% (p = 0.01, along with a 16 ms reduction in Tr (p = 0.03, 10 minutes post-exposure. Conclusion Acute exposure to diesel exhaust is associated with an immediate and transient increase in arterial stiffness. This may, in part, explain the increased risk for cardiovascular disease associated with air pollution exposure. If our findings are confirmed in larger cohorts of susceptible populations, this simple non-invasive method of assessing arterial stiffness may become a useful technique in measuring the impact of real world exposures to combustion derived-air pollution.

  5. Increased perfusion pressure enhances the expression of endothelin (ETB) and angiotensin II (AT1, AT2) receptors in rat mesenteric artery smooth muscle cells

    DEFF Research Database (Denmark)

    Lindstedt, Isak; Xu, Cang-Bao; Zhang, Yaping;

    2009-01-01

    and luminally perfused in a perfusion chamber. After either exposure to no ("organ culture" (0 mmHg)), normal (85/75 mmHg) or high pressure (160/150 mmHg) at constant flow for 1-17 h, the vessel segments were snap frozen and real-time polymerase chain reaction was performed to quantify the ET- and AT-receptor m......In the present study, we hypothesized that changes in perfusion pressure result in altered expression of mRNA and protein encoding for the ETA-, ETB-, AT1- and AT2-receptors in rat mesenteric vessels. Segments of the rat mesenteric artery were cannulated with glass micropipettes, pressurized......RNA content, or immersed in a fixative solution, dehydrated, frozen, cut in a cryostat and immunohistology stained for ET- and AT-receptor protein. The mRNA expressions of ETB and of AT2 were significantly enhanced in vessels exposed to high perfusion pressure, compared with normal and no perfusion pressure...

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

    International Nuclear Information System (INIS)

    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

  7. Effect of psychological stress on blood pressure increase: a meta-analysis of cohort studies Efeito do estresse psicológico no aumento da pressão arterial: uma metanálise de estudos de coorte

    Directory of Open Access Journals (Sweden)

    Daniela Gasperin

    2009-04-01

    Full Text Available Studies have suggested that chronic exposure to stress may have an influence on increased blood pressure. A systematic review followed by a meta-analysis was conducted aiming to assess the effect of psychological stress on blood pressure increase. Research was mainly conducted in Ingenta, Psycinfo, PubMed, Scopus and Web of Science. Inclusion criteria were: published in any language; from January 1970 to December 2006; prospective cohort design; adults; main exposure psychological/emotional stress; outcome arterial hypertension or blood pressure increase > 3.5mmHg. A total of 2,043 studies were found, of which 110 were cohort studies. Of these, six were eligible and yielded 23 comparison groups and 34,556 subjects. Median follow-up time and loss to follow-up were 11.5 years and 21%. Results showed individuals who had stronger responses to stressor tasks were 21% more likely to develop blood pressure increase when compared to those with less strong responses (OR: 1.21; 95%CI: 1.14-1.28; p Estudos sugerem que a exposição crônica ao estresse tenha influência no aumento dos níveis pressóricos. Foi realizada uma revisão sistemática seguida de metanálise com o objetivo de avaliar o efeito do estresse psicológico no aumento da pressão arterial. As principais bases de dados utilizadas foram Ingenta, Psycinfo, PubMed, Scopus e Web of Science. Os critérios de inclusão foram: publicado entre janeiro de 1970 e dezembro de 2006, delineamento de coorte prospectiva, adultos, estresse psicológico/emocional como exposição principal, hipertensão arterial ou aumento na pressão arterial > 3,5mmHg como desfecho. A busca resultou em 2.043 artigos, sendo 110 coortes. Desses, seis eram elegíveis, os quais geraram 23 grupos de comparação e 34.556 sujeitos. A mediana do tempo de seguimento e do percentual de perdas foi 11,5 anos e 21%. Indivíduos com maior reação a tarefas estressoras possuíam 21% mais chances de apresentar aumento na press

  8. Modifiable risk factors for increased arterial stiffness in outpatient nephrology.

    Directory of Open Access Journals (Sweden)

    Usama Elewa

    Full Text Available Arterial stiffness, as measured by pulse wave velocity (PWV, is an independent predictor of cardiovascular events and mortality. Arterial stiffness increases with age. However, modifiable risk factors such as smoking, BP and salt intake also impact on PWV. The finding of modifiable risk factors may lead to the identification of treatable factors, and, thus, is of interest to practicing nephrologist. We have now studied the prevalence and correlates of arterial stiffness, assessed by PWV, in 191 patients from nephrology outpatient clinics in order to identify modifiable risk factors for arterial stiffness that may in the future guide therapeutic decision-making. PWV was above normal levels for age in 85/191 (44.5% patients. Multivariate analysis showed that advanced age, systolic BP, diabetes mellitus, serum uric acid and calcium polystyrene sulfonate therapy or calcium-containing medication were independent predictors of PWV. A new parameter, Delta above upper limit of normal PWV (Delta PWV was defined to decrease the weight of age on PWV values. Delta PWV was calculated as (measured PWV - (upper limit of the age-adjusted PWV values for the general population. Mean±SD Delta PWV was 0.76±1.60 m/sec. In multivariate analysis, systolic blood pressure, active smoking and calcium polystyrene sulfonate therapy remained independent predictors of higher delta PWV, while age, urinary potassium and beta blocker therapy were independent predictors of lower delta PWV. In conclusion, arterial stiffness was frequent in nephrology outpatients. Systolic blood pressure, smoking, serum uric acid, calcium-containing medications, potassium metabolism and non-use of beta blockers are modifiable factors associated with increased arterial stiffness in Nephrology outpatients.

  9. 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...... factors 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...

  10. Arterial blood-pressure change and endogenous circulating substance P in man

    DEFF Research Database (Denmark)

    Henriksen, J H; Kastrup, J; Schaffalitzky De Muckadell, O B

    1985-01-01

    Substance P (SP) is a powerful vasodilator and this peptide is today considered to be a chemical messenger. The potential effects on circulating SP of acute changes in arterial blood-pressure was investigated in nine subjects. An increase in arterial mean blood-pressure (+33%, P less than 0.001, ...

  11. Cigarette smoke exposure induced pulmonary artery pressure increase through inhibiting Kv1.5 and Kv2.1 mRNA expression in rat pulmonary artery smooth muscles

    Institute of Scientific and Technical Information of China (English)

    林纯意

    2012-01-01

    Objective To investigate the effect of cigarette smoke exposure on Kv1.5 and Kv2.1 mRNA expression in rat pulmonary arterial smooth muscle cells(PASMCs), and further to clarify the possible mechanism of cigarette smoking induced pulmonary arterial hypertension. Methods Primary

  12. Determinants of an elevated pulmonary arterial pressure in patients with pulmonary arterial hypertension.

    Science.gov (United States)

    Sakao, Seiichiro; Voelkel, Norbert F; Tanabe, Nobuhiro; Tatsumi, Koichiro

    2015-01-01

    Given the difficulty of diagnosing early-stage pulmonary arterial hypertension (PAH) due to the lack of signs and symptoms, and the risk of an open lung biopsy, the precise pathological features of presymptomatic stage lung tissue remain unknown. It has been suggested that the maximum elevation of the mean pulmonary arterial pressure (P pa) is achieved during the early symptomatic stage, indicating that the elevation of the mean P pa is primarily driven by the pulmonary vascular tone and/or some degree of pulmonary vascular remodeling completed during this stage. Recently, the examination of a rat model of severe PAH suggested that the severe PAH may be primarily determined by the presence of intimal lesions and/or the vascular tone in the early stage. Human data seem to indicate that intimal lesions are essential for the severely increased pulmonary arterial blood pressure in the late stage of the disease.However, many questions remain. For instance, how does the pulmonary hemodynamics change during the course of the disease, and what drives the development of severe PAH? Although it is generally acknowledged that both pulmonary vascular remodeling and the vascular tone are important determinants of an elevated pulmonary arterial pressure, which is the root cause of the time-dependent progression of the disease? Here we review the recent histopathological concepts of PAH with respect to the progression of the lung vascular disease.

  13. Peroxisome Proliferator-Activated Receptor-α Activation Decreases Mean Arterial Pressure, Plasma Interleukin-6, and COX-2 While Increasing Renal CYP4A Expression in an Acute Model of DOCA-Salt Hypertension

    Directory of Open Access Journals (Sweden)

    Dexter L. Lee

    2011-01-01

    Full Text Available Peroxisome proliferator-activated receptor-alpha (PPAR-α activation by fenofibrate reduces blood pressure and sodium retention during DOCA-salt hypertension. PPAR-α activation reduces the expression of inflammatory cytokines, such as interleukin-6 (IL-6. Fenofibrate also induces cytochrome P450 4A (CYP4A and increases 20-hydroxyeicosatetraenoic acid (20-HETE production. This study tested whether the administration of fenofibrate would reduce blood pressure by attenuating plasma IL-6 and renal expression of cyclooxygenase-2 (COX-2, while increasing expression of renal CYP4A during 7 days of DOCA-salt hypertension. We performed uni-nephrectomy on 12–14 week old male Swiss Webster mice and implanted biotelemetry devices in control, DOCA-salt (1.5 mg/g treated mice with or without fenofibrate (500 mg/kg/day in corn oil, intragastrically. Fenofibrate significantly decreased mean arterial pressure and plasma IL-6. In kidney homogenates, fenofibrate increased CYP4A and decreased COX-2 expression. There were no differences in renal cytochrome P450, family 2, subfamily c, polypeptide 23 (CYP2C23 and soluble expoxide hydrolase (sEH expression between the groups. Our results suggest that the blood pressure lowering effect of PPAR-α activation by fenofibrate involves the reduction of plasma IL-6 and COX-2, while increasing CYP4A expression during DOCA-salt hypertension. Our results may also suggest that PPAR-α activation protects the kidney against renal injury via decreased COX-2 expression.

  14. Increased perfusion pressure enhances the expression of endothelin (ETB) and angiotensin II (AT1, AT2) receptors in rat mesenteric artery smooth muscle cells

    DEFF Research Database (Denmark)

    Lindstedt, Isak; Xu, Cang-Bao; Zhang, Yaping;

    2009-01-01

    and luminally perfused in a perfusion chamber. After either exposure to no ("organ culture" (0 mmHg)), normal (85/75 mmHg) or high pressure (160/150 mmHg) at constant flow for 1-17 h, the vessel segments were snap frozen and real-time polymerase chain reaction was performed to quantify the ET- and AT-receptor m......RNA content, or immersed in a fixative solution, dehydrated, frozen, cut in a cryostat and immunohistology stained for ET- and AT-receptor protein. The mRNA expressions of ETB and of AT2 were significantly enhanced in vessels exposed to high perfusion pressure, compared with normal and no perfusion pressure...

  15. Relating external compressing pressure to mean arterial pressure in non-invasive blood pressure measurements.

    Science.gov (United States)

    Chin, K Y; Panerai, R B

    2015-01-01

    Arterial volume clamping uses external compression of an artery to provide continuous non-invasive measurement of arterial blood pressure. It has been assumed that mean arterial pressure (MAP) corresponds to the point where unloading leads to the maximum oscillation of the arterial wall as reflected by photoplethysmogram (PPG), an assumption that has been challenged. Five subjects were recruited for the study (three males, mean age (SD) = 32 (15) years). The PPG waveform was analysed to identify the relationship between the external compressing pressure, PPG pulse amplitude and MAP. Two separate tests were carried out at compression step intervals of 10 mmHg and 2 mmHg, respectively. No significant differences were found between the two tests. The bias between the compressing pressure and the MAP was -4.7 ± 5.63 mmHg (p < 0.001) showing a normal distribution. Further research is needed to identify optimal algorithms for estimation of MAP using PPG associated with arterial compression. PMID:25429784

  16. Pressure Estimation in the Systemic Arteries Using a Transfer Function

    OpenAIRE

    Thore, Carl-Johan

    2007-01-01

    The aim of this thesis is to develop and study a method for estimation of the pulse pressure in centrally located arteries. Obtaining the central pulse pressure is desirable for several reasons. For example, the central pulse pressure can be used to assess aortic stiffness, which in turn is an important predictor of cardiovascular mortality. In this thesis a method of estimation based on a one--dimensional wave propagation theory applied to a physiological model of the human systemic arterial...

  17. Relationship between mean arterial pressure and end-tidal partial pressure of carbon dioxide during hemorrhagic shock and volume resuscitation

    OpenAIRE

    Grmec, Stefek; Golub, Mirjam; Jelatancev, Alina

    2009-01-01

    Objectives. We examined the relationship between partial end-tidal CO2 (pet) and mean arterial pressure in patients with traumatic hemorrhagic shock, who were receiving constant minute ventilation. Methods. In 61 patients we continuously measured pet CO2 with a capnograph, direct arterial pressure via a cannula, oxygen levels via pulse oximetry and body temperature. Results. We observed significant changes in pet CO2 (increase) after volume resuscitation and a quantitative linear relati...

  18. Clitoral blood flow increases following vaginal pressure stimulation.

    Science.gov (United States)

    Lavoisier, P; Aloui, R; Schmidt, M H; Watrelot, A

    1995-02-01

    The vascular responses of clitoral arteries to vaginal pressure stimulation in 10 volunteer women were evaluated by Doppler ultrasonography. Pressure stimulations (20-160 mm Hg) along the lower third of the vagina increased blood velocity and flow into clitoral arteries in 9 of the 10 women. The latency and duration of the Doppler responses ranged from 0.1 to 1.6 sec and from 3.2 to 9.5 sec, respectively, and the response was associated with a blood flow increase of 4 to 11 times the baseline prestimulation level. This response parallels that recorded in the cavernous arteries in men when a similar range of pressure stimulations are applied to the glans penis. Similar responses evoked in the male and female suggest a sexual synergy that may occur during intercourse in that such physiological responses and reflexes may be reciprocally reinforced.

  19. MEASUREMENTS OF THE BLOOD CAPILLARY PRESSURE AND ARTERIAL ELASTICITY

    Institute of Scientific and Technical Information of China (English)

    HuangMengcai; GuZhong; HangWenjing; ZhongQuan; TangFuyong

    1990-01-01

    Describe some new fully automatic instruments for the measurements of the blood capillary pressure (Pcap) and arterial elastic properties in human fingers using a photoelectric plethysmographic technique, With these instruments, the value of Pcap was in good agreement with those reported by other investigators, the arterial elastic properties in human fingers have been successfully measured. The measurements of Pcap and arterial elasticity are now required in clinics because they provide useful and important information for evaluating vascular haemodynamics.

  20. Harmonics tracking of intracranial and arterial blood pressure waves.

    Science.gov (United States)

    Shahsavari, Sima; McKelvey, Tomas

    2008-01-01

    Considering cardiorespiratory interaction and heart rate variability, a new approach is proposed to decompose intracranial pressure and arterial blood pressure to their different harmonics. The method is based on tracking the amplitudes of the harmonics by a Kalman filter based tracking algorithm. The algorithm takes benefit of combined frequency estimation technique which uses both Fast Fourier Transform and RR-interval detection. The result would be of use in intracranial pressure and arterial blood pressure waveform analysis as well as other investigations which need to estimate contribution of specific harmonic in above mentioned signals such as Pressure-Volume Compensatory Reserve assessment.

  1. Increasing pulse wave velocity in a realistic cardiovascular model does not increase pulse pressure with age

    OpenAIRE

    Mohiuddin, Mohammad W.; Rihani, Ryan J.; Laine, Glen A.; Quick, Christopher M.

    2012-01-01

    The mechanism of the well-documented increase in aortic pulse pressure (PP) with age is disputed. Investigators assuming a classical windkessel model believe that increases in PP arise from decreases in total arterial compliance (Ctot) and increases in total peripheral resistance (Rtot) with age. Investigators assuming a more sophisticated pulse transmission model believe PP rises because increases in pulse wave velocity (cph) make the reflected pressure wave arrive earlier, augmenting systol...

  2. Heart and Artery Damage and High Blood Pressure

    Science.gov (United States)

    ... Stroke More Heart and Artery Damage and High Blood Pressure Updated:Oct 22,2015 There are several harmful ... was last reviewed on 08/04/2014. High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

  3. Hemodynamic analysis of arterial pressure oscillations in conscious rats.

    Science.gov (United States)

    Julien, C; Zhang, Z Q; Cerutti, C; Barrès, C

    1995-01-01

    This study examined the contribution of rhythmic fluctuations of regional blood flow and vascular conductance to the genesis of low- (LF, 0.27-0.74 Hz) and high- (HF, 0.76-5 Hz) frequency oscillations of arterial pressure. In conscious 15-week-old male intact (n = 11), guanethidine-sympathectomized (n = 8) and chronically sinoaortic denervated (n = 7) rats, arterial pressure and regional blood flow velocities (pulsed Doppler probes) were simultaneously recorded. Indices of subdiaphragmatic aortic, hindquarters and superior mesenteric conductances were calculated on a beat-to-beat basis over a 60-min period. Spectral power was calculated in the LF and HF bands using a fast Fourier transform algorithm. Transfer function analysis was also performed to calculate coherence and phase between arterial pressure and regional flows and conductances. In the LF band, spectral power of arterial pressure was decreased by approx. 85% in sympathectomized and approx. 54% in sinoaortic denervated rats. In the HF band, spectral power did not differ between the groups. In the three groups of rats, relations between arterial pressure and blood flow were characterized by a significant coherence in the HF band with little or no phase delay (synchronous oscillations). Relations between arterial pressure and vascular conductance were characterized in intact rats by a significant coherence in the LF band and a phase delay tending to pi radians (opposite oscillations), whereas in both sympathectomized and sinoaortic denervated rats, coherence did not reach significance. It is concluded that LF oscillations of arterial pressure are mostly secondary to rhythmic fluctuations in the vasomotor sympathetic tone in several regional circulations. Part of these oscillations originate from the synchronizing influence of the baroreceptor reflex. The study also suggests that the respiratory (HF) oscillations of arterial pressure involve fluctuations in cardiac output of purely mechanical origin. PMID

  4. Medial circumflex femoral artery flap for ischial pressure sore

    OpenAIRE

    Palanivelu S

    2009-01-01

    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 s...

  5. 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 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.

  6. 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.

  7. Characterization and calibration of the central arterial pressure waveform obtained from vibrocardiographic signal

    Science.gov (United States)

    Casacanditella, L.; Cosoli, G.; Casaccia, S.; Rohrbaugh, J. W.; Scalise, L.; Tomasini, E. P.

    2016-06-01

    Laser Doppler Vibrometry (LDV) has been demonstrated to be a non-contact technique with high sensitivity, able to measure the skin vibrations related to cardiac activity. The obtainable mechanical signal (i.e. a velocity signal), VibroCardioGram (VCG), is able to provide significant physiological parameters, such as Heart Rate (HR). In this work, the authors aim to present a non-contact measurement method to obtain the arterial blood pressure signal from the mechanical vibrations assessed by LDV, in a central district of the arterial tree, such as carotid artery. In fact, in this way it is possible to indirectly assess Central Arterial Blood Pressure (CABP), which indicates the hemodynamic load on the heart, so that it is considered an important index predicting the cardiac risk of a subject. The measurement setup involves the use of an oscillometric cuff, to measure peripheral blood pressure at the radial artery level. Diastolic and Mean Arterial Pressure (MAP) at radial level were used to calibrate the integrated LDV signal (i.e. a displacement signal). As regard calibration, an exponential mathematical model was adopted to derive the pressure waveform from the displacement of the vessel detected by LDV. Results show an average difference of around 20% between systolic pressure measured at brachial level (i.e. peripheral pressure value) and systolic pressure derived from VCG signal measured over the carotid artery (i.e. central pressure). This is a physiological difference, consistent with the literature about the physiological increase of Systolic Blood Pressure (SBP) and Pressure Pulse (PP) at increased distances from the heart. However, this non-contact technique is affected by movement artifacts and by reflection phenomena not related to the studied vessel and so it is necessary to account of such issues in the results.

  8. Dopexamine increases internal mammary artery blood flow following coronary artery bypass grafting.

    LENUS (Irish Health Repository)

    Flynn, Michael J

    2012-02-03

    OBJECTIVE: Vasoactive agents and inotropes influence conduit-coronary blood flow following coronary artery bypass grafting (CABG). It was hypothesized that dopexamine hydrochloride, a dopamine A-1 (DA-1) and beta(2) agonist would increase conduit-coronary blood flow. A prospective randomized double blind clinical trial was carried out to test this hypothesis. DA-1 receptors have previously been localized to human left ventricle. METHODS: Twenty-six American Society of Anaesthesiology class 2-3 elective coronary artery bypass graft patients who did not require inotropic support on separation from cardiopulmonary bypass (CPB) were studied. According to a randomized allocation patients received either dopexamine (1 microg\\/kg per min) or placebo (saline) by intravenous infusion for 15 min. Immediately prior to and at 5,10 and 15 min of infusion, blood flow through the internal mammary and vein grafts (Transit time flow probes, Transonic Ltd.), heart rate, cardiac index, mean arterial pressure and pulmonary haemodynamics were noted. The data were analysed using multivariate analysis of variance. RESULTS: Low-dose dopexamine (1 microg\\/kg per min) caused a significant increase in mammary graft blood flow compared to placebo at 15 min of infusion (P=0.028, dopexamine group left internal mammary artery (LIMA) flow of 43.3+\\/-14.2 ml\\/min, placebo group LIMA flow at 26.1+\\/-16.3 ml\\/min). Dopexamine recipients demonstrated a non-significant trend to increased saphenous vein graft flow (P=0.059). Increased heart rate was the only haemodynamic change induced by dopexamine (P=0.004, dopexamine group at 85.2+\\/-9.6 beats\\/min and placebo group at 71.1+\\/-7.6 beats\\/min after 15 min of infusion). CONCLUSION: This study demonstrates that administration of dopexamine (1 microg\\/kg per min) was associated with a significant increase in internal mammary artery graft blood flow with mild increase in heart rate being the only haemodynamic change. Low-dose dopexamine may

  9. 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...

  10. [Features of arterial blood pressure in elderly persons of different ethnic groups in Yakutsk].

    Science.gov (United States)

    Nikitin, Iu P; Tatarinova, O V; Neustroeva, V N; Shcherbakova, L V; Sidorov, A S

    2013-01-01

    The differences in arterial blood pressure in the sample of population in the age of 60 and older of different ethnic groups in Yakutsk, as well as its connection with the other cardiovascular diseases risk factors have been analyzed. It was shown that the average values of systolic and diastolic blood pressure in subsample of the Yakuts appeared to be lower than in Caucasoid gerontic persons. The average values of systolic arterial blood pressure both in the Yakuts and in the Caucasoids were detected higher than normal values in all age-dependent subgroups. The average values of diastolic blood pressure in both ethnic groups were within the limits of high normal level. From 60 to 90 years and older the decrease in systolic and diastolic arterial blood pressure was detected; it was more marked in Caucasoid gerontic persons. The average values of pulse pressure in the Yakuts and in the Caucasoids appeared to be higher than the existing standard and didn't have any differences in ethnic groups. In both ethnical subsamples, pulse pressure values increase was observed in persons of 60-89 years old and its decrease after 90. Persons with overweight, obesity, central (abdominal) obesity, dyslypoproteidemias irrespective of belonging to ethnical group were characterized as having higher levels of arterial blood pressure. Statistically significant differences in the levels of arterial blood pressure in the Yakuts and in the Caucasoids depending on hyperglycemia, smoking, the presence of burdened anamnesis, educational level, marital status was not detected.

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

    Energy Technology Data Exchange (ETDEWEB)

    Gelido, G [Electronic department, Universidad Tecnologica Nacional FRBA, Bs. As. (Argentina); Angiletta, S [Electronic department, Universidad Tecnologica Nacional FRBA, Bs. As. (Argentina); Pujalte, A [Electronic department, Universidad Tecnologica Nacional FRBA, Bs. As. (Argentina); Quiroga, P [Electronic department, Universidad Favaloro FICEN, Bs. As. (Argentina); Cornes, P [Electronic department, Universidad Favaloro FICEN, Bs. As. (Argentina); Craiem, D [Electronic department, Universidad Favaloro FICEN, Bs. As. (Argentina)

    2007-11-15

    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.

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

    International Nuclear Information System (INIS)

    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

  13. 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...... 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 reduction in blood pressure and HR from daytime...

  14. 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; 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); A.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; 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. 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 = 48,60

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

    NARCIS (Netherlands)

    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; Doerr, Marcus; Bis, Joshua C.; Aspelund, Thor; Esko, Tonu; Janssens, A. Cecile J. W.; 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; Hottenga, Jouke-Jan; Vitart, Veronique; Chasman, Daniel I.; Trompet, Stella; Bragg-Gresham, Jennifer L.; Alizadeh, Behrooz Z.; Chambers, John C.; Guo, Xiuqing; Lehtimaki, Terho; Kuehnel, Brigitte; Lopez, Lorna M.; Polasek, Ozren; Boban, Mladen; Nelson, Christopher P.; Morrison, Alanna C.; Pihur, Vasyl; Ganesh, Santhi K.; Hofman, Albert; Kundu, Suman; Mattace-Raso, Francesco U. S.; Rivadeneira, Fernando; Sijbrands, Eric J. G.; Uitterlinden, Andre G.; Hwang, Shih-Jen; Vasan, Ramachandran S.; Wang, Thomas J.; Bergmann, Sven; Vollenweider, Peter; Waeber, Gerard; Laitinen, Jaana; Pouta, Anneli; Zitting, Paavo; McArdle, Wendy L.; Kroemer, Heyo K.; Voelker, Uwe; Voelzke, Henry; Glazer, Nicole L.; Taylor, Kent D.; Harris, Tamara B.; Alavere, Helene; Haller, Toomas; Keis, Aime; Tammesoo, Mari-Liis; Aulchenko, Yurii; Barroso, Ines; Khaw, Kay-Tee; Galan, Pilar; Hercberg, Serge; Lathrop, Mark; Eyheramendy, Susana; Org, Elin; Sober, 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, Fabiola M.; 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 J. C.; 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.; Kahonen, Mika; Viikari, Jorma; Doering, Angela; Meitinger, Thomas; Davies, Gail; Starr, John M.; Emilsson, Valur; Plump, Andrew; Lindeman, Jan H.; 't Hoen, Peter A. C.; Koenig, Inke R.; Felix, Janine F.; Clarke, Robert; Hopewell, Jemma C.; Ongen, Halit; Breteler, Monique; Debette, Stephanie; 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 J. F.; 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 C. M.; 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.; Tobin, Martin D.; Elliott, Paul; van Duijn, Cornelia M.

    2011-01-01

    Numerous genetic loci have been associated with 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

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

    NARCIS (Netherlands)

    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 J W; 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; Hottenga, 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 U S; Rivadeneira, Fernando; Sijbrands, Eric J G; 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, Fabiola M; 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 J C; 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; Hoen, Peter A C 't; 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 J F; 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 C M; 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; Tobin, Martin D; Elliott, Paul; van Duijn, Cornelia M

    2011-01-01

    Numerous 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 = 48,607), we ident

  17. Arterial pressure transfer characteristics: effects of travel time.

    Science.gov (United States)

    Westerhof, Berend E; Guelen, Ilja; Stok, Wim J; Wesseling, Karel H; Spaan, Jos A E; Westerhof, Nico; Bos, Willem Jan; Stergiopulos, Nikos

    2007-02-01

    We investigated the quantitative contribution of all local conduit arterial, blood, and distal load properties to the pressure transfer function from brachial artery to aorta. The model was based on anatomical data, Young's modulus, wall viscosity, blood viscosity, and blood density. A three-element windkessel represented the distal arterial tree. Sensitivity analysis was performed in terms of frequency and magnitude of the peak of the transfer function and in terms of systolic, diastolic, and pulse pressure in the aorta. The root mean square error (RMSE) described the accuracy in wave-shape prediction. The percent change of these variables for a 25% alteration of each of the model parameters was calculated. Vessel length and diameter are found to be the most important parameters determining pressure transfer. Systolic and diastolic pressure changed <3% and RMSE <1.8 mmHg for a 25% change in vessel length and diameter. To investigate how arterial tapering influences the pressure transfer, a single uniform lossless tube was modeled. This simplification introduced only small errors in systolic and diastolic pressures (1% and 0%, respectively), and wave shape was less well described (RMSE, approximately 2.1 mmHg). Local (arm) vasodilation affects the transfer function little, because it has limited effect on the reflection coefficient. Since vessel length and diameter translate into travel time, this parameter can describe the transfer accurately. We suggest that with a, preferably, noninvasively measured travel time, an accurate individualized description of pressure transfer can be obtained. PMID:16963619

  18. 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

    kept at 10 mmHg during elevation. In these patients, the increase in vascular resistance was significantly less compared with the situation in which venous pressure was 0 mmHg during elevation. The arterial pressure still did not decrease. It is concluded that perfusion pressure in the ischaemic lower......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...

  19. Central arterial pressure assessment with intensity POF sensor

    Science.gov (United States)

    Leitão, Cátia; Gonçalves, Steve; Antunes, Paulo; Bastos, José M.; Pinto, João. L.; André, Paulo

    2015-09-01

    The central pressure monitoring is considered a new key factor in hypertension assessment and cardiovascular prevention. In this work, it is presented the central arterial systolic pressure assessment with an intensity based POF sensor. The device was tested in four subjects, and stable pulse waves were obtained, allowing the calculation of the central pressure for all the subjects. The results shown that the sensor performs reliably, being a simple and low-cost solution to the intended application.

  20. Impact of blood pressure perturbations on arterial stiffness.

    Science.gov (United States)

    Lim, Jisok; Pearman, Miriam E; Park, Wonil; Alkatan, Mohammed; Machin, Daniel R; Tanaka, Hirofumi

    2015-12-15

    Although the associations between chronic levels of arterial stiffness and blood pressure (BP) have been fairly well studied, it is not clear whether and how much arterial stiffness is influenced by acute perturbations in BP. The primary aim of this study was to determine magnitudes of BP dependence of various measures of arterial stiffness during acute BP perturbation maneuvers. Fifty apparently healthy subjects, including 25 young (20-40 yr) and 25 older adults (60-80 yr), were studied. A variety of BP perturbations, including head-up tilt, head-down tilt, mental stress, isometric handgrip exercise, and cold pressor test, were used to encompass BP changes induced by physical, mental, and/or mechanical stimuli. When each index of arterial stiffness was plotted with mean BP, all arterial stiffness indices, including cardio-ankle vascular index or CAVI (r = 0.50), carotid-femoral pulse wave velocity or cfPWV (r = 0.51), brachial-ankle pulse wave velocity or baPWV (r = 0.61), arterial compliance (r = -0.42), elastic modulus (r = 0.52), arterial distensibility (r = -0.32), β-stiffness index (r = 0.19), and Young's modulus (r = 0.35) were related to mean BP (all P modulus were significantly associated with changes in mean BP in the pooled conditions, while changes in arterial compliance, arterial distensibility, β-stiffness index, and Young's modulus were not. In conclusion, this study demonstrated that BP changes in response to various forms of pressor stimuli were associated with the corresponding changes in arterial stiffness indices and that the strengths of associations with BP varied widely depending on what arterial stiffness indices were examined.

  1. 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.

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

    DEFF Research Database (Denmark)

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

    1995-01-01

    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......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...... 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...

  3. Arterial dysfunction but maintained systemic blood pressure in cavin-1-deficient mice.

    Directory of Open Access Journals (Sweden)

    Karl Swärd

    Full Text Available Caveolae are omega-shaped plasma membrane micro-domains that are abundant in cells of the vascular system. Formation of caveolae depends on caveolin-1 and cavin-1 and lack of either protein leads to loss of caveolae. Mice with caveolin-1 deficiency have dysfunctional blood vessels, but whether absence of cavin-1 similarly leads to vascular dysfunction is not known. Here we addressed this hypothesis using small mesenteric arteries from cavin-1-deficient mice. Cavin-1-reporter staining was intense in mesenteric arteries, brain arterioles and elsewhere in the vascular system, with positive staining of both endothelial and smooth muscle cells. Arterial expression of cavin-1, -2 and -3 was reduced in knockout (KO arteries as was expression of caveolin-1, -2 and -3. Caveolae were absent in the endothelial and smooth muscle layers of small mesenteric arteries as determined by electron microscopy. Arginase, a negative regulator of nitric oxide production, was elevated in cavin-1 deficient arteries as was contraction in response to the α1-adrenergic agonist cirazoline. Detailed assessment of vascular dimensions revealed increased media thickness and reduced distensibility, arguing that enhanced contraction was due to increased muscle mass. Contrasting with increased α1-adrenergic contraction, myogenic tone was essentially absent and this appeared to be due in part to increased nitric oxide production. Vasomotion was less frequent in the knock-out vessels. In keeping with the opposing influences on arterial resistance of increased agonist-induced contractility and reduced myogenic tone, arterial blood pressure was unchanged in vivo. We conclude that deficiency of cavin-1 affects the function of small arteries, but that opposing influences on arterial resistance balance each other such that systemic blood pressure in unstressed mice is well maintained.

  4. 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.

  5. The area of the pressure-flow loop for assessment of arterial stenosis: a new index.

    Science.gov (United States)

    Ovadia-Blechman, Zehava; Einav, Shmuel; Zaretsky, Uri; Castel, David; Toledo, Eran; Eldar, Michael

    2002-01-01

    This study describes a novel method for assessing stenotic severity, based on simultaneous pressure and flow wave measurements. Pressure and flow measurements were performed in latex and rubber tubes, and in a clinically-used vascular graft. Pressure waves were recorded at several degrees of stenosis and at different distances proximal to the stenosis. Pressure wave versus flow wave was plotted. Internal pressure-flow loop area (PFLA), loop slope and pressure-axis intercept were calculated. Values of these three indices significantly increased with increasing degrees of stenosis P sensor and stenosis (R2 > 0.96). In addition, tube compliance was measured and found to correlate with the polynomial coefficients (/R/ > 0.9). This innovative approach could significantly contribute to detecting and evaluating arterial stenoses, and to characterize the elasticity of the artery. PMID:11847447

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

    OpenAIRE

    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.

    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 pres...

  7. Non-invasive measurement of pulmonary arterial pressure

    International Nuclear Information System (INIS)

    Pulmonary artery pulse pressure (Psub(p)) and diastolic pressure (Psub(d)) may be obtained by applying a haemodynamic model of blood flow kinetics and wall mechanics to the pulmonary artery: Psub(P) = ρ(Wsub(s)/(Ssub(s)/Ssub(d) -1))2 log(Ssub(s)/Ssub(d)) - 1/2 ρw2sub(s) Psub(d) (Ssub(d)/Ssub(s))sup(1/2)Psub(p) where ρ is blood density, Wsub(s) is peak ejection velocity, and Ssub(s) and Ssub(d) are peak maximal and end diastolic cross-sectional areas of the main pulmonary artery. The different parameters of the equations were measured from radionuclide Tcsup(m) first pass and equilibrium studies. (author)

  8. Sex Differences in Peripheral Augmentation Index and Arterial Reservoir Pressure during Upper Limb Postural Shifts

    Directory of Open Access Journals (Sweden)

    Kevin S. Heffernan

    2014-01-01

    Full Text Available We examined the peripheral hemodynamic response to passive arm postural changes in young men and women. Radial artery pulse waveforms were captured using applanation tonometry in 20 men (age 27 ± 2 yrs, BMI 25 ± 1 kg/m2 and 20 women (age 27 ± 2 yrs, BMI 23±1 kg/m2. Arm position was maintained at either heart level or supported 14 cm above/below heart level in a randomized fashion. Systolic augmentation index (sAIx and diastolic augmentation index (dAIx were used as estimates of pressure from wave reflections arriving in systole and diastole, respectively. A novel reservoir-wave separation technique was used to obtain arterial reservoir pressure (pressure generated by arterial capacitance. Women showed a significant reduction in radial diastolic pressure-time integral (DPTI (P0.05 or dAIx (P>0.05 when moving the arm from below to above heart level. Conversely, men showed an attenuated change in radial DPTI (P>0.05 concomitant with significant increases in reservoir pressure (P<0.05, sAIx (P<0.05, and dAIx (P<0.05. Gravity-mediated changes in regional hemodynamics produced by passive arm postural shifts are sex specific. Men demonstrate less change in regional diastolic pressure concomitant with increased augmentation index and arterial reservoir pressure.

  9. 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 

  10. Skin autofluorescence is increased in patients with carotid artery stenosis and peripheral artery disease.

    Science.gov (United States)

    Noordzij, Marjon J; Lefrandt, Joop D; Loeffen, Erik A H; Saleem, Ben R; Meerwaldt, Robbert; Lutgers, Helen L; Smit, Andries J; Zeebregts, Clark J

    2012-02-01

    Advanced glycation end products (AGEs) have a pivotal role in atherosclerosis. We evaluated skin autofluorescence (SAF), a non-invasive measurement of tissue AGE accumulation, in patients with carotid artery stenosis with and without coexisting peripheral artery occlusive disease (PAOD). SAF was measured using the AGE Reader™ in 56 patients with carotid artery stenosis and in 56 age- and sex-matched healthy controls without diabetes, renal dysfunction or known atherosclerotic disease. SAF was higher in patients with carotid artery stenosis compared to the control group: mean 2.81 versus 2.46 (P = 0.002), but especially in the younger age group of 50-60 years old: mean 2.82 versus 1.94 (P = 0.000). Patients with carotid artery stenosis and PAOD proved to have an even higher SAF than patients with carotid artery stenosis only: mean 3.28 versus 2.66 (P = 0.003). Backward linear regression analysis showed that age, smoking, diabetes mellitus, renal function and the presence of PAOD were the determinants of SAF, but carotid artery stenosis was not. SAF is increased in patients with carotid artery stenosis and PAOD. The univariate and multivariate associations of SAF with age, smoking, diabetes, renal insufficiency and PAOD suggest that increased SAF can be seen as an indicator of widespread atherosclerosis.

  11. Skin autofluorescence is increased in patients with carotid artery stenosis and peripheral artery disease.

    Science.gov (United States)

    Noordzij, Marjon J; Lefrandt, Joop D; Loeffen, Erik A H; Saleem, Ben R; Meerwaldt, Robbert; Lutgers, Helen L; Smit, Andries J; Zeebregts, Clark J

    2012-02-01

    Advanced glycation end products (AGEs) have a pivotal role in atherosclerosis. We evaluated skin autofluorescence (SAF), a non-invasive measurement of tissue AGE accumulation, in patients with carotid artery stenosis with and without coexisting peripheral artery occlusive disease (PAOD). SAF was measured using the AGE Reader™ in 56 patients with carotid artery stenosis and in 56 age- and sex-matched healthy controls without diabetes, renal dysfunction or known atherosclerotic disease. SAF was higher in patients with carotid artery stenosis compared to the control group: mean 2.81 versus 2.46 (P = 0.002), but especially in the younger age group of 50-60 years old: mean 2.82 versus 1.94 (P = 0.000). Patients with carotid artery stenosis and PAOD proved to have an even higher SAF than patients with carotid artery stenosis only: mean 3.28 versus 2.66 (P = 0.003). Backward linear regression analysis showed that age, smoking, diabetes mellitus, renal function and the presence of PAOD were the determinants of SAF, but carotid artery stenosis was not. SAF is increased in patients with carotid artery stenosis and PAOD. The univariate and multivariate associations of SAF with age, smoking, diabetes, renal insufficiency and PAOD suggest that increased SAF can be seen as an indicator of widespread atherosclerosis. PMID:21336554

  12. Paradoxical centrally increased diffusivity in perinatal arterial ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Stence, Nicholas V.; Mirsky, David M.; Deoni, Sean C.L. [University of Colorado Anschutz School of Medicine, Department of Radiology, Aurora, CO (United States); Children' s Hospital Colorado, Department of Radiology, Aurora, CO (United States); Armstrong-Wells, Jennifer [University of Colorado Anschutz School of Medicine, Department of Pediatrics (Neurology) and OB/GYN, Aurora, CO (United States); University of Colorado Hemophilia and Thrombosis Center, Aurora, CO (United States)

    2016-01-15

    Restricted diffusion on acute MRI is the diagnostic standard for perinatal arterial ischemic stroke. In a subset of children with perinatal arterial ischemic stroke, primarily those with large infarct volumes, we noted a core of centrally increased diffusivity with a periphery of restricted diffusion. Given the paradoxical diffusion-weighted imaging (DWI) appearance observed in some children with perinatal arterial ischemic stroke, we sought to determine its significance and hypothesized that: (1) centrally increased diffusivity is associated with larger infarcts in perinatal arterial ischemic stroke and (2) this tissue is irreversibly injured (infarcted). We reviewed all perinatal arterial ischemic stroke cases in a prospective cohort study from Aug. 1, 2000, to Jan. 1, 2012. Infarct volumes were measured by drawing regions of interest around the periphery of the area of restricted diffusion on DWI. The Mann-Whitney U test was used to compare means between groups. Of 25 eligible cases, centrally increased diffusivity was seen in 4 (16%). Cases with centrally increased diffusivity had larger average infarct volumes (mean 117,182 mm{sup 3} vs. 36,995 mm{sup 3}; P = 0.008), higher average apparent diffusion coefficient (ADC) values in the infarct core (1,679 x 10{sup -6} mm{sup 2}/s vs. 611 x 10{sup -6} mm{sup 2}/s, P < 0.0001), and higher ADC ratio (1.2 vs. 0.5, P < 0.0001). At last clinical follow-up, children with perinatal arterial ischemic stroke and centrally increased diffusivity were more often treated for ongoing seizures (75% vs. 0%; P < 0.001) than those without. Centrally increased diffusivity was associated with larger stroke volume and the involved tissue was confirmed to be infarcted on follow-up imaging. Radiologists should be aware of this unusual appearance of perinatal arterial ischemic stroke in order to avoid underestimating infarct volume or making an incorrect early diagnosis. (orig.)

  13. Vasodilation increases pulse pressure variation, mimicking hypovolemic status in rabbits

    Directory of Open Access Journals (Sweden)

    Glauco A Westphal

    2010-01-01

    Full Text Available OBJECTIVE: To test the hypothesis that pulse pressure respiratory variation (PPV amplification, observed in hypovolemia, can also be observed during sodium nitroprusside (SNP-induced vasodilation. INTRODUCTION: PPV is largely used for early identification of cardiac responsiveness, especially when hypovolemia is suspected. PPV results from respiratory variation in transpulmonary blood flow and reflects the left ventricular preload variations during respiratory cycles. Any factor that decreases left ventricular preload can be associated with PPV amplification, as seen in hypovolemia. METHODS: Ten anesthetized and mechanically ventilated rabbits underwent progressive hypotension by either controlled hemorrhage (Group 1 or intravenous SNP infusion (Group 2. Animals in Group 1 (n = 5 had graded hemorrhage induced at 10% steps until 50% of the total volume was bled. Mean arterial pressure (MAP steps were registered and assumed as pressure targets to be reached in Group 2. Group 2 (n = 5 was subjected to a progressive SNP infusion to reach similar pressure targets as those defined in Group 1. Heart rate (HR, systolic pressure variation (SPV and PPV were measured at each MAP step, and the values were compared between the groups. RESULTS: SPV and PPV were similar between the experimental models in all steps (p > 0.16. SPV increased earlier in Group 2. CONCLUSION: Both pharmacologic vasodilation and graded hemorrhage induced PPV amplification similar to that observed in hypovolemia, reinforcing the idea that amplified arterial pressure variation does not necessarily represent hypovolemic status but rather potential cardiovascular responsiveness to fluid infusion.

  14. Systolic Pressure in Different Percents of Stenosis at Major Arteries

    CERN Document Server

    Mirzaee, Mohammad Reza; Firoozabadi, Bahar; Dandaneband, Meitham

    2016-01-01

    - Modeling Human cardiovascular system is always an important issue. One of the most effective methods is using lumped model to reach to a complete model of human cardiovascular system. Such modeling with advanced considerations is used in this paper. Some of these considerations are as follow: Exact simulating of ventricles as pressure suppliers, peristaltic motion of descending arteries as additional suppliers, and dividing each vessel into more than one compartment to reach more accurate answers. Finally a circuit with more than 150 RLC segments and different elements is made. Then the verification of our complex circuit is done and at the end, obstruction as an important abnormality is investigated. For this aim different percents of obstruction in vital arteries are considered and the results are brought as different graphs at the end. According to physiological texts the citation of our simulation and its results are obvious. To earn productive information about arteries characteristics a 36-vessels mod...

  15. 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...

  16. 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

    between tunica media and lumen areas along the length of the femoral/tibial arteries in the hindleg. Volume fraction of elastin, density of vasa vasorum and innervations was estimated by stereology. Immunohistological staining with S100 was used to examine the innervation. The pressure increase...

  17. The linear relationship between systolic pulmonary artery pressure and mean pulmonary artery pressure is maintained regardless of autonomic or rhythm disturbances

    OpenAIRE

    Vanden Eynden, Frédéric; Racapé, Judith; Vincent, Jame; Vachiéry, Jean-Luc; Bové, Thierry; Van Nooten, Guido

    2016-01-01

    Background In the pulmonary circulation, there is a linear relationship between systolic pulmonary arterial pressure (SPAP) and mean pulmonary arterial pressure (MPAP). The aim of this study was to determine the passive or active nature of this mechanism by exploring the relationship in patients with and without autonomic rhythm control of the heart and pulmonary circulation. Methods Pulmonary arterial pressure recordings from non-transplanted patients and patients with heart transplants or d...

  18. Starling resistor versus compliance. Which explains the zero-flow pressure of a dynamic arterial pressure-flow relation?

    Science.gov (United States)

    Magder, S

    1990-07-01

    Arterial pressure at zero flow (Pz = 0) that is higher than venous pressure (Pv) in dynamic pressure-flow relations has been explained by the presence of an arteriolar Starling resistor (SR) mechanism (i.e., vascular waterfall) or the discharge of vascular capacitance. To determine which was predominant, I studied in vivo hind limbs of 18 anesthetized dogs in which femoral arteries were cannulated with in-line electromagnetic flow probes to measure inflow (Qin), Pv was controlled, and collateral flow was eliminated with a tourniquet. Pz = 0 was obtained by turning flow to zero. Three tests were applied: 1) Pv was raised in steps with either constant Qin or constant arterial pressure (Pa) to determine the pressure at which upstream vascular characteristics were affected by a change in Pv, 2) the time to reach Pz = 0 was varied to determine compliance effects, and 3) an equation was developed to determine if experimentally derived parameters could explain Pz = 0 without invoking an SR. With constant Qin and a Pz = 0 of 56.9 +/- 11.7 mm Hg (time to Pz = 0, 3 seconds), Pv could be raised by 9.6 +/- 6.2 to 16.3 +/- 6.0 mm Hg before Pa increased, and with constant Pa, Pv could be raised by 6.8 +/- 7.3 to 14.0 +/- 8.0 mm Hg before Qin decreased. With increasing times to reach Pz = 0, Pz = 0 initially dropped precipitously, but then decreased by only a small amount over the next 5-10 seconds even though arterial pressure was much above Pv. This could be explained by an SR mechanism with a critical pressure of 42.3 +/- 11.4 mm Hg and an arterial compliance of 0.0104 +/- 0.0023 ml.mm Hg-1 (n = 6). There was no value for the compliance that described the results when the arterial outflow pressure was Pv. Thus, this study supports the hypothesis that an SR mechanism is present in the vascular system. It is most likely precapillary, and in the resting limb, it has a value of 40-50 mm Hg. However, Pz = 0 in dynamic pressure-flow studies of less than 4 seconds is also greatly

  19. Increased blood pressure can reduce fatigue of thenar muscles paralyzed after spinal cord injury

    NARCIS (Netherlands)

    Butler, JE; Ribot-Ciscar, E; Zijdewind, Inge; Thomas, CK

    2004-01-01

    The aim of this study was to evaluate whether increases in blood pressure, and presumably muscle perfusion pressure, improve the endurance of thenar muscles paralyzed chronically by cervical spinal cord injury (SCI). Resting mean arterial pressure (MAP) was low in all eight subjects (64 +/- 2 mmHg).

  20. Mean arterial pressure following prolonged exercise in the heat

    DEFF Research Database (Denmark)

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

    2012-01-01

    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......-exercise hypotension following prolonged exercise in the heat without fluid replacement. Furthermore, fluid replacement reverses the sustained post-exercise hypotension observed in trained individuals....

  1. The pulmonary vasculature in a neonatal porcine model with increased pulmonary blood flow and pressure

    DEFF Research Database (Denmark)

    Stenbøg, Elisabeth Vidstid; Steinbruchel, Daniel Andreas; Thomsen, Anne Bloch;

    2001-01-01

    . By three months of age, nearly all shunts had closed spontaneously, and haemodynamics were normal. Ligation of the left pulmonary artery resulted in a normal total pulmonary blood flow, despite only the right lung being perfused, and a 33% increase in systolic pulmonary arterial pressure...... included sham operations in 13, or no operations in 10 pigs. Follow-up was continued for three months. The interventions were compatible with survival in most pigs. The shunts resulted in an acute 85% increase in systolic pulmonary arterial pressure, and a more than twofold increase in pulmonary blood flow...

  2. Increasing pulse wave velocity in a realistic cardiovascular model does not increase pulse pressure with age.

    Science.gov (United States)

    Mohiuddin, Mohammad W; Rihani, Ryan J; Laine, Glen A; Quick, Christopher M

    2012-07-01

    The mechanism of the well-documented increase in aortic pulse pressure (PP) with age is disputed. Investigators assuming a classical windkessel model believe that increases in PP arise from decreases in total arterial compliance (C(tot)) and increases in total peripheral resistance (R(tot)) with age. Investigators assuming a more sophisticated pulse transmission model believe PP rises because increases in pulse wave velocity (c(ph)) make the reflected pressure wave arrive earlier, augmenting systolic pressure. It has recently been shown, however, that increases in c(ph) do not have a commensurate effect on the timing of the reflected wave. We therefore used a validated, large-scale, human arterial system model that includes realistic pulse wave transmission to determine whether increases in c(ph) cause increased PP with age. First, we made the realistic arterial system model age dependent by altering cardiac output (CO), R(tot), C(tot), and c(ph) to mimic the reported changes in these parameters from age 30 to 70. Then, c(ph) was theoretically maintained constant, while C(tot), R(tot), and CO were altered. The predicted increase in PP with age was similar to the observed increase in PP. In a complementary approach, C(tot), R(tot), and CO were theoretically maintained constant, and c(ph) was increased. The predicted increase in PP was negligible. We found that increases in c(ph) have a limited effect on the timing of the reflected wave but cause the system to degenerate into a windkessel. Changes in PP can therefore be attributed to a decrease in C(tot). PMID:22561301

  3. Arterial pulse pressure amplification described by means of a nonlinear wave model: characterization of human aging

    Science.gov (United States)

    Alfonso, M.; Cymberknop, L.; Armentano, R.; Pessana, F.; Wray, S.; Legnani, W.

    2016-04-01

    The representation of blood pressure pulse as a combination of solitons captures many of the phenomena observed during its propagation along the systemic circulation. The aim of this work is to analyze the applicability of a compartmental model for propagation regarding the pressure pulse amplification associated with arterial aging. The model was applied to blood pressure waveforms that were synthesized using solitons, and then validated by waveforms obtained from individuals from differentiated age groups. Morphological changes were verified in the blood pressure waveform as a consequence of the aging process (i.e. due to the increase in arterial stiffness). These changes are the result of both a nonlinear interaction and the phenomena present in the propagation of nonlinear mechanic waves.

  4. Redox signaling via oxidative inactivation of PTEN modulates pressure-dependent myogenic tone in rat middle cerebral arteries.

    Directory of Open Access Journals (Sweden)

    Debebe Gebremedhin

    Full Text Available The present study examined the level of generation of reactive oxygen species (ROS and roles of inactivation of the phosphatase PTEN and the PI3K/Akt signaling pathway in response to an increase in intramural pressure-induced myogenic cerebral arterial constriction. Step increases in intraluminal pressure of cannulated cerebral arteries induced myogenic constriction and concomitant formation of superoxide (O2 (.- and its dismutation product hydrogen peroxide (H2O2 as determined by fluorescent HPLC analysis, microscopic analysis of intensity of dihydroethidium fluorescence and attenuation of pressure-induced myogenic constriction by pretreatment with the ROS scavenger 4,hydroxyl-2,2,6,6-tetramethylpiperidine1-oxyl (tempol or Mito-tempol or MitoQ in the presence or absence of PEG-catalase. An increase in intraluminal pressure induced oxidation of PTEN and activation of Akt. Pharmacological inhibition of endogenous PTEN activity potentiated pressure-dependent myogenic constriction and caused a reduction in NPo of a 238 pS arterial KCa channel current and an increase in [Ca(2+]i level in freshly isolated cerebral arterial muscle cells (CAMCs, responses that were attenuated by Inhibition of the PI3K/Akt pathway. These findings demonstrate an increase in intraluminal pressure induced increase in ROS production triggered redox-sensitive signaling mechanism emanating from the cross-talk between oxidative inactivation of PTEN and activation of the PI3K/Akt signaling pathway that involves in the regulation of pressure-dependent myogenic cerebral arterial constriction.

  5. 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.

  6. Atrial distension, arterial pulsation, and vasopressin release during negative pressure breathing in humans

    DEFF Research Database (Denmark)

    Pump, B; Damgaard, M; Gabrielsen, A;

    2001-01-01

    During an antiorthostatic posture change, left atrial (LA) diameter and arterial pulse pressure (PP) increase, and plasma arginine vasopressin (AVP) is suppressed. By comparing the effects of a 15-min posture change from seated to supine with those of 15-min seated negative pressure breathing...... in eight healthy males, we tested the hypothesis that with similar increases in LA diameter, suppression of AVP release is dependent on the degree of increase in PP. LA diameter increased similarly during the posture change and negative pressure breathing (-9 to -24 mmHg) from between 30 and 31 +/- 1 to 34...... +/- 1 mm (P pressure breathing from 36 +/- 3 to 42 +/- 3 mmHg (P pressure decreased during the posture change...

  7. 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.

  8. Arterial compliance, systolic pressure and heart rate in elderly women at rest and on exercise.

    Science.gov (United States)

    Sebban, C; Berthaux, P; Lenoir, H; Eugene, M; Venet, R; Memin, Y; de la Fuente, X; Reisner, C

    1981-01-01

    In two groups of elderly women, the relationships between arterial compliance estimated by pulse wave velocity (PWV), and systolic blood pressure (SP), heart rate (HR), oxygen consumption and the time taken to run 400 m have been studies. Both at rest and with increasing levels of exercise, faster PWVs are associated with higher SPs. These is a tendency for resting HR to be higher with faster PWVs. The changes in HR and oxygen consumption from resting values are strikingly increased with faster PWVs. The time taken over 400 m rises as arterial compliance falls. Therefore, it seems that, with aging, reduced arterial compliance is a major factor affecting cardiovascular responses to exercise. PMID:7274682

  9. Arterial blood-pressure change and endogenous circulating substance P in man

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Kastrup, J; Schaffalitzky De Muckadell, O B

    1985-01-01

    Substance P (SP) is a powerful vasodilator and this peptide is today considered to be a chemical messenger. The potential effects on circulating SP of acute changes in arterial blood-pressure was investigated in nine subjects. An increase in arterial mean blood-pressure (+33%, P less than 0.001, n...... = 9) was obtained by infusion of angiotensin II and a decrease in pressure (-10%, P less than 0.005, n = 6) was obtained by ganglionic blockade. The concentration of SP in plasma, from supine subjects in the normotensive condition, ranged from 3 to 13 pmol/l (with a mean of 5.6 pmol/l). SP was thus...

  10. Amlodipine induces a flow and pressure-independent vasoactive effect on the brachial artery in hypertension.

    OpenAIRE

    Megnien, J L; Levenson, J.; Del-Pino, M; Simon, A

    1995-01-01

    1. The objectives of this study were to study the flow-dependent arterial reactivity and pressure-independent arterial compliance of the calcium antagonist amlodipine in hypertensive men. 2. Twenty-one hypertensive patients were randomized to receive 2 months treatment with placebo (n = 10) or 5-10 mg amlodipine (n = 11) once a day. Non-invasive measurement of brachial artery mean blood pressure, diameter and flow (pulsed Doppler) and compliance (arterial mechanography and logarithmic elastic...

  11. Acute nitric oxide synthase inhibition and endothelin-1-dependent arterial pressure elevation

    Directory of Open Access Journals (Sweden)

    Robert eRapoport

    2014-04-01

    Full Text Available Key evidence that endogenous nitric oxide (NO inhibits the continuous, endothelin (ET-1-mediated drive to elevate arterial pressure includes demonstrations that ET-1 mediates a significant component of the pressure elevated by acute exposure to NO synthase (NOS inhibitors. This review examines the characteristics of this pressure elevation in order to elucidate potential mechanisms associated with the negative regulation of ET-1 by NO and, thereby, provide potential insight into the vascular pathophysiology underlying NO dysregulation. We surmise that the magnitude of the ET-1-dependent component of the NOS inhibitor-elevated pressure is 1 independent of underlying arterial pressure and other pressor pathways activated by the NOS inhibitors and 2 dependent on relatively higher NOS inhibitor dose, release of stored and de novo synthesized ET-1, and ETA receptor-mediated increased vascular resistance. Major implications of these conclusions include: 1 the marked variation of the ET-1-dependent component, i.e., from 0-100% of the pressure elevation, reflects the NO-ET-1 regulatory pathway. Thus, NOS inhibitor-mediated, ET-1-dependent pressure elevation in vascular pathophysiologies is an indicator of the level of compromised/enhanced function of this pathway; 2 NO is a more potent inhibitor of ET-1-mediated elevated arterial pressure than other pressor pathways, due in part to inhibition of intravascular pressure-independent release of ET-1. Thus, the ET-1-dependent component of pressure elevation in vascular pathophysiologies associated with NO dysregulation is of greater magnitude at higher levels of compromised NO.

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

    International Nuclear Information System (INIS)

    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 (SDd) 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)

  13. Microalbuminuria associated with systolic blood pressure and arterial compliance in Chinese metabolic syndrome patients

    Institute of Scientific and Technical Information of China (English)

    LI Xin-li; XU Qiong; TONG Min; LU Xin-zheng; ZHANG Hai-feng; ZHOU Yan-li; CAO Ke-jiang; HUANG Jun

    2007-01-01

    Background There is significant evidence showing that microalbuminuria and arterial compliance are sensitive markers for early cardiovascular diseases. However, whether microalbuminuria is associated with reduced arterial compliance in Chinese metabolic syndrome (MS) patients remains unknown.Methods According to the definition of MS proposed by ATPⅢ in 2001, USA, subjects (n=362) were divided into three groups according to the number of risk factors: group 1 (control), group 2 (medium, < 3 risk factors) and group 3 (MS, ≥ 3 risk factors). Both large artery compliance (C1) and small artery compliance (C2) were measured with the CVProfilor DO-2020 Cardiovascular Profiling System, and microalbuminuria was evaluated with the ratio of albumin to urine creatinine.Results (1) As C1 and C2 levels elasticity decreased, albumin creatinine ratio (ACR) and the prevalence of microalbuminuria increased within those groups with MS risk factors. C1 and C2 were negatively correlated with the ranking of MS risk factors, ACR was positively correlated with the ranking of MS risk factors (all P<0.05). (2) Subjects were also categorized into a microalbuminuria group and a normal group, C1 and C2 in the microalbuminuria group were lower than in the normal group. (3) Multivariate regression analysis showed that increased systolic blood pressure (SBP) and reduced arterial compliance were the main risk factors for microalbuminuria in the MS group.Conclusions The risk of developing microalbuminuria was higher in the subjects with multiple metabolic abnormalities.Increased systolic blood pressure and reduced arterial compliance may be the main predictors for microalbuminuria in MS.

  14. Plasma viscosity increase with progression of peripheral arterial atherosclerotic disease.

    Science.gov (United States)

    Poredos, P; Zizek, B

    1996-03-01

    Increased blood and plasma viscosity has been described in patients with coronary and peripheral arterial disease. However, the relation of viscosity to the extent of arterial wall deterioration--the most important determinant of clinical manifestation and prognosis of the disease--is not well known. Therefore, the authors studied plasma viscosity as one of the major determinants of blood viscosity in patients with different stages of arterial disease of lower limbs (according to Fontaine) and its relation to the presence of some risk factors of atherosclerosis. The study encompassed four groups of subjects: 19 healthy volunteers (group A), 18 patients with intermittent claudication up to 200 m (stage II; group B), 15 patients with critical ischemia of lower limbs (stage III and IV; group C), and 16 patients with recanalization procedures on peripheral arteries. Venous blood samples were collected from an antecubital vein without stasis for the determination of plasma viscosity (with a rotational capillary microviscometer, PAAR), fibrinogen, total cholesterol, alpha-2-macroglobulin, and glucose concentrations. In patients with recanalization procedure local plasma viscosity was also determined from blood samples taken from a vein on the dorsum of the foot. Plasma viscosity was most significantly elevated in the patients with critical ischemia (1.78 mPa.sec) and was significantly higher than in the claudicants (1.68 mPa.sec), and the claudicants also had significantly higher viscosity than the controls (1.58 mPa.sec). In patients in whom a recanalization procedure was performed, no differences in systemic and local plasma viscosity were detected, neither before nor after recanalization of the diseased artery. In all groups plasma viscosity was correlated with fibrinogen concentration (r=0.70, P < 0.01) and total cholesterol concentration (r=0.24, P < 0.05), but in group C (critical ischemia) plasma viscosity was most closely linked to the concentration of alpha-2

  15. Respiratory sinus arrhythmia: opposite effects on systolic and mean arterial pressure in supine humans

    Science.gov (United States)

    Elstad, M.; Toska, K.; Chon, K. H.; Raeder, E. A.; Cohen, R. J.

    2001-01-01

    1. Are arterial blood pressure fluctuations buffered or reinforced by respiratory sinus arrhythmia (RSA)? There is still considerable debate about this simple question. Different results have been obtained, triggering a discussion as to whether or not the baroreflexes are responsible for RSA. We suspected that the measurements of different aspects of arterial pressure (mean arterial pressure (MAP) and systolic pressure (SP)) can explain the conflicting results. 2. Simultaneous recordings of beat-to-beat MAP, SP, left cardiac stroke volume (SV, pulsed ultrasound Doppler), heart rate (HR) and respiration (RE) were obtained in 10 healthy young adults during spontaneous respiration. In order to eliminate HR variations at respiratory frequency we used propranolol and atropine administration in the supine and tilted positions. Respiration-synchronous variation in the recorded variables was quantified by spectral analysis of the recordings of each of these variables, and the phase relations between them were determined by cross-spectral analysis. 3. MAP fluctuations increased after removing heart rate variations in both supine and tilted position, whereas SP fluctuations decreased in the supine position and increased in the head-up tilted position. 4. RSA buffers respiration-synchronous fluctuations in MAP in both positions. However, fluctuations in SP were reinforced by RSA in the supine and buffered in the tilted position.

  16. Non-invasive assessment of arterial stiffness using oscillometric blood pressure measurement

    OpenAIRE

    Komine Hidehiko; Asai Yoshiyuki; Yokoi Takashi; Yoshizawa Mutsuko

    2012-01-01

    Abstract Background Arterial stiffness is a major contributor to cardiovascular diseases. Because current methods of measuring arterial stiffness are technically demanding, the purpose of this study was to develop a simple method of evaluating arterial stiffness using oscillometric blood pressure measurement. Methods Blood pressure was conventionally measured in the left upper arm of 173 individuals using an inflatable cuff. Using the time series of occlusive cuff pressure and the amplitudes ...

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

    International Nuclear Information System (INIS)

    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. An adaptive transfer function for deriving the aortic pressure waveform from a peripheral artery pressure waveform.

    Science.gov (United States)

    Swamy, Gokul; Xu, Da; Olivier, N Bari; Mukkamala, Ramakrishna

    2009-11-01

    We developed a new technique to mathematically transform a peripheral artery pressure (PAP) waveform distorted by wave reflections into the physiologically more relevant aortic pressure (AP) waveform. First, a transfer function relating PAP to AP is defined in terms of the unknown parameters of a parallel tube model of pressure and flow in the arterial tree. The parameters are then estimated from the measured PAP waveform along with a one-time measurement of the wave propagation delay time between the aorta and peripheral artery measurement site (which may be accomplished noninvasively) by exploiting preknowledge of aortic flow. Finally, the transfer function with its estimated parameters is applied to the measured waveform so as to derive the AP waveform. Thus, in contrast to the conventional generalized transfer function, the transfer function is able to adapt to the intersubject and temporal variability of the arterial tree. To demonstrate the feasibility of this adaptive transfer function technique, we performed experiments in 6 healthy dogs in which PAP and reference AP waveforms were simultaneously recorded during 12 different hemodynamic interventions. The AP waveforms derived by the technique showed agreement with the measured AP waveforms (overall total waveform, systolic pressure, and pulse pressure root mean square errors of 3.7, 4.3, and 3.4 mmHg, respectively) statistically superior to the unprocessed PAP waveforms (corresponding errors of 8.6, 17.1, and 20.3 mmHg) and the AP waveforms derived by two previously proposed transfer functions developed with a subset of the same canine data (corresponding errors of, on average, 5.0, 6.3, and 6.7 mmHg). PMID:19783780

  19. Non-invasive assessment of arterial stiffness using oscillometric blood pressure measurement

    Directory of Open Access Journals (Sweden)

    Komine Hidehiko

    2012-02-01

    Full Text Available Abstract Background Arterial stiffness is a major contributor to cardiovascular diseases. Because current methods of measuring arterial stiffness are technically demanding, the purpose of this study was to develop a simple method of evaluating arterial stiffness using oscillometric blood pressure measurement. Methods Blood pressure was conventionally measured in the left upper arm of 173 individuals using an inflatable cuff. Using the time series of occlusive cuff pressure and the amplitudes of pulse oscillations, we calculated local slopes of the curve between the decreasing cuff pressure and corresponding arterial volume. Whole pressure-volume curve was derived from numerical integration of the local slopes. The curve was fitted using an equation and we identified a numerical coefficient of the equation as an index of arterial stiffness (Arterial Pressure-volume Index, API. We also measured brachial-ankle (baPWV PWV and carotid-femoral (cfPWV PWV using a vascular testing device and compared the values with API. Furthermore, we assessed carotid arterial compliance using ultrasound images to compare with API. Results The slope of the calculated pressure-volume curve was steeper for compliant (low baPWV or cfPWV than stiff (high baPWV or cfPWV arteries. API was related to baPWV (r = -0.53, P r = -0.49, P r = 0.32, P Conclusions These results suggest that our method can simply and simultaneously evaluate arterial stiffness and blood pressure based on oscillometric measurements of blood pressure.

  20. Left ventricular stroke volume in the fetal sheep is limited by extracardiac constraint and arterial pressure.

    Science.gov (United States)

    Grant, D A; Fauchère, J C; Eede, K J; Tyberg, J V; Walker, A M

    2001-08-15

    1. Extracardiac constraint and sensitivity to arterial pressure may be critical factors that limit the functional reserves of the developing fetal heart in utero. We hypothesise that extracardiac constraint is the predominant factor that limits fetal stroke volume (SV). To test this hypothesis we studied six chronically instrumented fetal sheep to determine the relative roles that extracardiac constraint and arterial pressure play in determining left ventricular (LV) function. 2. Pregnant ewes (128-131 days gestation, term = 147 days) were anaesthetised (5 mg kg(-1) Propofol I.V., then 1.5 % halothane, 50 % O(2), balance N(2)O by inhalation) and instrumented using sterile surgical techniques to record LV end-diastolic pressure (P(lved)), aortic pressure (P(ao)), pericardial pressure (P(per)), and LV SV. 3. After a minimum of 72 h recovery, LV function was assessed by altering fetal blood volume to vary P(lved). Ventricular function curves were generated using two measures of ventricular function, SV and stroke work index (SWI = SV x P(ao)), and two measures of ventricular filling, P(lved) and LV end-diastolic transmural pressure (P(lved,tm) = P(lved) - P(per)). 4. Although decreasing P(lved) from the resting level decreased SV, increasing P(lved) from the resting level did not increase SV because the ventricular function curve plateaued. This plateau was not explained solely by an increase in aortic pressure, as the plateau remained present in the SWI versus P(lved) curve. When extracardiac constraint was accounted for (SV against P(lved,tm)), the plateau was largely eliminated (approximately 80 %). The remaining portion of the plateau (approximately 20 %) was eliminated when both extracardiac constraint and arterial pressure were accounted for (SWI versus P(lved,tm)). 5. Thus, the major limitation upon LV function in the near-term fetus results from extracardiac constraint limiting ventricular filling while, at the same time, a much smaller limitation arises from

  1. Increase in vagal activity during hypotensive lower-body negative pressure in humans

    DEFF Research Database (Denmark)

    Sander-Jensen, K; Mehlsen, J; Stadeager, C;

    1988-01-01

    Progressive central hypovolemia is characterized by a normotensive, tachycardic stage followed by a reversible, hypotensive stage with slowing of the heart rate (HR). We investigated circulatory changes and arterial hormone concentrations in response to lower-body negative pressure (LBNP) in six...... volunteers before and after atropine administration. LBNP of 55 mmHg initially resulted in an increase in HR from 55 +/- 4 to 90 +/- 5 beats/min and decreases in mean arterial pressure (MAP) from 94 +/- 4 to 81 +/- 5 mmHg, in central venous pressure from 7 +/- 1 to -3 +/- 1 mmHg, and in cardiac output from 6...

  2. 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.

  3. Longitudinal perspective on the conundrum of central arterial stiffness, blood pressure, and aging.

    Science.gov (United States)

    Scuteri, Angelo; Morrell, Christopher H; Orrù, Marco; Strait, James B; Tarasov, Kirill V; Ferreli, Liana Anna Pina; Loi, Francesco; Pilia, Maria Grazia; Delitala, Alessandro; Spurgeon, Harold; Najjar, Samer S; AlGhatrif, Majd; Lakatta, Edward G

    2014-12-01

    The age-associated increase in arterial stiffness has long been considered to parallel or to cause the age-associated increase in blood pressure (BP). Yet, the rates at which pulse wave velocity (PWV), a measure of arterial stiffness, and BP trajectories change over time within individuals who differ by age and sex have not been assessed and compared. This study determined the evolution of BP and aortic PWV trajectories during a 9.4-year follow-up in >4000 community-dwelling men and women of 20 to 100 years of age at entry into the SardiNIA Study. Linear mixed effects model analyses revealed that PWV accelerates with time during the observation period, at about the same rate over the entire age range in both men and women. In men, the longitudinal rate at which BP changed over time, however, did not generally parallel that of PWV acceleration: at ages>40 years the rates of change in systolic BP (SBP) and pulse pressure (PP) increase plateaued and then declined so that SBP, itself, also declined at older ages, whereas PP plateaued. In women, SBP, diastolic BP, and mean BP increased at constant rates across all ages, producing an increasing rate of increase in PP. Therefore, increased aortic stiffness is implicated in the age-associated increase in SBP and PP. These findings indicate that PWV is not a surrogate for BP and that arterial properties other than arterial wall stiffness that vary by age and sex also modulate the BP trajectories during aging and lead to the dissociation of PWV, PP, and SBP trajectories in men.

  4. Arterial blood pressure measurement and pulse wave analysis--their role in enhancing cardiovascular assessment.

    Science.gov (United States)

    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. PMID:19940350

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

    International Nuclear Information System (INIS)

    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)

  6. Stiffness Indices and Fractal Dimension relationship in Arterial Pressure and Diameter Time Series in-Vitro

    Science.gov (United States)

    Cymberknop, L.; Legnani, W.; Pessana, F.; Bia, D.; Zócalo, Y.; Armentano, R. L.

    2011-12-01

    The advent of vascular diseases, such as hypertension and atherosclerosis, is associated to significant alterations in the physical properties of arterial vessels. Evaluation of arterial biomechanical behaviour is related to the assessment of three representative indices: arterial compliance, arterial distensibility and arterial stiffness index. Elasticity is the most important mechanical property of the arterial wall, whose natures is strictly non-linear. Intervention of elastin and collagen fibres, passive constituent elements of the arterial wall, is related to the applied wall stress level. Concerning this, appropriate tools are required to analyse the temporal dynamics of the signals involved, in order to characterize the whole phenomenon. Fractal geometry can be mentioned as one of those techniques. The aim of this study consisted on arterial pressure and diameter signals processing, by means of nonlinear techniques based on fractal geometry. Time series morphology was related to different arterial stiffness states, generated by means of blood flow variations, during experiences performed in vitro.

  7. Phytoestrogen genistein decreases contractile response of aortic artery in vitro and arterial blood pressure in vivo

    Institute of Scientific and Technical Information of China (English)

    Hong-fang LI; Long-de WANG; Song-yi QU

    2004-01-01

    AIM: To determine the mechanisms of effects of phytoestrogen genistein on the contracted rabbit aortic arteries in vitro, and observe the effect of genistein and 17-β estradiol on mean arterial pressure (MAP) in ovariectomized (OVX) rats. METHODS: (1) Strips of rabbit aortic smooth muscle were suspended in organ baths containing Kreb's solution, and then isometric tension was measured. (2) Female mature Wistar rats underwent a bilateral ovariectomy (OVX). Sham-operated rats (SHAM) were used as controls. After administration of genistein (0.4(1) Similar to 17-β estradiol, genistein could dose-dependently relax 40 mmol/L KCl-precontracted arterial strips.Incubation with Nω-L-nitro-arginine (L-NNA), methylene blue (MB), indomethacin, propranolol or endothelium removal did not affect relaxation induced by genistein. In calcium-free solution containing 0.01mmol/L egtazic acid (EGTA), genistein inhibited not only the first phase contraction induced by noradrenaline (NA), but also the second contraction induced by CaCl2. In addition, genistein could reduce the contractile responses of NA, KCl and CaCl2,and shift their cumulative concentration-response curves rightward. (2) MAP in OVX rats was significantly higher compared with that of SHAM rats. However, after chronically treatment with genistein or 17-β estradiol for 21 d the baseline MAP in OVX rats was reduced significantly. CONCLUSIONS: (1) The vasodilator effect of genistein in vitro is endothelium independent and not related to the nitric oxide, its mechanisms being probably due to inhibition of Ca2+ influx through calcium channels in a noncompetitive manner and Ca2+ release from intracellular store induced by NA. (2) Administration of genistein or 17-β estradiol can chronically decrease MAP in OVX rats.

  8. 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 myog...

  9. 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 compariso

  10. 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

  11. Simultaneous measurement of arterial and left ventricular pressure in conscious freely moving rats by telemetry.

    Science.gov (United States)

    Segreti, Jason A; Polakowski, James S; Blomme, Eric A; King, Andrew J

    2016-01-01

    Comprehensive cardiovascular assessment in conscious rodents by utilizing telemetry has been limited by the restriction of current devices to one pressure channel. The purpose of this study was to test and validate a dual pressure transmitter that allows the simultaneous measurement of arterial pressure (AP) and left ventricular pressure (LVP) in conscious freely moving rats. Six rats were surgically implanted with dual pressure transmitters. Baseline hemodynamics and circadian rhythm were observed to return within 7days. AP, heart rate (HR), LVP and indices of left ventricular contractility were stable and demonstrated a prominent circadian rhythm over a two-week period of uninterrupted recordings. Administration of the vasodilator nifedipine produced the anticipated dose-dependent decrease in AP which was accompanied by a baroreflex mediated increase in HR and cardiac contractility. The negative inotrope verapamil produced the expected dose-dependent decreases in AP and cardiac contractility. Finally, a terminal validation of the dual pressure transmitter was performed under anesthesia by measuring AP and LVP simultaneously via telemetry and from a fluid filled arterial catheter and an intraventricular Millar catheter, respectively. A range of pressures and cardiac contractility were studied by administering sequential intravenous infusions of the positive inotrope dobutamine followed by verapamil. Linear regression analysis revealed a high level of agreement between pressures measured by the dual pressure transmitter and the exteriorized catheters. Histopathologic analysis of the heart revealed mild peri-catheter fibrosis. In conclusion, the simultaneous measurement of AP and LVP offers the potential for more detailed cardiovascular assessment in conscious rats. PMID:26778372

  12. Correlation of invasive central arterial pressure with peripheral arterial pressure and coronary sclerosis%有创中心动脉压与外周动脉压和冠状动脉硬化的相关性

    Institute of Scientific and Technical Information of China (English)

    吴琪; 徐聪聪; 刘江; 陈琦; 吴延庆

    2013-01-01

    artery pressure and non-radial artery pressure and invasive central aortic pressure were compared.Results The systolic pressure values measured in invasive and non-invasive brachial artery and radial artery were higher than that measured by central aortic pressure,while the diastolic pressure values measured in the four peripheral artery were lower than that measured in central aorta.The pressure values measured by non-invasive brachial artery pressure were more close to that measured by invasive central aortic pressure (P>0.05).The systolic pressure was increased and the diastolic pressure was reduced in central aortic pressure with the coronary vessel lession numbers increased.The values of systolic pressure in patients with single-vessel,double-vessel and triple-vessel lesions were (118.2± 19.5) mm Hg,(124.9 ± 19.7) mm Hg and (137.7 ± 20.6) mm Hg,respectively and the values of diastolic pressure were (86.8±8.4) mm Hg,(85.3± 10.3) mm Hg and (83.1± 9.4) mm Hg,respectively.There were significant differences in systolic and diastolic pressure values among patients with single-vessel lesions,double vessel lesions and triple-vessel lesions(F=3.93,4.31,both P< 0.05).Conclusions The blood pressure values measured by noninvasive brachial artery pressure are more close to that measured by invasive central aortic pressure.There is a significant correlation between the severe degree of coronary heart disease and invasive central aortic pressure.Non invasive brachial artery pressure can be used in the early detection of cardiovascular dysfunction.

  13. Increased Mutagen Sensitivity and DNA Damage in Pulmonary Arterial Hypertension

    Science.gov (United States)

    Federici, Chiara; Drake, Kylie M.; Rigelsky, Christina M.; McNelly, Lauren N.; Meade, Sirena L.; Comhair, Suzy A. A.; Erzurum, Serpil C.

    2015-01-01

    Rationale: Pulmonary arterial hypertension (PAH) is a serious lung condition characterized by vascular remodeling in the precapillary pulmonary arterioles. We and others have demonstrated chromosomal abnormalities and increased DNA damage in PAH lung vascular cells, but their timing and role in disease pathogenesis is unknown. Objectives: We hypothesized that if DNA damage predates PAH, it might be an intrinsic cell property that is present outside the diseased lung. Methods: We measured DNA damage, mutagen sensitivity, and reactive oxygen species (ROS) in lung and blood cells from patients with Group 1 PAH, their relatives, and unrelated control subjects. Measurements and Main Results: Baseline DNA damage was significantly elevated in PAH, both in pulmonary artery endothelial cells (P < 0.05) and peripheral blood mononuclear cells (PBMC) (P < 0.001). Remarkably, PBMC from unaffected relatives showed similar increases, indicating this is not related to PAH treatments. ROS levels were also higher (P < 0.01). DNA damage correlated with ROS production and was suppressed by antioxidants (P < 0.001). PBMC from patients and relatives also showed markedly increased sensitivity to two chemotherapeutic drugs, bleomycin and etoposide (P < 0.001). Results were consistent across idiopathic, heritable, and associated PAH groups. Conclusions: Levels of baseline and mutagen-induced DNA damage are intrinsically higher in PAH cells. Similar results in PBMC from unaffected relatives suggest this may be a genetically determined trait that predates disease onset and may act as a risk factor contributing to lung vascular remodeling following endothelial cell injury. Further studies are required to fully characterize mutagen sensitivity, which could have important implications for clinical management. PMID:25918951

  14. Effect of oral garlic on arterial oxygen pressure in children with hepatopulmonary syndrome

    Institute of Scientific and Technical Information of China (English)

    Mehri Najafi Sani; Hamid Reza Kianifar; Abdolrazagh Kianee; Gholamreza Khatami

    2006-01-01

    AIM: To study the effect of oral garlic on arterial oxygen pressure in children with hepatopulmonary syndrome.METHODS: Garlic powder in a capsule form was given to 15 children with hepatopulmonary syndrome (confirmed by contrast echocardiography) at the dosage of 1g/1.73 m2 per day. Patients were evaluated clinically and by arterial blood gas every four weeks.RESULTS: The garlic capsule was administered to 15patients with hepatopulmonary syndrome. There were 10 boys and 5 girls with a mean age of 9.4±3.9 years.The underlying problems were biliary tract atresia (4patients), autoimmune hepatitis (4 patients), cryptogenic cirrhosis (4 patients) and presinusoidal portal hypertension (3 patients). Eight patients (53.3%) showed an increase of 10 mmHg in their mean arterial oxygen pressure. The baseline PaO2 was 65.6±12.1 mmHg in the responder group and 47.1±11.2 mmHg in nonresponder group. At the end of treatment the mean PaO2 in responders and non-responders was 92.2±7.75mmHg and 47.5±11.87 mmHg, respectively (P<0.01).CONCLUSION: Garlic may increase oxygenation and improve dyspnea in children with hepatopulmonary syndrome.

  15. Variability of arterial blood pressure in normal and hypertensive pregnancy.

    Science.gov (United States)

    Oney, T; Meyer-Sabellek, W

    1990-12-01

    In normal pregnancy the circadian blood pressure rhythm is similar to that in the non-pregnant state, with the highest blood pressure values in the morning and the lowest at midnight. This rhythm is lost in patients with pre-eclampsia. Women with severe pre-eclampsia show a reversed circadian rhythm, with a nocturnal increase in blood pressure during the sleeping phase. Although the reasons for this nocturnal hypertension in severe pre-eclampsia are poorly understood, the results suggest that pre-eclamptic women are endangered by hypertensive emergencies, mostly at night. Therefore blood pressure measurement should be extended to the night, and antihypertensive treatment must be adapted to the demands of a reversed circadian rhythm in relevant subgroups of patients. PMID:2082002

  16. Accuracy of invasive arterial pressure monitoring in cardiovascular patients: An observational study

    OpenAIRE

    Romagnoli, Stefano; Ricci, Zaccaria; Quattrone, Diego; Tofani, Lorenzo; Tujjar, Omar; Villa, Gianluca; Romano, Salvatore M.; A. R. De Gaudio

    2014-01-01

    INTRODUCTION: Critically ill patients and patients undergoing high-risk and major surgery, are instrumented with intra-arterial catheters and invasive blood pressure is considered the "gold standard" for arterial pressure monitoring. Nonetheless, artifacts due to inappropriate dynamic response of the fluid-filled monitoring systems may lead to clinically relevant differences between actual and displayed pressure values. We sought to analyze the incidence and causes of resonance/underdamping p...

  17. Accuracy of invasive arterial pressure monitoring in cardiovascular patients: an observational study

    OpenAIRE

    Romagnoli, Stefano; Ricci, Zaccaria; Quattrone, Diego; Tofani, Lorenzo; Tujjar, Omar; Villa, Gianluca; Romano, Salvatore M.; De Gaudio, A Raffaele

    2014-01-01

    Introduction Critically ill patients and patients undergoing high-risk and major surgery, are instrumented with intra-arterial catheters and invasive blood pressure is considered the “gold standard” for arterial pressure monitoring. Nonetheless, artifacts due to inappropriate dynamic response of the fluid-filled monitoring systems may lead to clinically relevant differences between actual and displayed pressure values. We sought to analyze the incidence and causes of resonance/underdamping ph...

  18. Myogenic constriction is increased in mesenteric resistance arteries from rats with chronic heart failure : instantaneous counteraction by acute AT(1) receptor blockade

    NARCIS (Netherlands)

    Gschwend, S; Henning, RH; Pinto, YM; de Zeeuw, D; van Gilst, WH; Buikema, H

    2003-01-01

    1 Increased vascular resistance in chronic heart failure (CHF) has been attributed to stimulated neurohumoral systems. However, local mechanisms may also importantly contribute to set arterial tone. Our aim, therefore, was to test whether pressure-induced myogenic constriction of resistance arteries

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

    International Nuclear Information System (INIS)

    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 (RSpearman = 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

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

    Science.gov (United States)

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

    2010-09-01

    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 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. PMID:20664157

  1. 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....../PP on one side and age, sex, body weight, portal pressure, systemic hemodynamics, biochemical variables, and severity of disease on the other. In the multiple-regression analysis, sex, age, mean arterial blood pressure, systemic vascular resistance, and biochemical variables were significant independent...

  2. Skin autofluorescence is increased in patients with carotid artery stenosis and peripheral artery disease

    OpenAIRE

    Noordzij, Marjon J.; Lefrandt, Joop D.; Loeffen, Erik A. H.; Saleem, Ben R.; Meerwaldt, Robbert; Lutgers, Helen L.; Smit, Andries J.; Zeebregts, Clark J.

    2011-01-01

    Advanced glycation end products (AGEs) have a pivotal role in atherosclerosis. We evaluated skin autofluorescence (SAF), a non-invasive measurement of tissue AGE accumulation, in patients with carotid artery stenosis with and without coexisting peripheral artery occlusive disease (PAOD). SAF was measured using the AGE Reader™ in 56 patients with carotid artery stenosis and in 56 age- and sex-matched healthy controls without diabetes, renal dysfunction or known atherosclerotic disease. SAF was...

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

    OpenAIRE

    Jong-Gu Choi; Keun-Ho Kim; Woo-Beom Lee; Dong-Hyun Nam; Il-Ho Son; You-Sik Hong; Sang-Suk Lee

    2011-01-01

    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...

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

    DEFF Research Database (Denmark)

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

    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 index seems to reflect abnormalities in the arterial compliance of these patients....

  5. Combined use of non-invasive techniques to predict pulmonary arterial pressure in chronic respiratory disease.

    OpenAIRE

    Bishop, J M; Csukas, M

    1989-01-01

    The value of non-invasive procedures for predicting pulmonary arterial pressure was investigated in 370 patients with chronic obstructive lung diseases and in 73 with fibrosing alveolitis in a combined study at nine centres in six European countries. Measurements included forced expiratory volume in one second, arterial blood gas tensions, standard electrocardiogram, radiographic dimensions of pulmonary artery, right ventricle dimensions by M mode echocardiography, and myocardial scintigraphy...

  6. Increased aortic stiffness and related factors in patients with peripheral arterial disease.

    Science.gov (United States)

    Catalano, Mariella; Scandale, Giovanni; Carzaniga, Gianni; Cinquini, Michela; Minola, Marzio; Dimitrov, Gabriel; Carotta, Maria

    2013-10-01

    A number of conditions have been associated with functional changes of large arteries. The aim of this study was to evaluate the factors associated with aortic stiffness in patients with peripheral arterial disease (PAD). The authors studied 86 patients with PAD (ankle-brachial pressure index [ABPI] ≤0.9) and 86 controls. Aortic stiffness was determined by pulse wave velocity (aPWV) using applanation tonometry. In PAD patients, aPWV was higher compared with controls (11 ± 3 vs 9.8 ± 1.8; P=.002). In multiple regression analysis, aPWV was independently associated with pulse pressure (β=0.05, P=.01) in the PAD patients and with age in the control group (β=0.08, P=.0005). The results of this study confirm an aPWV increase in patients with PAD and emphasize the association between blood pressure and aPWV. Further studies are necessary to assess whether higher aortic stiffening adds prognostic value to ABPI, which is the most powerful prognostic indicator in PAD. PMID:24088278

  7. Predicting Increased Blood Pressure Using Machine Learning

    Science.gov (United States)

    Golino, Hudson Fernandes; Amaral, Liliany Souza de Brito; Duarte, Stenio Fernando Pimentel; Soares, Telma de Jesus; dos Reis, Luciana Araujo

    2014-01-01

    The present study investigates the prediction of increased blood pressure by body mass index (BMI), waist (WC) and hip circumference (HC), and waist hip ratio (WHR) using a machine learning technique named classification tree. Data were collected from 400 college students (56.3% women) from 16 to 63 years old. Fifteen trees were calculated in the training group for each sex, using different numbers and combinations of predictors. The result shows that for women BMI, WC, and WHR are the combination that produces the best prediction, since it has the lowest deviance (87.42), misclassification (.19), and the higher pseudo R2 (.43). This model presented a sensitivity of 80.86% and specificity of 81.22% in the training set and, respectively, 45.65% and 65.15% in the test sample. For men BMI, WC, HC, and WHC showed the best prediction with the lowest deviance (57.25), misclassification (.16), and the higher pseudo R2 (.46). This model had a sensitivity of 72% and specificity of 86.25% in the training set and, respectively, 58.38% and 69.70% in the test set. Finally, the result from the classification tree analysis was compared with traditional logistic regression, indicating that the former outperformed the latter in terms of predictive power. PMID:24669313

  8. 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.

  9. 20-HETE induces remodeling of renal resistance arteries independent of blood pressure elevation in hypertension.

    Science.gov (United States)

    Ding, Yan; Wu, Cheng-Chia; Garcia, Victor; Dimitrova, Irina; Weidenhammer, Adam; Joseph, Gregory; Zhang, Frank; Manthati, Vijay L; Falck, John R; Capdevila, Jorge H; Schwartzman, Michal L

    2013-09-01

    20-Hydroxyeicosatetraenoic acid (20-HETE) is a cytochrome P-450 (Cyp)-derived arachidonic acid metabolite that has been shown to increase smooth muscle contractions and proliferation, stimulate endothelial dysfunction and activation, and promote hypertension. We examined if 20-HETE contributes to microvascular remodeling in hypertension. In Sprague-Dawley rats, administration of the 20-HETE biosynthesis inhibitor HET0016 or the 20-HETE antagonist N-20-hydroxyeicosa-6(Z),15(Z)-dienoic acid (20-HEDE) prevented 5α-dihydrotestosterone (DHT)-induced increases in blood pressure as well as abrogated DHT-induced increases in the media-to-lumen ratio (M/L), media thickness, and collagen IV deposition in renal interlobar arteries. Reserpine prevented blood pressure elevation in DHT-treated rats but did not affect microvascular remodeling (M/L, media thickness, and collagen deposition); under these conditions, treatment with the 20-HETE antagonist attenuated microvascular remodeling, suggesting that 20-HETE contributes to DHT-induced vascular remodeling independent of blood pressure elevation. In Cyp4a14(-/-) mice, which display androgen-driven and 20-HETE-dependent hypertension, treatment with the 20-HETE antagonist abolished remodeling of renal resistance arteries measured as media thickness (24 ± 1 vs. 15 ± 1 μm) and M/L (0.29 ± 0.03 vs. 0.17 ± 0.01). Moreover, in Cyp4a12 transgenic mice in which the expression of Cyp4a12-20-HETE synthase is driven by a tetracycline-sensitive promoter, treatment with doxycycline resulted in blood pressure elevation (140 ± 4 vs. 92 ± 5 mmHg) and a significant increase in remodeling of renal resistance arteries (media thickness: 23 ± 1 vs. 16 ± 1 μm; M/L: 0.39 ± 0.04 vs. 0.23 ± 0.02); these increases were abrogated by cotreatment with 20-HEDE. This study demonstrated that 20-HETE is a key regulator of microvascular remodeling in hypertension; its effect is independent of blood pressure elevation and androgen levels. PMID

  10. Skin autofluorescence is increased in patients with carotid artery stenosis and peripheral artery disease

    NARCIS (Netherlands)

    Noordzij, Marjon J.; Lefrandt, Joop D.; Loeffen, Erik A. H.; Saleem, Ben R.; Meerwaldt, Robbert; Lutgers, Helen L.; Smit, Andries J.; Zeebregts, Clark J.

    2012-01-01

    Advanced glycation end products (AGEs) have a pivotal role in atherosclerosis. We evaluated skin autofluorescence (SAF), a non-invasive measurement of tissue AGE accumulation, in patients with carotid artery stenosis with and without coexisting peripheral artery occlusive disease (PAOD). SAF was mea

  11. Thinking outside the box: Use of the pressure wire to assess intracranial large artery stenoses.

    Science.gov (United States)

    Sanon, Vani P; Prasad, Anand

    2016-08-01

    A novel study investigating the utility of the 0.014″ diameter pressure wire to assess the hemodynamic significance of intermediate intracranial stenosis. Technical aspects of pressure wire positioning across intracranial arteries are described. Further research is required to clarify the assessment of pressure gradients in the cerebral circulation and to define the optimal threshold for intervention. PMID:27530191

  12. Effects of physical training on pulmonary arterial pressure during exercise under hypobaric hypoxia in rats

    Science.gov (United States)

    Kashimura, Osamu; Sakai, Akio

    1991-12-01

    In this investigation, we assessed the effects of physical training on exercise-induced systemic and pulmonary hemodynamic changes under hypobaric hypoxia in catheter-implanted rats. We made continuous measurements of pulmonary and systemic arterial pressures during progressive treadmill exercises under hypobaric hypoxia (equivalent to altitudes of 2500 and 5500 m) in 46 control and 41 trained rats. Trained rats were exercised on two running schedules: 4 weeks (4-trained) and 6 weeks (6-trained). Both these groups of trained rats were exercised for the same length of running time each day. The increase in resting mean pulmonary arterial pressure(overline {P_{pa} } ) with increasing equivalent altitude was lower in the two trained groups than in the control group. The increase in(overline {P_{pa} } ) with progressive intensity of exercise was lower in the 6-trained than in the 4-trained and control groups at 610 and 2500 m. The 6-trained rats showed higher pH, P a CO 2 and O2 saturation in their blood than did the control group, whereas the P a O 2 was less. Lung tissue cyclic AMP concentration at rest was higher in the 6-trained than in the control group. Finally, it may be noted that exercise-induced lung tissue vasodilator responses seem to be enhanced in well-trained rats under both normobaric normoxia and hypobaric hypoxia. This study indicates that exercise training may be useful in preventing pulmonary hypertension resulting from both hypoxia and exercise.

  13. Venous cuff pressures from 30 mmHg to diastolic pressure are recommended to measure arterial inflow by plethysmography.

    NARCIS (Netherlands)

    Groothuis, J.T.; Vliet, L. van; Kooijman, H.M.; Hopman, M.T.E.

    2003-01-01

    Venous occlusion strain gauge plethysmography (VOP) is based on the assumption that the veins are occluded and arterial inflow is undisturbed by the venous cuff pressure. Literature is not clear concerning the pressure that should be used. The purpose of this study was to determine the optimal venou

  14. Changes in the retrobulbar arterial circulation after decrease of the elevated intraocular pressure in men and women with primary open angle glaucoma

    Directory of Open Access Journals (Sweden)

    Marjanović Ivan

    2013-01-01

    Full Text Available Introduction. An altered perfusion of the optic nerve head has been proposed as a pathogenic factor of glaucoma. Objective. The aim of this study was to evaluate the changes of the hemodynamic parameters in the retrobulbar arterial circulation after decrease of the elevated intraocular pressure (IOP in women and men with primary open angle glaucoma. Methods. The study included 60 patients (33 males and 27 females older than 50 years, with diagnosed and treated primary open angle glaucoma (77 eyes of 39 patients had increased IOP, >25 mm Hg. They were examined at the Clinic of Eye Diseases (complete ophthalmologic exam and Clinic of Neurology, Clinical Center of Serbia, Belgrade, from December 2009 to December 2010. Imaging of hemodynamic parameters of three retrobulbar arterial vessels: ophthalmic, central retinal and posterior ciliary arteries with color Doppler was performed. Results. Among women, hemodynamic arterial parameter of the peak-systolic velocity was increased in the central retinal artery and decreased in the ophthalmic artery and posterior ciliary arteries; end- diastolic velocity was increased in all three retrobulbar vascular levels; Pourcelot resistivity index was increased, but pulsatility index was decreased in all three vessels. Among men, peak-systolic velocity, end-diastolic velocity and pulsatility index were decreased in all three vessels; resistivity index was increased in the ophthalmic artery, but decreased in the central retinal artery and posterior ciliary arteries. There was a significant change of the ophthalmic artery pulsatility index in women, and the end-diastolic velocity of the ophthalmic artery in men. Conclusion. There was a difference of the retrobulbar arterial circulation between women and men with primary open angle glaucoma after decrease of the elevated intraocular pressure. The role of vascular factors in the supply of the optic disc neuroretinal rim is important.

  15. An Inexpensive Arterial Pressure Wave Sensor and its application in different physiological condition

    CERN Document Server

    Sur, S; Sur, Shantanu

    2005-01-01

    Arterial Blood Pressure wave monitoring is considered to be important in assessment of cardiovascular system. We developed a novel pulse wave detection system using low frequency specific piezoelectric material as pressure wave sensor. The transducer detects the periodic change in the arterial wall diameter produced by pressure wave and the amplified signal after integration represents the pressure wave. The signal before integration is proportional to the rate of change of pressure wave and it not only reproduces the pressure waveform faithfully, but also its sharper nature helps to reliably detect the heart period variability (HPV). We have studied the position-specific (e.g. over carotid or radial artery) nature of change of this pulse wave signal (shape and amplitude) and also the changes at different physiological states.

  16. Sildenafil has no effect on portal pressure but lowers arterial pressure in patients with compensated cirrhosis

    OpenAIRE

    Tandon, Puneeta; Inayat, Irteza; Tal, Michael; Spector, Marcelo; Shea, Martha; Groszmann, Roberto; Garcia-Tsao, Guadalupe

    2010-01-01

    The reduction of portal pressure in patients with early compensated cirrhosis may be more responsive to drugs increasing intrahepatic vasodilatation than those reducing portal venous inflow. The PDE-V inhibitor sildenafil can potentially reduce portal pressure by decreasing intrahepatic resistance, but its systemic vasodilatory effects may be deleterious.

  17. A rapid decrease in pulmonary arterial pressure by noninvasive positive pressure ventilation in a patient with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Dursunoglu Nese

    2007-01-01

    Full Text Available The natural history of chronic obstructive pulmonary disease (COPD is characterized by progressive decrements in expiratory airflow, increments in end-expired pulmonary volume, hypoxaemia, hypercapnia and the progression of pulmonary arterial hypertension (PAH. Noninvasive positive pressure ventilation (NPPV treatment is increasingly used for the treatment of acute and chronic respiratory failure in patients with COPD. NPPV can increase PaO2 and decrease PaCO2 by correcting the gas exchange in such patients. The acute effect of NPPV on decreasing PAP is seen in patients with respiratory failure, probably due to the effect on cardiac output. Here, a case with COPD whose respiratory acidosis and PAH rapidly improved by NPPV was presented and therefore we suggested to perform an echocardiographic assessment to reveal an improvement of PAH as well as respiratory acidosis, hypercapnia and hypoxemia with that treatment.

  18. Impaired renal allograft function is associated with increased arterial stiffness in renal transplant recipients

    DEFF Research Database (Denmark)

    Kneifel, M; Scholze, A; Burkert, A;

    2006-01-01

    It is important whether impairment of renal allograft function may deteriorate arterial stiffness in renal transplant recipients. In a cross-sectional study, arterial vascular characteristics were non-invasively determined in 48 patients with renal allograft using applanation tonometry and digital...... of large arteries S1 and small arteries S2 in renal transplant recipients (each p renal allograft (p ...-Wallis test between groups). It is concluded that impairment of renal allograft function is associated with an increased arterial stiffness in renal transplant recipients....

  19. 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. PMID:27333887

  20. Noninvasive Monitoring of Arterial Viscoelastic Indices Using a Foil-type Pressure Sensor

    Science.gov (United States)

    Maruyama, Hiromi; Hirano, Harutoyo; Kutluk, Abdugheni; Tsuji, Toshio; Fukuda, Osamu; Ueno, Naohiro; Ukawa, Teiji; Nakamura, Ryuji; Saeki, Noboru; Kawamoto, Masashi; Yoshizumi, Masao

    This paper proposes a noninvasive method for estimating the dynamic characteristics of arterial walls using pulse waves measured in various parts of the body by a foil-type pressure sensor. The sensor not only has high sensitivity and flexibility but also features the ability to continuously measure the alternating-current component of pulse waves. These capabilities make it suitable for estimating the dynamic characteristics of arterial walls. In this paper, a foil-type pressure sensor was employed to measure pulse waves based on the tonometry approach, and a method of estimating changes in arterial viscoelastic indices was proposed based on the measured pulse waves and photoplethysmograms. In order to accurately measure blood pressure, first, we examined suitable mechanical forces to the sensor, and found that values of 5-25[N] yielded the best performance. We then estimated the arterial viscoelastic indices of a radial artery and a dorsal pedis artery when mechanical pain stimuli were applied to the subjects. The results suggested that the estimated indices can be used to quantitatively assess vascular response caused by sympathicotonia. We thus concluded that the proposed method enabled noninvasive measurement of pulse waves in the dorsal pedis artery and estimation of arterial viscoelastic indices.

  1. Diencephalic regulation of respiration and arterial pressure during actual and fictive locomotion in cat.

    Science.gov (United States)

    Millhorn, D E; Eldridge, F L; Waldrop, T G; Kiley, J P

    1987-10-01

    The purpose of this study was to examine by experimentation the hypothesis that the respiratory and circulatory responses during exercise are attributable to command signals that emanate from the suprapontine brain. We studied the relations between locomotion (exercise) and phrenic nerve activity and arterial pressure in cats that walked or ran on a treadmill and in animals during fictive locomotion, i.e., locomotor activity in motor nerves to legs. Anesthetized cats with intact brains and unanesthetized decorticated cats were used. All preparations exhibited spontaneous actual and fictive locomotion. Electrical stimulation or microinjection of picrotoxin, a GABA antagonist, of the subthalamic locomotor areas always caused locomotion to develop. Phrenic nerve activity and arterial pressure increased in proportion to the level of locomotor activity despite control or ablation of feedback signals from chemoreceptors and vagal receptors. Similar relations were measured during fictive locomotion despite the absence of muscular contraction and limb movement and the lack of change in metabolic rate. These findings provide experimental support for the central command hypothesis for the genesis of the respiratory hyperpnea and increased cardiovascular function that occur during exercise. We believe that the command signals emanate from the subthalamic locomotor area of the diencephalon. PMID:3652403

  2. 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...... mmHg, half had arterial lesions proximal to the groin. None had diabetes. Fourteen per cent non-diabetic patients had chronic ulcerations on the foot with arterial lesions similar to those in patients with rest pain. Eleven per cent diabetic patients with chronic ulcerations had less pronounced...... occlusive arterial disease which was located distally on the legs. A classification in three groups is suggested: (1) ischemia only during exercise; (2) ischemia at rest with or without ulcerations: and (3) diabetics with chronic ulcerations....

  3. Arterial blood pressure regulation following aorta clamping and declamping during surgery.

    Science.gov (United States)

    Ferrario, Manuela; Aletti, Federico; Toschi, Nicola; Canichella, Antonio; Coniglione, Filadelfo; Sabato, Elisabetta; Della Badia Giussi, Florencia; Dauri, Mario; Sabato, Alessandro F; Guerrisi, Maria; Cerutti, Sergio

    2011-01-01

    In this paper, we propose the use of black box models for the system identification of the cardiopulmonary baroreflex control of arterial resistance and of ventricular contractility and of arterial baroreflex control of heart rate (HR) from invasive, continuous measurements of arterial blood pressure (ABP) and central venous pressure (CVP), and non invasive, continuous recordings of ECG and respiration. Two crucial phases of the abdominal aortic aneurism (AAA) repair were investigated: the clamping and declamping of aorta. The objective of the present work is to evaluate and to test the ability to monitor baroreflex responses to clamping and declamping maneuvers preceding and following aneurism removal. PMID:22256303

  4. Measurement of mean arterial pressure: comparison of the Vasotrac monitor with the finger differential oscillometric device.

    Science.gov (United States)

    Jagomägi, K; Raamat, R; Talts, J; Ragun, U; Tähepõld, P

    2010-01-01

    The Vasotrac monitor provides non-invasive near-continuous blood pressure monitoring and is designed to be an alternative to direct intra-arterial blood pressure (BP) measurement. As compared to radial artery invasive BP and upper arm non-invasive BP, Vasotrac readings have been found to have a good agreement with them. However, discrepancies have been reported when rapid changes in BP exist. In the present study we compared BP measured by the Vasotrac monitor on the radial artery with that recorded on the finger arteries by the differential oscillometric device allowing measurement on the beat-to-beat basis. Comparisons were performed on the mean arterial pressure (MAP) level. Special attention was paid to the signal conditioning before comparison of pressures of different temporal resolution. Altogether 383 paired MAP measurements were made in 14 healthy subjects. Based on all 383 paired measurements, the MAP values measured at the radial artery at rest were 4.8+/-6.0 mm Hg higher than those measured on fingers. The observed difference between the Vasotrac and differential oscillometric device can be explained by different measurement sites. This result is consistent with previous investigations, and the Vasotrac monitor can be considered to adequately track relatively rapid MAP changes on the radial artery. Attention should be paid to a proper signal conditioning before comparison of results obtained by different devices. PMID:20406039

  5. Increased risk of arterial thromboembolic events after Staphylococcus aureus bacteremia

    DEFF Research Database (Denmark)

    Mejer, N; Gotland, N; Uhre, M L;

    2015-01-01

    OBJECTIVES: An association between infection and arterial thromboembolic events (ATE) has been suggested. Here we examined the risk of myocardial infarction (MI), stroke and other ATE after Staphylococcus aureus bacteremia (SAB). METHODS: Danish register-based nation-wide observational cohort study...

  6. Arterial pressure and cerebral blood flow variability: friend or foe? A review

    Directory of Open Access Journals (Sweden)

    Caroline Alice Rickards

    2014-04-01

    Full Text Available Variability in arterial pressure and cerebral blood flow has traditionally been interpreted as a marker of cardiovascular decompensation, and has been associated with negative clinical outcomes across varying time scales, from impending orthostatic syncope to an increased risk of stroke. Emerging evidence, however, suggests that increased hemodynamic variability may, in fact, be protective in the face of acute challenges to perfusion, including significant central hypovolemia and hypotension (including hemorrhage, and during cardiac bypass surgery. This review presents the dichotomous views on the role of hemodynamic variability on clinical outcome, including the physiological mechanisms underlying these patterns, and the potential impact of increased and decreased variability on cerebral perfusion and oxygenation. We suggest that reconciliation of these two apparently discrepant views may lie in the time scale of hemodynamic variability; short time scale variability appears to be cerebroprotective, while mid to longer term fluctuations are associated with primary and secondary end-organ dysfunction.

  7. Opioid receptor antagonists increase [Ca2+]i in rat arterial smooth muscle cells in hemorrhagic shock

    Institute of Scientific and Technical Information of China (English)

    Li KAI; Zhong-feng WANG; Yu-liang SHI; Liang-ming LIU; De-yao HU

    2004-01-01

    AIM: To examine the effects of opioid receptor antagonists and norepinephrine on intracellular free Ca2+ concentration ([Ca2+]i) in mesenteric arterial (MA) smooth muscle cells (SMC) isolated from normal and hemorrhagic shocked rats in the vascular hyporesponse stage. METHODS: The rat model of hemorrhagic shock was made by withdrawing blood to decrease the artery mean blood pressure to 3.73-4.26 kPa and keeping at the level for 3 h.[Ca2+]i of vascular smooth muscle cells (VSMC) were detected by the laser scan confocal microscopy. RESULTS:In the hyporesponse VMSC of rats in hemorrhagic shock, selective δ-, κ-, and μ-opioid receptor antagonists (naltrindole, nor-binaltorphimine, and β-funaltrexamine, 100 nmol/L) as well as norepinephrine 5 μmol/L significantly increased [Ca2+]i by 47 %±13 %, 37 %±14 %, 33 %±10 %, and 54 %±17 %, respectively, although their effects were lower than those in the normal rat cells (the increased values were 148 %±54 %, 130 %±44 %, 63 %±17 %and 110 %±38 %, respectively); and the norepinephrine-induced increase in [Ca2+]i was further augmented by three δ-, κ-, and μ-opioid receptor antagonists (50 nmol/L, respectively) application (from 52 %± 16 % to 99 %±29 %,146 %±54 % and 137 %±47 %, respectively). CONCLUSION: The disorder of [Ca2+]i regulation induced by hemorrhagic shock was mediated by opioid receptor and α-adrenoceptor, which may be partly responsible for the vascular hyporesponse, and the opioid receptor antagonists improved the response of resistance arteries to vascular stimulants in decompensatory stage of hemorrhagic shock.

  8. 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

    International Nuclear Information System (INIS)

    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. (orig.)

  9. Augmented blood pressure measurement through the noninvasive estimation of physiological arterial pressure variability

    International Nuclear Information System (INIS)

    Current noninvasive blood pressure (BP) measurement methods, such as the oscillometric method, estimate the systolic and diastolic blood pressure (SBP and DBP) at two random instants in time and do not take into account the natural variability in BP. The standard for automated BP devices sets a maximum allowable system error of ±5 mmHg, even though natural BP variability often exceeds these limits. This paper proposes a new approach using simultaneous recordings of the oscillometric and continuous arterial pulse waveforms to augment the conventional noninvasive measurement by providing (1) the mean SBP and DBP over the measurement interval and the associated confidence intervals of the mean, (2) the standard deviation of SBP and DBP over the measurement interval, which indicates the degree of fluctuation in BP and (3) an indicator as to whether or not the oscillometric reading is an outlier. Recordings with healthy subjects demonstrate the potential utility of this approach to characterize BP, to detect outlier measurements, and that it does not suffer from bias relative to the conventional oscillometric method. (paper)

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

    Science.gov (United States)

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

    2015-11-01

    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. PMID:26393958

  11. Frequent ventricular premature beats increase blood pressure variability in rats

    Institute of Scientific and Technical Information of China (English)

    Chao-yu MIAO; Li-ping XU; Jian-guo LIU; He-hui XIE; Wen-jun YUAN; Ding-feng SU

    2004-01-01

    AIM: The present study was designed to test a hypothesis that nonfatal ventricular arrhythmia such as ventricular premature beats (VPB) is a contributing factor in the elevation of blood pressure variability (BPV). METHODS:Blood pressure (BP) and electrocardiogram were continuously recorded. The relation between VPB and BPV was observed under conscious state in chronic myocardial infarction (MI) rats one month after ligation of the left.coronary artery, and further verified under anesthetized state in rat model of ventricular arrhythmia produced by acute intravenous infusion of aconitine. RESULTS: MI rats exhibited a big difference in the count and pattern of VPB, and were divided into no VPB, occasional VPB, and frequent VPB groups. Among the three groups, there were no differences in BP, heart period (HP), and MI size. However, BPV was markedly higher in frequent not occasional VPB rats, and HP variability (HPV) was larger in both frequent and occasional VPB rats, when compared with no VPB rats. In the whole population of MI rats, BPV was positively correlated with VPB and HPV, not with BP, HP and MI size. Infusion of aconitine had no effect on BP, HP, BPV, and HPV during the period without VPB.Frequent VPB after several minutes of aconitine infusion induced significant increase in BPV and HPV with no change in BP and HP. BPV was also positively correlated with VPB and HPV, not with BP and HP. Hemodynamics in aconitine-evoked ventricular tachycardia was characterized as lower BP, higher BPV, and higher HPV.CONCLUSION: High BPV can be caused by frequent not occasional VPB in rats.

  12. 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)

    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 cmH2O) or high (8 cmH2O) 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

  13. Altered ATP-sensitive potassium channels may underscore obesity-triggered increase in blood pressure

    Institute of Scientific and Technical Information of China (English)

    Li-hong FAN; Hong-yan TIAN; Ai-qun MA; Zhi HU; Jian-hua HUO; Yong-xiao CAO

    2008-01-01

    Aim:To determine whether ATP-sensitive potassium channels are altered in VSMC from arotas and mesenteric arteries of obese rat,and their association with obesity-triggered increase in blood pressure.Methods:Obesity was induced by 24 weeks of high-fat diet feeding in male Sprague-Dawley rats.Control rats were fed with standard laboratory rat chow.Blood pressure and body weight of these rats were measured every 4 weeks.At the end of 24 weeks,KATP channel-mediated relaxation responses in the aortas and mesenteric arteries,KATP channel current,and gene expression were examined,respectively.Results:Blood pres-sure and body weight were increased in rats fed with high-fat diet.KATP channel-mediated relaxation responses,currents,and KATP expression in VSMC of both aortas and mesenteric arteries were inhibited in these rats.Conclusion:Altered ATP-sensitive potassium channels in obese rats may underscore obesity-triggered increase in blood pressure.

  14. Arterial pressure changes monitoring with a new precordial noninvasive sensor

    Directory of Open Access Journals (Sweden)

    Faita Francesco

    2008-08-01

    Full Text Available Abstract Background Recently, a cutaneous force-frequency relation recording system based on first heart sound amplitude vibrations has been validated. A further application is the assessment of Second Heart Sound (S2 amplitude variations at increasing heart rates. The aim of this study was to assess the relationship between second heart sound amplitude variations at increasing heart rates and hemodynamic changes. Methods The transcutaneous force sensor was positioned in the precordial region in 146 consecutive patients referred for exercise (n = 99, dipyridamole (n = 41, or pacing stress (n = 6. The curve of S2 peak amplitude variation as a function of heart rate was computed as the increment with respect to the resting value. Results A consistent S2 signal was obtained in all patients. Baseline S2 was 7.2 ± 3.3 mg, increasing to 12.7 ± 7.7 mg at peak stress. S2 percentage increase was + 133 ± 104% in the 99 exercise, + 2 ± 22% in the 41 dipyridamole, and + 31 ± 27% in the 6 pacing patients (p Conclusion S2 recording quantitatively documents systemic pressure changes.

  15. Low-pressure pulmonary artery aneurysm presenting with pulmonary embolism: a case series

    Directory of Open Access Journals (Sweden)

    Papoulidis Pavlos

    2011-04-01

    Full Text Available Abstract Introduction Pulmonary artery aneurysm is an uncommon disorder with severe complications. The diagnosis is often difficult, since the clinical manifestations are non-specific and the treatment is controversial, as the natural history of the disease is not completely understood. Case presentation We describe the cases of two patients with pulmonary artery aneurysms. The first patient was a 68-year-old Caucasian man with an idiopathic low-pressure pulmonary artery aneurysm together with a pulmonary embolism. The patient preferred a conservative approach and was stable at the 10-month follow-up visit after being placed on anti-coagulant treatment. The second patient was a 66-year-old Caucasian woman with a low-pressure pulmonary artery aneurysm also presented together with a pulmonary embolism. The aneurysm was secondary to pulmonary valve stenosis. She received anti-coagulants and, after stabilization, underwent percutaneous balloon valvuloplasty. Conclusion Pulmonary embolism may be the initial presentation of a low-pressure pulmonary artery aneurysm. No underlying cause for pulmonary embolism was found in either of our patients, suggesting a causal association with low-pressure pulmonary artery aneurysm.

  16. Carotid arterial blood pressure waveform monitoring using a portable ultrasound system.

    Science.gov (United States)

    Joohyun Seo; Pietrangelo, Sabino J; Hae-Seung Lee; Sodini, Charles G

    2015-08-01

    This work presents a non-invasive arterial blood pressure (ABP) waveform monitoring technique using ultrasound. A portable ultrasound system to excite ultrasound transducers and acquire data is designed with off-the-shelf components. The insonation angles are identified using a vector Doppler technique based on the cosine dependency of the Doppler signals. The pulse pressure of an estimated waveform at the left common carotid artery is compared to the standard sphygmomanometer measurement in a clinical test. The estimated carotid ABP waveform shows excellent agreement to the finger ABP waveform with expected discrepancy of the systolic peak shape due to different measurement sites. The proposed method also tracks slow blood pressure fluctuations. This validation on human subjects shows potential for a noninvasive blood pressure waveform monitoring device at central arterial sites. PMID:26737584

  17. Changes in Doppler waveforms can predict pressure reduction across internal carotid artery stenoses

    DEFF Research Database (Denmark)

    Sillesen, H; Schroeder, T

    1988-01-01

    perfusion pressure. Forty-nine patients were examined consecutively with ultrasound Doppler prior to carotid endarterectomy. Pulsatility index (PI), pulse rise-time (RT), and systolic width (SW) were related to angiographic degree of stenosis and the ratio of distal ICA blood pressure to common carotid...... artery (CCA) blood pressure (ICA/CCA pressure ratio). The latter was determined during surgery. All three waveform parameters were significantly correlated with the ICA/CCA pressure ratio when calculated from the mean frequency curve (p less than 0.001). A reduction in ICA pressure of 20% could...

  18. 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.

  19. The blood pressure-induced diameter response of retinal arterioles decreases with increasing diabetic maculopathy

    DEFF Research Database (Denmark)

    Frederiksen, Christian Alcaraz; Jeppesen, Peter; Knudsen, Søren Tang;

    2006-01-01

    were measured using the Retinal Vessel Analyzer (RVA, Imedos, Germany) before, during, and after an increase in the blood pressure induced by isometric exercise. Additionally, the retinal thickness was measured using optical coherence tomography scanning. RESULTS: The arterioles contracted during......BACKGROUND: The aim of the study was to compare the diameter response of retinal arterioles and retinal thickness in patients with different stages of diabetic maculopathy during an increase in the arterial blood pressure. METHODS: Four groups each consisting of 19 individuals were studied. Group...

  20. Results of ambulatory arterial blood pressure monitoring in children with obesity

    OpenAIRE

    Faruk Öktem

    2010-01-01

    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...

  1. Validation of the pulse decomposition analysis algorithm using central arterial blood pressure

    OpenAIRE

    Baruch, Martin C; Kalantari, Kambiz; Gerdt, David W; Adkins, Charles M

    2014-01-01

    Background There is a significant need for continuous noninvasive blood pressure (cNIBP) monitoring, especially for anesthetized surgery and ICU recovery. cNIBP systems could lower costs and expand the use of continuous blood pressure monitoring, lowering risk and improving outcomes. The test system examined here is the CareTaker® and a pulse contour analysis algorithm, Pulse Decomposition Analysis (PDA). PDA’s premise is that the peripheral arterial pressure pulse is a superposition of five ...

  2. Increased rate of arterial stiffening with obesity in adolescents: a five-year follow-up study.

    Directory of Open Access Journals (Sweden)

    Frida Dangardt

    Full Text Available BACKGROUND: We prospectively and longitudinally determined the effects of childhood obesity on arterial stiffening and vascular wall changes. Changes in arterial stiffness measured as pulse wave velocity (PWV and vascular morphology of the radial (RA and dorsal pedal arteries (DPA were examined in obese adolescents compared to lean subjects in a 5-year follow-up study. METHODOLOGY/PRINCIPAL FINDINGS: A total of 28 obese subjects and 14 lean controls participated in both baseline (14 years old and follow-up studies. PWV was measured by tonometer (SphygmoCor® and recorded at RA and carotid artery, respectively. Intima thickness (IT, intima-media thickness (IMT and RA and DPA diameters were measured using high-resolution ultrasound (Vevo 770™. Over the course of 5 years, PWV increased by 25% in the obese subjects as compared to 3% in the controls (p = 0.01. Diastolic blood pressure (DBP increased by 23% in the obese subjects as opposed to 6% in controls (p = 0.009. BMI increased similarly in both groups, as did the IT and IMT. The change in PWV was strongly associated to the baseline BMI z -score (r = 0.51, p<0.001, as was the change in DBP (r = 0.50, p = 0.001. CONCLUSIONS/SIGNIFICANCE: During the transition from early to late adolescence, there was a general increase in arterial stiffness, which was aggravated by childhood obesity. The increase in arterial stiffness and DBP after 5 years was closely correlated to the baseline BMI z -score, indicating that childhood obesity has an adverse impact on vascular adaptation.

  3. Inaccuracy of doppler echocardiographic estimates of pulmonary artery pressures in adult atrial septal defect patients with pulmonary arterial hypertension

    Institute of Scientific and Technical Information of China (English)

    Zhang Caojin; Huang Tao; Huang Xinsheng; Huang Yigao; Chen Jimei; Chen Jiyan; Wu Shulin

    2014-01-01

    Background While echocardiography has been a pivotal screening test in pulmonary arterial hypertension (PAH),the presence of structural cardiac defects may affect the ability to reliably predict pulmonary artery pressures (PAPs).This study sought to evaluate the accuracy of Doppler echocardiography (DE) for estimating PAPs in adult atrial septal defect (ASD) patients with PAH.Methods A prospective study was carried out to compare the echocardiographic assessment of PAP with the same pressures obtained by right heart catheterization (RHC) in adult ASD patients with PAH who underwent simultaneous DE and RHC.Bland-Altman analyses were performed to evaluate the agreement between DE and RHC measurements of PAPs.Results Two hundred and fifty-seven patients were included in the study.A significant overestimation of the systolic pulmonary arterial pressure (sPAP) and mean pulmonary artery pressure (mPAP) was reported by echocardiography compared with those by catheterization ((81.8±26.9) mmHg vs.(72.9±26.9) mmHg,P <0.01; (51.9±16.4) mmHg vs.(41.4±17.2) mmHg,P <0.01,respectively).Twenty-one percent (55/257) of the patients had PAH when estimated by echocardiography whereas showed normal results in the subsequent catheterization test.Using Bland-Altman analytic methods,the bias for the echocardiographic assessment of the sPAP was 9.1 mmHg with 95% limits of agreement ranging from-24.4 to 42.6 mmHg.For mPAP measurement,the bias was 10.5 mmHg with 95% limits of agreement ranging from-12.4 to 33.4 mmHg.On multiple linear regression analysis,age,gender,body surface area,ASDs' diameter,PVR,diastolic blood pressure,and echocardiographic assessment of right atrial pressure (RAP) explained 68.8% of the total variability in the model (r2=0.688,P <0.01).Conclusion Inaccuracy was frequently reported in Doppler echocardiographic assessment of the PAP in adult ASD patients with PAH and was often associated with age,gender,body surface area,ASDs' diameter

  4. Continuous Non-Invasive Arterial Pressure Technique Improves Patient Monitoring during Interventional Endoscopy

    Directory of Open Access Journals (Sweden)

    Sylvia Siebig, Felix Rockmann, Karl Sabel, Ina Zuber-Jerger, Christine Dierkes, Tanja Brünnler, Christian E. Wrede

    2009-01-01

    Full Text Available Introduction: Close monitoring of arterial blood pressure (BP is a central part of cardiovascular surveillance of patients at risk for hypotension. Therefore, patients undergoing diagnostic and therapeutic procedures with the use of sedating agents are monitored by discontinuous non-invasive BP measurement (NIBP. Continuous non-invasive BP monitoring based on vascular unloading technique (CNAP®, CN Systems, Graz may improve patient safety in those settings. We investigated if this new technique improved monitoring of patients undergoing interventional endoscopy. Methods: 40 patients undergoing interventional endoscopy between April and December 2007 were prospectively studied with CNAP® in addition to standard monitoring (NIBP, ECG and oxygen saturation. All monitoring values were extracted from the surveillance network at one-second intervals, and clinical parameters were documented. The variance of CNAP® values were calculated for every interval between two NIBP measurements. Results: 2660 minutes of monitoring were recorded (mean 60.1±34.4 min/patient. All patients were analgosedated with midazolam and pethidine, and 24/40 had propofol infusion (mean 90.9±70.3 mg. The mean arterial pressure for CNAP® was 102.4±21.2 mmHg and 106.8±24.8 mmHg for NIBP. Based on the first NIBP value in an interval between two NIBP measurements, BP values determined by CNAP® showed a maximum increase of 30.8±21.7% and a maximum decrease of 22.4±28.3% (mean of all intervals. Discussion: Conventional intermittent blood pressure monitoring of patients receiving sedating agents failed to detect fast changes in BP. The new technique CNAP® improved the detection of rapid BP changes, and may contribute to a better patient safety for those undergoing interventional procedures.

  5. Supine exercise restores arterial blood pressure and skin blood flow despite dehydration and hyperthermia.

    Science.gov (United States)

    González-Alonso, J; Mora-Rodríguez, R; Coyle, E F

    1999-08-01

    We determined whether the deleterious effects of dehydration and hyperthermia on cardiovascular function during upright exercise were attenuated by elevating central blood volume with supine exercise. Seven trained men [maximal oxygen consumption (VO(2 max)) 4.7 +/- 0. 4 l/min (mean +/- SE)] cycled for 30 min in the heat (35 degrees C) in the upright and in the supine positions (VO(2) 2.93 +/- 0.27 l/min) while maintaining euhydration by fluid ingestion or while being dehydrated by 5% of body weight after 2 h of upright exercise. When subjects were euhydrated, esophageal temperature (T(es)) was 37. 8-38.0 degrees C in both body postures. Dehydration caused equal hyperthermia during both upright and supine exercise (T(es) = 38. 7-38.8 degrees C). During upright exercise, dehydration lowered stroke volume (SV), cardiac output, mean arterial pressure (MAP), and cutaneous vascular conductance and increased heart rate and plasma catecholamines [30 +/- 6 ml, 3.0 +/- 0.7 l/min, 6 +/- 2 mmHg, 22 +/- 8%, 14 +/- 2 beats/min, and 50-96%, respectively; all P < 0. 05]. In contrast, during supine exercise, dehydration did not cause significant alterations in MAP, cutaneous vascular conductance, or plasma catecholamines. Furthermore, supine versus upright exercise attenuated the increases in heart rate (7 +/- 2 vs. 9 +/- 1%) and the reductions in SV (13 +/- 4 vs. 21 +/- 3%) and cardiac output (8 +/- 3 vs. 14 +/- 3%) (all P < 0.05). These results suggest that the decline in cutaneous vascular conductance and the increase in plasma norepinephrine concentration, independent of hyperthermia, are associated with a reduction in central blood volume and a lower arterial blood pressure. PMID:10444482

  6. Role of pressor mechanisms from the NTS and CVLM in control of arterial pressure.

    Science.gov (United States)

    Moreira, Thiago Santos; Sato, Monica Akemi; Takakura, Ana Carolina Thomaz; Menani, José Vanderlei; Colombari, Eduardo

    2005-11-01

    In the present study, we investigated the effects of inhibition of the caudal ventrolateral medulla (CVLM) with the GABA(A) agonist muscimol combined with the blockade of glutamatergic mechanism in the nucleus of the solitary tract (NTS) with kynurenic acid (kyn) on mean arterial pressure (MAP), heart rate (HR), and regional vascular resistances. In male Holtzman rats anesthetized intravenously with urethane/chloralose, bilateral injections of muscimol (120 pmol) into the CVLM or bilateral injections of kyn (2.7 nmol) into the NTS alone increased MAP to 186 +/- 11 and to 142 +/- 6 mmHg, respectively, vs. control: 105 +/- 4 mmHg; HR to 407 +/- 15 and to 412 +/- 18 beats per minute (bpm), respectively, vs. control: 352 +/- 12 bpm; and renal, mesenteric and hindquarter vascular resistances. However, in rats with the CVLM bilaterally blocked by muscimol, additional injections of kyn into the NTS reduced MAP to 88 +/- 5 mmHg and mesenteric and hindquarter vascular resistances below control baseline levels. Moreover, in rats with the glutamatergic mechanisms of the NTS blocked by bilateral injections of kyn, additional injections of muscimol into the CVLM also reduced MAP to 92 +/- 2 mmHg and mesenteric and hindquarter vascular resistances below control baseline levels. Simultaneous blockade of NTS and CVLM did not modify the increase in HR but also abolished the increase in renal vascular resistance produced by each treatment alone. The results suggest that important pressor mechanisms arise from the NTS and CVLM to control vascular resistance and arterial pressure under the conditions of the present study.

  7. Increased arterial inflammation in individuals with stage 3 chronic kidney disease

    Energy Technology Data Exchange (ETDEWEB)

    Takx, Richard A.P. [Massachusetts General Hospital and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); MacNabb, Megan H.; Emami, Hamed; Abdelbaky, Amr; Lavender, Zachary R. [Massachusetts General Hospital and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); Singh, Parmanand [Massachusetts General Hospital and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); New York Presbyterian Hospital, Weill Cornell Medical College, Division of Cardiology, New York, NY (United States); Di Carli, Marcelo; Taqueti, Viviany; Foster, Courtney [Brigham and Women' s Hospital and Harvard Medical School, Division of Radiology, Department of Medicine, Boston, MA (United States); Mann, Jessica; Comley, Robert A.; Weber, Chek Ing Kiu [F. Hoffmann-La Roche Ltd., Basel (Switzerland); Tawakol, Ahmed [Massachusetts General Hospital and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); Massachusetts General Hospital and Harvard Medical School, Cardiology Division, Boston, MA (United States); Massachusetts General Hospital, Boston, MA (United States)

    2016-02-15

    While it is well known that patients with chronic kidney disease (CKD) are at increased risk for the development and progression of atherosclerosis, it is not known whether arterial inflammation is increased in mild CKD. The aim of this study was to compare arterial inflammation using {sup 18}F-FDG PET/CT in patients with CKD and in matched controls. This retrospective study included 128 patients undergoing FDG PET/CT imaging for clinical indications, comprising 64 patients with stage 3 CKD and 64 control patients matched by age, gender, and cancer history. CKD was defined according to guidelines using a calculated glomerular filtration rate (eGFR). Arterial inflammation was measured in the ascending aorta as FDG uptake on PET. Background FDG uptake (venous, subcutaneous fat and muscle) were recorded. Coronary artery calcification (CAC) was assessed using the CT images. The impact of CKD on arterial inflammation and CAC was then assessed. Arterial inflammation was higher in patients with CKD than in matched controls (standardized uptake value, SUV: 2.41 ± 0.49 vs. 2.16 ± 0.43; p = 0.002). Arterial SUV correlated inversely with eGFR (r = -0.299, p = 0.001). Venous SUV was also significantly elevated in patients with CKD, while subcutaneous fat and muscle tissue SUVs did not differ between groups. Moreover, arterial SUV remained significantly elevated in patients with CKD compared to controls after correcting for muscle and fat background, and also remained significant after adjusting for clinical risk factors. Further, CKD was associated with arterial inflammation (SUV) independent of the presence of subclinical atherosclerosis (CAC). Moderate CKD is associated with increased arterial inflammation beyond that of controls. Further, the increased arterial inflammation is independent of presence of subclinical atherosclerosis. Current risk stratification tools may underestimate the presence of atherosclerosis in patients with CKD and thereby the risk of

  8. Coronary artery calcification is increased in patients with COPD and associated with increased morbidity and mortality

    DEFF Research Database (Denmark)

    Williams, M. C.; Murchison, J. T.; Edwards, L. D.;

    2014-01-01

    Background Coronary artery calcification is pathognomonic of coronary artery disease (CAD). Whether CAD in patients with COPD is linked to lung function, functional capacity and/or clinically relevant outcomes is unknown. The objective was to assess the association between CAD and disease severit...

  9. A simple model of cerebral blood flow dependence on arterial blood pressure

    CERN Document Server

    Gersten, Alexander

    2011-01-01

    It is shown that the dependence of the cerebral blood flow (CBF) on mean arterial blood pressure (MABP) can be described with a simple model having the following assumptions. Below certain MABP (denoted as MABP1) there are no autoregulatory or feedback mechanisms influencing CBF. Between MABP1 and MABP2 (MABP at which breakthrough accurs) there is a linear (on MABP) dependent feedback with a sloap depending very much on the individual considered. The classical autoregulation model with a plateau in between MABP1 and MABP2 is a particular case of this model. The model describes well the experiments performed on dogs (Harper 1966), for which the individual feedback sloap parameter varied to great extent, indicating the importance of mesurments on individuals against averaged mesurments (or measurments on diffent individuals) which superficially support the classical autoregulation. New effect of decreased CBF, while increasing MABP, was observed.

  10. 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

    patients undergoing serial examination after 7 (range, 2-10) days. Six of these patients had an uncomplicated course, one had a protracted recovery, and one died. Autoregulation was not restored in two patients; one died and one had a protracted recovery. CONCLUSION: In patients in the early phase of acute......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...... 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...

  11. Increasing pulmonary artery pulsatile flow improves hypoxic pulmonary hypertension in piglets.

    Science.gov (United States)

    Courboulin, Audrey; Kang, Chantal; Baillard, Olivier; Bonnet, Sebastien; Bonnet, Pierre

    2015-01-01

    Pulmonary arterial hypertension (PAH) is a disease affecting distal pulmonary arteries (PA). These arteries are deformed, leading to right ventricular failure. Current treatments are limited. Physiologically, pulsatile blood flow is detrimental to the vasculature. In response to sustained pulsatile stress, vessels release nitric oxide (NO) to induce vasodilation for self-protection. Based on this observation, this study developed a protocol to assess whether an artificial pulmonary pulsatile blood flow could induce an NO-dependent decrease in pulmonary artery pressure. One group of piglets was exposed to chronic hypoxia for 3 weeks and compared to a control group of piglets. Once a week, the piglets underwent echocardiography to assess PAH severity. At the end of hypoxia exposure, the piglets were subjected to a pulsatile protocol using a pulsatile catheter. After being anesthetized and prepared for surgery, the jugular vein of the piglet was isolated and the catheter was introduced through the right atrium, the right ventricle and the pulmonary artery, under radioscopic control. Pulmonary artery pressure (PAP) was measured before (T0), immediately after (T1) and 30 min after (T2) the pulsatile protocol. It was demonstrated that this pulsatile protocol is a safe and efficient method of inducing a significant reduction in mean PAP via an NO-dependent mechanism. These data open up new avenues for the clinical management of PAH. PMID:25993379

  12. 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.

  13. Non-invasive continuous arterial pressure and pulse pressure variation measured with Nexfin(®) in patients following major upper abdominal surgery: a comparative study.

    Science.gov (United States)

    de Wilde, R B P; de Wit, F; Geerts, B F; van Vliet, A L; Aarts, L P H J; Vuyk, J; Jansen, J R C

    2016-07-01

    We compared the accuracy and precision of the non-invasive Nexfin(®) device for determining systolic, diastolic, mean arterial pressure and pulse pressure variation, with arterial blood pressure values measured from a radial artery catheter in 19 patients following upper abdominal surgery. Measurements were taken at baseline and following fluid loading. Pooled data results of the arterial blood pressures showed no difference between the two measurement modalities. Bland-Altman analysis of pulse pressure variation showed significant differences between values obtained from the radial artery catheter and Nexfin finger cuff technology (mean (SD) 1.49 (2.09)%, p agreement -2.71% to 5.69%). The effect of volume expansion on pulse pressure variation was identical between methods (concordance correlation coefficient 0.848). We consider the Nexfin monitor system to be acceptable for use in patients after major upper abdominal surgery without major cardiovascular compromise or haemodynamic support. PMID:27291598

  14. Continuous blood pressure measurement using the pulse transit time: Comparison to intra-arterial measurement.

    Science.gov (United States)

    Patzak, Andreas; Mendoza, Yuri; Gesche, Heiko; Konermann, Martin

    2015-01-01

    Continuous blood pressure (BP) measurement allows the investigation of transient changes in BP and thus may give insights into mechanisms of BP control. We validated a continuous, non-invasive BP measurement based on the pulse transit time (PTT), i.e., BP(PTT), by comparing it with the intra-arterial BP (BP(i.a.)) measurement. Twelve subjects (five females and seven males) were included. BP(i.a.) was obtained from the radial artery using a system from ReCor Medical. Systolic and diastolic BP were calculated using the PTT (BP(PTT), SOMNOscreen). (PTT) was determined from the electrocardiogram and the peripheral pulse wave. The BP was modulated by application of increasing doses of dobutamine (5, 10, 20 μg/kg body mass). Systolic BP(PTT) and systolic BP(i.a.) correlated significantly (R = 0.94). The limits of agreement in the Bland-Altman plot were ± 19 mmHg; the mean values differed by 1 mmHg. The correlation coefficient for the diastolic BP measurements was R = 0.42. The limits of agreement in the Bland-Altman plot were ± 18 mmHg, with a mean difference of 5 mmHg in favour of the BP(PTT). The study demonstrates a significant correlation between the measurement methods for systolic BP. The results encourage the application of PTT-based BP measurement for the evaluation of BP dynamics and pathological BP changes. PMID:25857601

  15. Mean arterial pressure change associated with cerebral blood flow in healthy older adults.

    Science.gov (United States)

    Deverdun, Jeremy; Akbaraly, Tasnime N; Charroud, Celine; Abdennour, Meriem; Brickman, Adam M; Chemouny, Stephane; Steffener, Jason; Portet, Florence; Bonafe, Alain; Stern, Yaakov; Ritchie, Karen; Molino, François; Le Bars, Emmanuelle; Menjot de Champfleur, Nicolas

    2016-10-01

    We investigate over a 12-year period the association between regional cerebral blood flow (CBF) and cardiovascular risk factors in a prospective cohort of healthy older adults (81.96 ± 3.82 year-old) from the Cognitive REServe and Clinical ENDOphenotype (CRESCENDO) study. Cardiovascular risk factors were measured over 12 years, and gray matter CBF was measured at the end of the study from high-resolution magnetic resonance imaging using arterial spin labeling. The association between cardiovascular risk factors, their long-term change, and CBF was assessed using multivariate linear regression models. Women were observed to have higher CBF than men (p < 0.05). Increased mean arterial pressure (MAP) over the 12-year period was correlated with a low cerebral blood flow (p < 0.05, R(2) = 0.21), whereas no association was detected between CBF and MAP at the time of imaging. High levels of glycemia tended to be associated with low cerebral blood flow values (p < 0.05). Age, alcohol consumption, smoking status, body mass index, history of cardiovascular disease, and hypertension were not associated with CBF. Our main result suggests that change in MAP is the most significant predictor of future CBF in older adults.

  16. Evaluation of restenosis, renal function and blood pressure after the renal artery stenting in patients with atherosclerosis renovascular disease

    Institute of Scientific and Technical Information of China (English)

    王焱

    2006-01-01

    Objective To evaluate the restenosis, renal function and blood pressure after renal artery stenting in patients with atherosclerosis renovascular disease. Methods Percutaneous renal artery stent (PTRAS) was performed in 135 patients with single or bilateral renal artery stenosis (≥70%). Clinical data of above patients were studied during follow-up period. Results A total of 147

  17. Numerical simulation of blood flow and pressure drop in the pulmonary arterial and venous circulation.

    Science.gov (United States)

    Qureshi, M Umar; Vaughan, Gareth D A; Sainsbury, Christopher; Johnson, Martin; Peskin, Charles S; Olufsen, Mette S; Hill, N A

    2014-10-01

    A novel multiscale mathematical and computational model of the pulmonary circulation is presented and used to analyse both arterial and venous pressure and flow. This work is a major advance over previous studies by Olufsen et al. (Ann Biomed Eng 28:1281-1299, 2012) which only considered the arterial circulation. For the first three generations of vessels within the pulmonary circulation, geometry is specified from patient-specific measurements obtained using magnetic resonance imaging (MRI). Blood flow and pressure in the larger arteries and veins are predicted using a nonlinear, cross-sectional-area-averaged system of equations for a Newtonian fluid in an elastic tube. Inflow into the main pulmonary artery is obtained from MRI measurements, while pressure entering the left atrium from the main pulmonary vein is kept constant at the normal mean value of 2 mmHg. Each terminal vessel in the network of 'large' arteries is connected to its corresponding terminal vein via a network of vessels representing the vascular bed of smaller arteries and veins. We develop and implement an algorithm to calculate the admittance of each vascular bed, using bifurcating structured trees and recursion. The structured-tree models take into account the geometry and material properties of the 'smaller' arteries and veins of radii ≥ 50 μm. We study the effects on flow and pressure associated with three classes of pulmonary hypertension expressed via stiffening of larger and smaller vessels, and vascular rarefaction. The results of simulating these pathological conditions are in agreement with clinical observations, showing that the model has potential for assisting with diagnosis and treatment for circulatory diseases within the lung. PMID:24610385

  18. 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...

  19. 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...... 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...

  20. Random perturbations of arterial blood pressure for the assessment of dynamic cerebral autoregulation

    International Nuclear Information System (INIS)

    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)

  1. Strophanthus hispidus attenuates the Ischemia-Reperfusion induced myocardial Infarction and reduces mean arterial pressure in renal artery occlusion

    Directory of Open Access Journals (Sweden)

    Rohit Gundamaraju

    2014-01-01

    Full Text Available Background: The myocardium is generally injured in the case of reperfusion injury and arterial damage is caused by hypertension. In reference to these statements, the present study was focused. Cardiac glycosides were said to have protective effects against myocardial infarction and hypertension. Strophanthus hispidus was thus incorporated in the study. Objective: The prime objective of the study was to investigate the protective effects of Strophanthus hispidus against ischemia-reperfusion myocardial Infarction and renal artery occluded hypertension in rats. Materials and Methods: The animal model adopted was surgically-induced myocardial ischemia, performed by means of left anterior descending coronary artery occlusion (LAD for 30 min followed by reperfusion for another 4 h. Infarct size was assessed by using the staining agent TTC (2,3,5-triphenyl tetrazolium chloride. Hypertension was induced by clamping the renal artery with renal bulldog clamp for 4 h. Results: The study was fruitful by the effect of Strophanthus hispidus on infarction size, which got reduced to 27.2 ± 0.5and 20.0 ± 0.2 by 500 mg/Kg and 1000 mg/Kg ethanolic extracts which was remarkably significant when compared with that of the control group 52.8 ± 4.6. The plant extract did reduce heart rate at various time intervals. There was also a protective effect in the case of mean arterial blood pressure were the 500 mg/Kg and 1000 mg/Kg of the plant extract did reduce the hypertension after 60 minutes was 60.0 ± 4.80 and 50.50 ± 6.80. Conclusion: The results suggest that 500 mg/Kg and 100 mg/Kg ethanolic extract of Strophanthus hispidus was found to possess significant cardiac protective and anti-hypertensive activity.

  2. Increased plasma neopterin levels are associated with reduced endothelial function and arterial elasticity in hypertension.

    Science.gov (United States)

    Zhang, Y-Y; Tong, X-Z; Xia, W-H; Xie, W-L; Yu, B-B; Zhang, B; Chen, L; Tao, J

    2016-07-01

    Inflammation has been shown to play a pivotal role in the pathogenesis and development of hypertensive vascular injury. Neopterin is a novel marker of immune activation produced mainly by activated macrophages. Few data are available to show the association between neopterin and vascular function in hypertension. The present study was designed to investigate the relationship between neopterin levels related to arterial stiffness and endothelial function in patients with hypertension, and their changes after blood pressure-lowering treatment. Twenty-four hypertensive patients and 30 age- and gender-matched healthy volunteers were recruited. Plasma neopterin levels were higher in hypertensive patients compared with their counterparts (log-neopterin: 0.77±0.18 versus 0.61±0.16, P=0.003). Increased neopterin levels were correlated with increased brachial-ankle pulse wave velocity (baPWV; control: r=0.659, PFMD; control: r=-0.735, PFMD: 5.92±1.43% versus 7.73±1.31%, PFMD improvement (r=0.670, P=0.006) and blood pressure reduction (r=0.548, P=0.042). Our present study demonstrated for the first time that neopterin is closely correlated with vascular dysfunctions, and measurement of plasma neopterin levels might be used as a surrogate biomarker for the clinical evaluation of vascular damage and risk stratification of future atherosclerotic cardiovascular disease in patients with hypertension. PMID:26202692

  3. Indirect measurement of arterial blood pressure: physiotherapists’ theoretical knowledge

    Directory of Open Access Journals (Sweden)

    Marcelle Morgana Vieira de Assis

    2003-12-01

    Full Text Available Blood pressure checking and its theoretical knowledge are crucial to obtain reliable data in clinical examination. Although it is considered a simple technique to be learned and applied, it is not fully dealt with at physiotherapy university courses. Therefore, a wide range of mistakes and misinterpretations are likely to threaten treatment quality. This work aims to evaluate the theory background of physiotherapists for blood pressure measurement. From June to October 2002, 55 physiotherapists answered a 20- question multiple-choice questionnaire on general knowledge related to concepts, anatomy and physiology, suitable equipment, indirect measurement, blood pressure values, mistakes and misinterpretation factors related to blood pressure measurement. The results disclose faulty theory concepts in the sample studied, indicating the need of deeper approach to this complex theme during course and ongoing updating of professionals.

  4. Acute effects of supramaximal exercise on carotid artery compliance and pulse pressure in young men and women.

    Science.gov (United States)

    Rossow, Lindy; Fahs, Christopher A; Guerra, Myriam; Jae, Sae Young; Heffernan, Kevin S; Fernhall, Bo

    2010-11-01

    The purpose of this study was to determine the cumulative effects of repeated cycling sprints (Wingate tests) on carotid compliance and blood pressure (BP). Fourteen young, healthy men and women completed this study. Vascular and hemodynamic measurements were taken at rest, 5 min following a first Wingate test, 25 min following the first Wingate test, 5 min following a second Wingate test, and 25 min following the second Wingate test. At each time point, the measurements taken included brachial and carotid pulse pressure (PP), heart rate, carotid artery maximum and minimum diameters, and carotid compliance. Carotid BP was obtained with applanation tonometry. Carotid diameters were obtained using ultrasonography and compliance was calculated from carotid diameters and BP. Carotid and brachial PP increased significantly (P sprint, carotid arterial compliance decreased significantly more than 5 min following the first sprint (P sprint reduces carotid artery compliance immediately after exercise. Performance of a second identical cycling sprint further compounds this vascular change, reducing carotid artery compliance beyond levels seen following a single cycling sprint.

  5. Association of thyroid function with arterial pressure in normotensive and hypertensive euthyroid individuals: A cross-sectional study

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    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.

  6. Continuous estimates of dynamic cerebral autoregulation: influence of non-invasive arterial blood pressure measurements

    International Nuclear Information System (INIS)

    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, BPAO), together with bilateral transcranial Doppler ultrasound in the middle cerebral artery, surface ECG and transcutaneous CO2. 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 BPAO. Highly significant correlations were obtained between ARI(t) estimates from the right and left middle cerebral artery (MCA) (Finapres r = 0.60 ± 0.20; BPAO r = 0.56 ± 0.22) and also between the ARI(t) estimates from the Finapres and BPAO (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, but

  7. 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.

  8. 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.

  9. 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.

  10. Relaxin mediates uterine artery compliance during pregnancy and increases uterine blood flow.

    Science.gov (United States)

    Vodstrcil, Lenka A; Tare, Marianne; Novak, Jacqueline; Dragomir, Nicoleta; Ramirez, Rolando J; Wlodek, Mary E; Conrad, Kirk P; Parry, Laura J

    2012-10-01

    Normal pregnancy involves dramatic remodeling of the uterine vasculature, with abnormal vascular adaptations contributing to pregnancy diseases such as preeclampsia. The peptide hormone relaxin is important for the renal and systemic hemodynamic adaptations to pregnancy, and has been shown to increase arterial compliance and outward hypertrophic remodeling. Therefore, we investigated the possibility that relaxin acts on its receptor, RXFP1, to mediate uterine artery compliance in late pregnancy and increase uterine blood flow velocity in rats. RXFP1 was predominantly localized to the tunica media vascular smooth muscle cells in the uterine artery, although receptors were also detected in endothelial cells. Highest expression of Rxfp1 in the uterine artery occurred in estrus and early pregnancy. Isolated uterine arteries from late pregnant rats treated with a monoclonal antibody against circulating relaxin (MCA1) had significantly increased vessel wall stiffness compared with controls, with no reduction in wall thickness. Chronic infusion of relaxin (4 μg/h, osmotic minipump) for 5 d in nonpregnant rats significantly increased uterine artery blood flow velocity. Overall, these data demonstrate a functional role for relaxin in mediating uterine artery compliance in pregnant rats, which may be necessary to maintain adequate uterine blood flow to the uterus and placenta. PMID:22744867

  11. Development of a tonometric sensor for measurement and recording of arterial pressure waveform

    Science.gov (United States)

    Tomczuk, K.; Werszko, M.; Sasiadek, J. Z.; Kosek, J.; Berny, W.; Weiser, A.; Feder-Kubis, J.

    2013-09-01

    There are many techniques and devices for measurement and recording of arterial blood pressure. Some of them allow (enable) additionally to observe the shape of a wave of arterial pressure, which can be regarded as one of the most important diagnostic parameters of human cardiovascular system. This paper presents a novel design and prototype of a new, non-invasive blood waveform measuring device. It expounds theoretical and experimental (including latest preliminary clinical) results obtained during several years of extensive investigations into blood pressure waveform measuring and monitoring problem. According to investigations performed in the laboratory and preliminary clinical evaluation, the sensor has linear steady-state characteristics and satisfactory dynamic properties. It is an efficient and accurate tool for blood pressure waveform monitoring and assessing the cardiovascular condition of the patients. The novelty of this solution is that the device is equipped with a pneumatic pressure sensor based on the pneumatic nozzle flapper amplifier principle with negative feedback. Due to such a technical solution, the device does not require any cuff, which remains an essential component of the majority of contemporary non-invasive blood pressure measurement devices; therefore, it can be used on the artery where the application of a cuff would be impossible (e.g., carotid artery). This advantage makes possible to obtain an accurate shape of blood pressure waveform with high fidelity, comparable to a direct measurement method. Moreover, during the measurement the device converts directly "pressure into pressure." Such a principle of operation makes possible to eliminate additional calibration (at the current stage of research we have eliminated the necessity of calibration in laboratory conditions).

  12. Increased rhythmicity in hypertensive arterial smooth muscle is linked to transient receptor potential canonical channels

    DEFF Research Database (Denmark)

    Chen, Xiaoping; Yang, Dachun; Ma, Shuangtao;

    2010-01-01

    Vasomotion describes oscillations of arterial vascular tone due to synchronized changes of intracellular calcium concentrations. Since increased calcium influx into vascular smooth muscle cells from spontaneously hypertensive rats (SHR) has been associated with variances of transient receptor pot...

  13. Aortic and carotid arterial stiffness and epigenetic regulator gene expression changes precede blood pressure rise in stroke-prone Dahl salt-sensitive hypertensive rats.

    Directory of Open Access Journals (Sweden)

    Victoria L Herrera

    Full Text Available Multiple clinical studies show that arterial stiffness, measured as pulse wave velocity (PWV, precedes hypertension and is an independent predictor of hypertension end organ diseases including stroke, cardiovascular disease and chronic kidney disease. Risk factor studies for arterial stiffness implicate age, hypertension and sodium. However, causal mechanisms linking risk factor to arterial stiffness remain to be elucidated. Here, we studied the causal relationship of arterial stiffness and hypertension in the Na-induced, stroke-prone Dahl salt-sensitive (S hypertensive rat model, and analyzed putative molecular mechanisms. Stroke-prone and non-stroke-prone male and female rats were studied at 3- and 6-weeks of age for arterial stiffness (PWV, strain, blood pressure, vessel wall histology, and gene expression changes. Studies showed that increased left carotid and aortic arterial stiffness preceded hypertension, pulse pressure widening, and structural wall changes at the 6-week time-point. Instead, differential gene induction was detected implicating molecular-functional changes in extracellular matrix (ECM structural constituents, modifiers, cell adhesion, and matricellular proteins, as well as in endothelial function, apoptosis balance, and epigenetic regulators. Immunostaining testing histone modifiers Ep300, HDAC3, and PRMT5 levels confirmed carotid artery-upregulation in all three layers: endothelial, smooth muscle and adventitial cells. Our study recapitulates observations in humans that given salt-sensitivity, increased Na-intake induced arterial stiffness before hypertension, increased pulse pressure, and structural vessel wall changes. Differential gene expression changes associated with arterial stiffness suggest a molecular mechanism linking sodium to full-vessel wall response affecting gene-networks involved in vascular ECM structure-function, apoptosis balance, and epigenetic regulation.

  14. 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.

  15. 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.

  16. Local blood pressure associates with the degree of luminal stenosis in patients with atherosclerotic disease in the middle cerebral artery

    OpenAIRE

    Jiang, Yuanliang; Peng, Wenjia; Teng, Zhongzhao; Gillard, Jonathan H.; Hong, Bo; Liu, Qi; Lu, Jianping

    2016-01-01

    The mechanism underlying atherosclerotic ischemic events within the middle cerebral artery (MCA) is unclear. High structural stress induced by blood pressure might be a potential aetiology as plaque rupture occurs when such mechanical loading exceeds its material strength. To perform reliable analyses quantifying the mechanical loading within a plaque, the local blood pressure is needed. However, data on MCA blood pressure is currently lacking. In this study, the arterial pressure proximal to...

  17. Proprioceptive Neuromuscular Facilitation Flexibility Techniques: Acute Effects on Arterial Blood Pressure.

    Science.gov (United States)

    Cornelius, William L.; Craft-Hamm, Kelley

    1988-01-01

    The effects of stretching techniques on arterial blood pressure (ABP) were studied in three groups of 20 men each. Each group performed one of three proprioceptive neuromuscular facilitation (PNF) techniques. Results are presented. The study indicates that the benefits of stretching may outweigh the risk of elevated ABP. (JL)

  18. RR interval variability during galvanic vestibular stimulation correlates with arterial pressure upon head-up tilt.

    Science.gov (United States)

    Tanaka, Kunihiko; Ito, Yamato; Ikeda, Mayumi; Katafuchi, Tetsuro

    2014-10-01

    RR interval variability (RRIV) in the supine position without and with galvanic vestibular stimulation (GVS (off) and GVS (on), respectively), changes in mean arterial pressure (MAP) at the onset of 60° head-up tilt (HUT) during GVS (off), and their relationship were analyzed in 25 healthy young subjects. MAP decreased by less than 5mmHg or increased upon HUT in 12 subjects (UP), but MAP decreased by more than 5mmHg in 13 subjects (DOWN). Applying sinusoidal GVS of 2mA at a random frequency of 0.2 to 10.0Hz did not change the RR intervals or MAP. However, the high frequency component (HF) of RRIV increased in both UP and DOWN subjects. The increase in DOWN subjects was larger than that in UP subjects. The ratio of the low frequency component to HF (L/H) increased in UP subjects during GVS (on), but did not reach a significant level in DOWN subjects. The changes in the HF were significantly correlated with changes in MAP at the onset of HUT; i.e., the subjects with larger increases in the HF during GVS (on) showed larger decreases in MAP. Thus, GVS or vestibular input during HUT possibly activates the vagal nerves, and the dominance of excitation in sympathetic or vagal nerves during vestibular stimulation is important for controlling MAP at the onset of HUT. PMID:24783995

  19. Cardiovascular responses to lead are biphasic, while methylmercury, but not inorganic mercury, monotonically increases blood pressure in rats.

    Science.gov (United States)

    Wildemann, Tanja M; Mirhosseini, Naghmeh; Siciliano, Steven D; Weber, Lynn P

    2015-02-01

    Cardiovascular diseases, such as heart attack and stroke, are the major cause of death worldwide. It is well known that a high number of environmental and physiological risk factors contribute to the development of cardiovascular diseases. Although risk factors are additive, increased blood pressure (hypertension) is the greatest risk factor. Over the last two decades, a growing number of epidemiological studies associate environmental exposure to lead or mercury species with hypertension. However, cardiovascular effects beyond blood pressure are rarely studied and thresholds for effect are not yet clear. To explore effects of lead or mercury species on the cardiovascular system, normal male Wistar rats were exposed to a range of doses of lead, inorganic mercury or methylmercury through the drinking water for four weeks. High-resolution ultrasound was used to measure heart and vascular function (carotid artery blood flow) at baseline and at the end of the exposure, while blood pressure was measured directly in the femoral artery at the end of the 4-week exposure. After 4 weeks, blood pressure responses to lead were biphasic. Low lead levels decreased blood pressure, dilated the carotid artery and increased cardiac output. At higher lead doses, rats had increased blood pressure. In contrast, methylmercury-exposed rats had increased blood pressure at all doses despite dilated carotid arteries. Inorganic mercury did not show any significant cardiovascular effects. Based on the current study, the benchmark dose level 10% (BMDL10s) for systolic blood pressure for lead, inorganic mercury and methylmercury are 1.1, 1.3 and 1.0 μg/kg-bw/d, respectively. However, similar total mercury blood levels attributed to inorganic mercury or methylmercury produced strikingly different results with inorganic mercury having no observable effect on the cardiovascular system but methylmercury increasing systolic and pulse pressures. Therefore, adverse cardiovascular effects cannot be

  20. 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...... 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...... renal plasma flow (ERPF). Renal interstitial hydrostatic pressure (RIHP) was assessed by inserting a needle into the medullary parenchyma. Doppler ultrasound measurements provided renal artery resistive index (RI). Hormone concentrations as well as biomechanical, structural and histological...

  1. Cardiac signal estimation based on the arterial and venous pressure signals of a hemodialysis machine.

    Science.gov (United States)

    Holmer, M; Sandberg, F; Solem, K; Olde, B; Sörnmo, L

    2016-09-01

    Continuous cardiac monitoring is usually not performed during hemodialysis treatment, although a majority of patients with kidney failure suffer from cardiovascular disease. In the present paper, a method is proposed for estimating a cardiac pressure signal by combining the arterial and the venous pressure sensor signals of the hemodialysis machine. The estimation is complicated by the periodic pressure disturbance caused by the peristaltic blood pump, with an amplitude much larger than that of the cardiac pressure signal. Using different techniques for combining the arterial and venous pressure signals, the performance is evaluated and compared to that of an earlier method which made use of the venous pressure only. The heart rate and the heartbeat occurrence times, determined from the estimated cardiac pressure signal, are compared to the corresponding quantities determined from a photoplethysmographic reference signal. Signals from 9 complete hemodialysis treatments were analyzed. For a heartbeat amplitude of 0.5 mmHg, the median absolute deviation between estimated and reference heart rate was 1.3 bpm when using the venous pressure signal only, but dropped to 0.6 bpm when combining the pressure signals. The results show that the proposed method offers superior estimation at low heartbeat amplitudes. Consequently, more patients can be successfully monitored during treatment without the need of extra sensors. The results are preliminary, and need to be verified on a separate dataset. PMID:27511299

  2. Evidence that blood pressure remains under the control of arterial baroreceptors in renal hypertensive rats

    Directory of Open Access Journals (Sweden)

    A.S. Trindade Jr.

    2009-10-01

    Full Text Available The purpose of the present study was to determine the range of the influence of the baroreflex on blood pressure in chronic renal hypertensive rats. Supramaximal electrical stimulation of the aortic depressor nerve and section of the baroreceptor nerves (sinoaortic denervation were used to obtain a global analysis of the baroreceptor-sympathetic reflex in normotensive control and in chronic (2 months 1-kidney, 1-clip hypertensive rats. The fall in blood pressure produced by electrical baroreceptor stimulation was greater in renal hypertensive rats than in normotensive controls (right nerve: -47 ± 8 vs -23 ± 4 mmHg; left nerve: -51 ± 7 vs -30 ± 4 mmHg; and both right and left nerves: -50 ± 8 vs -30 ± 4 mmHg; P < 0.05. Furthermore, the increase in blood pressure level produced by baroreceptor denervation in chronic renal hypertensive rats was similar to that observed in control animals 2-5 h (control: 163 ± 5 vs 121 ± 1 mmHg; 1K-1C: 203 ± 7 vs 170 ± 5 mmHg; P < 0.05 and 24 h (control: 149 ± 3 vs 121 ± 1 mmHg; 1K-1C: 198 ± 8 vs 170 ± 5 mmHg; P < 0.05 after sinoaortic denervation. Taken together, these data indicate that the central and peripheral components of the baroreflex are acting efficiently at higher arterial pressure in renal hypertensive rats when the aortic nerve is maximally stimulated or the activity is abolished.

  3. A comparison of non-invasive continuous finger blood pressure measurement (Finapres) with intra-arterial pressure during prolonged head-up tilt.

    Science.gov (United States)

    Petersen, M E; Williams, T R; Sutton, R

    1995-11-01

    Simultaneous intra-radial and non-invasive (Finapres, Ohmeda) blood pressures were compared during prolonged head-up tilt, in eight patients (mean age 49 years) with malignant vasovagal syncope. Twelve tilts were performed, of which eight resulted in vasovagal syncope. The mean bias (difference between Finapres and intra-arterial pressures) for systolic pressure was +0.7 mmHg (standard deviation 11.3 mmHg) and for diastolic pressure was +5.4 mmHg (standard deviation 7 mmHg). The within-tilt precision (standard deviation of the bias) of the non-invasive measurements varied between 2.9-12.4 mmHg (median 4.5 mmHg) for systolic comparisons, and 1.6-8.4 mmHg (median 4.4 mmHg) for diastolic comparisons. In all but one tilt highly significant positive increases in both systolic (median 7.1 mmHg) and diastolic bias (median 8.1 mmHg) occurred on tilt with respect to resting pre-tilt levels. Independent of the absolute level of agreement, the non-invasive measurements followed changes in intra-arterial pressure closely, with 89% of beat-to-beat changes in systolic pressure, and 95% of beat-to-beat changes in diastolic pressure followed to within +/- 2 mmHg. This study suggests that the Finapres is well suited for use during diagnostic tilt testing, demonstrating an acceptable within-tilt precision and closely following pressure changes during vasovagal syncope. PMID:8881861

  4. Increased arterial stiffness and extracellular matrix reorganization in intrauterine growth–restricted fetal sheep

    Science.gov (United States)

    Dodson, Reuben Blair; Rozance, Paul J.; Fleenor, Bradley S.; Petrash, Carson C.; Shoemaker, Lauren G.; Hunter, Kendall S.; Ferguson, Virginia L.

    2013-01-01

    BACKGROUND Fetal intrauterine growth restriction (IUGR) results in increased placental resistance to blood flow, fetal hypertension, and increased pulsatility stresses shown to lead to vascular remodeling. We tested our hypothesis that IUGR causes decreased compliance in the carotid and umbilical arteries due to altered extracellular matrix (ECM) composition and structure. METHODS A sheep model of placental insufficiency–induced IUGR (PI-IUGR) was created by exposure of the pregnant ewe to elevated ambient temperatures. Umbilical and carotid arteries from near-term fetuses were tested with pressure–diameter measurements to compare passive compliance in control and PI-IUGR tissues. ECM composition was measured via biochemical assay, and the organization was determined by using histology and second-harmonic generation imaging. RESULTS We found that PI-IUGR increased arterial stiffness with increased collagen engagement, or transition stretch. PI-IUGR carotid arteries exhibited increased collagen and elastin quantity, and PI-IUGR umbilical arteries exhibited increased sulfated glycosaminoglycans. Histomorphology showed altered collagen-to-elastin ratios with altered cellular proliferation. Increased stiffness indicates altered collagen-to-elastin ratios with less elastin contribution leading to increased collagen engagement. CONCLUSION Because vessel stiffness is a significant predictor in the development of hypertension, disrupted ECM deposition in IUGR provides a potential link between IUGR and adult hypertension. PMID:23154756

  5. Relaxin mediates uterine artery compliance during pregnancy and increases uterine blood flow

    OpenAIRE

    Vodstrcil, Lenka A.; Tare, Marianne; Novak, Jacqueline; Dragomir, Nicoleta; Ramirez, Rolando J.; Wlodek, Mary E.; Conrad, Kirk P.; Parry, Laura J.

    2012-01-01

    Normal pregnancy involves dramatic remodeling of the uterine vasculature, with abnormal vascular adaptations contributing to pregnancy diseases such as preeclampsia. The peptide hormone relaxin is important for the renal and systemic hemodynamic adaptations to pregnancy, and has been shown to increase arterial compliance and outward hypertrophic remodeling. Therefore, we investigated the possibility that relaxin acts on its receptor, RXFP1, to mediate uterine artery compliance in late pregnan...

  6. Evaluation of accuracy of invasive and non-invasive blood pressure monitoring in relation to carotid artery pressure in anaesthetised ponies

    OpenAIRE

    Gent, Thomas C; Schwarz, Andrea; Hatz, Lea-Annina; Gozalo-Marcilla, Miguel; Stijn, Schauvliege; Gasthuys, Frank; Bettschart-Wolfensberger, Regula

    2015-01-01

    Invasive blood pressure measurement (IBP) using peripheral arteries is a commonly used technique in equine anaesthesia, although the accuracy has not been demonstrated. Non-invasive blood pressure monitoring (NIBP) may be indicated for field anesthesia, short procedures and foal anaesthesia. In the present report, the agreement of various IBP and NIBP measuring sites compared to carotid artery pressure was tested in anaesthetised experimental ponies. Six ponies were anaesthetised in lateral r...

  7. Comparison of oscillometric and intra-arterial blood pressure and pulse measurement.

    Science.gov (United States)

    Rithalia, S V; Edwards, D

    1994-01-01

    Non-invasive oscillometric blood pressure and pulse measured by an Omron HEM-703CP monitor were compared with arterial values obtained from direct measurements of the radial artery. An excellent correlation and agreement was found between the two methods (systolic r = 0.99; diastolic r = 0.97; pulse r = 0.99), although there was some variability among individual subjects. The range of difference between them was 0 to 10 mmHg for systolic and -6 to +5 mmHg for diastolic pressures. When tested on the bench using the Metron QA-1280 non-invasive blood pressure analyser the HEM-703CP monitor rarely exhibited errors exceeding 2-3 mmHg over a measurement range of 50-200 mmHg. PMID:7776359

  8. The effects of 10 cmH 2 O positive end-expiratory pressure on arterial oxygenation, respiratory mechanics and hemodynamic parameters in laparoscopic cholecystectomy operations

    Directory of Open Access Journals (Sweden)

    Fatma Çiçek

    2014-09-01

    Full Text Available Objective: The effects of 10cmH2O Positive End-expiratory Pressure (PEEP on respiratory mechanics, arterial oxygenation and hemodynamics in laparoscopic cholecystectomy operation were investigated. Methods: The study was planned on ASA I-II, 18-65 years old, forty patients scheduled for laparoscopic cholecystectomy under general anesthesia. The patients were divided into two groups which PEEP implemented Group 0 and 10 cmH2O PEEP applied Group P (Group 0, n=20; Group P, n=20. Heart rate, Mean arterial blood pressure, arterial oxygen saturation (SpO2, partial pressure of end-tidal carbon dioxide (PEtCO2, Peak inspiratory pressure (PİP, plato pressure (Pplato, partial pressure of oxygen in arterial blood (PaO2, partial pressure of carbon dioxide in arterial blood (PaCO2 values were evaluated at 5 minutes after induction, 5 minutes after CO2 insufflation, after the head-up position and the right side in the 10th and 30th minutes, After 10 minutes desufflation and in the recovery room. The Alveolar–arterial oxygen pressure gradient (P(A-a O2, the ratio of physiologic dead space over tidal volume (VD/VT, Arterial to End Tidal CO2 gradient (P(a-et CO2, static compliance (CS, dynamic compliance (CD were assessed same times. Results: The assessment between the groups, there were not statistical differences about mean blood pressure, heart rate, SpO2, PetCO2, PaO2, plateau pressure, and P (A-a values (p>0.05. Peak inspiratory pressure was higher in Group P (p<0.05. Peak inspiratory pressure and plateau pressure increased with CO2 insufflation in both groups. PaCO2 and P(a-et CO2 were higher statistically significantly in Group 0 (p<0.05. There was no difference between the groups in terms of the PetCO2 values. VD/VT ratios were statistically significantly lower in the Group P (p<0.05. There was no difference at static compliance values between the groups, dynamic compliance was lower in Group P. According to the initial values, there was a decrease in

  9. Pressão arterial entre trabalhadores de curtume Blood pressure among tannery workers

    Directory of Open Access Journals (Sweden)

    Ricardo Cordeiro

    1998-10-01

    death in Brazil since the 1970s. High blood pressure has been the major risk factor among the above mentioned diseases. A negative correlation between occupational qualification and blood pressure has been observed among workers. The above mentioned facts bring out the importance of the knowledge of high blood pressure distribution among the different occupational groups. The aim of the present study was to describe the distribution of blood pressure in stable and homogeneous population of unskilled, low wage larning industrial workers. The Prevalence of high blood pressure was established for this specific group. This prevalence was also related to some biological and socio-economical covariates as compared with that among other occupational groups in Brazil. METHOD: The subjects were 73 active employees at a tannery in Botucatu, state of S.Paulo, Brazil, in July 1993. These subjects underwent blood pressure measurements, anamnesis and clinical examination. The results were compared with those of similar studies carried out in elsewhere Brazil. Age confounding was controlled by different techniques. RESULT: The crude prevalence of high blood pressure detected in this group of workers was of 56.1%, with 15.8% of isolated systolic hypertension. Alcohol abuse and smoking were associated with high blood pressure and isolated systolic hypertension in the population studied. DISCUSSION: Prevalence of hypertension in the group studied is significantly higher than that observed in other groups of workers studied in Brazil. Such a finding points to the need for further investigation so as to isolate those factors involved in the increased blood pressure found in this group.

  10. Clinical characterization and survival of patients with borderline elevation in pulmonary artery pressure.

    Science.gov (United States)

    Heresi, Gustavo A; Minai, Omar A; Tonelli, Adriano R; Hammel, Jeffrey P; Farha, Samar; Parambil, Joseph G; Dweik, Raed A

    2013-12-01

    Normal resting mean pulmonary artery pressure (PAP) is 8-20 mmHg. Pulmonary hypertension is defined as mean PAP of ≥25 mmHg. Borderline PAP levels of 21-24 mmHg are of unclear significance. We sought to determine the clinical characteristics and survival of subjects with mean PAP of 21-24 mmHg. We examined 1,491 patients enrolled in the Cleveland Clinic Pulmonary Hypertension Registry between February 1990 and May 2012 with baseline right heart catheterization. The relationship between PAP and all-cause mortality was assessed by Cox models and a tree-based analysis. Sixty-three patients had borderline PAP (underlying conditions: 12 left heart disease, 20 respiratory disease, 17 connective-tissue disease, 4 others, and 10 none). We then compared 3 groups: borderline PAP without heart or lung disease ([Formula: see text]), normal PAP without heart or lung disease ([Formula: see text]), and category 1 pulmonary arterial hypertension (PAH; [Formula: see text]). Borderline-PAP patients had levels of hemodynamic and functional compromise between those for normal-PAP patients and those for patients with PAH. Borderline PAP was associated with increased mortality compared to normal PAP (hazard ratio: 4.03 [95% confidence interval: 0.78-20.80], [Formula: see text]). A tree-based analysis demonstrated almost identical cut points in mean PAP (≤20, 21-26, and ≥27 mmHg) associated with differential survival ([Formula: see text]). Connective-tissue disease and an elevated transpulmonary gradient were predictors of worse survival in the borderline-PAP population. Borderline PAP elevation is associated with decreased survival, particularly in the context of connective-tissue disease and an elevated transpulmonary gradient. PMID:25006408

  11. Increased arterial stiffness in healthy subjects with high-normal glucose levels and in subjects with pre-diabetes

    Directory of Open Access Journals (Sweden)

    Lee Duk Chul

    2011-04-01

    Full Text Available Abstract Background Increased fasting plasma glucose (FPG, which includes impaired fasting glucose (IFG, impaired glucose tolerance (IGT, and diabetes, is a risk factor for arterial stiffness. While IFG is widely accepted as a cardiovascular risk factor, recent studies have argued that subjects with high-normal glucose level were characterized by a high incidence of cardiovascular disease. The purpose of this study is to investigate the relationship between FPG and arterial stiffness in non-diabetic healthy subjects. Methods We recruited 697 subjects who visited the health promotion center of a university hospital from May 2007 to August 2008. Age, sex, body mass index (BMI, resting heart rate, smoking habits, alcohol intake, exercise, blood pressure, medical history, FPG, lipid profile, high sensitivity C-reactive protein (hs-CRP, and Brachial-ankle pulse wave velocity (ba-PWV were measured. We performed correlation and multiple linear regression analyses to divide the research subjects into quartiles: Q1(n = 172, 65 mg/dL ≤FPG Results FPG has an independent, positive association with ba-PWV in non-diabetic subjects after correcting for confounding variables, including age, sex, BMI, blood pressure, resting heart rate, hs-CRP, lipid profile, and behavioral habits. The mean ba-PWV of the high-normal glucose group (Q3, 1384 cm/s was higher than that of the low-normal glucose group (1303 ± 196 cm/s vs.1328 ± 167 cm/s, P Conclusions An increase in FPG, even within the normal range, was associated with aggravated arterial stiffness. Further research is needed to determine the glycemic target value for the prevention of arterial stiffness in clinical and public health settings.

  12. The accuracy of blood pressure measured by arterial line and non-invasive cuff in critically ill children

    OpenAIRE

    Joffe, Rachel; Duff, Jonathan; Garcia Guerra, Gonzalo; Pugh, Jodie; Ari R. Joffe

    2016-01-01

    Background The accuracy of arterial lines (AL) using the flush test or stopcock test has not been described in children, nor has the difference between invasive arterial blood pressure (IABP) versus non-invasive cuff (NIBP) blood pressure. Methods After ethics approval and consent, we performed the flush test and stopcock test on AL (to determine over damping, under damping, and optimal damping), and determined the difference (NIBP–IABP) in systolic, diastolic, and mean blood pressure (ΔSBP, ...

  13. Accelerated reendothelialization, increased neovascularization and erythrocyte extravasation after arterial injury in BAMBI-/- mice.

    Directory of Open Access Journals (Sweden)

    Nicolas Guillot

    Full Text Available BACKGROUND: Intimal injury rapidly activates TGFβ and enhances vascular repair by the growth of endothelial (EC and vascular smooth muscle cells (VSMC. The response to the TGFβ family of growth factors can be modified by BAMBI (BMP, Activin, Membrane Bound Inhibitor acting as a non-signaling, competitive antagonist of TGFβ type I receptors such as ALK 1 and 5. In vivo the effect of BAMBI will depend on its cell-specific expression and of that of the ALK type receptors. We recently reported EC restricted BAMBI expression and genetic elimination of BAMBI resulting in an in vitro and in vivo phenotype characterized by endothelial activation and proliferation involving alternative pathway activation by TGFβ through ALK 1. METHODOLOGY/PRINCIPAL FINDINGS: To test the hypothesis that BAMBI modulates arterial response to injury via its effects on endothelial repair and arterial wall neovascularization we used a model of femoral arterial denudation injury in wild type (WT and BAMBI(-/- mice. Arterial response was evaluated at 2 and 4 weeks after luminal endothelial denudation of femoral arteries. The BAMBI(-/- genotype mice showed accelerated luminal endothelial repair at 2 weeks and a highly unusual increase in arterial wall neovascularization compared to WT mice. The exuberant intimal and medial neovessel formation with BAMBI(-/- genotype was also associated with significant red blood cell extravasation. The bleeding into the neointima at 2 weeks transiently increased it's area in the BAMBI(-/-genotype despite the faster luminal endothelial repair in this group. Vascular smooth muscle cells were decreased at 2 weeks in BAMBI(-/- mice, but comparable to wild type at 4 weeks. CONCLUSIONS/SIGNIFICANCE: The absence of BAMBI results in a highly unusual surge in arterial wall neovascularization that surprisingly mimiks features of intra-plaque hemorrhage of advanced atheroma in a mechanical injury model. This suggests important effects of BAMBI on

  14. 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

  15. 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

  16. Contributions of tidal lung inflation to human R-R interval and arterial pressure fluctuations

    Science.gov (United States)

    Koh, J.; Brown, T. E.; Beightol, L. A.; Eckberg, D. L.

    1998-01-01

    We studied the effects of mechanical lung inflation on respiratory frequency R-R interval and arterial pressure fluctuations in nine healthy young adults undergoing elective orthopedic surgery. We conducted this research to define the contribution of pulmonary and thoracic stretch receptor input to respiratory sinus arrhythmia. We compared fast Fourier transform spectral power during three modes of ventilation: (1) spontaneous, frequency-controlled (0.25 Hz) breathing, (2) intermittent positive pressure ventilation (0.25 Hz, with a tidal volume of 8 ml/kg) and (3) high frequency jet ventilation (5.0 Hz, 2.5 kg/cm2), after sedation and vecuronium paralysis. Mean R-R intervals, arterial pressures and arterial blood gas levels were comparable during all three breathing conditions. Respiratory frequency systolic pressure spectral power was comparable during spontaneous breathing and conventional mechanical ventilation, but was significantly reduced during high frequency jet ventilation (P mechanical, than high frequency jet ventilation (P pulmonary and thoracic stretch receptors make a statistically significant contribution to respiratory sinus arrhythmia, that contribution is small.

  17. Systolic arterial pressure determination by a new pulse monitor technique.

    Science.gov (United States)

    Wong, D T; Volgyesi, G A; Bissonnette, B

    1992-07-01

    The Doppler ultrasound (DUS) technique is a widely accepted non-invasive technique to estimate systolic blood pressure (SBP) accurately in paediatric patients. The DUS has a number of limitations. A new pulse monitor, Mr Pulse (MP), operating on the principle of a finger plethysmograph, was developed to offer an alternative technique to estimate SBP. From 104 paired SBP measurements taken in 16 paediatric patients undergoing general anaesthesia, SBP determined by the MP technique correlated closely with that by the standard DUS technique (r2 = 0.98). Analysis of degree of agreement performed indicated that there was good agreement between SBP obtained by the MP and the DUS techniques. The mean +/- standard deviation of differences in paired SBP values between the two measurement techniques was 0.55 +/- 3.59 mmHg. Mr Pulse is as accurate as the DUS technique in estimating SBP and has the advantage of less critical sensor positioning as it is not subject to electrical interference. It has no electrical hazard. PMID:1643685

  18. 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.

  19. 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...... of healing correlated significantly with the three distal blood pressure parameters investigated, the closest correlation being with the SDBP measured at the final examination, i.e. just after healing of the ulcer or just before an inevitable major amputation. Of the 22 cases with SDBP below 20 mmHg only two...... and peripheral neuropathy were frequent in the diabetic group. The data show that the systolic digital blood pressure is a particularly valuable prognostic parameter....

  20. Dopamine-induced cyclic AMP increase in canine myocardium, kidney and superior mesenteric artery.

    Directory of Open Access Journals (Sweden)

    Kazuno,Hiroshi

    1982-04-01

    Full Text Available The effect of dopamine on cyclic AMP levels in tissue slices of canine myocardium and kidney, and in chopped superior mesenteric arterial wall was investigated to identify dopamine receptors. Tissues were incubated in modified Krebs-Henseleit Ringer bicarbonate solution at 37 degrees C for 20 min with test drugs, after 20-min preincubation. In the presence of 3-isobutyl-1-methylxanthine (IBMX, dopamine and apomorphine caused dose-dependent increases in cyclic AMP levels in the myocardium, kidney and superior mesenteric artery. Phentolamine significantly intensified the cyclic AMP-increasing effect of dopamine in the superior mesenteric artery, but it did not influence the cyclic AMP increase caused by dopamine or apomorphine in the myocardium and kidney. Propranolol markedly blocked the effect of dopamine on cyclic AMP levels in all tissues studied. Haloperidol slightly inhibited the effect of dopamine and completely blocked the effect of apomorphine in the myocardium and kidney. These data suggest that dopamine increases cyclic AMP levels by activating predominantly beta-adrenergic receptors and partly dopamine receptors in the canine myocardium, kidney and superior mesenteric artery. The present results also suggest that dopamine acts not only on beta-adrenergic and dopamine receptors but also on alpha-adrenergic receptors in the superior mesenteric artery. Contrary to the activation of beta-adrenergic and dopamine receptors, the activation of alpha-adrenergic receptors resulted in a decrease in cyclic AMP levels in this tissue.

  1. Future Treatment of Hypertension: Shifting the Focus from Blood Pressure Lowering to Arterial Stiffness Modulation?

    Science.gov (United States)

    Fok, Henry; Cruickshank, J Kennedy

    2015-08-01

    Isolated systolic hypertension is the commonest form of hypertension from middle age onwards. Achieving target systolic blood pressure (BP) control remains difficult in everyday clinical practice and even under clinical trial conditions. Most antihypertensive medicines were designed to lower peripheral vascular resistance, which was considered the haemodynamic determinant of hypertension; most are effective in reducing steady but not pulsatile components of BP. Arterial stiffness, defined via aortic length-specific pulse wave velocity (PWV), is thought to be an important determinant of pulse pressure widening through its effects on the timing and amplitude of pressure wave reflection, and/or the aorta's Windkessel function, or its excess 'reservoir' pressure. Whereas pulse pressure is neither an independent nor consistent cardiovascular risk factor, particularly below the age of about 60 years, PWV has become the most powerful predictor of cardiovascular outcomes including mortality, independent of systolic, pulse, mean or other BP components. PWV is therefore a more direct target for treatment. This review addresses the potential therapeutic options for targeting arterial stiffness and the role of pulse pressure.

  2. Effects of arterial and venous volume infusion on coronary perfusion pressures during canine CPR.

    Science.gov (United States)

    Gentile, N T; Martin, G B; Appleton, T J; Moeggenberg, J; Paradis, N A; Nowak, R M

    1991-08-01

    Intraarterial (IA) volume infusion has been reported to be more effective than intravenous (IV) infusion in treating cardiac arrest due to exsanguination. A rapid IA infusion was felt to raise intraaortic pressure and improve coronary perfusion pressure (CPP). The purpose of this study was to determine if IA or IV volume infusion could augment the effect of epinephrine on CPP during CPR in the canine model. Nineteen mongrel dogs with a mean weight of 26.3 +/- 4.2 kg were anesthetized and mechanically ventilated. Thoracic aortic (Ao), right atrial (RA) and pulmonary artery catheters were placed for hemodynamic monitoring. Additional Ao and central venous catheters were placed for volume infusion. Ventricular fibrillation was induced and Thumper CPR was begun after 5 min (t = 5). At t = 10, all dogs received 45 micrograms/kg IV epinephrine. Six animals received epinephrine alone (EPI). Five dogs received EPI plus a 500 cc bolus of normal saline over 3 min intravenously (EPI/IV). Another group (n = 8) received EPI plus the same fluid bolus through the aortic catheter (EPI/IA). Resuscitation was attempted at t = 18 using a standard protocol. There was a significant increase in CPP over baseline in all groups. The changes in CPP from baseline induced by EPI, EPI/IV and EPI/IA were 20.6 +/- 3.7, 22.8 +/- 4.2 and 22.2 +/- 2.4 mmHg, respectively. Volume loading did not augment the effect of therapeutic EPI dosing. By increasing both preload and afterload, volume administration may in fact be detrimental during CPR. PMID:1658894

  3. Pulmonary artery pressure limits exercise capacity at high altitude.

    OpenAIRE

    Naeije, Robert; Huez, Sandrine; Lamotte, Michel; Retailleau, Kathleen; Neupane, S; Abramowicz, Daniel; Faoro, Vitalie

    2010-01-01

    Altitude exposure is associated with decreased exercise capacity and increased pulmonary vascular resistance (PVR). Echocardiographic measurements of pulmonary haemodynamics and a cardiopulmonary exercise test were performed in 13 healthy subjects at sea level, in normoxia and during acute hypoxic breathing (1 h, 12% oxygen in nitrogen), and in 22 healthy subjects after acclimatisation to an altitude of 5,050 m. The measurements were obtained after randomisation, double-blinded to the intake ...

  4. Pathophysiology of increased cerebrospinal fluid pressure associated to brain arteriovenous malformations: The hydraulic hypothesis

    Science.gov (United States)

    Rossitti, Sandro

    2013-01-01

    Background: Brain arteriovenous malformations (AVMs) produce circulatory and functional disturbances in adjacent as well as in remote areas of the brain, but their physiological effect on the cerebrospinal fluid (CSF) pressure is not well known. Methods: The hypothesis of an intrinsic disease mechanism leading to increased CSF pressure in all patients with brain AVM is outlined, based on a theory of hemodynamic control of intracranial pressure that asserts that CSF pressure is a fraction of the systemic arterial pressure as predicted by a two-resistor series circuit hydraulic model. The resistors are the arteriolar resistance (that is regulated by vasomotor tonus), and the venous resistance (which is mechanically passive as a Starling resistor). This theory is discussed and compared with the knowledge accumulated by now on intravasal pressures and CSF pressure measured in patients with brain AVM. Results: The theory provides a basis for understanding the occurrence of pseudotumor cerebri syndrome in patients with nonhemorrhagic brain AVMs, for the occurrence of local mass effect and brain edema bordering unruptured AVMs, and for the development of hydrocephalus in patients with unruptured AVMs. The theory also contributes to a better appreciation of the pathophysiology of dural arteriovenous fistulas, of vein of Galen aneurismal malformation, and of autoregulation-related disorders in AVM patients. Conclusions: The hydraulic hypothesis provides a comprehensive frame to understand brain AVM hemodynamics and its effect on the CSF dynamics. PMID:23607064

  5. 脉压增大的高血压患者脉搏波传导速度、颈动脉内膜中层厚度和踝臂指数的检测现状%Examination status of pulse wave velocity, carotid artery intima-media thickness and ankle-brachial index in hypertensive patients with increased pulse pressure

    Institute of Scientific and Technical Information of China (English)

    隋辉; 马丽媛; 刘明波; 王文

    2014-01-01

    目的:了解脉压增大(脉压≥50 mmHg,1mmHg=0.133kPa)的高血压患者脉搏波传导速度(PWV)、颈动脉内膜中层厚度(IMT)和踝臂指数的检测现状。方法2011年4月至2012年9月,选取中国北部、南部和西部的96个大、中、小城市的709家医院进行的大型横断面调查。入选脉压增大(脉压≥50 mmHg)的高血压患者36259例。根据患者的血压水平、危险因素数量、靶器官损害和心血管疾患分为低危、中危、高危和很高危。根据脉压分为50~60 mmHg,60~70 mmHg和≥70 mmHg三层。询问病史(心血管病、脑血管病、肾脏病和糖尿病史)、吸烟史;记录PWV、IMT和踝臂指数的检查情况。现场测量血压、身高、体重、腰围。结果患者IMT、PWV和踝臂指数的检查率分别为20.7%、8.8%和7.8%,即未做IMT、PWV和踝臂指数检查的患者分别为79.3%、91.2%和92.2%。进一步分析,在检查的患者中, IMT(≥0.9 mm和粥样斑块)、PWV(>12 ms)和踝臂指数(≤0.9)异常的检出率分别为65.7%、40.9%和47.4%。IMT、PWV和踝臂指数异常的检出率在高危患者中分别为86.8%、68.5%和22.9%,在很高危患者中分别为66.1%、40.2%和48.2%。脉压50~60 mmHg,60~70 mmHg和≥70 mmHg组的IMT异常的检出率分别是39.3%,66.6%和80.7%;PWV异常的检出率分别是24.6%,43.0%和59.0%。结论我国城市中,脉压增大(≥50 mmHg)的高血压患者血管病变相关项目的检测率低。%Objective To get to know the examination status of pulse wave velocity (PWV), carotid artery intima-media thickness (CA-IMT) and ankle-brachial index (ABI) in hypertensive patients with increased pulse pressure (≥50 mmHg).Methods A large-scale cross-sectional survey was carried out in 709 hospitals in 96 large, medium and small cities in North, South and West China from Apr. 2011 to Sept. 2012. The patients (n=36259) were chosen and divided into low risk group, mid

  6. 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

  7. Leave-one-out prediction error of systolic arterial pressure time series under paced breathing

    CERN Document Server

    Ancona, N; Marinazzo, D; Nitti, L; Pellicoro, M; Pinna, G D; Stramaglia, S

    2004-01-01

    In this paper we show that different physiological states and pathological conditions may be characterized in terms of predictability of time series signals from the underlying biological system. In particular we consider systolic arterial pressure time series from healthy subjects and Chronic Heart Failure patients, undergoing paced respiration. We model time series by the regularized least squares approach and quantify predictability by the leave-one-out error. We find that the entrainment mechanism connected to paced breath, that renders the arterial blood pressure signal more regular, thus more predictable, is less effective in patients, and this effect correlates with the seriousness of the heart failure. The leave-one-out error separates controls from patients and, when all orders of nonlinearity are taken into account, alive patients from patients for which cardiac death occurred.

  8. Time Pressure Increases Cooperation in Competitively Framed Social Dilemmas

    OpenAIRE

    Jeremy Cone; Rand, David G.

    2014-01-01

    What makes people willing to pay costs to benefit others? Does such cooperation require effortful self-control, or do automatic, intuitive processes favor cooperation? Time pressure has been shown to increase cooperative behavior in Public Goods Games, implying a predisposition towards cooperation. Consistent with the hypothesis that this predisposition results from the fact that cooperation is typically advantageous outside the lab, it has further been shown that the time pressure effect is ...

  9. Effects of terlipressin on systolic pulmonary artery pressure of patients with liver cirrhosis:An echocardiographic assessment

    Institute of Scientific and Technical Information of China (English)

    Engin Altintas; Necdet Akkus; Ramazan Gen; M. Rami Helvaci; Orhan Sezgin; Dilek Oguz

    2004-01-01

    AIM: Portopulmonary hypertension is a serious complication of chronic liver disease. Our aim was to search into the effect of terlipressin on systolic pulmonary artery pressure among cirrhotic patients.METHODS: Twelve patients (6 males and 6 females) with liver cirrhosis were recruited in the study. Arterial blood gas samples were obtained in sitting position at rest. Contrast enhanced echocardiography and measurements of systolic pulmonary artery pressure were performed before and after the intravenous injection of 2 mg terlipressin.RESULTS: Of 12 patients studied, the contrast enhanced echocardiography was positive in 5, and the positive findings in contrast enhanced echocardiography were reversed to normal in two after terlipressin injection. The mean systolic pulmonary artery pressure was 25.5±3.6 mmHg before terlipressin injection, and was 22.5±2.5 mmHg after terlipressin (P=0.003). The systolic pulmonary artery pressure was above 25 mmHg in seven of these 12 patients.After the terlipressin injection, systolic pulmonary artery pressure was <25 mmHg in four of these cases (58.3% vs 25%, P=0.04).CONCLUSION: Terlipressin can decrease the systolic pulmonary artery pressure in patients with liver cirrhosis.

  10. The Effect of Respiratory Functions and Pulmonary Artery Pressure on Right and Left Ventricular Diastolic Function

    OpenAIRE

    Alpsoy, Şeref; Akyüz, Aydın; Akkoyun, Dursun Çayan; Oran, Mustafa; Mutlu, Levent Cem; TOPÇU, Birol; Değirmenci, Hasan; Yalçın, Banu Çiçek

    2012-01-01

    Introduction: The aim of the study was to evaluate of biventricular diastolic function and to investigate the effect of pulmonary function and pulmonary artery pressure on diastolic functions in people with chronic obstructive pulmonary disease (COPD). Patients and Methods: Sixty patients with COPD and 40 healthy individuals were assessed by echocardiography and pulmonary function tests (PFTs). Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were determined. Co...

  11. 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.

  12. HRCT score in bronchiectasis: Correlation with pulmonary function tests and pulmonary artery pressure

    OpenAIRE

    Alzeer Abdulaziz

    2008-01-01

    Background: High resolution CT scan (HRCT) and its score have an important role in delineating pathological changes and pulmonary functional impairment in patients with bronchiectasis. Aims: To assess pulmonary function tests (PFTs) in patients with cystic and cylindrical bronchiectasis. To correlate HRCT score with PFTs and systolic pulmonary artery pressure (SPAP) in both radiological types. Materials and Methods: A cross-sectional study of patients with bronchiectasis diagnosed by HR...

  13. Effect of Algerian Varieties Dates on Glycemic, Arterial Blood Pressure and Satiety Responses

    OpenAIRE

    Gourchala Freha, Mihoub Fatma, Derradj Meriem, Henchiri Cherifa

    2016-01-01

    The purpose of our study is to determine the Glycemic Indexes (GIs)of three Algerians varieties of dates in healthy subjects, evaluate the satiety and effect on arterial pressure after their consumption. We have first documented the chemical composition of the dates. 10 healthy subjects consumed the dates (carbohydrates content of 50 g) in order to determine the GIs. The responses of glycaemia were monitored during two hours after the dates taking and compared to the reference glucose. In a r...

  14. Aspects of the continuous clinical measurement of arterial blood pressure and cardiac output

    International Nuclear Information System (INIS)

    In this paper the authors try to classify circulatory measurements as to certain characteristics such as ''activeness'', ''invasivenesss'', etc. Next they turn to defining some fundamental measurements in the blood circulation and focus attention on the continuous measurement of systemic arterial pressure and flow to finally emphasize the inaccuracy of clinical cardiac output methods. The conclusion is that clinical circulatory measurement methods have accuracies at least an order of magnitude worse than common physical methods used in electrical or mechanical engineering. (Auth.)

  15. Continuous Non-Invasive Arterial Pressure Technique Improves Patient Monitoring during Interventional Endoscopy

    OpenAIRE

    Sylvia Siebig, Felix Rockmann, Karl Sabel, Ina Zuber-Jerger, Christine Dierkes, Tanja Brünnler, Christian E. Wrede

    2009-01-01

    Introduction: Close monitoring of arterial blood pressure (BP) is a central part of cardiovascular surveillance of patients at risk for hypotension. Therefore, patients undergoing diagnostic and therapeutic procedures with the use of sedating agents are monitored by discontinuous non-invasive BP measurement (NIBP). Continuous non-invasive BP monitoring based on vascular unloading technique (CNAP®, CN Systems, Graz) may improve patient safety in those settings. We investigated if this new...

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

    OpenAIRE

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

    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, lab-based measurements cannot fully gauge the effects of medical interventions on EFMA. EFMA and BP have, arg...

  17. Continuous Non-Invasive Arterial Pressure Technique Improves Patient Monitoring during Interventional Endoscopy

    OpenAIRE

    Siebig, Sylvia; Rockmann, Felix; Sabel, Karl; Zuber-Jerger, Ina; Dierkes, Christine; Brünnler, Tanja; Wrede, Christian E.

    2009-01-01

    Introduction: Close monitoring of arterial blood pressure (BP) is a central part of cardiovascular surveillance of patients at risk for hypotension. Therefore, patients undergoing diagnostic and therapeutic procedures with the use of sedating agents are monitored by discontinuous non-invasive BP measurement (NIBP). Continuous non-invasive BP monitoring based on vascular unloading technique (CNAP®, CN Systems, Graz) may improve patient safety in those settings. We investigated if this new tech...

  18. Relationship of blood pressure variability and ambulatory arterial stiffness index with coronary artery lesions%血压变异性及动态动脉硬化指数与冠状动脉病变的相关性

    Institute of Scientific and Technical Information of China (English)

    蔡战友; 茶春喜; 罗仁

    2012-01-01

    (P<0. 05). BPV and AASI increased with the number of coronary artery lesions. AASI was positively correlated with 24-hour and day systolic blood pressure standard deviation. The age, hypertension, diabetes mellitus, 24-hour systolic blood pressure standard deviation, day systolic blood pressure standard deviation, night systolic blood pressure standard deviation, night diastolic blood pressure standard deviation and AASI were positively correlated with coronary heart disease. Many factors logistic stepwise regression analysis showed that 24-hour systolic blood pressure standard deviation, night systolic blood pressure standard deviation and dynamic arteriosclerosis index were independent risk factors for coronary heart disease. Conclusion Systolic blood pressure standard deviation and dynamic arteriosclerosis index have much better prediction value to coronary artery lesion degree.

  19. [Significance of pulmonary artery diastolic pressure after myocardial infarction for physical training (author's transl)].

    Science.gov (United States)

    Koenig, W; Toth, L; Többicke, K; Linden, G; Kohn, E

    1978-07-01

    Functional disorders of the left ventricle after myocardial infarction at rest and with exercise can be evaluated with right heart floating catheter by measuring pulmonary artery diastolic pressure. 45% of 200 patients with myocardial infarctions did not tolerate bicycle exercise test with a work load of 50 Watt during 6 minutes. A routine digitalisation of these patients without strict indication did not improve the results. The upper borderline to admit a physical training program is a pulmonary artery diastolic pressure of 20 mm Hg; this should be realised otherwise additional complications have to be expected in long term follow up. The effects of digitalis should be controlled with floating catheter observations in these patients too. There are some indications, that it is possible with the same technique to evaluate hemodynamic responses on psychological strain. Measurements of pulmonary artery diastolic pressure after myocardial infarction open a wide field for individual therapy from drugs to physical training and even to behaviour therapy for stressfull situations. PMID:685379

  20. Cardiac output in idiopathic normal pressure hydrocephalus: association with arterial blood pressure and intracranial pressure wave amplitudes and outcome of shunt surgery

    Directory of Open Access Journals (Sweden)

    Eide Per K

    2011-02-01

    Full Text Available Abstract Background In patients with idiopathic normal pressure hydrocephalus (iNPH responding to shunt surgery, we have consistently found elevated intracranial pressure (ICP wave amplitudes during diagnostic ICP monitoring prior to surgery. It remains unknown why ICP wave amplitudes are increased in these patients. Since iNPH is accompanied by a high incidence of vascular co-morbidity, a possible explanation is that there is reduced vascular compliance accompanied by elevated arterial blood pressure (ABP wave amplitudes and even altered cardiac output (CO. To investigate this possibility, the present study was undertaken to continuously monitor CO to determine if it is correlated to ABP and ICP wave amplitudes and the outcome of shunting in iNPH patients. It was specifically addressed whether the increased ICP wave amplitudes seen in iNPH shunt responders were accompanied by elevated CO and/or ABP wave amplitude levels. Methods Prospective iNPH patients (29 were clinically graded using an NPH grading scale. Continuous overnight minimally-invasive monitoring of CO and ABP was done simultaneously with ICP monitoring; the CO, ABP, and ICP parameters were parsed into 6-second time windows. Patients were assessed for shunt surgery on clinical grade, Evan's index, and ICP wave amplitude. Follow-up clinical grading was performed 12 months after surgery. Results ICP wave amplitudes but not CO or ABP wave amplitude, showed good correlation with the response to shunt treatment. The patients with high ICP wave amplitude did not have accompanying high levels of CO or ABP wave amplitude. Correlation analysis between CO and ICP wave amplitudes in individual patients showed different profiles [significantly positive in 10 (35% and significantly negative in 16 (55% of 29 recordings]. This depended on whether there was also a correlation between ABP and ICP wave amplitudes and on the average level of ICP wave amplitude. Conclusions These results gave no

  1. Re-evaluation of Pre-pump Arterial Pressure to Avoid Inadequate Dialysis and Hemolysis: Importance of Prepump Arterial Pressure Monitoring in Hemodialysis Patients.

    Science.gov (United States)

    Shibata, Eriko; Nagai, Kojiro; Takeuchi, Risa; Noda, Yasuhiro; Makino, Tomomi; Chikata, Yusuke; Hann, Michael; Yoshimoto, Sakiya; Ono, Hiroyuki; Ueda, Sayo; Tamaki, Masanori; Murakami, Taichi; Matsuura, Motokazu; Abe, Hideharu; Doi, Toshio

    2015-07-01

    Prepump arterial pressure (PreAP) is monitored to avoid generating excessive negative pressure. The National Kidney Foundation K/DOQI clinical practice guidelines for vascular access recommend that PreAP should not fall below -250 mm Hg because excessive negative PreAP can lead to a decrease in the delivery of blood flow, inadequate dialysis, and hemolysis. Nonetheless, these recommendations are consistently disregarded in clinical practice and pressure sensors are often removed from the dialysis circuit. Thus far, delivered blood flow has been reported to decrease at values more negative than -150 mm Hg of PreAP. These values have been analyzed by an ultrasonic flowmeter and not directly measured. Furthermore, no known group has evaluated whether PreAP-induced hemolysis occurs at a particular threshold. Therefore, the aim of this study was to clarify the importance of PreAP in the prediction of inadequate dialysis and hemolysis. By using different diameter needles, human blood samples from healthy volunteers were circulated in a closed dialysis circuit. The relationship between PreAP and delivered blood flow or PreAP and hemolysis was investigated. We also investigated the optimal value for PreAP using several empirical monitoring methods, such as a pressure pillow. Our investigation indicated that PreAP is a critical factor in the determination of delivered blood flow and hemolysis, both of which occured at pressure values more negative than -150 mm Hg. With the exception of direct pressure monitoring, commonly used monitoring methods for PreAP were determined to be ineffective. We propose that the use of a vacuum monitor would permit regular measurement of PreAP. PMID:25940509

  2. 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

  3. High-Normal Arterial Blood Pressure in Children With Excess Body Weight

    Science.gov (United States)

    Kolpa, Malgorzata; Jankowicz-Szymanska, Agnieszka; Jurkiewicz, Beata

    2016-01-01

    Background Childhood overweight and obesity are common causes of metabolic disorders that persist until adulthood. Objectives The purpose of this study was to determine the prevalence of high-normal arterial blood pressure (ABP) in children with excess body weight. Material and Methods A total of 1,093 schoolchildren aged 10 - 12 years (51% girls and 49% boys) participated in the study. The children’s weight, height, body fat percentage (BFP), waist and hip circumference, and ABP were measured. The waist-to-height ratio (WHtR) and body mass index (BMI) were calculated and compared to the normative reference values accepted by the International obesity task force (IOTF). Results Excess weight was identified in 20% of the participants, and obesity in 5%. A total of 35.5% of overweight children had above-normal ABP, which implied hypertension. In obese children, that proportion equaled 59.3%. BFP was 6.5% greater in children with hypertension than in those with normal BP. The children with hypertension also had a 7.6-cm larger waist circumference, a 7.6-cm larger hip circumference, and a greater WHtR (by 0.04). Conclusions Excess body weight was identified in 25% of children aged 10 - 12 years, significantly increasing their risk of developing hypertension.

  4. High-Normal Arterial Blood Pressure in Children With Excess Body Weight

    Directory of Open Access Journals (Sweden)

    Malgorzata Kolpa

    2016-06-01

    Full Text Available Background Childhood overweight and obesity are common causes of metabolic disorders that persist until adulthood. Objectives The purpose of this study was to determine the prevalence of high-normal arterial blood pressure (ABP in children with excess body weight. Material and Methods A total of 1,093 schoolchildren aged 10 - 12 years (51% girls and 49% boys participated in the study. The children’s weight, height, body fat percentage (BFP, waist and hip circumference, and ABP were measured. The waist-to-height ratio (WHtR and body mass index (BMI were calculated and compared to the normative reference values accepted by the International obesity task force (IOTF. Results Excess weight was identified in 20% of the participants, and obesity in 5%. A total of 35.5% of overweight children had above-normal ABP, which implied hypertension. In obese children, that proportion equaled 59.3%. BFP was 6.5% greater in children with hypertension than in those with normal BP. The children with hypertension also had a 7.6-cm larger waist circumference, a 7.6-cm larger hip circumference, and a greater WHtR (by 0.04. Conclusions Excess body weight was identified in 25% of children aged 10 - 12 years, significantly increasing their risk of developing hypertension.

  5. 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....

  6. Transfer function for vital infrasound pressures between the carotid artery and the tympanic membrane.

    Science.gov (United States)

    Furihata, Kenji; Yamashita, Masato

    2013-02-01

    While occupational injury is associated with numerous individual and work-related risk factors, including long working hours and short sleep duration, the complex mechanisms causing such injuries are not yet fully understood. The relationship between the infrasound pressures of the tympanic membrane [ear canal pressure (ECP)], detected using an earplug embedded with a low-frequency microphone, and the carotid artery [carotid artery pressure (CAP)], detected using a stethoscope fitted with the same microphone, can be quantitatively characterized using systems analysis. The transfer functions of 40 normal workers (19 to 57 years old) were characterized, involving the analysis of 446 data points. The ECP waveform exhibits a pulsatile character with a slow respiratory component, which is superimposed on a biphasic recording that is synchronous with the cardiac cycle. The respiratory ECP waveform correlates with the instantaneous heart rate. The results also revealed that various fatigue-related risk factors may affect the mean magnitudes of the measured pressures and the delay transfer functions between CAP and ECP in the study population; these factors include systolic blood pressure, salivary amylase activity, age, sleep duration, postural changes, chronic fatigue, and pulse rate. PMID:23363133

  7. Low frequency arterial wall movements for indirect blood pressure measurement in man. Validation of a method for non-invasive assessment of blood pressure under the influence of isoprenaline and angiotensin.

    Science.gov (United States)

    Dietz, U; Belz, G G

    1991-05-01

    In order to measure blood pressure noninvasively, the second derivative of the low frequency wall movements of the brachial artery were registered with a piezo-electric pressure probe during deflation of a Riva-Rocci cuff along with the actual cuff pressure. Two characteristic phenomena of this signal have been suggested to reflect systolic and diastolic blood pressure. Appearance of a positive spike phenomenon (S) was suggested to indicate systolic blood pressure and disappearance of a negative preanacrotic notch (D) to indicate diastolic blood pressure. To prove the validity of these suggestions, these phenomena were assessed in 10 young healthy males during isoprenaline and angiotensin induced changes of blood pressure. Intraarterial (A. radialis) and auscultatory (A. brachialis) blood pressures were recorded simultaneously. Determination of systolic blood pressure with the S phenomenon agreed well with invasive and auscultatory results. Invasive diastolic values agreed well with the cuff pressure at the last signal before disappearance of the preanacrotic notch (D1). Data from auscultation agreed less well with the D1 phenomenon. With increasing doses of isoprenaline, the diastolic measurements (D1) tended to be lower than the invasive ones. However, this discrepancy was far discreeter than that seen with ordinary auscultatory blood pressure measurement. We therefore conclude that registrations of low frequency arterial wall movements yield distinct characteristic spike phenomena useful for measurement of blood pressure in good agreement with the invasive method. In addition, the method provides clearly documented records and should be useful in situations which rely on a valid indirect method. PMID:1898428

  8. 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.

  9. 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.

  10. The relationship of pulmonary vascular resistance and compliance to pulmonary artery wedge pressure during submaximal exercise in healthy older adults

    Science.gov (United States)

    Wright, Stephen P.; Granton, John T.; Esfandiari, Sam; Goodman, Jack M.

    2016-01-01

    Key points A consistent inverse hyperbolic relationship has been observed between pulmonary vascular resistance and compliance, although changes in pulmonary artery wedge pressure (PAWP) may modify this relationship.This relationship predicts that pulmonary artery systolic, diastolic and mean pressure maintain a consistent relationship relative to the PAWP.We show that, in healthy exercising human adults, both pulmonary vascular resistance and compliance decrease in relation to exercise‐associated increases in PAWP.Pulmonary artery systolic, diastolic and mean pressures maintain a consistent relationship with one another, increasing linearly with increasing PAWP.Increases in PAWP in the setting of exercise are directly related to a decrease in pulmonary vascular compliance, despite small decreases in pulmonary vascular resistance, thereby increasing the pulsatile afterload to the right ventricle. Abstract The resistive and pulsatile components of right ventricular afterload (pulmonary vascular resistance, Rp; compliance, Cp) are related by an inverse hyperbolic function, expressed as their product known as RpCp‐time. The RpCp‐time exhibits a narrow range, although it may be altered by the pulmonary artery wedge pressure (PAWP). Identifying the determinants of RpCp‐time should improve our understanding of the physiological behaviour of pulmonary arterial systolic (PASP), diastolic (PADP) and mean (mPAP) pressures in response to perturbations. We examined the effect of exercise in 28 healthy non‐athletic adults (55 ± 6 years) who underwent right heart catheterization to assess haemodynamics and calculate Rp and Cp. Measurements were made at rest and during two consecutive 8–10 min stages of cycle ergometry, at targeted heart‐rates of 100 beats min–1 (Light) and 120 beats min–1 (Moderate). Cardiac output increased progressively during exercise. PASP, PADP, mPAP and PAWP increased for Light exercise, without any further rise for Moderate

  11. Antenatal hypoxia induces programming of reduced arterial blood pressure response in female rat offspring: role of ovarian function.

    Directory of Open Access Journals (Sweden)

    DaLiao Xiao

    Full Text Available In utero exposure to adverse environmental factors increases the risk of cardiovascular disease in adulthood. The present study tested the hypothesis that antenatal hypoxia causes a gender-dependent programming of altered arterial blood pressure response (BP in adult offspring. Time-dated pregnant rats were divided into normoxic and hypoxic (10.5% O2 from days 15 to 21 of gestation groups. The experiments were conducted in adult offspring. Antenatal hypoxia caused intrauterine growth restriction, and resulted in a gender-dependent increase Angiotensin II (Ang II-induced BP response in male offspring, but significant decrease in BP response in female offspring. The baroreflex sensitivity was not significantly altered. Consistent with the reduced blood pressure response, antenatal hypoxia significantly decreased Ang II-induced arterial vasoconstriction in female offspring. Ovariectomy had no significant effect in control animals, but significantly increased Ang II-induced maximal BP response in prenatally hypoxic animals and eliminated the difference of BP response between the two groups. Estrogen replacement in ovariectomized animals significantly decreased the BP response to angiotensin II I only in control, but not in hypoxic animals. The result suggests complex programming mechanisms of antenatal hypoxia in regulation of ovary function. Hypoxia-mediated ovary dysfunction results in the phenotype of reduced vascular contractility and BP response in female adult offspring.

  12. Indirect arterial blood pressure measurement in healthy anesthetized cats using a device that combines oscillometry with photoplethysmography.

    Science.gov (United States)

    Heishima, Yasuhiro; Hori, Yasutomo; Chikazawa, Seishiro; Kanai, Kazutaka; Hoshi, Fumio; Itoh, Naoyuki

    2016-08-01

    We investigated the basic characteristics of indirect arterial blood pressure (ABP) measurement using a device that combines oscillometry and photoplethysmography in cats. Dobutamine was infused intravenously in four anesthetized cats. Direct ABP was measured by a catheter. Indirect ABP was measured from the left forelimb. Dobutamine significantly elevated both systolic arterial pressure (SAP) and mean arterial pressure (MAP) in a dose-dependent manner. The indirect SAP, MAP and diastolic arterial pressure (DAP) values were closely correlated with the direct ABP values (r=0.88, 0.89 and 0.83, respectively). The mean bias for SAP, MAP and DAP was 3.4, 0.2 and -2.4 mmHg, respectively. The indirect ABP measured by this device may be used to reliably monitor ABP changes in anesthetized cats. PMID:27003226

  13. Assessment of right ventricular function by pressure-volume loops in off-pump coronary artery bypass surgery

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hong-wei; YUE Yun; WU An-shi; LIU Yu; RUI Yan; WU Di; LIU Juan; ZHAO Qiu-hua; GUO Shu-rong; ZHANG Yong-qian

    2008-01-01

    Background Right ventricular function plays an important role in the hemodynamic derangement during off-pump coronary artery bypass (OPCAB) surgery. Pressure-volume loops have been shown to provide load-independent information of cardiac function. Therefore, the aim of this study was to investigate the feasibility of construction of right ventricular pressure-volume loops with pressure and volume data measured by a volumetric pulmonary artery catheter (PAC) and to evaluate right ventricular systolic and diastolic function by end-systolic elastance (EEs) and end-diastolic stiffness (EED) in OPCAB surgery.Methods Twenty-eight patients who underwent OPCAB surgery were included. After anesthesia induction, a volumetric PAC was placed via the right internal jugular vein. Data were recorded at: anesthesia steady-state before skin incision (T1); 5 minutes after the stabilizer device was placed for anastomosis on the heart's anterior wall (T2), lateral wall (T3),posterior wall (T4), respectively; after sternal closure (T5). Three sets of data were collected at each time point: first,hemodynamic variables were measured; second, right ventricular EES and EED were calculated; third, right ventricular pressure-volume loops were constructed with pressure and volume data measured from end-diastole point,end-isovolumic systole point, peak-ejection point, end-systole point and end-isovolumic diastole point.Results Right ventricular pressure-volume loops generally shifted to the left during OPCAB surgery. Especially, the end-diastolic point shifted upward and to the left at T2-T5 compared with that at T1. Decrease in right ventricular ejection fraction, stroke volume index and end-diastolic volume index occurred (P<0.05) at T4 compared with values at T1. Pulmonary vascular resistance index at T4 increased relatively compared with that at T2 and T3. The change of EES was not statistically significant during operation. Right atrial pressure increased only during coronary

  14. Pulmonary Artery Denervation Reduces Pulmonary Artery Pressure and Induces Histological Changes in an Acute Porcine Model of Pulmonary Hypertension

    OpenAIRE

    Rothman, A.M.K.; Arnold, N D; Chang, W.; Watson, O.; Swift, A J; Condliffe, R; Elliot, C A; Kiely, D. G.; Suvarna, S K; Gunn, J.; Lawrie, A.

    2015-01-01

    Background— Pulmonary arterial hypertension is a devastating disease with high morbidity and mortality and limited treatment options. Recent studies have shown that pulmonary artery denervation improves pulmonary hemodynamics in an experimental model and in an early clinical trial. We aimed to evaluate the nerve distribution around the pulmonary artery, to determine the effect of radiofrequency pulmonary artery denervation on acute pulmonary hypertension induced by vasoconstriction, and to de...

  15. Maternal endotoxemia results in increases in blood pressure and body weight in rats

    Institute of Scientific and Technical Information of China (English)

    WEI Yan-ling; LI Xiao-hui

    2008-01-01

    Objective To investigate the effects of prenatal exposure to lipopolysaccharide (LPS) on blood pressure and body weight of offspring in rats. Methods Sixteen healthy pregnant rats were randomly divided into two groups. The rats in LPS group were injected intraperitoneally with LPS (0.79 mg·kg-1) at the 8th, 10th, 12th day of gestation. Those in the control group were only treated with NS. After delivery, all offspring were weighed and blood pressure was measured by tail-cuff method once every two weeks from the 6th to 24th week. In the 15th week, their food intakes were weighed every day. At the end of the 24th week, the rats were put to death by decapitation. Abdominal adipose tissues were taken to weigh, and serum level of leptin was detected by RIA. Results The offspring with prenatal LPS exposure showed increased systemic arterial pressure, heavier body weight, elevated food intake, increased adipose tissue weight and increased circulating leptin compared with controls. Conclusions Prenatal exposure to LPS leads to increases in blood pressure and body weight in rats.

  16. Prenatal exposure to lipopolysaccharide results in increases in blood pressure and body weight in rats

    Institute of Scientific and Technical Information of China (English)

    Yan-ling WEI; Xiao-hui LI; Jian-zhi ZHOU

    2007-01-01

    Aim: To investigate the effects of prenatal exposure to lipopolysacchadde (LPS) on blood pressure and body weight of offspring in rats. Methods: Sixteen healthy,pregnant rats were randomly divided into 2 groups. The rats in the LPS group were injected intraperitoneally with LPS (0.79 mg/kg) on the d 8, d 10, and d 12 of gestation. Those in the control group were only treated with normal saline. After delivery, all offspring were weighed and blood pressure was measured by the tail-cuff method once every 2 weeks from the 6th to the 24th week. In the 15th week,their food intake was weighed every day. At the end of the 24th week, the rats were killed by decapitation. Abdominal adipose tissues were weighed, and the serum level of leptin was detected by radioimmunoassay. Results: The offspring with prenatal LPS exposure showed increased systemic arterial pressure, heavier body weight, elevated food intake, increased adipose tissue weight, and increased circulating leptin compared with the controls. Conclusion: Prenatal exposure to LPS leads to increases in blood pressure and body weight in rats.

  17. Calculation and analysis of velocity and viscous drag in an artery with a periodic pressure gradient

    Science.gov (United States)

    Alizadeh, M.; Seyedpour, S. M.; Mozafari, V.; Babazadeh, Shayan S.

    2012-07-01

    Blood as a fluid that human and other living creatures are dependent on has been always considered by scientists and researchers. Any changes in blood pressure and its normal velocity can be a sign of a disease. Whatever significant in blood fluid's mechanics is Constitutive equations and finding some relations for analysis and description of drag, velocity and periodic blood pressure in vessels. In this paper, by considering available experimental quantities, for blood pressure and velocity in periodic time of a thigh artery of a living dog, at first it is written into Fourier series, then by solving Navier-Stokes equations, a relation for curve drawing of vessel blood pressure with rigid wall is obtained. Likewise in another part of this paper, vessel wall is taken in to consideration that vessel wall is elastic and its pressure and velocity are written into complex Fourier series. In this case, by solving Navier-Stokes equations, some relations for blood velocity, viscous drag on vessel wall and blood pressure are obtained. In this study by noting that vessel diameter is almost is large (3.7 mm), and blood is considered as a Newtonian fluid. Finally, available experimental quantities of pressure with obtained curve of solving Navier-Stokes equations are compared. In blood analysis in rigid vessel, existence of 48% variance in pressure curve systole peak caused vessel blood flow analysis with elastic wall, results in new relations for blood flow description. The Resultant curve is obtained from new relations holding 10% variance in systole peak.

  18. Intra-arterial blood pressure response in hypertensive subjects during low- and high-intensity resistance exercise

    Directory of Open Access Journals (Sweden)

    Sandra de Souza Nery

    2010-01-01

    Full Text Available OBJECTIVE: The aim of this study was to describe blood pressure responses during resistance exercise in hypertensive subjects and to determine whether an exercise protocol alters these responses. INTRODUCTION: Resistance exercise has been recommended as a complement for aerobic exercise for hypertensive patients. However, blood pressure changes during this kind of exercise have been poorly investigated in hypertensives, despite multiple studies of normotensives demonstrating significant increases in blood pressure. METHODS: Ten hypertensive and ten normotensive subjects performed, in random order, two different exercise protocols, composed by three sets of the knee extension exercise conducted to exhaustion: 40% of the 1-repetition maximum (1RM with a 45-s rest between sets, and 80% of 1RM with a 90-s rest between sets. Radial intra-arterial blood pressure was measured before and throughout each protocol. RESULTS: Compared with normotensives, hypertensives displayed greater increases in systolic BP during exercise at 80% (+80±3 vs. +62±2 mmHg, P<0.05 and at 40% of 1RM (+75±3 vs. +67±3 mmHg, P<0.05. In both exercise protocols, systolic blood pressure returned to baseline during the rest periods between sets in the normotensives; however, in the hypertensives, BP remained slightly elevated at 40% of 1RM. During rest periods, diastolic blood pressure returned to baseline in hypertensives and dropped below baseline in normotensives. CONCLUSION: Resistance exercise increased systolic blood pressure considerably more in hypertensives than in normotensives, and this increase was greater when lower-intensity exercise was performed to the point of exhaustion.

  19. 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

  20. Long-Run Impact of Increased Wage Pressure

    DEFF Research Database (Denmark)

    Hansen, Claus Thustrup

    1999-01-01

    An unanticipated permanent increase in wage pressure is analyzed in a dynamic general-equilibrium model combining standard theory of capital accumulation and monopolistic wage setting. The long-run (steady-state) implications are identical percentage reduction in employment, consumption, and...

  1. 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. PMID:26495200

  2. Treinamento resistido controla a pressão arterial de ratos hipertensos induzidos por l-NAME Resistance training controls arterial blood pressure in rats with L-NAME- induced hypertension

    Directory of Open Access Journals (Sweden)

    Ayslan Jorge Santos de Araujo

    2013-04-01

    -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. RESULTS: 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 (p<0.05 but there was no difference when compared to TH arteries. CONCLUSIONS: 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.

  3. [The response of cerebral blood flow and systemic arterial blood pressure to hypercapnia and hypocapnia in humans].

    Science.gov (United States)

    Kulikov, V P; Kuznetsova, D V

    2013-01-01

    In 11 healthy volunteers 21 +/- 3.7 years old was monitored cerebral blood flow (CBF) by transcranial Doppler (TCD) of middle cerebral artery and mean hemodynamic arterial blood pressure (MAP) by continuous non-invasive measurement "beat-to-beat" at normocapnia, hypercapnia and hypocapnia. Hypercapnia was creating by rebreathing, hypocapnia was creating by spontaneous hyperventilation. The partial pressure of CO2 in alveolar air (PetCO2) was monitored by capnograph, embedded in the TCD-analyzer. During hypercapnia the velocity of CBF and PetCO2 were significantly increased already at 10 s, which was considerably earlier than the increase in the MAP (30 s). During hypocapnia velocity CBF and PetCO2 were significantly decreased at 10 s, and MAP was not changed. We have installed the threshold PetCO2 42 (41; 44) mm Hg, below which amplification CBF occurs at a constant MAP and reflects the true cerebrovascular reactivity to CO2. PMID:23805713

  4. A RETROSPECTIVE STUDY OF THE IMPACT OF MEAN ARTERIAL PRESSURE ON ESTIMATED BLOOD LOSS DURING ENDOSCOPIC SINUS SURGERY

    Directory of Open Access Journals (Sweden)

    George W Williams

    2014-10-01

    Full Text Available The current practice of lowering mean arterial pressure (MAP during endoscopic sinus surgery (ESS is common, but unproven with regard to peer reviewed literature. The controlled hypotension induced is aimed for improved surgical field and lower the blood loss. Lower mean arterial pressures especially for prolonged surgeries may result in end organ hypoperfusion. The authors reviewed all patients who underwent outpatient endoscopic sinus surgery for the diagnosis of chronic sinusitis from January 1, 2012 to December 31, 2012 at Memorial Hermann Hospital – Texas Medical Centre. We individually reviewed case sheets of every patient and documented blood loss as recorded on the anaesthesia record or in the surgical procedure note, among other variables. A total of 326 patients were included in this study. The median estimated blood loss (EBL was found to be 50 ml. The multivariate regression analysis between these three groups showed that EBL was higher in MAP 75 group. The average of EBL in MAP75 group and the average of EBL in MAP 65-70 group is 42% higher than that in MAP>75 group when other variables were fixed. Hence we found the trend toward higher blood loss with lower MAP. The authors conclude that lower MAP does not result in lower EBL in endoscopic sinus surgery. Furthermore, increases in BMI and crystalloid administered during an aesthetic management of these cases correlates with increased estimate blood loss.

  5. Influence of a history of arterial hypertension and pretreatment blood pressure on the effect of angiotensin converting enzyme inhibition after acute myocardial infarction. Trandolapril Cardiac Evaluation Study

    DEFF Research Database (Denmark)

    Gustafsson, F; Køber, L; Torp-Pedersen, C;

    1998-01-01

    OBJECTIVE: To evaluate the influence of a history of arterial hypertension and the level of pretreatment blood pressure on the efficacy of the angiotensin converting enzyme (ACE) inhibitor trandolapril on mortality and morbidity in patients with acute myocardial infarction (AMI) and left....... Follow up time was 24-50 months (mean 26 months). RESULTS: Four hundred patients (23%) had a history of arterial hypertension. A total of 173 (43%) patients with a history of hypertension died during follow up versus 500 (37%) patients in the normotensive group. Treatment with trandolapril...... for a broad spectrum of potential confounders. Also, benefit from ACE inhibition increased with increasing blood pressure at the time of randomization. Significant interactions between benefit from ACE inhibition and hypertension history, and systolic and diastolic blood pressure were found. CONCLUSION: ACE...

  6. Pressures to Increase Public Expenditure and Patterns of Procyclical Expenditure

    OpenAIRE

    Andrew Abbott; Philip Jones

    2014-01-01

    This paper draws on the literature that explains why governments spend procyclically, to predict the pattern of cyclical expenditure across government budgets. Procyclical expenditure increases at a faster rate than income in economic upturns and falls at a faster rate in recessions. The more politicians indulge pressures to increase expenditure in an economic upturn, the more they find it difficult to sustain expenditure in a recession. In this paper, differences in politicians' willingness ...

  7. An innovative method to measure the peripheral arterial elasticity: spring constant modeling based on the arterial pressure wave with radial vibration.

    Science.gov (United States)

    Wei, Ching-Chuan

    2011-11-01

    In this study, we propose an innovative method for the direct measurement of the peripheral artery elasticity using a spring constant model, based on the arterial pressure wave equation, vibrating in a radial direction. By means of the boundary condition of the pressure wave equation at the maximum peak, we can derive the spring constant used for evaluating peripheral arterial elasticity. The calculated spring constants of six typical subjects show a coincidence with their proper arterial elasticities. Furthermore, the comparison between the spring constant method and pulse wave velocity (PWV) was investigated in 70 subjects (21-64 years, 47 normotensives and 23 hypertensives). The results reveal a significant negative correlation for the spring constant vs. PWV (correlation coefficient = -0.663, p constant method to assess the arterial elasticity is carefully verified, and it is shown to be effective as well as fast. This method should be useful for healthcare, not only in improving clinical diagnosis of arterial stiffness but also in screening subjects for early evidence of cardio-vascular diseases and in monitoring responses to therapy in the future.

  8. The effects of venous cannulation technique and cardioplegia type on plasma potassium concentration and arterial blood pressure during cardiopulmonary bypass.

    LENUS (Irish Health Repository)

    Coleman, E T

    2012-02-03

    The cannulation method and cardioplegia solution used during cardiopulmonary bypass (CPB) may both influence plasma potassium concentrations ([K+]) and mean arterial blood pressure (MAP). Bi-caval or right atrial cannulation methods are routinely used in conjunction with crystalloid or blood cardioplegia. We investigated the influence of cannulation method and cardioplegia solutions on plasma [K+] and MAP during cardiopulmonary bypass. Sixty consecutive patients undergoing elective coronary artery bypass grafting (CABG) using CPB were studied. They were randomly divided into three groups of 20 patients. Patients in Group A underwent bi-caval venous cannulation and received crystalloid cardioplegia. Group B patients underwent right atrial cannulation and received crystalloid cardioplegia. Group C patients underwent right atrial cannulation and received blood cardioplegia. In each case. cardioplegia was administered antegrade via the aortic root. Plasma [K+], MAP. and hemoglobin concentration (Hb) were measured over an 8-min period following cardioplegia administration (pilot studies indicated pressure changes occuring post cardioplegia administration up to this time). The combination of bi-caval cannulation and crystalloid cardioplegia (Group A) was associated with the least increase in plasma [K+] and no decrease in MAP. The maximum [K+] for this Group was 4.2 mmol\\/L (4.6% increase). The minimum mean pressure was 57 mmHg (13.6% increase). Both right atrial cannulation groups (B and C) showed a large rise in plasma [K+] and a decrease in MAP. Group B maximum [K+] was 5.2 mmol\\/L (27.5% increase). Group C was also 5.2 mmol\\/L (26.0% increase). Group C showed the largest pressure decrease, the minimum mean pressure was 45 mmHg (21.3% decrease). The Group B minimum mean pressure was 45 mmHg (8.7% decrease). Our results show that patients undergoing CPB operations who are deemed to be at increased risk of suffering adverse effects from hypotensive episodes may

  9. Does high altitude increase risks of the elderly patients with coronary artery disease?

    Institute of Scientific and Technical Information of China (English)

    Tian-Yi Wu; Zhong-Yan Zhan; Qin-Li Wu; Suo-Lung Baomu; Yu-Ling Jie; Min Sun

    2009-01-01

    Objective To assess the effect of altitude hypoxia on the elderly patients with coronary artery disease (CAD). Methods Three subject groups were surveyed during their train trip on the highest railroad--the Qinghai-Tibet Railway: 22 elderly individuals with documented CAD, 20 healthy elderly controls, and 20 healthy young controls, all of whom from Beijing near the sea level (76 m). Survey questions addressed clinical features of their healthy conditions and aspects of their coronary disease. The baseline study was performed at Xining at an altitude of 2261 m, and then during acute exposure to altitudes of 2808 m, 4768m, 5072 m and 4257 m by train for 24 hours. Resting pulse rate, blood pressure, oxygen saturation, electrocardiograph (ECG), and cardiac work estimated by the heart rate-blood pressure double product were obtained five times in each subject at different altitudes. Results On arrival to altitudes between 4768 m and 5072 m, the older passengers, especially those with preexisting coronary disease, had higher HR, higher BP, and lower SaO2, as well as more frequent abnormalities on ECG, as compared to the younger healthy subjects. As compared with the healthy elderly controls, incomplete right bundle branch block, left ventricular hypertrophy, and ST segment depression were more frequently seen in the elderly coronary patients (P<0.01). Cardiac work in group 1 was increased by 13% 12 hours after arrival to altitudes between 2808 m and 5072 m. Oxygen saturation decreased significantly with the altitude increasing by train ascent but improved after inhalation of oxygen. Most of the older subjects tolerated their sojourn at high altitude well except one who developed angina repeatedly with a significant ST segment depression. Conclusions Coronary events and ECG signs of myocardial ischemia are rare in elderly individuals with CAD who travel from sea level to moderate altitudes of 1500m to 2800 m. Patients with CAD who are well compensated at sea level

  10. High selection pressure promotes increase in cumulative adaptive culture.

    Directory of Open Access Journals (Sweden)

    Carolin Vegvari

    Full Text Available The evolution of cumulative adaptive culture has received widespread interest in recent years, especially the factors promoting its occurrence. Current evolutionary models suggest that an increase in population size may lead to an increase in cultural complexity via a higher rate of cultural transmission and innovation. However, relatively little attention has been paid to the role of natural selection in the evolution of cultural complexity. Here we use an agent-based simulation model to demonstrate that high selection pressure in the form of resource pressure promotes the accumulation of adaptive culture in spite of small population sizes and high innovation costs. We argue that the interaction of demography and selection is important, and that neither can be considered in isolation. We predict that an increase in cultural complexity is most likely to occur under conditions of population pressure relative to resource availability. Our model may help to explain why culture change can occur without major environmental change. We suggest that understanding the interaction between shifting selective pressures and demography is essential for explaining the evolution of cultural complexity.

  11. Renal blood flow regulation and arterial pressure fluctuations: a case study in nonlinear dynamics

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H; Marsh, D J

    1994-01-01

    The arterial blood pressure, a physiological variable on which all renal excretory processes depend, fluctuates over a wide range of amplitudes and frequencies. Much of this variation originates in nonrenal vascular beds to support nonrenal tasks, and the fluctuations provide a noisy environment...... a relatively noise-free environment in which to work. Because of the time-varying nature of the blood pressure, we have concentrated in this review on the now substantial body of work on the dynamics of renal blood flow regulation and the underlying mechanisms. Renal vascular control mechanisms are not simply...... of experimental hypertension provide tubular pressure records that pass statistical tests for ordered structure and sensitive dependence on initial conditions in the reconstructed state space, two of the hallmarks of deterministic chaos. These records also pass recent more stringent tests for chaos...

  12. Monounsaturated fatty acid, carbohydrate intake, and diabetes status are associated with arterial pulse pressure

    Directory of Open Access Journals (Sweden)

    Vaccaro Joan A

    2011-11-01

    Full Text Available Abstract Background Diabetes is a global epidemic. Cardiovascular disease (CVD is one of the most prevalent consequences of diabetes. Nutrition is considered a modifiable risk factor for CVD, particularly for individuals with diabetes; albeit, there is little consensus on the role of carbohydrates, proteins and fats for arterial health for persons with or without diabetes. In this study, we examined the association of macronutrients with arterial pulse pressure (APP, a surrogate measure of arterial health by diabetes status and race. Methods Participants were 892 Mexican Americans (MA, 1059 Black, non-Hispanics (BNH and 2473 White, non-Hispanics (WNH with and without diabetes of a weighted sample from the National Nutrition and Health Examination Survey (NHANES 2007-2008. The cross-sectional analysis was performed with IBM-SPSS version 18 with the complex sample analysis module. The two-year sample weight for the sub-sample with laboratory values was applied to reduce bias and approximate a nationally, representative sample. Arterial stiffness was assessed by arterial pulse pressure (APP. Results APP was higher for MA [B = 0.063 (95% CI 0.015 to 0.111, p = 0.013] and BNH [B = 0.044 (95% CI 0.006 to 0.082, p = 0.018] than WNH, controlling for diabetes, age, gender, body mass index (BMI, fiber intake, energy intake (Kcal and smoking. A two-way interaction of diabetes by carbohydrate intake (grams was inversely associated with APP [B = -1.18 (95% CI -0.178 to -0.058, p = 0.001], controlling for race, age, gender, BMI, Kcal and smoking. BNH with diabetes who consumed more mono-unsaturated fatty acids (MUFA than WNH with diabetes had lower APP [B = -0.112 (95%CI-0.179 to -0.045, p = 0.003] adjusting for saturated fatty acids, Kcal, age, gender, BMI and smoking. Conclusion Higher MUFA and carbohydrate intake for persons with diabetes reflecting lower APP may be due to replacement of saturated fats with CHO and MUFA. The associations of APP with

  13. Taurine supplementation attenuates delayed increase in exercise-induced arterial stiffness.

    Science.gov (United States)

    Ra, Song-Gyu; Choi, Youngju; Akazawa, Nobuhiko; Ohmori, Hajime; Maeda, Seiji

    2016-06-01

    There is a delayed increase in arterial stiffness after eccentric exercise that is possibly mediated by the concurrent delayed increase in circulating oxidative stress. Taurine has anti-oxidant action, and taurine supplementation may be able to attenuate the increase in oxidative stress after exercise. The purpose of the present study was to investigate whether taurine supplementation attenuates the delayed increase in arterial stiffness after eccentric exercise. In the present double-blind, randomized, and placebo-controlled trial, we divided 29 young, healthy men into 2 groups. Subjects received either 2.0 g of placebo (n = 14) or taurine (n = 15) 3 times per day for 14 days prior to the exercise, on the day of exercise, and the following 3 days. The exercise consisted of 2 sets of 20 maximal-effort eccentric repetitions with the nondominant arm only. On the morning of exercise and for 4 days thereafter, we measured serum malondialdehyde (MDA) and carotid-femoral pulse wave velocity (cfPWV) as indices of oxidative stress and arterial stiffness, respectively. On the third and fourth days after exercise, both MDA and cfPWV significantly increased in the placebo group. However, these elevations were significantly attenuated in the taurine group. The increase in MDA was associated with an increase in cfPWV from before exercise to 4 days after exercise (r = 0.597, p taurine group. Our results suggest that delayed increase in arterial stiffness after eccentric exercise was probably affected by the exercise-induced oxidative stress and was attenuated by the taurine supplementation. PMID:27163699

  14. Percutaneous transluminal renal angioplasty with stent is effective for blood pressure control and renal function improvement in atherosclerotic renal artery stenosis patients

    Institute of Scientific and Technical Information of China (English)

    LIAO Chuan-jun; YANG Bao-zhong; WANG Zhong-gao

    2012-01-01

    Background Percutaneous transluminal renal angioplasty with stent is an effective procedure for atherosclerotic renal artery stenosis.However,the decision to perform this procedure has recently raised considerable debate.The aim of this study was to assess the effects of percutaneous transluminal renal angioplasty with stent in atherosclerotic renal artery stenosis patients,especially as it relates to blood pressure control and renal function improvement.Methods A retrospective analysis was made of the clinical data from 125 atherosclerotic renal artery stenosis patients who underwent percutaneous transluminal renal angioplasty from July 2004 to June 2008 in the Department of Vascular Surgery of Beijing Chaoyang Hospital.We compared blood pressure,number of oral antihypertensive medications,and renal function changes pre and post-procedure at 24 months follow-up.Results A total of 125 atherosclerotic renal artery stenosis patients underwent percutaneous transluminal renal angioplasty and 143 stents were placed.At 24 months follow-up,both systolic and diastolic blood pressure and the number of oral antihypertensive medications were significantly reduced (P <0.05).Overall,the estimated glomerular filtration rate did not change significantly (P >0.05); however,a significant increase in estimated glomerular filtration rate was observed in the subgroup of patients with a lower baseline estimated glomerular filtration rate and in the subgroup of patients with bilateral renal artery stenosis (P <0.05).Conclusion Percutaneous transluminal renal angioplasty is a safe procedure for atherosclerotic renal artery stenosis patients,providing a significant improvement in blood pressure control and reduction in the number of oral antihypertensive medications.

  15. Scintigraphic prediction of pulmonary arterial systolic pressure by regional right ventricular ejection fraction during the second half of systole

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, B.J.; Holman, B.L.

    1982-11-01

    In 49 patients in whom gated equilibrium ventriculography and cardiac catheterization were performed within a 6 day interval, total and fractional portions of global and regional right ventricular ejection fraction (RVEF) were correlated with pulmonary arterial systolic pressure. Pulmonary arterial systolic pressure was normal (30 mm Hg or less) in 27 patients (Group I) and elevated (31 mm Hg or greater) in 22 patients (Group II). The second-half regional RVEF was 38 +/- 8% (mean +/- standard deviation) with a range of 30 to 54% for Group I and 22 +/- 6% with a range of 13 to 32% for Group II. The difference between the means was statistically significant (p less than 0.001). Use of a second-half regional RVEF of 30% as the criterion of elevated pulmonary arterial systolic pressure resulted in a sensitivity of 0.86 and a specificity of 1.00. A power curve fit in which pulmonary arterial systolic pressure . 10.91 (second-half regional RVEF)-0.87 allowed accurate estimation (r . -0.85) of pulmonary arterial systolic pressure from the second-half regional RVEF. It is concluded that second-half regional RVEF may be used to accurately detect pulmonary arterial hypertension and to estimate its extent.

  16. Visual Impairment/Increased Intracranial Pressure (VIIP): Layman's Summary

    Science.gov (United States)

    Fogarty, Jennifer

    2011-01-01

    To date NASA has documented that seven long duration astronauts have experienced in-flight and post-flight changes in vision and eye anatomy including degraded distant vision, swelling of the back of the eye, and changes in the shape of the globe. We have also documented in a few of these astronauts post-flight, increases in the pressure of the fluid that surrounds the brain and spinal cord. This is referred to as increased intracranial pressure (ICP). The functional and anatomical changes have varied in severity and duration. In the post-flight time period, some individuals have experienced a return to a pre-flight level of visual function while others have experienced changes that remain significantly altered compared to pre-flight. In addition, the increased ICP also persists in the post-flight time period. Currently, the underlying cause or causes of these changes is/are unknown but the spaceflight community at NASA suspects that the shift of blood toward the head and the changes in physiology that accompany it, such as increased intracranial pressure, play a significant role.

  17. Effects of smoking cessation on central blood pressure and arterial stiffness

    Science.gov (United States)

    Takami, Takeshi; Saito, Yoshihiko

    2011-01-01

    Purpose: Smoking affects arterial stiffness, thus causing an elevation in central blood pressure (CBP). The present study was designed to examine whether smoking cessation treatment improved CBP and arterial stiffness. Patients and methods: We conducted an observational study of 70 patients receiving smoking cessation treatment. Before and 60 weeks after the start of a 12-week varenicline treatment, we measured brachial blood pressure, CBP, brachial-ankle pulse wave velocity (baPWV), normalized radial augmentation index (rAIx@75), left ventricular weight, and left ventricular diastolic function of each patient. The data were compared between the patients who succeeded in quitting smoking (smoking cessation group; n = 37) and those who failed to quit smoking (smoking group; n = 33). Results: Baseline characteristics were similar in both groups. Brachial blood pressure remained unchanged in both groups. CBP, baPWV, and rAIx@75 decreased significantly in the smoking cessation group, while these parameters showed no significant change in the smoking group. Thus, CBP, baPWV, and rAIx@75 showed greater decrease in the smoking cessation group than in the smoking group (CBP, −7.1 ± 1.4 mmHg vs 1.2 ± 2.7 mmHg; P < 0.01; baPWV, −204 ± 64 cm/s vs −43 ± 72 cm/s; P < 0.01; rAIx@75, −6.4 ± 2.8% vs −1.0 ± 3.9%; P < 0.01). Left ventricular weight and left ventricular diastolic function remained unchanged in both groups. Conclusion: Patients in the smoking cessation group showed significant improvement in CBP, baPWV, and rAIx@75. These results indicate that smoking cessation can improve arterial stiffness and CBP. PMID:22102787

  18. Ex Vivo and in Silico Study of Human Common Carotid Arteries Pressure Response in Physiological and Inverted State

    Science.gov (United States)

    Piechna, A.; Cieślicki, K.; Lombarski, L.; Ciszek, B.

    2015-02-01

    Arterial walls are a multilayer structures with nonlinear material characteristics. Furthermore, residual stresses exist in unloaded state (zero-pressure condition) and they affect arterial behavior. To investigate these phenomena a number of theoretical and numerical studies were performed, however no experimental validation was proposed and realized yet. We cannot get rid of residual stresses without damaging the arterial segment. In this paper we propose a novel experiment to validate a numerical model of artery with residual stresses. The inspiration for our study originates from experiments made by Dobrin on dogs' arteries (1999). We applied the idea of turning the artery inside out. After such an operation the sequence of layer is reversed and the residual stresses are re-ordered. We performed several pressure-inflation tests on human Common Carotid Arteries (CCA) in normal and inverted configurations. The nonlinear responses of arterial behavior were obtained and compared to the numerical model. Computer simulations were carried out using the commercial software which applied the finite element method (FEM). Then, these results were discussed.

  19. Sex dependent effects of perinatal taurine exposure on the arterial pressure control in adult offspring

    OpenAIRE

    Roysommuti, Sanya; Suwanich, Atchariya; Lerdweeraphon, Wichaporn; Thaeomor, Atcharaporn; Jirakulsomchok, Dusit; Wyss, J. Michael

    2009-01-01

    The present study tests the sex-dependent effect of perinatal taurine exposure on arterial pressure control in adults. Female Sprague-Dawley rats were fed normal rat chow with 3% beta-alanine (taurine depletion, TD), 3% taurine (taurine supplementation, TS) or water alone (C) from conception to weaning. Their male and female offspring were then fed normal rat chow and tap water with 5% glucose (C with glucose, CG; TD with glucose, TDG; TS with glucose, TSG) or water alone (CW, TDW or TSW). At...

  20. Increased metabolite levels of glycolysis and pentose phosphate pathway in rabbit atherosclerotic arteries and hypoxic macrophage.

    Directory of Open Access Journals (Sweden)

    Atsushi Yamashita

    Full Text Available AIMS: Inflammation and possibly hypoxia largely affect glucose utilization in atherosclerotic arteries, which could alter many metabolic systems. However, metabolic changes in atherosclerotic plaques remain unknown. The present study aims to identify changes in metabolic systems relative to glucose uptake and hypoxia in rabbit atherosclerotic arteries and cultured macrophages. METHODS: Macrophage-rich or smooth muscle cell (SMC-rich neointima was created by balloon injury in the iliac-femoral arteries of rabbits fed with a 0.5% cholesterol diet or a conventional diet. THP-1 macrophages stimulated with lipopolysaccharides (LPS and interferon-γ (INFγ were cultured under normoxic and hypoxic conditions. We evaluated comprehensive arterial and macrophage metabolism by performing metabolomic analyses using capillary electrophoresis-time of flight mass spectrometry. We evaluated glucose uptake and its relationship to vascular hypoxia using (18F-fluorodeoxyglucose ((18F-FDG and pimonidazole, a marker of hypoxia. RESULTS: The levels of many metabolites increased in the iliac-femoral arteries with macrophage-rich neointima, compared with those that were not injured and those with SMC-rich neointima (glycolysis, 4 of 9; pentose phosphate pathway, 4 of 6; tricarboxylic acid cycle, 4 of 6; nucleotides, 10 of 20. The uptake of (18F-FDG in arterial walls measured by autoradiography positively correlated with macrophage- and pimonidazole-immunopositive areas (r = 0.76, and r = 0.59 respectively; n = 69 for both; p<0.0001. Pimonidazole immunoreactivity was closely localized with the nuclear translocation of hypoxia inducible factor-1α and hexokinase II expression in macrophage-rich neointima. The levels of glycolytic (8 of 8 and pentose phosphate pathway (4 of 6 metabolites increased in LPS and INFγ stimulated macrophages under hypoxic but not normoxic condition. Plasminogen activator inhibitor-1 protein levels in the supernatant were closely

  1. “Expiratory holding” approach in measuring end-expiratory pulmonary artery wedge pressure for mechanically ventilated patients

    Directory of Open Access Journals (Sweden)

    Yang W

    2013-10-01

    Full Text Available Wanjie Yang,1 Xuefeng Zhao,1 Qingguo Feng,1 Youzhong An,2 Kai Wei,1 Wei Wang,1 Chang Li,1 Xiuling Cheng1 1Intensive Care Unit, the Fifth Central Hospital of Tianjin, Tianjin, People’s Republic of China; 2Intensive Care Unit, Peking University People’s Hospital, Beijing, People’s Republic of China Objective: To accurately measure the end-expiratory pulmonary artery wedge pressure (PAWP with the “expiration holding” function on the ventilator and the “pulmonary artery wedge pressure review” software on the monitor. Materials and methods: Fifty prospective measurements were made on 12 patients undergoing pulmonary artery catheter and mechanical ventilation. All measurements were divided into <8 mmHg or ≥8 mmHg subgroups according to respiratory variability, and they were then subdivided into either an airway pressure display measurement group (AM group or an expiration holding (EH group for comparison. Results: In all measurements, the two groups showed similar levels of accuracy; however, for the time spent for measurement, the EH group was much faster than the airway pressure display measurement group (P<0.001. Additionally, the EH group was associated with lower medical costs. Conclusion: The expiration holding approach measured the PAWP more accurately, more quickly, and with reduced costs in comparison to the airway pressure display approach. Keywords: expiration holding, pulmonary artery wedge pressure, eePAWP, mechanical ventilation, pulmonary artery catheter

  2. End-tidal arterial CO2 partial pressure gradient in patients with severe hypercapnia undergoing noninvasive ventilation

    Directory of Open Access Journals (Sweden)

    Defilippis V

    2013-06-01

    Full Text Available Vito Defilippis,1 Davide D’Antini,2 Gilda Cinnella,2 Michele Dambrosio,2 Fernando Schiraldi,3 Vito Procacci1 1Emergency Department, Riuniti Hospital, 2Department of Anaesthesiology and Intensive Care, University of Foggia, Foggia, 3Emergency Department, San Paolo Hospital, Naples, Italy Background: Patients with severe hypercapnia represent a particularly serious condition in an emergency department (ED, requiring immediate attention. Noninvasive ventilation (NIV is an integral part of the treatment for acute respiratory failure. The present study aimed to validate the measurement of end-tidal CO2 (EtCO2 as a noninvasive technique to evaluate the effectiveness of NIV in acute hypercapnic respiratory failure. Methods: Twenty consecutive patients admitted to the ED with severe dyspnea were enrolled in the study. NIV by means of bilevel positive airway pressure, was applied to the patients simultaneously with standard medical therapy and continued for 12 hours; the arterial blood gases and side-stream nasal/oral EtCO2 were measured at subsequent times: T0 (admission to the ED, T1h (after 1 hour, T6h (after 6 hours, and T12h (after 12 hours during NIV treatment. Results: The arterial CO2 partial pressure (PaCO2–EtCO2 gradient decreased progressively, reaching at T6h and T12h values lower than baseline (P < 0.001, while arterial pH increased during the observation period (P < 0.001. A positive correlation was found between EtCO2 and PaCO2 values (r = 0.89, P < 0.001 at the end of the observation period. Conclusion: In our hypercapnic patients, the effectiveness of the NIV was evidenced by the progressive reduction of the PaCO2–EtCO2 gradient. The measurement of the CO2 gradient could be a reliable method in monitoring the effectiveness of NIV in acute hypercapnic respiratory failure in the ED. Keywords: arterial end-tidal CO2 gradient, noninvasive ventilation, bilevel positive airway pressure, acute respiratory failure

  3. 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...

  4. Effect of beta-1-blocker, nebivolol, on central aortic pressure and arterial stiffness in patients with essential hypertension

    Directory of Open Access Journals (Sweden)

    Radhika Soanker

    2012-01-01

    Conclusion: 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.

  5. Validation of noninvasive pulse contour cardiac output using finger arterial pressure in cardiac surgery patients requiring fluid therapy

    NARCIS (Netherlands)

    Hofhuizen, C.M.; Lansdorp, B.; Hoeven, J.G. van der; Scheffer, G.J.; Lemson, J.

    2014-01-01

    INTRODUCTION: Nexfin (Edwards Lifesciences, Irvine, CA) allows for noninvasive continuous monitoring of blood pressure (ABPNI) and cardiac output (CONI) by measuring finger arterial pressure (FAP). To evaluate the accuracy of FAP in measuring ABPNI and CONI as well as the adequacy of detecting chang

  6. Validation of noninvasive pulse contour cardiac output using finger arterial pressure in cardiac surgery patients requiring fluid therapy

    NARCIS (Netherlands)

    Hofhuizen, Charlotte; Lansdorp, Benno; Hoeven, van der Johannes G.; Scheffer, Gert-Jan; Lemson, Joris

    2014-01-01

    Introduction Nexfin (Edwards Lifesciences, Irvine, CA) allows for noninvasive continuous monitoring of blood pressure (ABPNI) and cardiac output (CONI) by measuring finger arterial pressure (FAP). To evaluate the accuracy of FAP in measuring ABPNI and CONI as well as the adequacy of detecting change

  7. 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

    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...

  8. Correlation of the intraocular pressure with increased intracranial pressure in rabbits

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    Eskandari H

    2000-08-01

    Full Text Available Although measurement of intracranial pressure by noninvasive methods has been suggested, but mainly invasive methods are used for this purpose-Increase in episcleral venous pressure can be expected to result in a linear increase in intraocular pressure. Congested oculat veins with capillary leakage and hemorrhage are seen when the ICP is increased, thus theoretically measurement of intraocular pressure can be a procedure for estimation of the ICP. This study was performed to find whether there is andy relationship between intraocular pressure and ICP, so we used 12 albino rabbits in two divided groups. Our study was not designed to elucidate the mechanism of change but merely to record any changes observed. All measures except an increase in ICP were applied on the test group as well as on the control group. After general anesthesia with the combination of ketamin, rampune, and pentobarbital a burr hole was made in the lambda region of the skull and a cannula was placed in the subdural space. The ICP in the test group increased up to 15 mmHg and was constant throughout the experiment. Intraocular pressure was measured by Schiotz tonometers afte general anesthesia, after cannulation of the skull, and immediately after increasing the ICP which was repated in 15 minutes interval for 4 hours. There was no statistical difference between the two groups (P:0.997 . results show that neither cannulation nor general anesthesia for 4 hours produce alteration in IOP in the control group nor increasing of the ICP to level of 15 mmHg produces any alteration in IOP on the test group.

  9. Role of the vestibular system in the arterial pressure response to parabolic-flight-induced gravitational changes in human subjects.

    Science.gov (United States)

    Iwata, Chihiro; Abe, Chikara; Tanaka, Kunihiko; Morita, Hironobu

    2011-05-16

    Arterial pressure (AP) is known to fluctuate during parabolic-flight-induced gravitational changes in human subjects, increasing during hypergravity and decreasing during microgravity. In this study, we examined whether the vestibular system participates in the AP response to the gravitational changes induced by parabolic flight in human subjects. Eight subjects performed parabolic flights in a supine position as their AP was measured. Their vestibular inputs during the gravitational changes were reversibly masked by artificial electrical stimulation (galvanic vestibular stimulation, GVS). The AP responses during the parabolas were then compared between the GVS-off and GVS-on conditions. AP increased during hypergravity and decreased during microgravity. The AP responses at the onset of hypergravity and microgravity were abolished by GVS. These results indicate that the vestibular system elicits pressor and depressor responses during parabolic-flight-induced hypergravity and microgravity, respectively.

  10. Human neuronal changes in brain edema and increased intracranial pressure.

    Science.gov (United States)

    Faragó, Nóra; Kocsis, Ágnes Katalin; Braskó, Csilla; Lovas, Sándor; Rózsa, Márton; Baka, Judith; Kovács, Balázs; Mikite, Katalin; Szemenyei, Viktor; Molnár, Gábor; Ozsvár, Attila; Oláh, Gáspár; Piszár, Ildikó; Zvara, Ágnes; Patócs, Attila; Barzó, Pál; Puskás, László G; Tamás, Gábor

    2016-01-01

    Functional and molecular changes associated with pathophysiological conditions are relatively easily detected based on tissue samples collected from patients. Population specific cellular responses to disease might remain undiscovered in samples taken from organs formed by a multitude of cell types. This is particularly apparent in the human cerebral cortex composed of a yet undefined number of neuron types with a potentially different involvement in disease processes. We combined cellular electrophysiology, anatomy and single cell digital PCR in human neurons identified in situ for the first time to assess mRNA expression and corresponding functional changes in response to edema and increased intracranial pressure. In single pyramidal cells, mRNA copy numbers of AQP1, AQP3, HMOX1, KCNN4, SCN3B and SOD2 increased, while CACNA1B, CRH decreased in edema. In addition, single pyramidal cells increased the copy number of AQP1, HTR5A and KCNS1 mRNAs in response to increased intracranial pressure. In contrast to pyramidal cells, AQP1, HMOX1and KCNN4 remained unchanged in single cell digital PCR performed on fast spiking cells in edema. Corroborating single cell digital PCR results, pharmacological and immunohistochemical results also suggested the presence of KCNN4 encoding the α-subunit of KCa3.1 channels in edema on pyramidal cells, but not on interneurons. We measured the frequency of spontaneous EPSPs on pyramidal cells in both pathophysiological conditions and on fast spiking interneurons in edema and found a significant decrease in each case, which was accompanied by an increase in input resistances on both cell types and by a drop in dendritic spine density on pyramidal cells consistent with a loss of excitatory synapses. Our results identify anatomical and/or physiological changes in human pyramidal and fast spiking cells in edema and increased intracranial pressure revealing cell type specific quantitative changes in gene expression. Some of the edema/increased

  11. Effect of probe contact pressure on the photoplethysmographic assessment of conduit artery stiffness

    Science.gov (United States)

    Grabovskis, Andris; Marcinkevics, Zbignevs; Rubins, Uldis; Kviesis-Kipge, Edgars

    2013-02-01

    Currently, photoplethysmography (PPG) is a frequently studied optical blood pulsation detection technique among biophotonic and biomedical researchers due to the fact that it shows high potential for estimating the arterial stiffness (AS). The extraction of diagnostically useful information requires standardized measurement procedure with good repeatability. However, the effects of a crucially important factor-the optimal contact pressure (CP) of the probe-are often ignored. Also, CP values are not reported to evaluate those effects. It is hypothesized that AS estimated from PPG pulse wave 2nd derivative parameter b/a is strongly inconsistent when recorded at nonoptimal probe CP. Our pilot study confirmed this during in vivo PPG recordings from conduit artery sites on five healthy subjects at variable probe CP (0 to 15 kPa) by using 880 nm reflectance type sensor, force transducer, and PPG alternating current (AC) signal pulse area derived optimal CP criterion. The b/a values, calculated from PPG with variable CP, showed variation >300 percent. In contrast, at the optimal CP, the b/a showed high repeatability (coefficient of variability pulse pressure-volume relationship model which indicates the optimal CP range.

  12. Effects of three days of dry immersion on muscle sympathetic nerve activity and arterial blood pressure in humans.

    Science.gov (United States)

    Iwase, S; Sugiyama, Y; Miwa, C; Kamiya, A; Mano, T; Ohira, Y; Shenkman, B; Egorov, A I; Kozlovskaya, I B

    2000-03-15

    The present study was performed to determine how sympathetic function is altered by simulated microgravity, dry immersion for 3 days, and to elucidate the mechanism of post-spaceflight orthostatic intolerance in humans. Six healthy men aged 21-36 years old participated in the study. Before and after the dry immersion, subjects performed head-up tilt (HUT) test to 30 degrees and 60 degrees (5 min each) with recordings of muscle sympathetic nerve activity (MSNA, by microneurography), electrocardiogram, and arterial blood pressure (Finapres). Resting MSNA was increased after dry immersion from 23.7+/-3.2 to 40.9+/-3.0 bursts/min (p<0.005) without significant changes in resting heart rate (HR). MSNA responsiveness to orthostasis showed no significant difference but HR response was significantly augmented after dry immersion (p<0. 005). A significant diastolic blood pressure fall at 5th min of 60 degrees HUT was observed in five orthostatic tolerant subjects despite enough MSNA discharge after dry immersion. A subject suffered from presyncope at 2 min after 60 degrees HUT. He showed gradual blood pressure fall 10 s after 60 degrees HUT with initially well-maintained MSNA response and then with a gradually attenuated MSNA, followed by a sudden MSNA withdrawal and abrupt blood pressure drop. In conclusion, dry immersion increased MSNA without changing MSNA response to orthostasis, and resting HR, while increasing the HR response to orthostasis. Analyses of MSNA and blood pressure changes in orthostatic tolerant subjects and a subject with presyncope suggested that not only insufficient vasoconstriction to sympathetic stimuli, but also a central mechanism to induce a sympathetic withdrawal might play a role in the development of orthostatic intolerance after microgravity exposure.

  13. 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.

  14. Marked Increase in Flow Velocities During Deep Expiration: A Duplex Doppler Sign of Celiac Artery Compression Syndrome

    International Nuclear Information System (INIS)

    Symptoms of chronic mesenteric ischemia develop when the celiac artery is constricted by the median arcuate ligament of the diaphragm. Lateral aortography is the primary modality for diagnosing ligamentous compression of the celiac artery. However, duplex Doppler sonography performed during deep expiration can cause a marked increase in flow velocities at the compressed region of the celiac artery and suggest the diagnosis of celiac arterial constriction due to the diaphragmatic ligament. RID='''' ID='''' Correspondence to: A. Erden, M.D., Hafta sokak. 23/6, Gaziosmanpasa, 06700 Ankara, Turkey

  15. Borderline pulmonary arterial pressure in systemic sclerosis patients: a post-hoc analysis of the DETECT study

    OpenAIRE

    Visovatti, Scott H; Distler, Oliver; Coghlan, J.; Denton, Christopher P; Grünig, Ekkehard; Bonderman, Diana; Müller-Ladner, Ulf; Pope, Janet E; Vonk, Madelon C; Seibold, James R; Torres-Martin, Juan-Vicente; Doelberg, Martin; Chadha-Boreham, Harbajan; Rosenberg, Daniel M; McLaughlin, Vallerie V.

    2014-01-01

    Introduction Patients with mean pulmonary artery pressures (mPAP) of 21 to 24 mm Hg have a so-called borderline elevation of mPAP (BoPAP)—a condition thought to represent early-stage pulmonary arterial vasculopathy. Based on the DETECT study, this post-hoc analysis examined patient characteristics of systemic sclerosis (SSc) patients with normal mPAP, BoPAP and elevated mPAP, fulfilling pulmonary arterial hypertension (PAH) criteria. Methods Adult patients with a duration of SSc more than 3 y...

  16. Hypoxia stimulates prostacyclin synthesis in newborn pulmonary artery endothelium by increasing cyclooxygenase-1 protein.

    Science.gov (United States)

    North, A J; Brannon, T S; Wells, L B; Campbell, W B; Shaul, P W

    1994-07-01

    In newborn lambs, pulmonary prostacyclin (PGI2) production increases acutely in response to low oxygen. We tested the hypothesis that decreased oxygenation directly stimulates PGI2 synthesis in arterial segments and cultured endothelial cells from newborn lamb intrapulmonary arteries. In segments studied at PO2 of 680 mm Hg, the synthesis of PGI2 exceeded prostaglandin E2 (PGE2) by 73%. Endothelium removal lowered PGI2 by 77% and PGE2 by 66%. At low oxygen tension (PO2, 40 mm Hg), PGI2 and PGE2 synthesis rose by 96% and 102%, respectively. Similarly, in endothelial cells studied at PO2 of 680 mm Hg, the synthesis of PGI2 exceeded PGE2 by 50%, and at low oxygen tension both PGI2 and PGE2 increased (89% and 64%, respectively). Endothelial cell PGI2 synthesis maximally stimulated by bradykinin, A23187, or arachidonic acid was also increased at low PO2 by 50%, 66%, and 48%, respectively. PGE2 synthesis was similarly altered, increasing by 33%, 37%, and 41%, respectively. In contrast, lowering oxygen had minimal effect on PGI2 and PGE2 synthesis with exogenous PGH2, which is the product of cyclooxygenase. Immunoblot analyses revealed that there was a 2.6-fold greater abundance of cyclooxygenase-1 protein at PO2 of 40 versus 680 mm Hg, and the increase at lower oxygen tension was inhibited by cycloheximide. The cyclooxygenase-2 isoform was not detected. Thus, attenuated oxygenation directly stimulates PGI2 and PGE2 synthesis in intrapulmonary arterial segments and endothelial cells from newborn lambs. This process is due to enhanced cyclooxygenase activity related to increased abundance of the cyclooxygenase-1 protein, and this effect may be due to increased synthesis of the enzyme protein.

  17. Neural reflex regulation of arterial pressure in pathophysiological conditions: interplay among the baroreflex, the cardiopulmonary reflexes and the chemoreflex

    Directory of Open Access Journals (Sweden)

    E.C. Vasquez

    1997-04-01

    Full Text Available The maintenance of arterial pressure at levels adequate to perfuse the tissues is a basic requirement for the constancy of the internal environment and survival. The objective of the present review was to provide information about the basic reflex mechanisms that are responsible for the moment-to-moment regulation of the cardiovascular system. We demonstrate that this control is largely provided by the action of arterial and non-arterial reflexes that detect and correct changes in arterial pressure (baroreflex, blood volume or chemical composition (mechano- and chemosensitive cardiopulmonary reflexes, and changes in blood-gas composition (chemoreceptor reflex. The importance of the integration of these cardiovascular reflexes is well understood and it is clear that processing mainly occurs in the nucleus tractus solitarii, although the mechanism is poorly understood. There are several indications that the interactions of baroreflex, chemoreflex and Bezold-Jarisch reflex inputs, and the central nervous system control the activity of autonomic preganglionic neurons through parallel afferent and efferent pathways to achieve cardiovascular homeostasis. It is surprising that so little appears in the literature about the integration of these neural reflexes in cardiovascular function. Thus, our purpose was to review the interplay between peripheral neural reflex mechanisms of arterial blood pressure and blood volume regulation in physiological and pathophysiological states. Special emphasis is placed on the experimental model of arterial hypertension induced by N-nitro-L-arginine methyl ester (L-NAME in which the interplay of these three reflexes is demonstrable

  18. Oxidized low-density lipoprotein and ankle-brachial pressure index in patients with clinically evident peripheral arterial disease

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    Ruben Miguel Ayzin Rosoky

    2010-01-01

    Full Text Available OBJECTIVES: To investigate whether oxidized low-density lipoprotein is a suitable predictor of peripheral arterial disease severity. The role of oxidized low-density lipoprotein in the pathogenesis of atherosclerosis has already been investigated. Its relevance as a predictor of the appearance and worsening of coronary arterial disease is also well known. However, the same is not true regarding peripheral arterial disease. METHOD: Eighty-five consecutive patients with an ankle-brachial pressure index (ABPI < 0.9 and the presence of either intermittent claudication or critical lower leg ischemia were included. The plasma level of IgG autoantibodies against oxidized low-density lipoprotein was evaluated through an enzyme-linked immunosorbent assay. The results were categorized into quartiles according to the ankle-brachial pressure index (a marker of peripheral arterial disease severity, and significant differences were investigated with the Kruskal-Wallis test. RESULTS: There was no significant difference between the quartiles for this population (p = 0.33. No correlation was found between the ankle-brachial pressure index and oxidized low-density lipoprotein levels in subjects with clinically evident peripheral arterial disease with a wide range of clinical manifestations. CONCLUSIONS: Oxidized low-density lipoprotein is not a good predictor of peripheral arterial disease severity.

  19. Effects of smoking cessation on central blood pressure and arterial stiffness

    Directory of Open Access Journals (Sweden)

    Takami T

    2011-10-01

    Full Text Available Takeshi Takami1,Yoshihiko Saito21Department of Internal Medicine, Clinic Jingumae, Kashihara, Nara, Japan; 2First Department of Internal Medicine, Nara Medical University, Kashihara, Nara, JapanPurpose: Smoking affects arterial stiffness, thus causing an elevation in central blood pressure (CBP. The present study was designed to examine whether smoking cessation treatment improved CBP and arterial stiffness.Patients and methods: We conducted an observational study of 70 patients receiving smoking cessation treatment. Before and 60 weeks after the start of a 12-week varenicline treatment, we measured brachial blood pressure, CBP, brachial-ankle pulse wave velocity (baPWV, normalized radial augmentation index (rAIx@75, left ventricular weight, and left ventricular diastolic function of each patient. The data were compared between the patients who succeeded in quitting smoking (smoking cessation group; n = 37 and those who failed to quit smoking (smoking group; n = 33.Results: Baseline characteristics were similar in both groups. Brachial blood pressure remained unchanged in both groups. CBP, baPWV, and rAIx@75 decreased significantly in the smoking cessation group, while these parameters showed no significant change in the smoking group. Thus, CBP, baPWV, and rAIx@75 showed greater decrease in the smoking cessation group than in the smoking group (CBP, −7.1 ± 1.4 mmHg vs 1.2 ± 2.7 mmHg; P < 0.01; baPWV, −204 ± 64 cm/s vs −43 ± 72 cm/s; P < 0.01; rAIx@75, −6.4 ± 2.8% vs −1.0 ± 3.9%; P < 0.01. Left ventricular weight and left ventricular diastolic function remained unchanged in both groups.Conclusion: Patients in the smoking cessation group showed significant improvement in CBP, baPWV, and rAIx@75. These results indicate that smoking cessation can improve arterial stiffness and CBP.Keywords: central blood pressure, augmentation index, brachial-ankle pulse wave velocity, smoking cessation, varenicline

  20. Arterial blood pressure oscillation after active standing up in kidney transplant recipients.

    Science.gov (United States)

    Gerhardt, U; Schäfer, M; Hohage, H

    2000-04-12

    Dynamic arterial blood pressure (FINAPRES) response to active standing up, normally consisting of initial rise, fall and recovery above the baseline (overshoot), was compared with the early steady-state arterial blood pressure level to measure sympathetic vasomotor function in healthy subjects [group 1: n=50, 10 female subjects, age 51+/-2.5 years; weight 78+/-2.3 kg; height 174+/-1.4 cm (mean+/-standard error of the mean)] and in kidney transplant recipients under basal (group 2a: n=50, age 51.7+/-1.7 years; weight 77+/-2.1 kg; height 174+/-1.5 cm) and under high (group 2b: same subjects as in group 2a) cyclosporine A whole blood levels. Furthermore, baroreflex sensitivity and the activity of the generating compounds of the sympathetic nervous systems (Mayer waves) were measured. Systolic and diastolic overshoot values did not differ statistically significant in the present study. In the control subjects, a systolic overshoot of 15.4+/-2.7 mmHg and a diastolic overshoot of 15.2+/-2 mmHg was detected. The systolic overshoot disappeared in 57% of group 2a (-7.1+/-2.7 mmHg; P<0.001) and in 50% of group 2b recipients (-8.0+/-2.7 mmHg; P<0.001). Systolic early steady-state level was not lower in kidney transplant recipients before cyclosporine (baseline+2 mmHg) intake, but after cyclosporine administration (baseline-3 mmHg; controls: baseline+3 mmHg; P<0.05). There was a strong association between the overshoot and steady-state levels (P for chi(2)<0.001, n=150). Overshoot of group 1 levels (r=0.428; P<0.01) and group 2 levels (r=0.714; P<0. 001) correlated to their respective steady-state blood pressure. Furthermore, recipients had reduced baroreceptor sensitivities estimated by sequence analysis as compared to controls (10+/-1 ms/mmHg vs. 7.5+/-1.4 ms/mmHg; P<0.05). Mayer waves amplitudes of the heart rate spectrum were elevated statistically significant in renal transplant recipients (44.4+/-0.2 vs. 43.8+/-2.2 A.U.). In conclusion, baroreceptor reflex

  1. Adenoviral gene transfer of endothelial nitric-oxide synthase (eNOS) partially restores normal pulmonary arterial pressure in eNOS-deficient mice

    Science.gov (United States)

    Champion, Hunter C.; Bivalacqua, Trinity J.; Greenberg, Stanley S.; Giles, Thomas D.; Hyman, Albert L.; Kadowitz, Philip J.

    2002-01-01

    It has been shown that mice deficient in the gene coding for endothelial nitric-oxide synthase (eNOS) have increased pulmonary arterial pressure and pulmonary vascular resistance. In the present study, the effect of transfer to the lung of an adenoviral vector encoding the eNOS gene (AdCMVeNOS) on pulmonary arterial pressure and pulmonary vascular resistance was investigated in eNOS-deficient mice. One day after intratracheal administration of AdCMVeNOS to eNOS−/− mice, there was an increase in eNOS protein, cGMP levels, and calcium-dependent conversion of l-arginine to l-citrulline in the lung. The increase in eNOS protein and activity in eNOS−/− mice was associated with a reduction in mean pulmonary arterial pressure and pulmonary vascular resistance when compared with values in eNOS-deficient mice treated with vehicle or a control adenoviral vector coding for β-galactosidase, AdCMVβgal. These data suggest that in vivo gene transfer of eNOS to the lung in eNOS−/− mice can increase eNOS staining, eNOS protein, calcium-dependent NOS activity, and cGMP levels and partially restore pulmonary arterial pressure and pulmonary vascular resistance to near levels measured in eNOS+/+ mice. Thus, the major finding in this study is that in vivo gene transfer of eNOS to the lung in large part corrects a genetic deficiency resulting from eNOS deletion and may be a useful therapeutic intervention for the treatment of pulmonary hypertensive disorders in which eNOS activity is reduced. PMID:12237402

  2. Measurement of intramedullary pressure in an animal experiment and propositions to reduce the pressure increase.

    Science.gov (United States)

    Stürmer, K M

    1993-01-01

    1. During reaming of the medullary cavity prior to nailing, hydraulic pressure builds up in the cavity which far exceeds that of blood pressure. The peak values for 29 sheep clearly exceeds 2.5 bar. The highest values for individual reamers average 1.3 bar. The differences between the various reamers are only small. Intraoperative measurements on patients have confirmed these results. 2. The reamer acts as a hydraulic piston in a piston sleeve which is filled with a mixture of medullary fat, blood, blood clots and bone debris. The level of pressure depends on the flow rate of the medullary cavity contents between the reamer and the bone according to the gap formula. This is particularly dependent on the gap height which is to the third power in the gap equation. 3. The pressure rise can be most effectively prevented by reducing viscosity of the medullary content using the irrigation-suction technique. The reaming rod is cannulated and is continuously filled with Ringer solution in the distal part of the medullary cavity. This is then drawn off proximally after rinsing the reamer. Experimental measurements on 19 sheep did not produce high pressures, but rather negative pressures. 4. Venting holes in the bone only have little effect because their diameter is too small and local peak values must be assumed during the passage of the reamer. 5. Reaming the medullary cavity less does not prevent pressure increase. Pressure is high even for reamers of small diameter.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8168880

  3. Epworth's sleepiness scale in outpatients with different values of arterial blood pressure

    Directory of Open Access Journals (Sweden)

    Gus Miguel

    2002-01-01

    Full Text Available OBJECTIVE: To compare sleepiness scores of the Epworth scale in patients with different levels of arterial pressure when undergoing outpatient monitoring within the context of clinical evaluation. METHODS: A total of 157 patients selected for outpatient monitoring of arterial pressure during hypertension evaluation were divided into 3 groups: group 1 - normotensive; group 2 - hypertensive; group 3 - resistant hypertensive. For analysis, values > or = 11 were considered as associated with respiratory disturbances during sleep. RESULTS: Seventeen (10.8% patients in group 1, 112 (71.3% in group 2, and 28 (17.8% in group 3, which was composed of aged, more severely hypertensive individuals, were analyzed. Groups were similar relative to sex and body mass index, but different in relation to systolic and diastolic pressure levels and age. Despite an absolute difference, no statistically significant difference occurred between Epworth scores and in the proportion of patients with values > or = 11 (5.9% vs. 18.8% vs. 212.4%; P=0.37. Despite the positive association between degree of sleepiness measured with the scale and the severity of the hypertension, no statistical significance occurred following control by age (p=0.18. CONCLUSION: A positive correlation exists between degree of sleepiness and hypertension severity. The absence of a statistical significance shown in the present study could be due to a beta type of error. Instruments that render this complaint into an objective finding could help in the pursuit of an investigation of respiratory disturbances during sleep in more severely hypertensive patients, and should therefore be studied better.

  4. Increasing TRPV4 expression restores flow-induced dilation impaired in mesenteric arteries with aging.

    Science.gov (United States)

    Du, Juan; Wang, Xia; Li, Jie; Guo, Jizheng; Liu, Limei; Yan, Dejun; Yang, Yunyun; Li, Zhongwen; Zhu, Jinhang; Shen, Bing

    2016-01-01

    The flow-stimulated intracellular Ca(2+) concentration ([Ca(2+)]i) rise in endothelial cells is an important early event leading to flow-induced blood vessel dilation. Transient receptor potential vanilloid subtype 4 (TRPV4), a Ca(2+)-permeable cation channel, facilitates the flow-stimulated [Ca(2+)]i rise. To determine whether TRPV4 is involved in age-related flow-induced blood vessel dilation impairment, we measured blood vessel diameter and nitric oxide (NO) levels and performed Ca(2+) imaging, immunoblotting, and immunostaining assays in rats. We found that the flow-induced and TRPV4 activator 4α-PDD-induced dilation of mesenteric arteries from aged rats were significantly decreased compared with those from young rats. The flow- or 4α-PDD-induced [Ca(2+)]i rise was also markedly reduced in primary cultured mesenteric artery endothelial cells (MAECs) from aged rats. Immunoblotting and immunostaining results showed an age-related decrease of TRPV4 expression levels in MAECs. Additionally, the 4α-PDD-induced NO production was significantly reduced in aged MAECs. Compared with lentiviral GFP-treated aged rats, lentiviral vector delivery of TRPV4 increased TRPV4 expression level in aged MAECs and restored the flow- and 4α-PDD-induced vessel dilation in aged mesenteric arteries. We concluded that impaired TRPV4-mediated Ca(2+) signaling causes endothelial dysfunction and that TRPV4 is a potential target for clinical treatment of age-related vascular system diseases. PMID:26947561

  5. Changes in arterial blood pressure elicited by severe passive heating at rest is associated with hyperthermia-induced hyperventilation in humans.

    Science.gov (United States)

    Fujii, Naoto; Ichinose, Masashi; Honda, Yasushi; Tsuji, Bun; Watanabe, Kazuhito; Kondo, Narihiko; Nishiyasu, Takeshi

    2013-01-01

    The arterial blood pressure and ventilatory responses to severe passive heating at rest varies greatly among individuals. We tested the hypothesis that the increase in ventilation seen during severe passive heating of resting humans is associated with a decrease in arterial blood pressure. Passive heating was performed on 18 healthy males using hot water immersion to the level of the iliac crest and a water-perfused suit. We then divided the subjects into two groups: MAP(NOTINC) (n = 8), whose mean arterial blood pressure (MAP) at the end of heating had increased by ≤3 mmHg, and MAP(INC) (n = 10), whose MAP increased by >3 mmHg. Increases in esophageal temperature (T (es)) elicited by the heating were similar in the two groups (+2.3 ± 0.3 vs. +2.4 ± 0.4 °C). Early during heating (increase in T (es) was ventilation ([Formula: see text]), and end-tidal CO(2) pressure ([Formula: see text]) were similar between the groups. However, during the latter part of heating (increase in T (es) was ≥1.5 °C), the increase in [Formula: see text] and decrease in [Formula: see text] were significantly greater or tended to be greater, while the increase in MAP was significantly smaller in MAP(NOTINC) than MAP(INC). Among all subjects, heating-induced changes in [Formula: see text] significantly and negatively correlated with heating-induced changes in MAP during the latter part of heating (r = -0.52 to -0.74, P passive heating can be explained by the magnitude of hyperthermia-induced hyperventilation.

  6. Effects of renal artery stenting on renal function and blood pressure in patients with atherosclerotic renovascular disease

    Institute of Scientific and Technical Information of China (English)

    张奇; 沈卫峰; 张瑞岩; 张建盛; 胡健; 张宪

    2003-01-01

    Objective To study the effects of percutaneous renal artery intervention on renal function and blood pressure in patients with renal artery stenosis. Methods Eighty-seven patients with severe uni- or bi-lateral renal artery stenosis (luminal diameter narrowing ≥70%) and clinical hypertension received renal artery stenting between January 2002 and December 2002. The changes in blood pressure and serum creatinine level and creatinine clearance (CCr) 48 hours after intervention and during 6 months of follow-up were assessed.Results Renal stenting was performed in 98 stenotic arteries of 87 patients, and the procedural success rate was 100%. Serum creatinine level was slightly elevated from (176±21) μmol/L to (179±11) μmol/L (P=0.15) 48 hours after the procedure, but significantly decreased to (149±15) μmol/L at 6 months (P<0.001). CCr was also greatly improved [(37±11) ml/min before versus (51±8) ml/min at 6 months, P<0.001]. During follow-up, 61% of the patients experienced a normal renal function. Despite conventional medical treatment, systolic and diastolic blood pressures were also significantly decreased after stenting [(163±23)/(96±13) mm Hg before versus (148±12)/(79±15) mm Hg at 6 months, all P<0.001], and hypertension was well controlled in 67% of the patients at 6 months ' follow-up.Conclusion Renal artery stenting has a high success rate and is effective in improving renal function and blood pressure for patients with severe renal artery stenosis.

  7. Immediate responses of arterial blood pressure and heart rate to sudden inhalation of high concentrations of isoflurane in normotensive and hypertensive patients.

    Science.gov (United States)

    Ishikawa, T; Nishino, T; Hiraga, K

    1993-11-01

    Inhalation of pungent volatile anesthetics elicits respiratory reflex responses. To clarify whether an upper airway irritation produced by pungent anesthetics can also induce circulatory reflex responses that are clinically significant, a sudden administration of 5% isoflurane by mask was performed during continuous measurement of arterial blood pressure (BP) and heart rate (HR) in eight normotensive and eight hypertensive patients anesthetized with thiamylal and paralyzed with vecuronium. The sudden administration of 5% isoflurane caused immediate increases in BP, HR, and rate pressure products (RPP) in both normotensive and hypertensive patients. The responses observed were more pronounced in hypertensive than in normotensive patients. The circulatory changes in hypertensive patients were sufficient to be clinically significant. Our findings suggest that sudden administration of a high concentration of pungent volatile anesthetics may be associated with transient hypertensive responses in hypertensive patients with coronary artery disease. PMID:8214702

  8. One-dimensional model for propagation of a pressure wave in a model of the human arterial network: comparison of theoretical and experimental results.

    Science.gov (United States)

    Saito, Masashi; Ikenaga, Yuki; Matsukawa, Mami; Watanabe, Yoshiaki; Asada, Takaaki; Lagrée, Pierre-Yves

    2011-12-01

    Pulse wave evaluation is an effective method for arteriosclerosis screening. In a previous study, we verified that pulse waveforms change markedly due to arterial stiffness. However, a pulse wave consists of two components, the incident wave and multireflected waves. Clarification of the complicated propagation of these waves is necessary to gain an understanding of the nature of pulse waves in vivo. In this study, we built a one-dimensional theoretical model of a pressure wave propagating in a flexible tube. To evaluate the applicability of the model, we compared theoretical estimations with measured data obtained from basic tube models and a simple arterial model. We constructed different viscoelastic tube set-ups: two straight tubes; one tube connected to two tubes of different elasticity; a single bifurcation tube; and a simple arterial network with four bifurcations. Soft polyurethane tubes were used and the configuration was based on a realistic human arterial network. The tensile modulus of the material was similar to the elasticity of arteries. A pulsatile flow with ejection time 0.3 s was applied using a controlled pump. Inner pressure waves and flow velocity were then measured using a pressure sensor and an ultrasonic diagnostic system. We formulated a 1D model derived from the Navier-Stokes equations and a continuity equation to characterize pressure propagation in flexible tubes. The theoretical model includes nonlinearity and attenuation terms due to the tube wall, and flow viscosity derived from a steady Hagen-Poiseuille profile. Under the same configuration as for experiments, the governing equations were computed using the MacCormack scheme. The theoretical pressure waves for each case showed a good fit to the experimental waves. The square sum of residuals (difference between theoretical and experimental wave-forms) for each case was <10.0%. A possible explanation for the increase in the square sum of residuals is the approximation error for flow

  9. Nitric Oxide Increases Arterial Endotheial Permeability through Mediating VE-Cadherin Expression during Arteriogenesis

    Science.gov (United States)

    Wu, Xiaoqiong; Guan, Yinglu; Zhang, Bin; Cai, Weijun; Schaper, Jutta; Schaper, Wolfgang

    2015-01-01

    Macrophage invasion is an important event during arteriogenesis, but the underlying mechanism is still only partially understood. The present study tested the hypothesis that nitric oxide (NO) and VE-cadherin, two key mediators for vascular permeability, contribute to this event in a rat ischemic hindlimb model. In addition, the effect of NO on expression of VE-caherin and endothelial permeability was also studied in cultured HUVECs. We found that: 1) in normal arteriolar vessels (NAV), eNOS was moderately expressed in endothelial cells (EC) and iNOS was rarely detected. In contrast, in collateral vessels (CVs) induced by simple femoral artery ligation, both eNOS and iNOS were significantly upregulated (PEBE) was low in the musculus gracilis, FITC-dextron leakage was not detected in the vascular wall and few macrophages were observed in perivascular space. In contrast, EBE was significantly increased in femoral artery ligation rats, FITC-dextron leakage and increased amounts of macrophages were detected in CVs, which were further enhanced by administration of NONOate, but inhibited by L-NAME supplement; 4) in vitro experiments confirmed that an increase in NO production reduced VE-cadherin expression, correlated with increases in the permeability of HUVECs. In conclusion, our data for the first time reveal the expression profile of VE-cadherin and alterations of vascular permeability in CVs, suggesting that NO-mediated VE-cadherin pathway may be one important mechanism responsible, at least in part, for macrophage invasion during arteriogenesis. PMID:26133549

  10. Multichannel Blind Deconvolution of the Arterial Pressure using Ito Calculus Method

    Directory of Open Access Journals (Sweden)

    M. El-Sayed Waheed

    2015-11-01

    Full Text Available Multichannel Blind Deconvolution (MBD is a powerful tool particularly for the identification and estimation of dynamical systems in which a sensor, for measuring the input, is difficult to place. This paper presents Ito calculus method for the estimation of the unknown time-varying coefficient. The arterial network is modelled as a Finite Impulse Response (FIR filter with unknown coefficients. A new tool for estimation of both the central arterial pressure and the unknown channel dynamics has been developed. The convolution process is modelled as a Finite Impulse Response (FIR filter with unknown coefficients. The source signal is also unknown. Assuming that one of the FIR filter coefficients are time varying, we have been able to get accurate estimation results for the source signal, even though the filter order is unknown. The time varying filter coefficients have been estimated through the SC algorithm, and we have been able to deconvolve the measurements and obtain both the source signal and the convolution path. The positive results demonstrate that the SC approach is superior to conventional methods.

  11. Clinical significance of inter-arm pressure difference and ankle-brachial pressure index in patients with suspected coronary artery disease

    International Nuclear Information System (INIS)

    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

  12. Examining the response pressure along a fluid-filled elastic tube to comprehend Frank's arterial resonance model.

    Science.gov (United States)

    Lin Wang, Yuh-Ying; Sze, Wah-Keung; Lin, Chin-Chih; Chen, Jiang-Ming; Houng, Chin-Chi; Chang, Chi-Wei; Wang, Wei-Kung

    2015-04-13

    Frank first proposed the arterial resonance in 1899. Arteries are blood-filled elastic vessels, but resonance phenomena for a fluid-filled elastic tube has not drawn much attention yet. In this study, we measured the pressure along long elastic tubes in response to either a single impulsive water ejection or a periodic water input. The experimental results showed the low damped pressure oscillation initiated by a single impulsive water input; and the natural frequencies of the tube, identified by the peaks of the response in the frequency domain, were inversely proportional to the length of the tube. We found that the response to the periodic input reached a steady distributed oscillation with the same period of the input after a short transient time; and the optimal pressure response, or resonance, occurred when the pumping frequency was near the fundamental natural frequency of the system. We pointed out that the distributed forced oscillation could also be a suitable approach to analyze the arterial pressure wave. Unlike Frank's resonance model in which the whole arterial system was lumped together to a simple 0-D oscillator and got only one natural frequency, a tube has more than one natural frequency because the pressure P(z,t) is a 1-D oscillatory function of the axial position z and the time t. The benefit of having more than one natural frequency was then discussed. PMID:25773589

  13. How Do Antihypertensive Drugs Work? Insights from Studies of the Renal Regulation of Arterial Blood Pressure.

    Science.gov (United States)

    Digne-Malcolm, Holly; Frise, Matthew C; Dorrington, Keith L

    2016-01-01

    Though antihypertensive drugs have been in use for many decades, the mechanisms by which they act chronically to reduce blood pressure remain unclear. Over long periods, mean arterial blood pressure must match the perfusion pressure necessary for the kidney to achieve its role in eliminating the daily intake of salt and water. It follows that the kidney is the most likely target for the action of most effective antihypertensive agents used chronically in clinical practice today. Here we review the long-term renal actions of antihypertensive agents in human studies and find three different mechanisms of action for the drugs investigated. (i) Selective vasodilatation of the renal afferent arteriole (prazosin, indoramin, clonidine, moxonidine, α-methyldopa, some Ca(++)-channel blockers, angiotensin-receptor blockers, atenolol, metoprolol, bisoprolol, labetolol, hydrochlorothiazide, and furosemide). (ii) Inhibition of tubular solute reabsorption (propranolol, nadolol, oxprenolol, and indapamide). (iii) A combination of these first two mechanisms (amlodipine, nifedipine and ACE-inhibitors). These findings provide insights into the actions of antihypertensive drugs, and challenge misconceptions about the mechanisms underlying the therapeutic efficacy of many of the agents. PMID:27524972

  14. Egg ovotransferrin‐derived ACE inhibitory peptide IRW increases ACE2 but decreases proinflammatory genes expression in mesenteric artery of spontaneously hypertensive rats

    Science.gov (United States)

    Majumder, Kaustav; Liang, Guanxiang; Chen, Yanhong; Guan, LeLuo; Davidge, Sandra T.

    2015-01-01

    Scope Egg ovotransferrin‐derived angiotensin converting enzyme (ACE) inhibitory peptide IRW was previously shown to reduce blood pressure in spontaneously hypertensive rats through reduced vascular inflammation and increased nitric oxide‐mediated vasorelaxation. The main objective of the present study was to investigate the molecular mechanism of this peptide through transcriptome analysis by RNAseq technique. Methods and results Total RNA was extracted from kidney and mesenteric arteries; the RNAseq libraries (from untreated and IRW‐treated groups) were constructed and subjected to sequence using HiSeq 2000 system (Illumina) system. A total of 12 764 and 13 352 genes were detected in kidney and mesenteric arteries, respectively. The differentially expressed (DE) genes between untreated and IRW‐treated groups were identified and the functional analysis through ingenuity pathway analysis revealed a greater role of DE genes identified from mesenteric arteries than that of kidney in modulating various cardiovascular functions. Subsequent qPCR analysis further confirmed that IRW significantly increased the expression of ACE‐2, ABCB‐1, IRF‐8, and CDH‐1 while significantly decreased the expression ICAM‐1 and VCAM‐1 in mesenteric arteries. Conclusion Our research showed for the first time that ACE inhibitory peptide IRW could contribute to its antihypertensive activity through increased ACE2 and decreased proinflammatory genes expression. PMID:26016560

  15. Small artery structure adapts to vasodilatation rather than to blood pressure during antihypertensive treatment

    DEFF Research Database (Denmark)

    2007-01-01

    OBJECTIVE: Correction of the abnormal structure of resistance arteries in essential hypertension may be an important treatment goal in addition to blood pressure (BP) reduction. We investigated how this may be achieved in a prospective clinical study. METHODS: Plethysmography was used to measure...... forearm resting vascular resistance (Rrest) and minimum vascular resistance (Rmin) as a measure of vascular structure. Two different groups of patients with essential hypertension were examined at baseline and after 6 months of antihypertensive treatment. In group A, 21 patients with never......-treated essential hypertension were treated by their general practitioners using a variety of drugs to allow an assessment of the drug-independent effects. In group B, 28 beta-blocker-treated patients were shifted to angiotensin II receptor blocker treatment (eprosartan) to allow vasodilatation with no change in BP...

  16. A correlation study between ankle brachial pressure index and the severity of coronary artery disease.

    Science.gov (United States)

    Benyakorn, Thoetphum; Kuanprasert, Sarun; Rerkasem, Kittipan

    2012-06-01

    Previous studies have shown that there was a correlation between low ankle brachial pressure index (ABPI) and the presence of the coronary artery disease (CAD). However, few studies have investigated the correlation between ABPI and the severity of CAD by using a scoring system. The authors aimed to investigate this correlation by using ABPI and CAD diagnosed by coronary angiography (CAG). A total of 213 consecutive patients awaiting CAG in Maharaj Nakorn Chiang Mai Hospital from July 2009 to November 2009 were enrolled in this study. The ABPI was measured before CAG. The severity of CAD was graded on CAG by using SYNTAX scores. The authors found a significantly negative correlation between ABPI and SYNTAX scores (correlation coefficient = -.172, P = .01). The authors concluded that ABPI appeared to correlate negatively with the severity of CAD in the Thai population. PMID:22561522

  17. Increased risk of venous thromboembolism and arterial cardiovascular events in patients with inflammatory bowel disease

    DEFF Research Database (Denmark)

    Kristensen, Søren Lund; Ahlehoff, Ole; Lindhardsen, Jesper;

    2012-01-01

    This focused review describes the current knowledge of the association between inflammatory bowel disease (IBD) and cardiovascular disease. Atherosclerosis is a chronic inflammatory disease, and as well as venous thromboembolism this disease shares inflammatory mechanisms with IBD. Patients...... with IBD have a high risk of venous thromboembolism especially during IBD flare-ups. Their risk of arterial cardiovascular disease may also be increased. The risk of cardiovascular disease in patients with IBD warrants clinical attention, and it is possible that the risk can be modified by applying anti...

  18. ISH PRE-1 REDUCTION OF CARDIOVASCULAR MORTALITY IN HYPERTENSIVES WITH COMORBIDITIES: BEYOND BLOOD PRESSURE LOWERING - THE ROLE OF ARTERIAL AGING.

    Science.gov (United States)

    Safar, Michel E

    2016-09-01

    Mid-life elevated BP is classically associated with a raised systemic vascular resistance. A classical interpretation of the association between aortic stiffness and blood pressure (BP) invokes hypertension as a simple form of premature aging that increases stress on the arterial wall and accelerates age-related stiffening of the aorta. Recent clinical and experimental data have called into question the directionality of this sequence of events associating stiffness and hypertension.Therefore an initial abnormality in stiffness may antedate and contribute initially to the pathogenesis of hypertension, namely isolated systolic hypertension. This possibility is important to consider since it might affect the individual estimation of cardiovascular risk even in low risk prehypertensive subjects. Therefore, it might be essential to direct therapy of hypertension toward the reduction of both BP and aortic stiffness.Cardiovascular (CV) complications are dominant causes of death in severe hypertensive patients with comorbidities, especially diabetic hypertensive patients (DHS) and patients with end-stage renal disease (ESRD). Vascular calcifi cation and arterial stiffness are highly prevalent in such subjects, particularly in those with co-morbidities. Carotid-femoral pulse wave velocity (CFPWV) is the gold standard and simple, non-invasive and reproducible measure of large artery stiffness.This measurement have been frequently used as predictors for CV events and CV mortality in the general population, in specifi c populations such as in patients with DHS and ESRD. These fi ndings have been widely observed using conventional cross-sectional investigations. However, in such studies, it has been observed that the association between single measurements of CFPWV and CV events is frequently driven by the high incidence of late events, i.e. after 12 months of follow-up.New data from our prospective studies in DHS and ESRD evaluated the association between longitudinal changes

  19. The Intracranial Volume Pressure Response in Increased Intracranial Pressure Patients: Clinical Significance of the Volume Pressure Indicator

    Science.gov (United States)

    2016-01-01

    Background For patients suffering from primary brain injury, monitoring intracranial pressure alone is not enough to reflect the dynamic intracranial condition. In our previous study, a segment of the pressure-volume curve can be expressed by the parabolic regression model with single indicator “a”. The aim of this study is to evaluate if the indicator “a” can reflect intracranial conditions. Methods Patients with traumatic brain injury, spontaneous intracranial hemorrhage, and/or hydrocephalus who had external ventricular drainage from January 2009 to February 2010 were included. The successive volume pressure response values were obtained by successive drainage of cerebral spinal fluid from intracranial pressure 20–25 mm Hg to 10 mm Hg. The relationship between withdrawn cerebral spinal fluid volume and intracranial pressure was analyzed by the parabolic regression model with single parameter “a”. Results The overall mean for indicator “a” was 0.422 ± 0.046. The mean of “a” in hydrocephalus was 0.173 ± 0.024 and in severe intracranial mass with slender ventricle, it was 0.663 ± 0.062. The two extreme intracranial conditions had a statistical significant difference (phydrocephalus. Brain computed tomography should be performed early if a rapid elevation of indicator “a” is detected, as it can reveal some ongoing intracranial pathology prior to clinical deterioration. Increased intracranial pressure was frequently observed in patients with intracranial pathology. The progression can be differentiated using the pattern of the volume pressure indicator. PMID:27723794

  20. 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

  1. Associations of blood pressure and arterial compliance with occupational noise exposure in female workers of textile mill

    Institute of Scientific and Technical Information of China (English)

    NI Chun-hui; ZHANG Yu-jun; CHEN Zhi-yong; ZHOU Yin; ZHOU Jian-wei; Pan Jing-jing; LIU Nian; WANG Jun; LIANG Chen-ke; ZHANG Zhi-zhong

    2007-01-01

    Background There are few studies on the arterial compliance of noise exposure. The purpose of this study was to understand the relationship between hearing loss, blood pressure and arterial compliance of female workers who exposed to occupational noise in a textile mill.Methods The noise levels in the workplace were measured with a HS6288 sound level meter. Cumulated noise exposure (CNE) was calculated according to the noise intensity and the exposure period. Hearing ability and arterial compliance were measured in 618 noise exposed workers. The database was set up with EpiData and the statistical analysis was performed with SAS software 9.1.3.Results The noise levels were 80.1dB(A) to 113.5dB(A), of which the levels at 92.5% of the noise monitoring sites were over the national standard. The incidence of high frequency hearing loss (HFHL) was 24.43% and language frequency hearing impairment (LFHI) was 0.81%. The incidence of hypertension was 7.93%. Both systolic blood pressure (SBP)and diastolic blood pressure (DBP) in the high frequency hearing loss group were significantly higher than those in the normal hearing group (P<0.05), while C1 (large artery compliance) and C2 (small artery compliance) were significantly lower (P<0.05). The high frequency hearing threshold (HFHT) of the hypertension group was significantly higher than in the normal blood pressure group (P<0.05), while C1 and C2 were significantly lower (P<0.05). C1 and C2 had a negative correlation with HFHT, SBP, DBP, mean of arterial pressure (MAP), pulse pressure (PP) and pulse rate (PR) (P<0.05).The multiple regression analyses showed that blood pressure and PR were the main influencing factors on C1 and C2.LFHT was an influence on C2 and HFHT on C1.Conclusions Textile mill noise pollution is very serious and has an obvious influence on worker's auditory function. The female workers with Iow artery compliance or with high blood pressure might be suffering from hearing loss; those with noise

  2. [Arterial CO2- and O2 partial pressure at rest and during exertion in pulmonary emphysema].

    Science.gov (United States)

    Scherrer, M; Zeller, C; Bachofen, H

    1977-07-30

    In 83 patients with severe, largely irreversible bronchial obstruction (FEV1/VC less than 40% and FEV1 after orciprenaline inhalation less than 120% of the control value) and radiologie evidence of AD-emphysema, arterial PCO2 and PO2 were measured at rest in supine position and on the bicycle ergometer during a steady-state exercice of 5 min. Alveolar hypoventilation (PCO2 greater than 45 mm Hg) was most often observed in the cases with FEV1 less than 1.01 (in 22 patients [27%] at rest and in 26 patients [31%] during exercise). However, there was no significant correlation of the PCO2 increase with the degree of bronchial obstruction. In all patients there was a marked inhomogeneity of the alveolar ventilation or the alveolar-capillary O2 transfer in relation to alveolar blood perfusion. Indeed, the alveolar-arterial PO2 difference was increased (40 mm Hg at rest and 45 mm Hg during exercise). The additional increase of this gradient during exercise was due to an unequal distribution of alveolar O2 diffusing capacities in connection with the alveolar blood flow (preceding measurements of the N2 gradient between alveolar air and arterial blood revealed a mean fall from 18 at rest to 8 mm Hg during exercise). The observed deterioration of hypoxemia during exercise (without additional hypercapnia) is to a great extent related to the degree of bronchial obstruction measured by simple spirometry. Thus, measurements of PCO2 and PO2 at rest and during exercise appear to be a helpful adjuvant to routine spirometry in the diagnosis of subclinical emphysema.

  3. Perfusion Pressure Cerebral Infarct (PPCI) trial - the importance of mean arterial pressure during cardiopulmonary bypass to prevent cerebral complications after cardiac surgery: study protocol for a randomised controlled trial

    DEFF Research Database (Denmark)

    Vedel, Anne G.; Holmgaard, Frederik; Rasmussen, Lars Simon;

    2016-01-01

    to be caused by emboli, but inadequate blood flow caused by other mechanisms may increase ischaemia in the penumbra or cause watershed infarcts. During cardiopulmonary bypass, blood pressure can be below the lower limit of cerebral autoregulation. Although much debated, the constant blood flow provided...... by the cardiopulmonary bypass system is still considered by many as appropriate to avoid cerebral ischaemia despite the low blood pressure. METHODS/DESIGN: The Perfusion Pressure Cerebral Infarct trial is a single-centre superiority trial with a blinded outcome assessment. The trial is randomising 210 patients...... with coronary vessel and/or valve disease and who are undergoing cardiac surgery with the use of cardiopulmonary bypass. Patients are stratified by age and surgical procedure and are randomised 1:1 to either an increased mean arterial pressure (70-80 mmHg) or 'usual practice' (40-50 mmHg) during cardiopulmonary...

  4. Association between long-term air pollution and increased blood pressure and hypertension in China.

    Science.gov (United States)

    Dong, Guang-Hui; Qian, Zhengmin Min; Xaverius, Pamela K; Trevathan, Edwin; Maalouf, Salwa; Parker, Jamaal; Yang, Laiji; Liu, Miao-Miao; Wang, Da; Ren, Wan-Hui; Ma, Wenjun; Wang, Jing; Zelicoff, Alan; Fu, Qiang; Simckes, Maayan

    2013-03-01

    Several studies have investigated the short-term effects of ambient air pollutants in the development of high blood pressure and hypertension. However, little information exists regarding the health effects of long-term exposure. To investigate the association between residential long-term exposure to air pollution and blood pressure and hypertension, we studied 24 845 Chinese adults in 11 districts of 3 northeastern cities from 2009 to 2010. Three-year average concentration of particles with an aerodynamic diameter ≤10 µm (PM(10)), sulfur dioxide (SO(2)), nitrogen dioxides (NO(2)), and ozone (O(3)) were calculated from monitoring stations in the 11 districts. We used generalized additive models and 2-level logistic regressions models to examine the health effects. The results showed that the odds ratio for hypertension increased by 1.12 (95% confidence interval [CI], 1.08-1.16) per 19 μg/m(3) increase in PM(10), 1.11 (95% CI, 1.04-1.18) per 20 μg/m(3) increase in SO(2), and 1.13 (95% CI, 1.06-1.20) per 22 μg/m(3) increase in O(3). The estimated increases in mean systolic and diastolic blood pressure were 0.87 mm Hg (95% CI, 0.48-1.27) and 0.32 mm Hg (95% CI, 0.08-0.56) per 19 μg/m(3) interquartile increase in PM(10), 0.80 mm Hg (95% CI, 0.46-1.14) and 0.31 mm Hg (95% CI, 0.10-0.51) per 20 μg/m(3) interquartile increase in SO(2), and 0.73 mm Hg (95% CI, 0.35-1.11) and 0.37 mm Hg (95% CI, 0.14-0.61) per 22 μg/m(3) interquartile increase in O(3). These associations were only statistically significant in men. In conclusion, long-term exposure to PM(10), SO(2), and O(3) was associated with increased arterial blood pressure and hypertension in the study population.

  5. l-Citrulline supplementation attenuates blood pressure, wave reflection and arterial stiffness responses to metaboreflex and cold stress in overweight men.

    Science.gov (United States)

    Figueroa, Arturo; Alvarez-Alvarado, Stacey; Jaime, Salvador J; Kalfon, Roy

    2016-07-01

    Combined isometric exercise or metaboreflex activation (post-exercise muscle ischaemia (PEMI)) and cold pressor test (CPT) increase cardiac afterload, which may lead to adverse cardiovascular events. l-Citrulline supplementation (l-CIT) reduces systemic arterial stiffness (brachial-ankle pulse wave velocity (baPWV)) at rest and aortic haemodynamic responses to CPT. The aim of this study was to determine the effect of l-CIT on aortic haemodynamic and baPWV responses to PEMI+CPT. In all, sixteen healthy, overweight/obese males (age 24 (sem 6) years; BMI 29·3 (sem 4·0) kg/m2) were randomly assigned to placebo or l-CIT (6 g/d) for 14 d in a cross-over design. Brachial and aortic systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP), aortic augmented pressure (AP), augmentation index (AIx), baPWV, reflection timing (Tr) and heart rate (HR) were evaluated at rest and during isometric handgrip exercise (IHG), PEMI and PEMI+CPT at baseline and after 14 d. No significant effects were evident after l-CIT at rest. l-CIT attenuated the increases in aortic SBP and wave reflection (AP and AIx) during IHG, aortic DBP, MAP and AIx during PEMI, and aortic SBP, DBP, MAP, AP, AIx and baPWV during PEMI+CPT compared with placebo. HR and Tr were unaffected by l-CIT in all conditions. Our findings demonstrate that l-CIT attenuates aortic blood pressure and wave reflection responses to exercise-related metabolites. Moreover, l-CIT attenuates the exaggerated arterial stiffness response to combined metaboreflex activation and cold exposure, suggesting a protective effect against increased cardiac afterload during physical stress. PMID:27160957

  6. Carotid artery wall stiffness is increased in patients with small vessel disease: A case-control study

    OpenAIRE

    Salihović-Hajdarević Denisa; Pavlović Aleksandra M.; Smajlović Dževdet; Podgorac Ana; Jovanović Zagorka; Švabić-Međedović Tamara; Čovičković-Šternić Nadežda

    2016-01-01

    Introduction. Cerebral ischemic small-vessel disease (SVD), causing lacunar infarcts and white matter hyperintensities on brain magnetic resonance imaging (MRI), is a progressive disease associated with an increased risk of stroke, dementia and death. Increased arterial stiffness has been associated with ischemic stroke and cerebral SVD independently of common vascular risk factors. Objective. The aim of the study was to analyze arterial stiffness in our pa...

  7. Increased shear stress inhibits angiogenesis in veins and not arteries during vascular development.

    Science.gov (United States)

    Chouinard-Pelletier, Guillaume; Jahnsen, Espen D; Jones, Elizabeth A V

    2013-01-01

    Vascular development is believed to occur first by vasculogenesis followed by angiogenesis. Though angiogenesis is the formation of new vessels, we found that vascular density actually decreases during this second stage. The onset of the decrease coincided with the entry of erythroblasts into circulation. We therefore measured the level of shear stress at various developmental stages and found that it was inversely proportional to vascular density. To investigate whether shear stress was inhibitory to angiogenesis, we altered shear stress levels either by preventing erythroblasts from entering circulation ("low" shear stress) or by injection of a starch solution to increase the blood plasma viscosity ("high" shear stress). By time-lapse microscopy, we show that reverse intussusception (merging of two vessels) is inversely proportional to the level of shear stress. We also found that angiogenesis (both sprouting and splitting) was inversely proportional to shear stress levels. These effects were specific to the arterial or venous plexus however, such that the effect on reverse intussusception was present only in the arterial plexus and the effect on sprouting only in the venous plexus. We cultured embryos under altered shear stress in the presence of either DAPT, a Notch inhibitor, or DMH1, an inhibitor of the bone morphogenetic protein (BMP) pathway. DAPT treatment phenocopied the inhibition of erythroblast circulation ("low" shear stress) and the effect of DAPT treatment could be partially rescued by injection of starch. Inhibition of the BMP signaling prevented the reduction in vascular density that was observed when starch was injected to increase shear stress levels.

  8. [Anesthesia management of geriatric patients with arterial pressure-based cardiac output monitoring FloTrac sensor for emergency surgery].

    Science.gov (United States)

    Yamamoto, Shunsuke; Goto, Koji; Yasuda, Norihisa; Kusaka, Junya; Hidaka, Seigo; Miyakawa, Hiroshi; Noguchi, Takayuki

    2009-06-01

    In cases of emergency surgery for geriatric patients, immediate anesthesia induction and careful intraoperative management is necessary without sufficient preoperative information. We report anesthesia management of a 96-year and a 90-year old patients with FloTrac sensor which is an arterial pressure-based cardiac output monitoring device and is able to manage critical patients effectively and safely during anesthesia.

  9. 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.; Siebelink, 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

  10. Ambulatory instrument for monitoring indirect beat-to-beat blood pressure in superficial temporal artery using volume-compensation method.

    Science.gov (United States)

    Tanaka, S; Yamakoshi, K

    1996-11-01

    A portable instrument, based on a volume-compensation technique, is designed for ambulatory monitoring of indirect beat-to-beat blood pressure (BP) in the superficial temporal artery. The instrument consists of a small disc-type cuff and a portable unit carried by the subject. Several components are integrated in the cuff for applying counter-pressure to the artery, i.e. a reflectance-type photo-plethysmographic sensor for arterial volume detection, a pressure sensor for cuff pressure Pc measurement and a nozzle flapper-type- electro-pneumatic convertor for controlling Pc. The portable unit includes volume servo control circuitry and a microprocessor-based signal-processing and recording unit. This automatically performs all the necessary measurement procedures and stores into a memory IC element the processed systolic, mean and diastolic blood pressure data, together with pulse intervals on a beat-to-beat basis from the servo-controlled Pc (indirectly measured BP waveform). With this instrument, momentary changes in BP during ambulatory situations such as bicycle ergometer exercise and daily activities including motorway driving are successfully recorded. From the results of simultaneous measurement of the subject's posture changes, the effect of posture change on blood pressure, e.g. baroreceptor-cardiac reflex, is also clearly demonstrated.

  11. Investigating complex patterns of blocked intestinal artery blood pressure signals by empirical mode decomposition and linguistic analysis

    Science.gov (United States)

    Yeh, J.-R.; Lin, T.-Y.; Shieh, J.-S.; Chen, Y.; Huang, N. E.; Wu, Z.; Peng, C.-K.

    2008-02-01

    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. 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

  13. A functional SNP in FLT1 increases risk of coronary artery disease in a Japanese population.

    Science.gov (United States)

    Konta, Atsuko; Ozaki, Kouichi; Sakata, Yasuhiko; Takahashi, Atsushi; Morizono, Takashi; Suna, Shinichiro; Onouchi, Yoshihiro; Tsunoda, Tatsuhiko; Kubo, Michiaki; Komuro, Issei; Eishi, Yoshinobu; Tanaka, Toshihiro

    2016-05-01

    Coronary artery disease (CAD) including myocardial infarction is one of the leading causes of death in many countries. Similar to other common diseases, its pathogenesis is thought to result from complex interactions among multiple genetic and environmental factors. Recent large-scale genetic association analysis for CAD identified 15 new loci. We examined the reproducibility of these previous association findings with 7990 cases and 6582 controls in a Japanese population. We found a convincing association of rs9319428 in FLT1, encoding fms-related tyrosine kinase 1 (P=5.98 × 10(-8)). Fine mapping using tag single-nucleotide polymorphisms (SNPs) at FLT1 locus revealed that another SNP (rs74412485) showed more profound genetic effect for CAD (P=2.85 × 10(-12)). The SNP, located in intron 1 in FLT1, enhanced the transcriptional level of FLT1. RNA interference experiment against FLT1 showed that the suppression of FLT1 resulted in decreased expression of inflammatory adhesion molecules. Expression of FLT1 was observed in endothelial cells of human coronary artery. Our results indicate that the genetically coded increased expression of FLT1 by a functional SNP implicates activation in an inflammatory cascade that might eventually lead to CAD. PMID:26791355

  14. Urbanization Increases Pathogen Pressure on Feral and Managed Honey Bees.

    Directory of Open Access Journals (Sweden)

    Elsa Youngsteadt

    Full Text Available Given the role of infectious disease in global pollinator decline, there is a need to understand factors that shape pathogen susceptibility and transmission in bees. Here we ask how urbanization affects the immune response and pathogen load of feral and managed colonies of honey bees (Apis mellifera Linnaeus, the predominant economically important pollinator worldwide. Using quantitative real-time PCR, we measured expression of 4 immune genes and relative abundance of 10 honey bee pathogens. We also measured worker survival in a laboratory bioassay. We found that pathogen pressure on honey bees increased with urbanization and management, and the probability of worker survival declined 3-fold along our urbanization gradient. The effect of management on pathogens appears to be mediated by immunity, with feral bees expressing immune genes at nearly twice the levels of managed bees following an immune challenge. The effect of urbanization, however, was not linked with immunity; instead, urbanization may favor viability and transmission of some disease agents. Feral colonies, with lower disease burdens and stronger immune responses, may illuminate ways to improve honey bee management. The previously unexamined effects of urbanization on honey-bee disease are concerning, suggesting that urban areas may favor problematic diseases of pollinators.

  15. Pulmonary arterial hypertension : an update

    NARCIS (Netherlands)

    Hoendermis, E. S.

    2011-01-01

    Pulmonary arterial hypertension (PAH), defined as group 1 of the World Heart Organisation (WHO) classification of pulmonary hypertension, is an uncommon disorder of the pulmonary vascular system. It is characterised by an increased pulmonary artery pressure, increased pulmonary vascular resistance a

  16. Prognostic role of alveolar-arterial oxygen pressure difference in acute pulmonary embolism

    International Nuclear Information System (INIS)

    This study investigated the utility of the alveolar-arterial oxygen pressure difference (AaDO2) 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 AaDO2 cut-off value for predicting primary and composite endpoints. Statistical analysis demonstrated significant differences in AaDO2 between the 30-day composite endpoint group and the 30-day composite event-free survival group (p=0.012). The AaDO2 had a strong trend between the 30-day death group and the survival group (p=0.062). The best cut-off value for AaDO2 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 AaDO2 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 AaDO2 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, AaDO2≥53 mmHg). (author)

  17. School burnout: increased sympathetic vasomotor tone and attenuated ambulatory diurnal blood pressure variability in young adult women.

    Science.gov (United States)

    May, Ross W; Sanchez-Gonzalez, Marcos A; Fincham, Frank D

    2015-01-01

    Two studies examined autonomic and cardiovascular functioning that may link school burnout to cardiovascular risk factors in young healthy adult females. Study 1 (N = 136) investigated whether school burnout was related to resting values of blood pressure (BP) and blood pressure variability (BPV) through laboratory beat-to-beat BP assessment. Study 2 (N = 94) examined the link between school burnout and diurnal BPV through ambulatory BP monitoring. Controlling for anxiety and depressive symptomatology, school burnout demonstrated strong positive relationships with indices of cardiac sympathovagal tone, sympathetic vasomotor tone, inefficient myocardial oxygen consumption, increased 24-h ambulatory heart rate and BP, blunted BP diurnal variability, and increased arterial stiffness. These studies establish cardiovascular biomarkers of school burnout and suggest that even in a seemingly healthy sample school burnout may predispose females to increased cardiovascular risk. Several future lines of research are outlined.

  18. Association between poor glycemic control, impaired sleep quality, and increased arterial thickening in type 2 diabetic patients.

    Directory of Open Access Journals (Sweden)

    Koichiro Yoda

    Full Text Available Poor sleep quality is an independent predictor of cardiovascular events. However, little is known about the association between glycemic control and objective sleep architecture and its influence on arteriosclerosis in patients with type-2 diabetes mellitus (DM. The present study examined the association of objective sleep architecture with both glycemic control and arteriosclerosis in type-2 DM patients.Cross-sectional study in vascular laboratory.The subjects were 63 type-2 DM inpatients (M/F, 32/31; age, 57.5±13.1 without taking any sleeping promoting drug and chronic kidney disease. We examined objective sleep architecture by single-channel electroencephalography and arteriosclerosis by carotid-artery intima-media thickness (CA-IMT.HbA1c was associated significantly in a negative manner with REM sleep latency (interval between sleep-onset and the first REM period (β=-0.280, p=0.033, but not with other measurements of sleep quality. REM sleep latency associated significantly in a positive manner with log delta power (the marker of deep sleep during that period (β=0.544, p=0.001. In the model including variables univariately correlated with CA-IMT (REM sleep latency, age, DM duration, systolic blood pressure, and HbA1c as independent variables, REM sleep latency (β=-0.232, p=0.038, but not HbA1c were significantly associated with CA-IMT. When log delta power was included in place of REM sleep latency, log delta power (β=-0.257, p=0.023 emerged as a significant factor associated with CA-IMT.In type-2 DM patients, poor glycemic control was independently associated with poor quality of sleep as represented by decrease of REM sleep latency which might be responsible for increased CA-IMT, a relevant marker for arterial wall thickening.

  19. Increased arterial stiffness in healthy subjects with high-normal glucose levels and in subjects with pre-diabetes

    OpenAIRE

    Lee Duk Chul; Lee Hye Ree; Shin Jin Young

    2011-01-01

    Abstract Background Increased fasting plasma glucose (FPG), which includes impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and diabetes, is a risk factor for arterial stiffness. While IFG is widely accepted as a cardiovascular risk factor, recent studies have argued that subjects with high-normal glucose level were characterized by a high incidence of cardiovascular disease. The purpose of this study is to investigate the relationship between FPG and arterial stiffness in no...

  20. Portal venous arterialization resulting in increased portal inflow and portal vein wall thickness in rats

    Institute of Scientific and Technical Information of China (English)

    Wen-Gang Li; Yong-Liang Chen; Jing-Xi Chen; Lei Qu; Bin-Dang Xue; Zhi-Hai Peng; Zhi-Qiang Huang

    2008-01-01

    AIM:To explore the influence of portal vein hemodynamic changes after portal venous arterialization(PVA) on peribiliary vascular plexus (PVP)morphological structure and hepatic pathology,and to establish a theoretical basis for the clinical application of PVA.METHODS:Sprague-Dawley rats were randomly divided into control and PVA groups.After PVA,hemodynamic changes of the portal vein and morphological structure of hepatohilar PVP were observed using Doppler ultrasound,liver function tests,ink perfusion transparency management and three-dimensional reconstruction of computer microvisualization,and pathological examination was performed on tissue from the bile duct wall and the liver.RESULTS:After PVA,the cross-sectional area and blood flow of the portal vein were increased,and the increase became more significant over time,in a certain range.If the measure to limit the flow in PVA was not adopted,the high blood flow would lead to dilatation of intrahepatic portal vein and its branches,increase in collagen and fiber degeneration in tunica intima.Except glutamic pyruvic transaminase (GPT),other liver function tests were normal.CONCLUSION:Blood with a certain flow and oxygen content is important for filling the PVP and meeting the oxygen requirement of the bile duct wall.After PVA,It is the anatomic basis to maintain normal morphology of hepatohilar bile duct wall that the blood with high oxygen content and high flow in arterialized portal vein may fill PVP by collateral vessel reflux.A adequate measure to limit blood flow is necessary in PVA.

  1. Noninvasive assessment of cardiac output from arterial pressure profiles during exercise.

    Science.gov (United States)

    Antonutto, G; Girardis, M; Tuniz, D; di Prampero, P E

    1995-01-01

    The stroke volume of the left ventricle (SV) was assessed in nine young men (mean age 22.2, ranging from 20 to 25 years) during cycle ergometer upright exercise at exercise intensities from 60 to 150 W (about 20% to 80% of individual maximal aerobic power). The SV was calculated from noninvasive tracings of the arterial blood pressure, determined from photoplethysmograph records and compared to the SV determined simultaneously by pulsed Doppler echocardiography (PDE). Given the relationship SV = As.Z-1 in which A(s) is the area underneath the systolic pressure profile (in millimetres of mercury and second), and Z (in millimetres of mercury and second per millilitre) is the apparent hydraulic impedance of the circulatory system, a prerequisite for the assessment of SV from the photoplethysmograph tracings is a knowledge of Z. The experimental value of Z (hereafter defined Z*) was calculated by dividing A(s) (from the finger photoplethysmograph) by SV as obtained by PDE. When the whole group of subjects was considered, Z* was not greatly affected by the exercise intensity: it amounted to 0.089 (SD 0.028; n = 36). The Z was also estimated independently of any parameter other than heart rate (HR), mean (MAP) and pulse (PP) arterial blood pressure obtained from the photoplethysmograph. A computerized statistical method allowed us to interpolate the experimental values of Z*, HR, PP and MAP by the equation Zm = a.(b + c.HR + d.PP + e.MAP)-1, thus obtaining the coefficients a to e. The mean percentage error between Zm (calculated from the coefficients obtained and Z* was 21.8 (SD 14.3)%. However, it was observed that, in a given subject, Z* was significantly affected by the exercise intensity. Therefore, to improve the estimate of Z a second algorithm was developed to update the experimental value of Z determined initially at rest (Zin). This updated value (Zcor) of Z was calculated as Zcor = Zin. [(f/(i + g.(HR/HRin) + h.(PP/PPin) + 1.(MAP/MAPin)], where HRin, PPin

  2. Cytokines increase endothelin ETB receptor contractile activity in rat cerebral artery

    DEFF Research Database (Denmark)

    Leseth, K H; Adner, M; Berg, H K;

    1999-01-01

    The plasticity of endothelin ETB receptor activity and the influence of pro-inflammatory cytokines was examined in cerebral artery. In fresh rat basilar artery, the selective ETB receptor agonist, sarafotoxin S6c, induced negligible contractions. However, after 1 day of organ culture, fully defined...... receptor expression in cerebral arteries and sensitivity for pro-inflammatory cytokines, suggest a role in inflammatory cerebral diseases such as stroke....

  3. Non-invasive assessment of the left ventricular pressure to volume relationships during ejection period using a single cardiac probe system and tonometric measurement of radial arterial pressure

    International Nuclear Information System (INIS)

    The left ventricular (LV) pressure to volume relationships are very sensitive parameters for the evaluation of the LV function. For measurement of LV pressure in an entire cardiac cycle, an invasive method is always needed. However, on the assumption that the LV pressure is similar to that of aorta and radial artery during ejection period, we have developed a new system for simple and non-invasive assessment of the LV pressure to volume relationships. The LV volume is estimated by ECG-gated radionuclide ventriculography using a single cardiac probe system and the data were collected every 10 msec. The radial arterial pressure was measured simultaneously every 10 msec by a tonometry system. These data were transferred to the personal computer through RS-232c cable. Then the pressure to volume curves during ejection phase was generated automatically. Emax was calculated from these curves. Moreover, the new parameter called the ejection rate of change of power (ERCP) can be calculated. These parameters are very useful for the evaluation of the effect of the drugs on the LV performance. (author)

  4. Local blood pressure associates with the degree of luminal stenosis in patients with atherosclerotic disease in the middle cerebral artery.

    Science.gov (United States)

    Jiang, Yuanliang; Peng, Wenjia; Teng, Zhongzhao; Gillard, Jonathan H; Hong, Bo; Liu, Qi; Lu, Jianping

    2016-01-01

    The mechanism underlying atherosclerotic ischemic events within the middle cerebral artery (MCA) is unclear. High structural stress induced by blood pressure might be a potential aetiology as plaque rupture occurs when such mechanical loading exceeds its material strength. To perform reliable analyses quantifying the mechanical loading within a plaque, the local blood pressure is needed. However, data on MCA blood pressure is currently lacking. In this study, the arterial pressure proximal to the stenotic site in the MCA was measured in 15 patients scheduled for intervention. The relationships between these local measurements and pre-intervention and intra-intervention non-invasive arm measurements were assessed. The impact of luminal stenosis on the local blood pressure was quantified. Compared with the pre-intervention arm measurement, the intra-intervention arm pressure decreased significantly by 23.9 ± 11.8 and 9.3 ± 14.7 % at diastole and systole, respectively. The pressure proximal to the stenosis was much lower than the pre-intervention arm measurement (diastole: 65.3 ± 15.7 vs 82.0 ± 9.7, p pressure in the MCA in patients with stenosis pressure (22.8 ± 6.4 vs 11.1 ± 8.3, p = 0.01; unit: mmHg). However, diastolic pressure remained unaffected (69.2 ± 9.3 vs 62.8 ± 19.0, p = 0.58; unit: mmHg). In conclusion, the obtained results are helpful in understanding the local hemodynamic environment modulated by the presence of atherosclerosis. The local pressure measurements can be used for computational analysis to quantify the critical mechanical condition within an MCA lesion. PMID:27349223

  5. Stratification of Ambulatory Blood Pressure Monitoring Findings by Cluster Analysis in Patients with Arterial Hypertension, Obesity and Albuminuria

    Directory of Open Access Journals (Sweden)

    Samoyavcheva S.V.

    2013-12-01

    Full Text Available The aim of the investigation was to study the characteristics of ambulatory blood pressure monitoring (ABPM indices in the combination of arterial hypertension (AH with obesity and albuminuria using cluster analysis. Material and Methods. The study involved 70 AH patients randomly chosen, aged from 23 to 71 years (mean age — 47.9 years. ABPM was performed before antihypertensive therapy administration. We estimated body mass index and albuminuria level. ABPM indices were stratified into clusters. Results. Clusters with normal heart rate prevailed in patients with normal weight and overweight, I degree obesity in all AH varuants. Hypertensive clusters with tachycardia were found to prevail in patients with II–III degree obesity. AH structure changed with body mass increase. In overweight and I degree obesity there grows the occurrence of systolic-diastolic AH clusters. In II–III degree obesity the clusters of systolic-diastolic and isolated diastolic AH were revealed less frequently than in normal body weight, while isolated systolic AH clusters were found more frequently. Their occurrence increased in patients with a high albuminuria level as well. Conclusion. ABPM data can be grouped into clusters, and their own pathogenic mechanisms of AH maintenance and regulation seem to prevail in each cluster. In overweight and I degree obesity patients the occurrence of systolic-diastolic AH increases. With obesity degree increase there is the tendency for heart rate rise, and hemodynamic AH variants are redistributed towards the increase of isolated systolic AH, which is likely to be due to the increase in AH severity with vascular wall remodeling progression. Isolated systolic AH prevalence is increasing not only in II–III degree obesity, but also in high albuminuria supporting the significance of systolic AH in albuminuria development. No interaction between albuminuria and heart rate was revealed.

  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. The effect of chronic reductions in the arterial partial pressure of oxygen on the radiation response of an experimental tumour

    International Nuclear Information System (INIS)

    A previous study by the same authors has reported the effect of acute reductions in the arterial partial pressure of oxygen (Pa02) on tumour response to radiation. The results have been extended in the present paper to investigate tumour response to radiation in animals in which the Pa02 is chronically reduced. The purpose of these experiments was to simulate the condition of cancer patients undergoing radiotherapy in the presence of chronically low Pa02 values as might be expected in patients with chronic respiratory disease. Mice bearing transplantable KHT sarcomas were kept in a 12% 02 environment prior to (10-16 days), during and following the radiation treatment of their tumours. During the period of low Pa02, (about 50 mm Hg) exposure, the mice were found to increase their haemoglobin (Hb) levels by approximately 50%. Because of this increase, the response, determined using a growth delay assay of the tumours irradiated at reduced Pa02 was found to be the same as that observed for tumours in mice breathing air throughout the experiment. In mice with reduced Pa02 levels maintained at normal Hb concentrations by periodic bleeding, tumour response was found to be similar to that of mice with acute Pa02 reductions. These results indicate that chronic Pa02 reductions in the absence of Hb compensation may have a detrimental effect on the success of a radiation treatment. (author)

  8. Temporary arterial stenting in a full-house spaghetti wrist injury in a remote rural setting: benefit for hand perfusion or risk of increased morbidity?

    Science.gov (United States)

    Bauer, Stefan; Savundra, James

    2013-01-01

    We report a case of temporary arterial plastic tube stenting of the ulnar and radial artery in a complete spaghetti wrist injury in a remote rural setting. Exploration in a specialist centre 18 h postinjury revealed that the tubes were clotted off with adjacent thrombi but hand perfusion was maintained. Intimal damage required vein grafting of both arteries 24 h postinjury. Hand perfusion was not compromised at follow-up. This case highlights that arterial hand perfusion can be maintained without the ulnar and radial artery. Arterial manipulation and tube insertion outside a specialist centre bears the risk of increased morbidity and potential microembolism and must therefore not be attempted.

  9. Increased angiotensin II type 1 receptor expression in temporal arteries from patients with giant cell arteritis

    DEFF Research Database (Denmark)

    Dimitrijevic, Ivan; Malmsjö, Malin; Andersson, Christina;

    2009-01-01

    -AT(2) antibodies, was performed on formalin-fixed and paraffin-embedded temporal arteries. MAIN OUTCOME MEASURES: AT(1) and AT(2) receptor immunostaining intensity was quantified. RESULTS: Hematoxylin-eosin-stained sections of temporal arteries from patients with GCA showed intimal hyperplasia...

  10. 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)

    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 (Va) relationship (Va = 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

  11. Nitric Oxide Increases Arterial Endotheial Permeability through Mediating VE-Cadherin Expression during Arteriogenesis.

    Directory of Open Access Journals (Sweden)

    Baolin Yang

    Full Text Available Macrophage invasion is an important event during arteriogenesis, but the underlying mechanism is still only partially understood. The present study tested the hypothesis that nitric oxide (NO and VE-cadherin, two key mediators for vascular permeability, contribute to this event in a rat ischemic hindlimb model. In addition, the effect of NO on expression of VE-caherin and endothelial permeability was also studied in cultured HUVECs. We found that: 1 in normal arteriolar vessels (NAV, eNOS was moderately expressed in endothelial cells (EC and iNOS was rarely detected. In contrast, in collateral vessels (CVs induced by simple femoral artery ligation, both eNOS and iNOS were significantly upregulated (P<0.05. Induced iNOS was found mainly in smooth muscle cells, but also in other vascular cells and macrophages; 2 in NAV VE-cadherin was strongly expressed in EC. In CVs, VE-cadherin was significantly downregulated, with a discontinuous and punctate pattern. Administration of nitric oxide donor DETA NONOate (NONOate further reduced the amounts of Ve-cadherin in CVs, whereas NO synthase inhibitor L-NAME inhibited downregulation of VE-cadherin in CVs; 3 in normal rats Evans blue extravasation (EBE was low in the musculus gracilis, FITC-dextron leakage was not detected in the vascular wall and few macrophages were observed in perivascular space. In contrast, EBE was significantly increased in femoral artery ligation rats, FITC-dextron leakage and increased amounts of macrophages were detected in CVs, which were further enhanced by administration of NONOate, but inhibited by L-NAME supplement; 4 in vitro experiments confirmed that an increase in NO production reduced VE-cadherin expression, correlated with increases in the permeability of HUVECs. In conclusion, our data for the first time reveal the expression profile of VE-cadherin and alterations of vascular permeability in CVs, suggesting that NO-mediated VE-cadherin pathway may be one important

  12. Noninvasive tracking of systolic arterial blood pressure using pulse transit time measured with ECG and carotid doppler signals with intermittent calibration

    OpenAIRE

    Fujita, Yoshihisa

    2016-01-01

    We have developed a non-invasive blood pressure measurement system using pulse transit time (PTT) from the heart to the common carotid artery, measured by using an electrocardiogram (ECG) R-wave and carotid arterial Doppler signals at the anterior neck. In this study, we examined the validity of our system by comparing PTT derived systolic blood pressure (Dopp_SBP) with invasive radial systolic arterial pressure (Inv_SBP) with calibration every 15 min in the ICU setting.Methods: 17 patients u...

  13. Tricuspid Regurgitation Improvement in Relation to the Amount of Pulmonary Artery Pressure Reduction

    Directory of Open Access Journals (Sweden)

    Mahmood Sheikhfathollahi

    2010-08-01

    Full Text Available Background: Given the common concomitance of tricuspid regurgitation (TR with significant mitral stenosis, we aimed at exploring the relation between TR severity and pulmonary artery hypertension (PAH in patients who underwent mitral balloon valvotomy (MBV.Methods: We analyzed the echocardiography data of 133 consecutive patients (82.0% female, mean age 44.68 ± 12.56 years with different degrees of TR severity that underwent MBV between April 2006 and March 2008. The pulmonary artery systolic pressure (PAPs > 35 mmHg was considered as PAH.Results: Before MBV, 36.20% of the patients had moderate to severe TR, 92.5% PAH, and 18.0% right ventricular (RVdilation (RV dimension ≥ 33 mm. After MBV, TR severity improved in 41.4%, worsened in 8.3%, and did not change in 50.4%. Before and after MBV, PAPs was significantly correlated with TR severity, and the mean PAPs change in patients with improved TR was significantly more than that of patients without TR improvement (p value = 0.042. Tricuspid regurgitation severity and mean PAPs (from 52.83 ± 18.82 to 35.89 ± 9.39 mmHg decreased significantly after MBV (both p values <0.001; this reduction was significantly correlated to the amount of PAPs decrease. A cut-off point of ≥ 19 mmHg reductionin PAPs had a specificity of 71.79% and sensitivity of 52.73% to show TR severity improvement (by Receiver-Operative-Characteristics analysis. The mean of RV dimension decreased from 28.94 ± 5.43 to 27.95 ± 4.67 mm (p value < 0.001. In contrast to patients with RV dilation, TR reduced significantly in patients without RV dilation (p value < 0.001.Conclusion: Improvement in TR severity was directly correlated with the amount of PAPs reduction after MBV. Morestudies are needed to better define a cut-off value for PAPs reduction related to TR severity improvement.

  14. Outflow boundary conditions for 3D simulations of non-periodic blood flow and pressure fields in deformable arteries

    CERN Document Server

    Vignon-Clementel, Irene; Jansen, K E; Taylor, C A; 10.1080/10255840903413565

    2010-01-01

    The simulation of blood flow and pressure in arteries requires outflow boundary conditions that incorporate models of downstream domains. We previously described a coupled multidomain method to couple analytical models of the downstream domains with 3D numerical models of the upstream vasculature. This prior work either included pure resistance boundary conditions or impedance boundary conditions based on assumed periodicity of the solution. However, flow and pressure in arteries are not necessarily periodic in time due to heart rate variability, respiration, complex transitional flow or acute physiological changes. We present herein an approach for prescribing lumped parameter outflow boundary conditions that accommodate transient phenomena. We have applied this method to compute haemodynamic quantities in different physiologically relevant cardiovascular models, including patient-specific examples, to study non-periodic flow phenomena often observed in normal subjects and in patients with acquired or congen...

  15. Spatial Orientation and Morphology of the Pulmonary Artery: Relevance to Optimising Design and Positioning of a Continuous Pressure Monitoring Device.

    Science.gov (United States)

    Lee, Su-Lin; Aguib, Heba; Chapron, Julien; Bahmanyar, Reza; Borghi, Alessandro; Murphy, Olive; McLeod, Chris; ElGuindy, Ahmed; Yacoub, Magdi

    2016-06-01

    Personalised treatment of heart disease requires an understanding of the patient-specific characteristics, which can vary over time. A newly developed implantable surface acoustic wave pressure sensor, capable of continuous monitoring of the left ventricle filling pressure, is a novel device for personalised management of patients with heart disease. However, a one-size-fits-all approach to device sizing will affect its positioning within the pulmonary artery and its relationship to the interrogating device on the chest wall on a patient-specific level. In this paper, we analyse the spatial orientation and morphology of the pulmonary artery and its main branches in patients who could benefit from the device and normal controls. The results could optimise the design of the sensor, its stent, and importantly its placement, ensuring long-term monitoring in patient groups. PMID:27075735

  16. Increased Intraocular Pressure after Extensive Conjunctival Removal: A Case Report

    OpenAIRE

    Lee, Young Rok; Na, Jung Hwa; Kim, Jae Yong; Sung, Kyung Rim

    2013-01-01

    A 50-year-old woman, who had undergone extensive removal of conjunctiva on the right eye for cosmetic purposes at a local clinic 8 months prior to presentation, was referred for uncontrolled intraocular pressure (IOP) elevation (up to 38 mmHg) despite maximal medical treatment. The superior and inferior conjunctival and episcleral vessels were severely engorged and the nasal and temporal bulbar conjunctival areas were covered with an avascular epithelium. Gonioscopic examination revealed an o...

  17. Stratification of Ambulatory Blood Pressure Monitoring Findings by Cluster Analysis in Patients with Arterial Hypertension, Obesity and Albuminuria

    OpenAIRE

    Samoyavcheva S.V.; Shkarin Vl.V.

    2013-01-01

    The aim of the investigation was to study the characteristics of ambulatory blood pressure monitoring (ABPM) indices in the combination of arterial hypertension (AH) with obesity and albuminuria using cluster analysis. Material and Methods. The study involved 70 AH patients randomly chosen, aged from 23 to 71 years (mean age — 47.9 years). ABPM was performed before antihypertensive therapy administration. We estimated body mass index and albuminuria level. ABPM indices were stratified int...

  18. The Impact of Pulmonary Arterial Pressure on Exercise Capacity in Mild-to-Moderate Cystic Fibrosis: A Case Control Study

    OpenAIRE

    Katerina Manika; Pitsiou, Georgia G.; Boutou, Afroditi K.; Vassilis Tsaoussis; Nikolaos Chavouzis; Marina Antoniou; Maria Fotoulaki; Ioannis Stanopoulos; Ioannis Kioumis

    2012-01-01

    Background. Pulmonary hypertension (PH) is an often complication of severe cystic fibrosis (CF); however, data on the presence and impact of pulmonary vasculopathy in adult CF patients with milder disease, is very limited. Aim. To investigate, for the first time, the impact of systolic pulmonary arterial pressure (PASP) on maximal exercise capacity in adults with mild-to-moderate cystic fibrosis, without PH at rest. Methods. This is a Case Control study. Seventeen adults with mild-to-moderate...

  19. Management of initial orthostatic hypotension: lower body muscle tensing attenuates the transient arterial blood pressure decrease upon standing from squatting

    OpenAIRE

    Go-Schön, Ingeborg K.; Kim, Yu-Sok; Linzer, Mark; van Lieshout, Johannes J.; Wieling, Wouter; Krediet, C. T. Paul

    2007-01-01

    Abstract Initial orthostatic hypotension (IOH) comprises symptoms of cerebral hypoperfusion caused by an abnormally large transient mean arterial blood pressure (MAP) decrease 5-15 s after arising from a supine, sitting or squatting position. Few treatment options are available. We set out to test the hypothesis that lower body muscle tensing (LBMT) attenuates IOH after rising from squatting and its symptoms in daily life. Thirteen IOH patients (9 males, 27 years) rose twice from s...

  20. Inadvertent arterial insertion of a central venous catheter: delayed recognition with abrupt changes in pressure waveform during surgery -A case report-.

    Science.gov (United States)

    Choi, Yong Sun; Park, Ji Young; Kwak, Young Lan; Lee, Jong Wha

    2011-01-01

    We present a case of inadvertent arterial insertion of a central venous catheter, identified during a pericardiectomy procedure after observing abrupt changes in pressure waveform and confirmed via arterial blood gas analysis and transesophageal echocardiography. Central venous pressure measurement was initially 20 mmHg in supine, and then elevated to 30-40 mmHg in right lateral decubitus, presumably resulting from constrictive physiology of pericarditis. The pressure waveforms, however, abruptly changed from a venous to an arterial waveform during surgery. When visual discrimination between arterial and venous blood regurgitation is unreliable, anesthesiologists should confirm that using all the available methods one has on the scene, especially after at least two unsuccessful attempts or in patients with advanced age or clinical conditions resulting in jugular venous dilation. To prevent arterial catheterization, one should limit the leftward rotation of the head by <40° and consider using ultrasound-guided method after more than two unsuccessful attempts.

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

    Science.gov (United States)

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

    2002-10-01

    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 FAP by waveform filtering (transfer function) and generalized level (bias) correction that reduces the bias for short-term blood pressure records. OBJECTIVE To investigate if this methodology also decreases the extra bias during the night, thereby yielding a better estimate of the nocturnal dip. METHODS Twenty-four-hour FAP and BAP blood pressure recordings were simultaneously obtained in eight healthy normotensive volunteers and 14 patients with hypertension (ages 19-60 years), during standardized scheduled activities. The data were analysed off-line, applying the brachial reconstruction technique (reBAP) consisting of a waveform filter and level correction. Simultaneous beats yielded systolic, diastolic and mean pressures that were averaged per 30 min, per day, per night, per activity, over the 24-h period, and for volunteers and patients separately. RESULTS Over the full 24 h, FAP systolic, diastolic and mean values for the total group differed from BAP by +1 +/- 10, -8 +/- 7 and -10 +/- 8 mmHg (mean +/- SD), respectively. Similarly, reBAPs differed by +1 +/- 11, -2 +/- 7 and -2 +/- 7 mmHg. BAPs dipped by 20 +/- 8, 13 +/- 6 and 15 +/- 6 mmHg, respectively, during the night. These dips were overestimated by +8, +4 and +4 mmHg by FAP, but not by reBAP: -1, +1 and +1 mmHg. The volunteer and the patient groups showed slight differences in results, but these were not statistically significant. CONCLUSIONS The generalized reconstruction technique to obtain near-brachial pressure from non-invasive FAP almost completely removed bias over the full 24-h day-night period and improved tracking of diurnal changes for all three blood pressure values. PMID:12359976

  2. Clinical and psychological characteristics of patients with arterial hypertension, consuming an increased amount of salt

    Directory of Open Access Journals (Sweden)

    O. B. Poselyugina

    2015-01-01

    Full Text Available Objective: to Study the potential development of links between the formation of neurotic disorders personality and high salt intake (S with food in patients with arterial hypertension (AH.Materials and methods: the study involved 229 patients with essential hypertension. We determined the threshold of taste sensitivity to salt (TTS, the daily excretion of sodium ions in urine, was assessed psychological status of the patients, the type of attitude to the disease (LOBI, the severity of depression (Beck questionnaire.Results. It turned out that people consume AH TTS is much more than a healthy person. Patients consuming an increased amount of S, the disease develops earlier and runs a more aggressive accompanied by the emergence of a large number of neurotic complaints and cardiovascular nature. Their psychological status is dominated by anxiety and tension. Almost half of these patients have depression. Harmonious type of attitude to the disease occurs in them only in 1/3 of the cases, whereas a dominant role is played by neurotic and anxious types.Conclusions: Patients with hypertension high consumption of S represent a distinct group of patients in whom an increased intake of salt simulates the course of their illness and promotes the development of certain psychological characteristics.

  3. Artery by Neuropeptides

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    Esmeralda Sofia Costa Delgado

    2012-01-01

    Methods. Isolated rabbit eyes (n=12 were perfused in situ with tyrode through the external ophthalmic artery. Effects of intra-arterial injections of NPY 200 μg/ml (Group A; n=6 and VIP 200 μg/ml (Group B; n=6 on the recorded pressure were obtained. For statistical analysis, Student's paired t-test and Fast Fourier Transform were used. Results. Spontaneous oscillations were observed before any drug administration in the 12 rabbit models. NPY produced an increase in total vascular resistance and a higher frequency and amplitude of oscillations, while VIP evoked the opposite effects. Conclusions. This study provides evidence of vasomotion in basal conditions in rabbit external ophthalmic artery. Concerning drug effects, NPY increased arterial resistance and enhanced vasomotion while VIP produced opposite effects which demonstrates their profound influence in arterial vasomotion.

  4. A lumped-parameter model to investigate the effect of plantar pressure on arterial blood flow in a diabetic foot.

    Science.gov (United States)

    Hahn, C; Mahajan, A; Chu, T; Schoen, M

    2007-08-01

    This paper presents a lumped-parameter model for the big-toe region that investigates the effect of plantar pressure on the diameter of the blood vessels, specifically the arteries, in the presence of arterial and/or tissue changes. The model developed in this paper uses a multi-domain energy system approach to develop the lumped-parameter differential equations. Blood flow is modelled as fluidic flow through compliant pipes that have inertia, stiffness, and damping. The tissue material is treated as a soft compliant material that transmits the external force to the blood vessels. Conclusions have been drawn to show the effect of plantar pressure, tissue damage, and their combination on the diameter of the blood vessels. The principles used here can be used to model the entire foot and the model used to investigate the effect of plantar pressure, tissue damage, and arterial changes on different parts of the foot. The work presented here may also have applications in other vascular diseases. PMID:17937206

  5. Determination of the Effect of Nasal Septoplasty on Pulmonary Artery Pressure in Patients with Deviated Nasal Septum

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    Ghazipour

    2014-07-01

    Full Text Available Background Nasal septal deviation (NSD can cause upper airway obstruction, which results in hypoxia and therefore, pulmonary vasoconstriction, ventricular hypertrophy and right-sided heart failure. Objectives The aim of this study is to determine the mean pulmonary arterial pressure (mPAP of the patients with NSD and the effect of septoplasty on pulmonary arterial pressure. Patients and Methods Thirty five patients with NSD (mean age, 31.37 years; 19 men and 16 women were included in the study. Mean pulmonary arterial pressure was measured in the preoperative period and after third month postsurgery. Results The preoperative mPAP value (23.43 mmHg [SD, 3.84] was higher than postoperative values (20.17 mmHg [SD, 3.36]. There was a significant decrease in mPAP after the surgery (3.26 mmHg. P-value in our study was smaller than 0.001. Conclusions Nasal septal deviation like other causes of upper airway obstruction such as adenotonsillar hypertrophy affects mPAP. Nasal septoplasty is effective in reduction of mPAP in patients with NSD.

  6. Long term survival of patients with raised pulmonary arterial systolic pressure utilizing echocardiography—a five-year prospective study

    Institute of Scientific and Technical Information of China (English)

    Maw Pin Tan; Sushil K Bansal; Nu Nu Wynn; Murad Umerov; Angela Gillham; Alison Henderson; Anthony Hildreth; Shahid Junejo

    2012-01-01

    Background Pulmonary arterial systolic pressure (PASP) can be estimated with transthoracic echocardiography. However, the significance of raised PASP on routine echocardiography is uncertain. In this study, we evaluated the mortality and hospitalization rates of subjects with raised PASP in a cohort of patients referred directly by their general practitioners for routine outpatient (open access)echocardiography for further analysis of suspected heart failure. Results A total of 485 subjects were referred for open access echocardiography at our hospital in 2002. A cohort of 209/485 (43%) consecutive subjects with measurable tricuspid regurgitation were followed for a minimum of five years investigating hospitalization rates and survival. Some 62 of 209 (30%) subjects had pulmonary hypertension (PH). Subjects with PH were significantly more likely to have four or more hospital admissions (22% vs. 8%; P 30 days of cumulative hospital stay over five years (29% vs. 13%; P < 0.01). PH was significantly associated with mortality (P = 0.003),Records from the Office of National Statistics revealed that subjects with PH were more likely to have chronic lung diseases recorded as immediate or contributory causes of death (50% vs. 14%; P < 0.05). Conclusions PASP ≥ 36 mmHg on routine echocardiography is associated with recurrent hospital admissions, prolonged hospitalizations and increased cause of mortality. Therefore, the diagnosis of PH on echocardiography deserves further clinical evaluation, with future studies designed at defining a suitable diagnostic strategy.

  7. Low-dose plasmid DNA treatment increases plasma vasopressin and regulates blood pressure in experimental endotoxemia

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    Malardo Thiago

    2012-11-01

    Full Text Available Abstract Background Although plasmid DNA encoding an antigen from pathogens or tumor cells has been widely studied as vaccine, the use of plasmid vector (without insert as therapeutic agent requires further investigation. Results Here, we showed that plasmid DNA (pcDNA3 at low doses inhibits the production of IL-6 and TNF-α by lipopolysaccharide (LPS-stimulated macrophage cell line J774. These findings led us to evaluate whether plasmid DNA could act as an anti-inflammatory agent in a Wistar rat endotoxemia model. Rats injected simultaneously with 1.5 mg/kg of LPS and 10 or 20 μg of plasmid DNA had a remarkable attenuation of mean arterial blood pressure (MAP drop at 2 hours after treatment when compared with rats injected with LPS only. The beneficial effect of the plasmid DNA on MAP was associated with decreased expression of IL-6 in liver and increased concentration of plasma vasopressin (AVP, a known vasoconstrictor that has been investigated in hemorrhagic shock management. No difference was observed in relation to nitric oxide (NO production. Conclusion Our results demonstrate for the first time that plasmid DNA vector at low doses presents anti-inflammatory property and constitutes a novel approach with therapeutic potential in inflammatory diseases.

  8. Myosin heavy chain 15 is associated with bovine pulmonary arterial pressure.

    Science.gov (United States)

    Neary, Marianne T; Neary, Joseph M; Lund, Gretchen K; Holt, Timothy N; Garry, Franklyn B; Mohun, Timothy J; Breckenridge, Ross A

    2014-09-01

    Bovine pulmonary hypertension, brisket disease, causes significant morbidity and mortality at elevations above 2,000 m. Mean pulmonary arterial pressure (mPAP) is moderately heritable, with inheritance estimated to lie within a few major genes. Invasive mPAP measurement is currently the only tool available to identify cattle at risk of hypoxia-induced pulmonary hypertension. A genetic test could allow selection of cattle suitable for high altitude without the need for invasive testing. In this study we evaluated three candidate genes (myosin heavy chain 15 [MYH15], NADH dehydrogenase flavoprotein 2, and FK binding protein 1A) for association with mPAP in 166 yearling Angus bulls grazing at 2,182 m. The T allele (rs29016420) of MYH15 was linked to lower mPAP in a dominant manner (CC 47.2 ± 1.6 mmHg [mean ± standard error of the mean]; CT/TT 42.8 ± 0.7 mmHg; P = 0.02). The proportions of cattle with MYH15 CC, CT, and TT genotypes were 55%, 41%, and 4%, respectively. Given the high frequency of the deleterious allele, it is likely that the relative contribution of MYH15 polymorphisms to pulmonary hypertension is small, supporting previous predictions that the disease is polygenic. We evaluated allelic frequency of MYH15 in the Himalayan yak (Bos grunniens), a closely related species adapted to high altitude, and found 100% prevalence of T allele homozygosity. In summary, we identified a polymorphism in MYH15 significantly associated with mPAP. This finding may aid selection of cattle suitable for high altitude and contribute to understanding human hypoxia-induced pulmonary hypertension.

  9. Mechanisms underlying phase lag between systemic arterial blood pressure and cerebral blood flow velocity.

    Science.gov (United States)

    Kuo, Terry B J; Chern, Chang-Ming; Yang, Cheryl C H; Hsu, Hung-Yi; Wong, Wen-Jang; Sheng, Wen-Yung; Hu, Han-Hwa

    2003-01-01

    To explore the mechanisms underlying the phase lag between oscillations in arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV), ABP and CBFV signals were recorded noninvasively from normal volunteers who lay quietly in a supine position. Mean ABP (MAP) and CBFV (MFV) were calculated beat-to-beat by means of integration. Cerebral vascular resistance (CVR) was calculated by dividing MAP with MFV. Frequency domain analysis of MAP, MFV and CVR signals revealed very-low frequency (VLF, 0.016-0.04 Hz), low-frequency (LF, 0.04-0.15 Hz), and high-frequency (HF, 0.15-0.4 Hz) components. The transfer phase of MAP-CVR coupling in the LF and HF range was frequency-dependent, which is equivalent to a time delay of 2 s. However, the transfer phase differed in the CVR-MFV coupling in that the phase was distributed around 180 degrees across the LF and HF ranges. Cross-correlation analysis revealed a positive relationship between MAP-CVR coupling, with MAP leading by 2 s, and a negative relationship between CVR-MFV coupling, with CVR leading by 0.3 s. We concluded that the phase lag between oscillations in ABP and CBFV was chiefly contributed to by the starting latency of cerebral autoregulation (i.e. cerebral vasomotion, revealed by MAP-CVR coupling). Moreover, the negative correlation of the CVR-MFV coupling could offer a different explanation for the physiologic significance of the phase lead of CBFV-ABP oscillations.

  10. Effects of hypocretin and norepinephrine interaction in bed nucleus of the stria terminalis on arterial pressure.

    Science.gov (United States)

    Ciriello, J; Caverson, M M; Li, Z

    2013-01-01

    Forebrain neuronal circuits containing hypocretin-1 (hcrt-1) and norepinephrine (NE) are important components of central arousal-related processes. Recently, these two systems have been shown to have an overlapping distribution within the bed nucleus of the stria terminalis (BST), a limbic structure activated by stressful challenges, and which functions to adjust arterial pressure (AP) and heart rate (HR) to the stressor. However, whether hcrt-1 and NE interact in BST to alter cardiovascular function is unknown. Experiments were done in urethane-α-chloralose anesthetized, paralyzed, and artificially ventilated male Wistar rats to investigate the effect of hcrt-1 and NE on the cardiovascular responses elicited by l-glutamate (Glu) stimulation of BST neurons. Microinjections of hcrt-1, NE or tyramine into BST attenuated the decrease in AP and HR to Glu stimulation of BST. Additionally, combined injections of hcrt-1 with NE or tyramine did not elicit a greater attenuation than either compound alone. Furthermore, injections into BST of the α2-adrenergic receptor (α2-AR) antagonist yohimbine, but not the α1-AR antagonist 2-{[β-(4-hydroxyphenyl)ethyl]aminomethyl}-1-tetralone hydrochloride, blocked both the hcrt-1 and NE-induced inhibition of the BST cardiovascular depressors responses. Finally, injections into BST of the GABAA receptor antagonist bicuculline, but not the GABAB receptor antagonist phaclofen, blocked the hcrt-1 and NE attenuation of the BST Glu-induced depressor and bradycardia responses. These data suggest that hcrt-1 effects in BST are mediated by NE neurons, and hcrt-1 likely acts to facilitate the synaptic release of NE. NE neurons, acting through α2-AR may activate Gabaergic neurons in BST, which in turn through the activation of GABAA receptors inhibit a BST sympathoinhibitory pathway. Taken together, these data suggest that hcrt-1 pathways to BST through their interaction with NE and Gabaergic neurons may function in the coordination of

  11. [Influence of treatment with olmesartan on ambulatory blood pressure monitoring parameters in patients with arterial hypertension].

    Science.gov (United States)

    Bregvadze, T R; Tseluĭko, V I; Mishchuk, N E

    2013-12-01

    Hypertension is the most common disease of the cardiovascular system. Active treatment of hypertension with adequate control of blood pressure (BP) can prevent complications, improve life quality and increase life expectancy. One of the interesting new antihypertensive agents, from the group of angiotensin receptor blockers is olmesartan. The obvious advantages of ambulatory blood pressure monitoring to traditional one-time measurements of BP make this method perspective for quality control of anti-hypertensive therapy. The aim of this study was to evaluate the influence of treatment with olmesartan on ambulatory blood pressure monitoring parameters in patients with hypertension. 38 out-patients with hypertension at the age of 25-84 years (mean 55,3±10,6) were studied. Patients received olmesartan 20 mg daily as monotherapy (20 patients (52,6%)) or in combination with other antihypertensive agents (18 patients (47,4%)). Treatment continued for 6 months. The complex examination included: measurement of office brachial BP, electrocardiography, echocardiography and ambulatory blood pressure monitoring (ABPM). As a result of treatment, office BP and diurnal BP, according to ABPM, significantly decreased; the favorable circadian BP profile dynamics were found: significantly less frequently observed lack of reduction in BP during night (daily index - non-dipper) - 18% vs. 64% (p treatment of hypertensive patients with olmesartan provides significant decline not only in office BP, but also in diurnal BP, normalizes BP of active and passive periods, also - daily index and reduces BP variability.

  12. Increased Plasma Dipeptidyl Peptidase-4 Activities in Patients with Coronary Artery Disease

    Science.gov (United States)

    Yang, Guang; Li, Yuzi; Cui, Lan; Jiang, Haiying; Li, Xiang; Jin, Chunzi; Jin, Dehao; Zhao, Guangxian; Jin, Jiyong; Sun, Rui; Piao, Limei; Xu, Wenhu; Fang, Chenghu; Lei, Yanna; Yuan, Kuichang; Xuan, Chunhua; Ding, Dazi

    2016-01-01

    Dipeptidyl peptidase-4 (DPP4) is one of the most potent mammalian serine proteases participated in the pathogenesis of subclinical atherosclerosis. Here we investigated whether the plasma soluble form of DPP4 is associated with the prevalence of coronary artery disease (CAD) with and without diabetes mellitus (DM). A cross-sectional study was conducted of 496 aged 26–81 years with (n = 362) and without (n = 134) CAD. Plasma DPP4 activity, high sensitive C-reactive protein (hs-CRP), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein levels were measured. The coronary atherosclerotic plaques were evaluated by coronary angiography. The CAD patients with (n = 84) and without (n = 278) DM had significantly higher DPP4 levels (11.8 ± 3.1 vs. 6.9 ± 3.5 ng/mL, Psyntax scores. A multiple logistic regression analysis demonstrated that plasma DPP4 activity was independent predictor of CAD (odds ratio, 1.56; 95% CI, 1.19–1.73; P<0.01). Our study shows that increased DPP4 activity levels are associated with the presence of CAD and that the plasma DPP4 level serves as a novel biomarker for CAD even without DM. PMID:27654253

  13. Inverting Notions of the Biological Role of the Renin → Angiotensin-II → Aldosterone System and the Function of Arterial Pressure as a Metabolism Regulator

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    Vladimir N. Titov

    2014-09-01

    Full Text Available The phylogenetic theory of general pathology postulates that notions of the biological role of arterial pressure (AP in physiology and pathology have been subjected to inversion. The nephron’s activation of the synthesis of the components renin → angiotensin-II (A-II and the augmentation of aldosterone secretion are directed not at an increase in AP but at preserving the volume of the piece of the third world ocean, privatized by each species, - the pool of the intercellular milieu in which, just like millions of years before, there continue to live all cells. Phylogenetically earlier organs cannot regulate the action of a later one in AP phylogenesis – a physical factor in metabolism regulation. It is not the kidneys that increase AP but the vasomotor center, which, increasing AP in the proximal segment and further hydrodynamic pressure in the distal segment of the arterial bed, seeks to reanimate the function of nephrons, the biological function of endoecology and the biological reaction of excretion. In addition to playing a major role in the biological function of locomotion, AP is a physical factor in compensating for impairments in the biological functions of homeostasis, trophology, endoecology, and adaptation. There have formed sequentially three levels of metabolic regulation in phylogenesis. At an autocrine level, there occurs a specific regulation of biochemical reactions. Within paracrinally regulated communities of cells, in the distal segment of the arterial bed, metabolism is regulated by millions of local peristaltic pumps through compensating for the biological reaction of endothelium-dependent vasodilation, microcirculation, and the action of humoral mediators and hormonal principles. In vivo from the level of the vasomotor center metabolism is non-specifically, systemically regulated by the physical factor – AP – through sympathetic activation of the heart; in the proximal segment of the arterial bed and the distal

  14. Determination of Vascular Reactivity of Middle Cerebral Arteries from Stroke and Spinal Cord Injury Animal Models Using Pressure Myography.

    Science.gov (United States)

    Anwar, Mohammad A; Eid, Ali H

    2016-01-01

    Stroke and other neurovascular derangements are main causes of global death. They, along with spinal cord injuries, are responsible for being the principal cause of disability due to neurological and cognitive problems. These problems then lead to a burden on scarce financial resources and societal care facilities as well as have a profound effect on patients' families. The mechanism of action in these debilitating diseases is complex and unclear. An important component of these problems arises from derangement of blood vessels, such as blockage due to clotting/embolism, endothelial dysfunction, and overreactivity to contractile agents, as well as alteration in endothelial permeability. Moreover, the cerebro-vasculature (large vessels and arterioles) is involved in regulating blood flow by facilitating auto-regulatory processes. Moreover, the anterior (middle cerebral artery and the surrounding region) and posterior (basilar artery and its immediate locality) regions of the brain play a significant role in triggering the pathological progression of ischemic stroke particularly due to inflammatory activity and oxidative stress. Interestingly, modifiable and non-modifiable cardiovascular risk factors are responsible for driving ischemic and hemorrhagic stroke and spinal cord injury. There are different stroke animal models to examine the pathophysiology of middle cerebral and basilar arteries. In this context, arterial myography offers an opportunity to determine the etiology of vascular dysfunction in these diseases. Herein, we describe the technique of pressure myography to examine the reactivity of cerebral vessels to contractile and vasodilator agents and a prelude to stroke and spinal cord injury. PMID:27604741

  15. Correlations of ambulatory pulse pressure to large artery elasticity and vascular endothelial function in patients with primary hypertension%原发高血压患者动态脉压与大动脉弹性及血管内皮功能的关系

    Institute of Scientific and Technical Information of China (English)

    杜大勇; 李运田; 王红宇; 丁康; 李艳

    2008-01-01

    measured using a non-invasive portable ambulatory blood pressure monitor (ABPM-04, Meditech Inc, USA). Carotid-femoral and carotid-radial arterial pulse wave velocities were measured using an automatic pulse wave velocity determinator to evaluate large artery dilation. Blood flow mediated and nitroglycerin-dependent dilatation of the brachial artery was determined using a high-resolution ultrasound technique to evaluate vascular endothelial function. MAIN OUTCOME MEASURES: Correlations of ambulatory pulse pressure to large artery dilation and arterial endothelial function. RESULTS: All 156 patients were included in the final analysis. Correlation of ambulatory pulse pressure to large artery dilation: Carotid-femoral arterial pulse wave velocity was significantly positively correlated to daytime pulse pressure, night-time pulse pressure and 24-hour mean pulse pressure, with coefficient of partial correlation being 0.310, 0.281 and 0.303, respectively, P < 0.01). There were no significant correlations of carotid-radial arterial pulse wave velocity to daytime pulse pressure, night-time pulse pressure or 24-hour pulse pressure (P > 0.05). Correlation of ambulatory pulse pressure to arterial endothelial function: There was a linear relationship between ambulatory pulse pressure and blood flow-mediated blood vessel dilatation values. Linear correlation analysis was performed, taking ambulatory pulse pressure as an independent variable, and endothelial-dependent dilatation as a dependent variable. Results demonstrated that blood flow-mediated blood vessel dilatation was significantly negatively correlated to daytime pulse pressure, night-time pulse pressure and 24- hour mean pulse pressure (r = -0.684, -0.597, -0.668, P < 0.01). There was no correlation of ambulatory pulse pressure to non-endothelial-dependent blood vessel dilatation. CONCLUSION: Ambulatory pulse pressure increase is closely related to large artery elasticity decrease and injury to endothelial function in

  16. Selective increase of the contractile response to endothelin-1 in subcutaneous arteries from patients with essential hypertension

    DEFF Research Database (Denmark)

    Lind, H; Adner, M; Erlinge, D;

    1999-01-01

    arteries from subjects with established essential hypertension with matched controls. Furthermore, with RT-PCR, the occurrence of mRNA for the ETA and ET(B) receptors was shown in the tunica media layer of subcutaneous arteries in controls and hypertensives. The maximum contractile response to endothelin-1...... was significantly higher in the subcutaneous arteries of the hypertensives (by 88% with no change in potency) as compared to controls. The responses to noradrenaline, acetylcholine and potassium chloride did not differ between the groups. This selective increase in the contractile response to......Endothelin-1 has been shown to contribute to basal vascular tone in man. Since endothelin-1 is a potent vasoconstrictor putatively involved in hypertension, we have compared the contractile responses of endothelin-1 and noradrenaline in relation to potassium chloride in subcutaneous resistance...

  17. AGE, ARTERIAL STIFFNESS AND CARDIOVASCULAR RISK

    Institute of Scientific and Technical Information of China (English)

    蒋雄京; 刘国仗; 刘力生

    2001-01-01

    The recent researches on the structure and function of large artery find that increasing pulse pressure is associated with greater cardiovascular risk, especially risk of coronary events. Such risk is not explicable on the basis of increasing systolic pressure with age, and is apparent even when the major reason for increased pulse pressure is a relative decrease of diastolic pressure. The finding challenges the conventional approach to arterial pressure where diastolic pressure is traditionally viewed as the most robust indicator of caridovascular risk. An explanation is available. This is based on the perception of Harriet Dustan that hypertension in the older popula-

  18. Body Weight and Not Exercise Capacity Determines Central Systolic Blood Pressure, a Surrogate for Arterial Stiffness, in Children and Adolescents.

    Science.gov (United States)

    Müller, Jan; Meyer, Joanna; Elmenhorst, Julia; Oberhoffer, Renate

    2016-08-01

    Cardiopulmonary fitness benefits cardiovascular health. Various studies have shown a strong negative correlation between exercise capacity and arterial stiffness in adults. However, evidence for this connection in children and adolescents is scarce. About 320 healthy children and adolescents (252 male, 14.0±2.1 years) were evaluated with regard to their demographic, anthropometric and hemodynamic parameters, and their peak oxygen uptake. Peripheral and central systolic blood pressures were measured with patients in a supine position using an oscillometric device. Peak oxygen uptake was assessed by cardiopulmonary exercise testing. In multivariate regression, only peripheral systolic blood pressure (β=0.653, P<.001) and body weight (β=0.284, P<.001) emerged as independent determinants for central systolic blood pressure. Body weight therefore determines central systolic blood pressure in children and adolescents rather than measures of cardiorespiratory fitness. The prevention of overweight in childhood is necessary to reduce stiffening of the arteries and delay the onset of cardiovascular disease. PMID:26689169

  19. Drought Increases Consumer Pressure on Oyster Reefs in Florida, USA.

    Directory of Open Access Journals (Sweden)

    Hanna G Garland

    Full Text Available Coastal economies and ecosystems have historically depended on oyster reefs, but this habitat has declined globally by 85% because of anthropogenic activities. In a Florida estuary, we investigated the cause of newly reported losses of oysters. We found that the oyster reefs have deteriorated from north to south and that this deterioration was positively correlated with the abundance of carnivorous conchs and water salinity. In experiments across these gradients, oysters survived regardless of salinity if conchs were excluded. After determining that conchs were the proximal cause of oyster loss, we tested whether elevated water salinity was linked to conch abundance either by increasing conch growth and survivorship or by decreasing the abundance of a predator of conchs. In field experiments across a salinity gradient, we failed to detect spatial variation in predation on conchs or in conch growth and survivorship. A laboratory experiment, however, demonstrated the role of salinity by showing that conch larvae failed to survive at low salinities. Because this estuary's salinity increased in 2006 in response to reduced inputs of freshwater, we concluded that the ultimate cause of oyster decline was an increase in salinity. According to records from 2002 to 2012, oyster harvests have remained steady in the northernmost estuaries of this ecoregion (characterized by high reef biomass, low salinity, and low conch abundance but have declined in the southernmost estuaries (characterized by lower reef biomass, increases in salinity, and increases in conch abundance. Oyster conservation in this ecoregion, which is probably one of the few that still support viable oyster populations, may be undermined by drought-induced increases in salinity causing an increased abundance of carnivorous conchs.

  20. Effect of continuous positive airway pressure treatment on serum adiponectin level and mean arterial pressure in male patients with obstructive sleep apnea syndrome

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xi-long; YIN Kai-sheng; LI Chong; JIA En-zhi; LI Yan-qun; GAO Zhao-fang

    2007-01-01

    Background Recent research suggested that obstructive sleep apnea syndrome (OSAS) might be independently associated with hypoadiponectinemia, which was linked to some complications of OSAS, such as hypertension, diabetes,etc. This study was conducted to investigate the effect of continuous positive airway pressure (CPAP) treatment on changes of both serum adiponectin levels and mean arterial pressure and their possible links in male OSAS patients.Methods Twenty-three adult male patients with moderate-to-severe OSAS but without obesity, coronary heart disease and diabetes were recruited. Their blood sampleswere collected and moming mean arterial pressure (MAP) was measured before CPAP treatment and on day 3, 7, 14 of CPAP treatment respectively. The serum adiponectin concentration was tested with radioimmunoassay.Results Compared with the serum adiponectin level before CPAP treatment, no significant change was found in OSAS patients on day 3 and day 7 of CPAP treatment (P>0.05). It was not until day 14 of CPAP treatment did a significant elevation in serum adiponectin level occur (P<0.01). Meanwhile, the MAP showed no statistically significant difference among its levels before CPAP, on day 3 and day 7 of CPAP treatment (P>0.05). However, on day 14 of CPAP treatment,a significantly lower MAP than that obtained before treatment was observed (P<0.05).Conclusions CPAP treatment can gradually reverse hypoadiponectinemia and reduce MAP in OSAS patients.Hypoadiponectinemia might be involved in the pathogenesis of OSAS-mediated hypertension.

  1. Renal Denervation Normalizes Arterial Pressure With No Effect on Glucose Metabolism or Renal Inflammation in Obese Hypertensive Mice.

    Science.gov (United States)

    Asirvatham-Jeyaraj, Ninitha; Fiege, Jessica K; Han, Ruijun; Foss, Jason; Banek, Christopher T; Burbach, Brandon J; Razzoli, Maria; Bartolomucci, Alessandro; Shimizu, Yoji; Panoskaltsis-Mortari, Angela; Osborn, John W

    2016-10-01

    Hypertension often occurs in concurrence with obesity and diabetes mellitus, commonly referred to as metabolic syndrome. Renal denervation (RDNx) lowers arterial pressure (AP) and improves glucose metabolism in drug-resistant hypertensive patients with high body mass index. In addition, RDNx has been shown to reduce renal inflammation in the mouse model of angiotensin II hypertension. The present study tested the hypothesis that RDNx reduces AP and renal inflammation and improves glucose metabolism in obesity-induced hypertension. Eight-week-old C57BL/6J mice were fed either a low-fat diet (10 kcal%) or a high-fat diet (45 kcal%) for 10 weeks. Body weight, food intake, fasting blood glucose, and glucose metabolism (glucose tolerance test) were measured. In a parallel study, radiotelemeters were implanted in mice for AP measurement. High fat-fed C57BL/6J mice exhibited an inflammatory and metabolic syndrome phenotype, including increased fat mass, increased AP, and hyperglycemia compared with low-fat diet mice. RDNx, but not Sham surgery, normalized AP in high-fat diet mice (115.8±1.5 mm Hg in sham versus 96.6±6.7 mm Hg in RDNx). RDNx had no significant effect on AP in low-fat diet mice. Also, RDNx had no significant effect on glucose metabolism or renal inflammation as measured by the number of CD8, CD4, and T helper cells or levels of inflammatory cytokines in the kidneys. These results indicate that although renal nerves play a role in obesity-induced hypertension, they do not contribute to impaired glucose metabolism or renal inflammation in this model.

  2. VARIATION IN THE SYSTOLIC ARTERIAL PRESSURE WITH THE CHANGES OF POSITION, AS PREDICTOR OF POSTANESTHETIC HYPOTENSION IN ELECTIVE CESAREAN (IN SPANISH

    Directory of Open Access Journals (Sweden)

    De la Peña-Martínez Michael

    2014-01-01

    Full Text Available Introduction: It is important to identify to those pregnant women with risk to present postanesthetic arterial hypotension, when they are submitted to cesarean under spinal anesthesia. Objective: to identify if the variability in the systolic arterial pressure (SAP with the preoperative changes of position is predictor of postanesthetic arterial hypotension in elective cesarean. Methods: 244 women with pregnancy at term, programmed for elective cesarean were studied. Preanesthetic measures of the SAP in supine decubitus and in left lateral decubitus position were carried out, estimating the difference between the two measures. Postanesthetic arterial hypotension was defined as SAP lower than 90 mmHg or reduction higher to 30% of the SAP in supine decubitus position. Results: postanesthetic arterial hypotension was presented in 107 (43.8% of the pregnant women. The variation of the SAP in the group that presented postanesthetic arterial hypotension was 10.5 [2.0 to 16.5] Vs 2.5 [-6.5 to 6.0] between those who did not present it (P<0,0001. It was estimated that variability higher to 11 mmHg of the SAP predicted postanesthetic arterial hypotension with sensibility: 47.6%, specificity: 93.4%, LR (+: 7.26, LR (-: 0.58 and area under the curve of 0.737 (CI 95%: 0.677-0.791, (p=0.0001. In turn such a variation was significant risk factor for the decrease of the arterial pressure. RR: 2.79 (CI95%: 2.19-3.56. Conclusion: the preanesthetic variation of the SAP with the change of position from supine decubitus to lateral decubitus position was predictor of arterial hypotension subsequent to the use of spinal anesthesia in pregnant women submitted to elective cesareans. Rev.Cienc.Biomed. 2014;5(1:29-34 KEYWORDS Arterial Pressure; Blood Pressure; Cesarean Section; Anesthesia, Obstetric.

  3. Increased angiotensin II type 1 receptor expression in temporal arteries from patients with giant cell arteritis

    DEFF Research Database (Denmark)

    Dimitrijevic, Ivan; Malmsjö, Malin; Andersson, Christina;

    2009-01-01

    immunohistochemical study of temporal arteries using archival formalin-fixed, paraffin-embedded tissue. PARTICIPANTS: Ten patients with GCA and 10 control patients, who were clinically suspected of having GCA but were diagnosed as not having GCA, were included. METHODS: Immunohistochemistry, using anti-AT(1) and anti......-AT(2) antibodies, was performed on formalin-fixed and paraffin-embedded temporal arteries. MAIN OUTCOME MEASURES: AT(1) and AT(2) receptor immunostaining intensity was quantified. RESULTS: Hematoxylin-eosin-stained sections of temporal arteries from patients with GCA showed intimal hyperplasia...... with antibodies for the AT(2) receptor was similar in the patients with GCA and in controls. CONCLUSIONS: These results suggest that AT(1) receptors play a role in the development of GCA. Inhibition of the angiotensin system may thus provide a noncorticosteroid alternative for the treatment of GCA. FINANCIAL...

  4. Decreased adiponectin and increased inflammation expression in epicardial adipose tissue in coronary artery disease

    Directory of Open Access Journals (Sweden)

    Sun Zongquan

    2011-01-01

    Full Text Available Abstract Background Disorders of endocrine substances in epicardial adipose tissue are known causes of coronary artery disease (CAD. Adiponectin is associated with cardiovascular disease. However, expression of adiponectin in epicardial adipose tissue and its function in CAD pathogenesis is unclear. This study investigates adiponectin expression in epicardial adipose tissue in CAD patients. Methods Vessels or adipose tissue samples collected from CAD patients and non-CAD controls were examined after immunochemical staining. Adiponectin, cytokines of interleukin-6 (IL-6 and necrosis factor-α (TNF-α and toll-like receptor 4 (TLR4 expression level in adipose tissue were measured using real-time quantitative RT-PCR. Adiponectin concentrations in peripheral and coronary sinus vein plasma were measured with enzyme-linked immunosorbent assay. Peripheral vein plasma biochemistries were performed with routine laboratory techniques. Monocytes were collected from blood using lymphocyte separation medium. Expression level of cytokines and transcription factor NF-κB were measured to learn the effect of adiponectin on stearic acid-stimulated monocytes. Percentage of TLR4 positive monocytes was analyzed using flow cytometry. Results Histological examination revealed increased macrophage infiltration into epicardial adipose tissue of CAD patients. Decreased adiponectin displayed by real-time quantitative RT-PCR was associated with enhanced cytokines of IL-6 and TNF-α or TLR4 expression level in epicardial adipose tissue, suggesting decreased circulating adiponectin may be useful as a more sensitive predictor for coronary atherosclerosis than routine laboratory examinations. Adiponectin suppressed secretion of IL-6 and TNF-α in stimulated monocytes and TLR4 was expressed on cell surfaces. Conclusions Endocrine disorders in epicardial adipose tissue are strongly linked to CAD, and adiponectin has a protective effect by inhibiting macrophage

  5. Correlation between 24-hour profile of blood pressure and ventricular arrhythmias and their prognostic significance in patients with arterial hypertension

    Directory of Open Access Journals (Sweden)

    Đorđević Dragan

    2008-01-01

    Full Text Available Background/Aim. Left ventricular hypertrophy (LVH, apart from arterial hypertension, is a risk factor for electrophysiologic heart condition disorder and sudden cardiac death. The aim of this study was to examine a relationship between complex ventricular arrhythmias and parameters of 24-hour ambulatory blood pressure monitoring in the patients with arterial hypertension and left ventricular hypertrophy (LVH, as well as their prognostic significance during a five-year follow-up. Methods. Ninety patients with arterial hypertension and LVH were included in this study (mean age 55.2±8.3 years. There were 35 healthy people in the control group (mean age 54.5±7.1 years. Left ventricular mass index was 171.9±32.4 g/m2 in the LVH group and 102.4±13.3 g/m2 in the control group. Clinical examination, echocardiogram, 24-hour ambulatory blood pressure monitoring and 24-hour holter monitoring were done in all of the examined persons. Ventricular arrhythmias were classified by the Lown classification. Results. In the LVH group there were 54 (60.0% of the patients with ≥ III Lown class. The best predictor of a Lown class were left ventricular mass index by using multivariate stepwise regression analyses (β = 0.212; p < 0.05 and small decrease of diastolic blood pressure during the night (β = -0.293; p < 0.01. The main predictor of bad prognosis was left ventricular mass index during a five year follow-up (β = 0.302; p < 0.01, for stepwise regression model: F = 8.828; p < 0.01, adjusted R2 = 0.091. Conclusion. Left ventricular arrhythmias are frequent in patients with lower decrease of blood pressure during the night. There was no correlation between the degree of ventricular arrhythmias and parameters from 24-hour blood pressure monitoring and a five-year prognosis in the patients with arterial hypertension and LVH. A bad five-year follow-up outcome of hypertensive disease depends on left ventricular mass index.

  6. Exercise increases pressure pain tolerance but not pressure and heat pain thresholds in healthy young men

    DEFF Research Database (Denmark)

    Vaegter, H. B.; Bement, M. Hoeger; Madsen, A. B.;

    2016-01-01

    : On three different days, 20 healthy young men performed two submaximal isometric knee extensions (30% maximal voluntary contraction in 3 min) and a control condition (quiet rest). Before and immediately after exercise and rest, the sensitivity to heat pain and pressure pain was assessed in randomized......BACKGROUND: Exercise causes an acute decrease in the pain sensitivity known as exercise-induced hypoalgesia (EIH), but the specificity to certain pain modalities remains unknown. This study aimed to compare the effect of isometric exercise on the heat and pressure pain sensitivity. METHODS...

  7. Increased levels of endothelin ETB receptor mRNA in human omental arteries after organ culture

    DEFF Research Database (Denmark)

    Möller, S; Adner, M; Edvinsson, L

    1998-01-01

    1. Using competitive reverse transcription-polymerase chain reaction (RT-PCR) and in vitro pharmacology, smooth muscle endothelin ETB receptor expression was studied in segments of human omental artery, fresh and after organ culture for 1 and 5 days. 2. The competitive RT-PCR assay used in the pr...

  8. Calcium intake is not associated with increased coronary artery calcification: The Framingham Study

    Science.gov (United States)

    Adequate calcium intake is known to protect the skeleton. However, studies that have reported adverse effects of calcium supplementation on vascular events have raised widespread concern. We assessed the association between calcium intake (from diet and supplements) and coronary artery calcification...

  9. Inhibition of PKC activity blocks the increase of ETB receptor expression in cerebral arteries

    DEFF Research Database (Denmark)

    Henriksson, Marie; Vikman, Petter; Stenman, Emelie;

    2006-01-01

    BACKGROUND: Previous studies have shown that there is a time-dependent upregulation of contractile endothelin B (ETB) receptors in middle cerebral arteries (MCA) after organ culture. This upregulation is dependent on mitogen-activated protein kinases and possibly protein kinase C (PKC). The aim o...

  10. Dietary selenium increases the antioxidant levels and ATPase activity in the arteries and veins of poultry.

    Science.gov (United States)

    Cao, Changyu; Zhao, Xia; Fan, Ruifeng; Zhao, Jinxin; Luan, Yilin; Zhang, Ziwei; Xu, Shiwen

    2016-07-01

    Selenium (Se) deficiency is associated with the pathogenesis of vascular diseases. It has been shown that oxidative levels and ATPase activity were involved in Se deficiency diseases in humans and mammals; however, the mechanism by how Se influences the oxidative levels and ATPase activity in the poultry vasculature is unclear. We assessed the effects of dietary Se deficiency on the oxidative stress parameters (superoxide dismutase, catalase, and hydroxyl radical) and ATPase (Na(+)K(+)-ATPase, Ca(++)-ATPase, Mg(++)-ATPase, and Ca(++)Mg(++)-ATPase) activity in broiler poultry. A total of 40 broilers (1-day old) were randomly divided into a Se-deficient group (L group, fed a Se-deficient diet containing 0.08 mg/kg Se) and a control group (C group, fed a diet containing sodium selenite at 0.20 mg/kg Se). Then, arteries and veins were collected following euthanasia when typical symptoms of Se deficiency appeared. Antioxidant indexes and ATPase activity were evaluated using standard assays in arteries and veins. The results indicated that superoxide dismutase activity in the artery according to dietary Se deficiency was significantly lower (p < 0.05) compared with the C group. The catalase activity in the veins and hydroxyl radical inhibition in the arteries and veins by dietary Se deficiency were significantly higher (p < 0.05) compared with the C group. The Se-deficient group showed a significantly lower (p < 0.05) tendency in Na(+)K(+)-ATPase activity, Ca(++)-ATPase activity, and Ca(++)Mg(++)-ATPase activity. There were strong correlations between antioxidant indexes and Ca(++)-ATPase activity. Thus, these results indicate that antioxidant indexes and ATPases may have special roles in broiler artery and vein injuries under Se deficiency. PMID:26637493

  11. Increasing severity of cardiovascular risk factors with increasing middle cerebral artery stenotic involvement in type 2 diabetic Chinese patients with asymptomatic cerebrovascular disease

    OpenAIRE

    Thomas, GN; Lin, JW; Lam, WWM; Tomlinson, B; Yeung, V; Chan, JCN; Liu, R; Wong, KS

    2004-01-01

    OBJECTIVE: To identify determinants associated with increasing severity of middle cerebral artery (MCA) stenosis in asymptomatic Chinese type 2 diabetic patients with and without MCA stenosis determined using transcranial Doppler. Conventional risk factors contribute to the pathogenesis of ischemic stroke, and differences in the pattern of these may explain the heterogeneity of disease presentation in different populations. In Chinese patients, MCA stenosis is the most commonly identified int...

  12. Effect of stellate block on vasomotor factor, vascular endothelial nitricoxide synthase and pulmonary arterial pressure in rabbits with hypoxic pulmonary artery hypertension

    Institute of Scientific and Technical Information of China (English)

    Shunhou He; Qing Li; Sen Chen; Qingxiu Wang

    2007-01-01

    BACKGROUND: At present, inhalation of nitrogen monoxidum (NO) or other angiotenic is widely used to cure hypoxic pulmonary artery hypertension. In addition, recent researches demonstrate that postganglionic fiber of stellate ganglion can regulate contents of blood vessel endothelium-calcitonin gene-related peptide (BE-CGRP) and nitricoxide synthase (NOS) in lung tissue. Therefore, stellate ganglion which is blocked with the local anesthetic may cause therapeutic effects on hypoxic pulmonary artery hypertension.OBJECTIVE: To observe the effects of stellate block on calcitonin gene-related peptide (CGRP) of vasodilation factors, prostacyclin, endothelin-1 of vasoconstriction factors, thromboxan, blood vessel endothelium-nitricoxide synthase (BE-NOS) and mean arterial pressure of lung tissue in rabbits with hypoxic pulmonary artery hypertension.DESIGN: Randomly controlled animal study.SETTING: Neurological Institute of Taihe Hospital Affiliated to Yunyang Medical College.MATERIALS: A total of 24 adult Japanese rabbits of both genders and weighing 2.3 - 2.6 kg were provided by Animal Experimental Center of Hubei Academy of Medical Science. SP kit was provided by Beijing Zhongshan Biotechnology Co., Ltd.; moreover, kits of endothelin-1, CGRP, prostacyclin and thromboxan were provided by Radioimmunity Institute, Scientific and Technological Developing Center, General Hospital of Chinese PLA, and color image analytical system (Leica-Q500IW) was made in Germany.METHODS: The experiment was carried out in the Neurological Institute of Taihe Hospital affiliated to Yunyang Medical College from February to December 2002, ① Rabbits were performed with aseptic manipulation to exposure left stellate ganglion and then it was put in epidural catheter for 1 week. In addition,one end of epidural catheter was fixed near by stellate ganglion and the other end was fixed through dorsal neck. All rabbits were randomly divided into 4 groups, including normal control group, stellate block

  13. Morphological, histochemical, and interstitial pressure changes in the tibialis anterior muscle before and after aortofemoral bypass in patients with peripheral arterial occlusive disease

    Directory of Open Access Journals (Sweden)

    Grigoriadis Nikolaos

    2002-02-01

    Full Text Available Abstract Background Morphological and electrophysiological studies of ischemic muscles in peripheral arterial disease disclosed evidence of denervation and fibre atrophy. The purpose of the present study is to describe morphological changes in ischemic muscles before and after reperfusion surgery in patients with peripheral occlusive arterial disease, and to provide an insight into the effect of reperfusion on the histochemistry of the reperfused muscle. Methods Muscle biopsies were obtained from the tibialis anterior of 9 patients with chronic peripheral arterial occlusive disease of the lower extremities, before and after aortofemoral bypass, in order to evaluate the extent and type of muscle fibre changes during ischemia and after revascularization. Fibre type content and muscle fibre areas were quantified using standard histological and histochemical methods and morphometric analysis. Each patient underwent concentric needle electromyography, nerve conduction velocity studies, and interstitial pressure measurements. Results Preoperatively all patients showed muscle fibre atrophy of both types, type II fibre area being more affected. The mean fibre cross sectional area of type I was 3,745 μm2 and of type II 4,654 μm2 . Fibre-type grouping, great variation in fibre size and angular fibres were indicative of chronic dennervation-reinnervation, in the absence of any clinical evidence of a neuropathic process. Seven days after the reperfusion the areas of both fibre types were even more reduced, being 3,086 μm2 for type I and 4,009 μm2 for type II, the proportion of type I fibres, and the interstitial pressure of tibialis anterior were increased. Conclusions The findings suggest that chronic ischemia of the leg muscles causes compensatory histochemical changes in muscle fibres resulting from muscle hypoxia, and chronic dennervation-reinnervation changes, resulting possibly from ischemic neuropathy. Reperfusion seems to bring the oxidative

  14. Increased regional epicardial fat volume associated with reversible myocardial ischemia in patients with suspected coronary artery disease.

    Science.gov (United States)

    Khawaja, Tuba; Greer, Christine; Thadani, Samir R; Kato, Tomoko S; Bhatia, Ketan; Shimbo, Daichi; Kontak, Andrew; Konkak, Andrew; Bokhari, Sabahat; Einstein, Andrew J; Schulze, P Christian

    2015-04-01

    Epicardial adipose tissue is a source of pro-inflammatory cytokines and has been linked to the development of coronary artery disease. No study has systematically assessed the relationship between local epicardial fat volume (EFV) and myocardial perfusion defects. We analyzed EFV in patients undergoing SPECT myocardial perfusion imaging combined with computed tomography (CT) for attenuation correction. Low-dose CT without contrast was performed in 396 consecutive patients undergoing SPECT imaging for evaluation of coronary artery disease. Regional thickness, cross-sectional areas, and total EFV were assessed. 295 patients had normal myocardial perfusion scans and 101 had abnormal perfusion scans. Mean EFVs in normal, ischemic, and infarcted hearts were 99.8 ± 82.3 cm(3), 156.4 ± 121.9 cm(3), and 96.3 ± 102.1 cm(3), respectively (P coronary artery (87.1 ± 76.4 vs 46.7 ± 40.6 cm(3); P = 0.005). Our results demonstrate increased regional epicardial fat in patients with active myocardial ischemia compared to patients with myocardial scar or normal perfusion on nuclear perfusion scans. Our results suggest a potential role for cardiac CT to improve risk stratification in patients with suspected coronary artery disease.

  15. Fatores de risco associados à pressão arterial elevada em adolescentes Risk factors associated with high blood pressure in adolescents

    Directory of Open Access Journals (Sweden)

    Kelly Samara da Silva

    2007-08-01

    = 5.5; CI 95% = 1.11-27.53, and girls: OR = 4.8; CI 95% = 1.51-15.45. The other variables did not seem to be associated with high AP. In this study, among the various risk factors analyzed, body overweight acted out as the only potential risk factor increasing arterial blood pressure in adolescents, irrespective of their sex and age.

  16. 杀菌性/通透性增加蛋白模拟肽对内毒素休克模型家兔动脉血压影响的研究%Effects of bactericidal/permeability increasing protein modeling peptide on arterial blood pressure of endotoxin-shocked rabbits

    Institute of Scientific and Technical Information of China (English)

    卫国; 吕根法; 郭毅斌; 郑江

    2003-01-01

    杀菌性/通透性增加蛋白(Bactericidal/permeability increasing protein,BPI)是一种存在于人及哺乳动物中性粒细胞嗜天青颗粒中带正电荷的蛋白质,具有较强的杀灭革兰阴性菌(Gramnegative bacteria,GNB)及中和内毒素(Lipopolysaeeharide,LPS)的能力,对严重GNB感染具有一定疗效。通过多年的研究,本室采用计算机分子模拟技术设计合成了BP1模拟肽,本研究拟通过观察BP1模拟肽对平均动脉压、脉压的影响,以了解其抗内毒素休克功效。

  17. Small artery elasticity is decreased in patients with systemic lupus erythematosus without increased intima media thickness

    OpenAIRE

    Nienhuis, Hans LA; de Leeuw, Karina; Bijzet, Johan; van Doormaal, Jasper J.; van Roon, Arie M.; Smit, Andries J; Graaff, Reindert; Kallenberg, Cees GM; Bijl, Marc

    2010-01-01

    Introduction The objectives of this study were to determine small arterial elasticity (SAE) in systemic lupus erythematosus (SLE) and to investigate its relationship with intima media thickness (IMT), accumulation of advanced glycation end products (AGEs), endothelial activation and inflammation. Methods Thirty SLE patients with inactive disease and 30 age- and sex-matched healthy controls were included. Twenty patients with essential hypertension (EH) served as positive control. SAE was asse...

  18. Chronic intrauterine pulmonary hypertension increases main pulmonary artery stiffness and adventitial remodeling in fetal sheep

    OpenAIRE

    Dodson, R. Blair; Morgan, Matthew R.; Galambos, Csaba; Hunter, Kendall S.; Abman, Steven H.

    2014-01-01

    Persistent pulmonary hypertension of the newborn (PPHN) is a clinical syndrome that is characterized by high pulmonary vascular resistance due to changes in lung vascular growth, structure, and tone. PPHN has been primarily considered as a disease of the small pulmonary arteries (PA), but proximal vascular stiffness has been shown to be an important predictor of morbidity and mortality in other diseases associated with pulmonary hypertension (PH). The objective of this study is to characteriz...

  19. An acoustical pump capable of significantly increasing pressure ratio of thermoacoustic heat engines

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Pressure ratio is one of the important parameters for evaluating a thermoacoustic heat engine. A so-called acoustical pump, which is capable of significantly increasing pressure ratio of a thermoacoustic heat engine, is proposed. Its operating principle is given. Also, a verification experiment is done with nitrogen gas in the energy-focused thermoacoustic heat engine, showing that the pressure ratio increased from 1.25 to 1.47.

  20. Benidipine has effects similar to losartan on the central blood pressure and arterial stiffness in mild to moderate essential hypertension

    Institute of Scientific and Technical Information of China (English)

    Sang-Hyun Ihm; Hui-Kyung Jeon; Shung Chull Chae; Do-Sun Lim; Kee-Sik Kim; Dong-Ju Choi; Jong-Won Ha

    2013-01-01

    Background Central blood pressure (BP) is pathophysiologically more important than peripheral BP for the pathogenesis of cardiovascular disease.Arterial stiffness is also a good predictor of cardiovascular morbidity and mortality.The effects of benidipine,a unique dual L-/T-type calcium channel blocker,on central BP have not been reported.This study aimed to compare the effect of benidipine and losartan on the central BP and arterial stiffness in mild to moderate essential hypertensives.Methods This 24 weeks,multi-center,open label,randomized,active drug comparative,parallel group study was designed as a non-inferiority study.The eligible patients (n=200) were randomly assigned to receive benidipine (n=101)or losartan (n=99).Radial artery applanation tonometry and pulse wave analysis were used to measure the central BP,pulse wave velocity (PWV) and augmentation index (Alx).We also measured the metabolic and inflammatory markers.Results After 24 weeks,the central BP decreased significantly from baseline by (16.8+14.0/10.5+9.2) mmHg (1mmHg =0.133 kPa) (systolic/diastolic BP; P <0.001) in benidipine group and (18.9+14.7/12.1+10.2) mmHg (P <0.001)in losartan group respectively.Both benidipine and losartan groups significantly lowered peripheral BP (P <0.001) and Alx (P <0.05),but there were no significant differences between the two groups.The mean aortic,brachial and femoral PWV did not change in both groups after 24-week treatment.There were no significant changes of the blood metabolic and inflammatory biomarkers in each group.Conclusion Benidipine is as effective as losartan in lowering the central and peripheral BP,and improving arterial stiffness.

  1. 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.

  2. Maternal carotid remodeling and increased carotid arterial stiffness in normal late-gestational pregnancy as assessed by radio-frequency ultrasound technique

    OpenAIRE

    Yuan, Li-Jun; Xue, Dan; DUAN, YUN-YOU; Cao, Tie-Sheng; Zhou, Ning

    2013-01-01

    Background The adaption of elastic arteries to transient increase in hemodynamic load in normal pregnancy (NP) remains controversial. The purpose of this study was to investigate the NP carotid remodeling and regional arterial stiffness before and after parturition. Methods Fifty-one NP women and 30 age-matched non-pregnant women were included. All women underwent right common carotid artery (RCCA) measurements with MylabTwice ultrasound instrument (Esaote, Italy). Carotid intima-medial thick...

  3. Quantitative 3D pulmonary MR-perfusion in patients with pulmonary arterial hypertension: Correlation with invasive pressure measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ley, Sebastian [Department of Pediatric Radiology, Children' s Hospital University Heidelberg, Im Neuenheimer Feld 153, 69120 Heidelberg (Germany) and Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)]. E-mail: ley@gmx.net; Mereles, Derliz [Internal Medicine III, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg (Germany); Risse, Frank [Medical Physics in Radiology (E020), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Gruenig, Ekkehard [Internal Medicine III, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg (Germany); Ley-Zaporozhan, Julia [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Tecer, Zueleyha [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Puderbach, Michael [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Fink, Christian [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Department of Clinical Radiology, University Medical Center Grosshadern, Ludwigs-Maximilians-University, Munich (Germany); Kauczor, Hans-Ulrich [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)

    2007-02-15

    Purpose: Pathological changes of the peripheral pulmonary arteries induce pulmonary arterial hypertension (PAH). Aim of this study was to quantitatively assess the effect of PAH on pulmonary perfusion by 3D-MR-perfusion techniques and to compare findings to healthy controls. Furthermore, quantitative perfusion data were correlated with invasive pressure measurements. Material and methods: Five volunteers and 20 PAH patients (WHO class II or III) were examined using a 1.5 T MR scanner. Measurement of pulmonary perfusion was done in an inspiratory breathhold (FLASH3D; 3.5 mm x 1.9 mm x 4 mm; TA per 3D dataset 1.5 s). Injection of contrast media (0.1 mmol Gd-DTPA/kg BW) and image acquisition were started simultaneously. Evaluation of 3D perfusion was done using singular value decomposition. Lung borders were outlined manually. Each lung volume was divided into three regions (anterior, middle, posterior), and the following parameters were assessed: Time-to-Peak (TTP), blood flow (PBF), blood volume (PBV), and mean transit time (MTT). In 10 patients invasive pulmonary artery pressure measurements were available and correlated to the perfusion measurements. Results: In both, controls and patients, an anterior-to-posterior gradient with higher PBF and PBV posterior was observed. In the posterior lung region, a significant difference (p < 0.05) was found for TTP (12 s versus 16 s) and MTT (4 s versus 6 s) between volunteers and patients. PBF and PBV were lower in patients than in volunteers (i.e. dorsal regions: 124 versus 180 ml/100 ml/min and 10 versus 12 ml/100 ml), but the difference failed to be significant. The ratio of PBF and PBV between the posterior and the middle or ventral regions showed no difference between both groups. A moderate linear correlation between mean pulmonary arterial pressure (mPAP) and PBV (r = 0.51) and MTT (r = 0.56) was found. Conclusion: The only measurable effect of PAH on pulmonary perfusion is a prolonging of the MTT. There is only a

  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. Important role of PLC-γ1 in hypoxic increase in intracellular calcium in pulmonary arterial smooth muscle cells.

    Science.gov (United States)

    Yadav, Vishal R; Song, Tengyao; Joseph, Leroy; Mei, Lin; Zheng, Yun-Min; Wang, Yong-Xiao

    2013-02-01

    An increase in intracellular calcium concentration ([Ca(2+)](i)) in pulmonary arterial smooth muscle cells (PASMCs) induces hypoxic cellular responses in the lungs; however, the underlying molecular mechanisms remain incompletely understood. We report, for the first time, that acute hypoxia significantly enhances phospholipase C (PLC) activity in mouse resistance pulmonary arteries (PAs), but not in mesenteric arteries. Western blot analysis and immunofluorescence staining reveal the expression of PLC-γ1 protein in PAs and PASMCs, respectively. The activity of PLC-γ1 is also augmented in PASMCs following hypoxia. Lentiviral shRNA-mediated gene knockdown of mitochondrial complex III Rieske iron-sulfur protein (RISP) to inhibit reactive oxygen species (ROS) production prevents hypoxia from increasing PLC-γ1 activity in PASMCs. Myxothiazol, a mitochondrial complex III inhibitor, reduces the hypoxic response as well. The PLC inhibitor U73122, but not its inactive analog U73433, attenuates the hypoxic vasoconstriction in PAs and hypoxic increase in [Ca(2+)](i) in PASMCs. PLC-γ1 knockdown suppresses its protein expression and the hypoxic increase in [Ca(2+)](i). Hypoxia remarkably increases inositol 1,4,5-trisphosphate (IP(3)) production, which is blocked by U73122. The IP(3) receptor (IP(3)R) antagonist 2-aminoethoxydiphenyl borate (2-APB) or xestospongin-C inhibits the hypoxic increase in [Ca(2+)](i). PLC-γ1 knockdown or U73122 reduces H(2)O(2)-induced increase in [Ca(2+)](i) in PASMCs and contraction in PAs. 2-APB and xestospongin-C produce similar inhibitory effects. In conclusion, our findings provide novel evidence that hypoxia activates PLC-γ1 by increasing RISP-dependent mitochondrial ROS production in the complex III, which causes IP(3) production, IP(3)R opening, and Ca(2+) release, playing an important role in hypoxic Ca(2+) and contractile responses in PASMCs.

  6. Early increase in arterial lactate concentration under epinephrine infusion is associated with a better prognosis during shock.

    Science.gov (United States)

    Wutrich, Yann; Barraud, Damien; Conrad, Marie; Cravoisy-Popovic, Aurélie; Nace, Lionel; Bollaert, Pierre-Edouard; Levy, Bruno; Gibot, Sébastien

    2010-07-01

    To determine whether an epinephrine-induced early increase in arterial lactate concentration can prognosticate the outcome during shock state, we conducted a retrospective study in a 16-bed medical intensive care unit of a teaching hospital in France. One hundred consecutive patients admitted because of a shock state irrespective of etiology and treated with epinephrine were included. Patients were not enrolled if they received epinephrine administration before intensive care unit admission. Sequential arterial lactate measurements were performed at the time of epinephrine infusion (H0) and 4 h later (H4) in which Deltalactate was defined as (100 x [arterial lactate(H4)-arterial lactate(H0)]/arterial lactate(H0)) and expressed as a percentage. Etiology of shock was septic (82%), cardiogenic (10%), or hemorrhagic (8%). Twenty-eight-day mortality rate was 72%. At admission, arterial lactate concentration was elevated (4.96 +/- 3.8 mmol/L) and was further increased upon epinephrine administration, reaching a peak at H4 (8.22 +/- 3.66). When patients were stratified according to their outcome, nonsurvivors displayed the same pattern as survivors, although with a significant upward shift in values (ANOVA, P = 0.0003). The Sequential Organ Failure Assessment score and Deltalactate were the only variables associated with the 28-day risk of death, with an odds ratio of 1.32 (95% confidence interval [CI], 1.06-1.65; P = 0.01) and 0.99 (95% CI, 0.99-0.99; P = 0.03), respectively, in multivariate analysis. At a value of 100%, Deltalactate predicted death, with a 71% sensitivity (95% CI, 51%-87%) and a 67% specificity (95% CI, 43%-85%). Kaplan-Meier survival analysis confirmed this finding, with a 52.4% death rate among patients with Deltalactate greater than 100 comparatively to 84.7% when Deltalactate was less than 100 (log-rank test, P = 0.0002). An adapted response (lactate production) to a pharmacological trigger (epinephrine) is associated with better prognosis during

  7. Vital Signs – Presión arterial alta (High Blood Pressure)

    Centers for Disease Control (CDC) Podcasts

    2012-10-02

    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.  Created: 10/2/2012 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 10/17/2012.

  8. Possibility of non-invasive blood pressure estimation by measurements of force and arteries diameter

    OpenAIRE

    Veye, Florent; Mestre, Sandrine; Perez-Martin, Antonia; Triboulet, Jean

    2014-01-01

    International audience Ultrasound examination is the first line procedure for the diagnosis and follow-up of cardiovascular diseases. Instrumenting an ultrasound probe with a force sensor may improve the non-invasive measurement of arterial biomechanical parameters (diameter, pulsatility, intima-media thickness and flow-dependent dilation) by measuring and controlling the force exerted by the sonographer. We present here the results obtained with this approach coupled with image processing...

  9. Pulmonary arterial hypertension: an update

    OpenAIRE

    Hoendermis, E.S.

    2011-01-01

    Pulmonary arterial hypertension (PAH), defined as group 1 of the World Heart Organisation (WHO) classification of pulmonary hypertension, is an uncommon disorder of the pulmonary vascular system. It is characterised by an increased pulmonary artery pressure, increased pulmonary vascular resistance and specific histological changes. It is a progressive disease finally resulting in right heart failure and premature death. Typical symptoms are dyspnoea at exercise, chest pain and syncope; furthe...

  10. Low Physical Activity Is Associated With Increased Arterial Stiffness in Patients Recently Diagnosed With Type 2 Diabetes

    DEFF Research Database (Denmark)

    Funck, Kristian L; Laugesen, Esben; Høyem, Pernille;

    2015-01-01

    AIMS: Several studies have indicated that low physical activity is associated with increased risk of cardiovascular disease (CVD) and all-cause mortality among patients with diabetes. The association between physical activity and subclinical cardiovascular changes preceding clinical events remains...... to be elucidated. We investigated the relationship between physical activity and arterial stiffness, an independent predictor of CVD, in patients with type 2 diabetes and controls. METHODS: We included 100 patients with type 2 diabetes and 100 sex- and age-matched controls in a cross-sectional study. Arterial...... of physical activity was defined according to the median level of activity (cpm = 31). RESULTS: Sixty-five patients and 65 controls were included in the final analysis (median age 59 years, 55% men, median diabetes duration 1.9 years). Participants with low physical activity had higher cfPWV compared...

  11. Study of the Effect of Hydro-Alcoholic Extract of Lactuca sativa on Arterial Blood Pressure and Heart Rate in Rats

    Directory of Open Access Journals (Sweden)

    R. Dehbooreh

    2013-04-01

    Full Text Available Introduction & Objective: Cardiovascular diseases are main causes of mortality and morbidity in the current world. Hypertension is one of the most important risk factors for the cardiovas-cular diseases. Herbal medicine is much regarded because of their natural source and less side effects. This study was done to evaluate the effects of hydro- alcoholic extract of Luc-tuca-Sativa (LS on blood pressure in rats. Materials & Methods: Hypertension was induced in the rats by Desoxycorticosterone (DOCA-Salt then the hypertension induction was confirmed by tail-cuff method before treatment. The effects of one week treatment by LS hydro-alcoholic extract (100 mg/kg/day on blood pressure; Heart Rate (HR and Plasma Renin Activity (PRA were investigated and compared with the control groups. Under anesthesia (urethane 1gr/kg Mean Arterial blood Pressure (MAP and HR were measured directly from Femoral Artery. In order to investigate the extract effects on MAP and HR, also possible mechanisms of these effects, intravenous injection of differ-ent concentrations of extract with and without pretreatment with histamine H1 receptor an-tagonist (Chlorpheniramine 10 mg/kg were performed. PRA was measured by radio-immuonoassay method. Urine volume was also measured during the treatment Results: The results of this study show that DOCA-Salt induced hypertension and decreased PRA in the rats. LS hydro- alcoholic extract treatment causes significant decrease of MAP in hypertension- treated group in comparison with non-treated group and also the level of PRA and urine volume increased by extract treatment. Our Findings showed that LS extract has no significant effect on HR. Conclusion: The results of this study indicated hat LS hydro- alcoholic extract due to interac-tion with kidney and diuretic effects decreased MAP and normalized PRA in the DOCA- Salt hypertensive. (Sci J Hamadan Univ Med Sci 2013; 20 (1:66-76

  12. Measurement of arterial compliance in vivo.

    Science.gov (United States)

    Wiinberg, N

    2000-01-01

    Measurement of arterial compliance is of interest in evaluating patients with atherosclerosis and other diseases which affect the vessels. Arterial compliance is the relation between changes in transmural pressure and volume of an arterial segment, where a high compliance signifies large changes in volume per change in transmural pressure. The relation between changes in transmural pressure and volume is far from linear as compliance increases progressively with decreases in blood pressure. A change in compliance could indicate static changes in arterial wall composition, i.e. the relation between elastic and collagen fibres and accumulation of disease related deposits or dynamic changes caused by alterations in muscular tone. The most used method reflecting arterial compliance is the measurement of pulse wave velocity. However, the pulse wave velocity method measures compliance at ambient transmural pressures and is affected both by the actual blood pressure and the rate of pressure change. Another commonly used method employs the echo-tracking technique to measure the arterial diameter simultaneously with continuous blood pressure monitoring. By this method it is possible to calculate arterial compliance for continuous pressure values between the diastole and the systole. The volume-oscillometry method is based on the fact that the artery can be made to collapse at the end of the diastole by an occlusive cuff while it remains open in a pressure dependent manner during the rest of the cardiac cycle. Changes in the arterial volume is transmitted to the cuff, where it induces a measurable change in pressure, and hence the volume of the artery can be calculated at different values of transmural pressures. Using this method on normal subjects has shown that the arterial compliance decreases with increasing age and that females have lower compliance than males primarily due to a smaller diameter of their arteries. It has also been shown that patients with essential

  13. Acute effects of haemodialysis on central venous and arterial pressure characteristics

    OpenAIRE

    Thalhammer, Christoph; Segerer, Stephan; Augustoni, Marlene; Jacomella, Vincenzo; Clemens, Robert K; Wüthrich, Rudolf P.; Amann-Vesti, Beatrice R; Husmann, Marc

    2015-01-01

    BACKGROUND Hemodynamic stability of patients during dialysis sessions is of pivotal importance in daily practice and accurate determination of dry weight (DW) remains a challenge. Little information is available about central venous and aortic pressure during dialysis. In this pilot study we used a new non-invasive technique to describe the changes in central venous pressure (CVP) during dialysis. METHODS An ultrasound-assisted silicon-based pressure-manometer was used at the contralateral...

  14. Mulberry leaf extract restores arterial pressure in streptozotocin-induced chronic diabetic rats.

    Science.gov (United States)

    Naowaboot, Jarinyaporn; Pannangpetch, Patchareewan; Kukongviriyapan, Veerapol; Kukongviriyapan, Upa; Nakmareong, Saowanee; Itharat, Arunporn

    2009-08-01

    Free radical-induced vascular dysfunction plays a key role in the pathogenesis of vascular disease found in chronic diabetic patients. Morus alba (MA) leaf extract is promoted for good health especially in diabetic patients. Interestingly, antidiabetic and antioxidant activities of MA have been reported in experimental animals. Thus, the hypothesis of this study was that the long-term treatment with MA could improve vascular reactivity of chronic diabetic rats. To test this hypothesis, we examined the effect of long-term treatment with MA on the vascular responses to vasoactive agents in streptozotocin-induced chronic diabetic rats. The diabetic rats were either orally administered with distilled water, MA (0.25, 0.5 and 1 g/kg per day) or subcutaneously injected with insulin (4 U/kg per day) for 8 weeks. After each treatment, the fasting blood glucose, blood pressure, vascular responses to vasoactive agents and tissue malondialdehyde were examined. Morus alba at the doses of 0.5 and 1 g/kg, which significantly reduced blood glucose level, also significantly decreased the high blood pressure in diabetic rats. Vascular responses of the chronic diabetic rats to vasodilators, acetylcholine (3-30 nmol/kg) and sodium nitroprusside (1-10 nmol/kg) were significantly suppressed by 26% to 44% and 45% to 77% respectively, whereas those to vasoconstrictor, phenylephrine (0.01-0.1 micromol/kg) were significantly increased by 23% to 38% as compared to normal rats. Interestingly, the administration of 0.5 and 1 g/kg MA or 4 U/kg insulin significantly restored the vascular reactivities of diabetic rats. Moreover, 8 weeks of diabetes resulted in the elevation of malondialdehyde content in tissues (liver, kidney, heart, and aorta), and MA treatment significantly lessened this increase. These results provide the first evidence for the efficacy of MA in restoring the vascular reactivity of diabetic rats, the mechanism of which may associate with the alleviation of oxidative stress

  15. Skin perfusion pressure measured by isotope washout in legs with arterial occlusive disease. Evaluation of different tracers, comparison to segmental systolic pressure, angiography and transcutaneous oxygen tension and variations during changes in systemic blood pressure

    DEFF Research Database (Denmark)

    Holstein, P; Trap-Jensen, J; Bagger, H;

    1983-01-01

    digit (strain gauge technique). The two different methods correlated statistically significant at all four levels, but the systolic blood pressures were higher than the SPP in particular in diabetic legs; (3) Angiograms in 35 legs with AOD showed that the SPP on the ankle was only consistently decreased......The skin perfusion pressure (SPP) measured as the isotope washout cessation external pressure is valuable in selection of major amputation level. Five methodological investigations important to clinical use were carried out: (1) In five normal legs and 10 legs with arterial occlusive disease (AOD......Hg (range 18-98) (P less than 0.02). The average washout constant for the three different tracers were approximately equal and correlated statistically significant with the SPP; (2) In 59 legs with AOD, segmental SPP was compared to segmental systolic blood pressures on the thigh, calf, ankle and first...

  16. Increased requirement for minute ventilation and negative arterial to end-tidal carbon dioxide gradient may indicate malignant hyperthermia.

    Science.gov (United States)

    Lin, Ho-Tien; Wang, Shen-Chih; Zuo, Zhiyi; Tsou, Mei-Yung; Chan, Kwok-Hon; Yuan, Hui-Bih

    2014-04-01

    Characteristic signs of malignant hyperthermia (MH) include unexplained tachycardia, increased end-tidal carbon dioxide (Etco₂) concentration, metabolic and respiratory acidosis, and an increase in body temperature above 38.8°C. We present the case of a patient with highly probable MH. In addition to sinus tachycardia and metabolic and respiratory acidosis, this patient also had a negative arterial to Etco₂ gradient and an increased requirement for minute ventilation to maintain a normal Etco₂ concentration, with signs of increased CO₂ production. Despite these signs of MH, the patient's rectal temperature monitoring equipment did not show an increase in temperature, although the temperature measured in the mouth was increased. This case illustrates the unreliability of measuring rectal temperature as a means of reflecting body temperature during MH and the usefulness of increased CO₂ production signs in helping to diagnose MH. PMID:24560543

  17. Vascular KCNQ Potassium Channels as Novel Targets for the Control of Mesenteric Artery Constriction by Vasopressin, Based on Studies in Single Cells, Pressurized Arteries, and in Vivo Measurements of Mesenteric Vascular ResistanceS

    OpenAIRE

    Mackie, Alexander R.; Brueggemann, Lioubov I.; Henderson, Kyle K.; Shiels, Aaron J.; Cribbs, Leanne L.; Scrogin, Karie E.; Byron, Kenneth L.

    2008-01-01

    Pressor effects of the vasoconstrictor hormone arginine vasopressin (AVP), observed when systemic AVP concentrations are less than 100 pM, are important for the physiological maintenance of blood pressure, and they are also the basis for therapeutic use of vasopressin to restore blood pressure in hypotensive patients. However, the mechanisms by which circulating AVP induces arterial constriction are unclear. We examined the novel hypothesis that KCNQ potassium channels mediate the physiologic...

  18. Localization of relaxin receptors in arteries and veins, and region-specific increases in compliance and bradykinin-mediated relaxation after in vivo serelaxin treatment.

    Science.gov (United States)

    Jelinic, Maria; Leo, Chen-Huei; Post Uiterweer, Emiel D; Sandow, Shaun L; Gooi, Jonathan H; Wlodek, Mary E; Conrad, Kirk P; Parkington, Helena; Tare, Marianne; Parry, Laura J

    2014-01-01

    Relaxin is a potent vasodilator of small resistance arteries and modifies arterial compliance in some systemic vascular beds, yet receptors for relaxin, such as RXFP1, have only been localized to vascular smooth muscle. This study first aimed to localize RXFP1 in rat arteries and veins from different organ beds and determine whether receptors are present in endothelial cells. We then tested the hypothesis that region-specific vascular effects of relaxin may be influenced by the cellular localization of RXFP1 within different blood vessels. The aorta, vena cava, mesenteric artery, and vein had significantly higher (PRXFP1 immunostaining in endothelial cells compared with vascular smooth muscle, whereas the femoral artery and vein and small pulmonary arteries had higher (PRXFP1 immunostaining in the vascular smooth muscle. Male rats were treated subcutaneously with recombinant human relaxin-2 (serelaxin; 4 μg/h) for 5 d; vasodilation and compliance in mesenteric and femoral arteries and veins were compared with placebo controls. Serelaxin significantly (P=0.04) reduced wall stiffness and increased volume compliance in mesenteric arteries but not in the other vessels examined. This was associated with changes in geometrical properties, and not compositional changes in the extracellular matrix. Serelaxin treatment had no effect on acetylcholine-mediated relaxation but significantly (PRXFP1 on endothelial and smooth muscle across the vasculature. In rats, mesenteric arteries exhibit the greatest functional response to chronic serelaxin treatment. PMID:24036884

  19. Increasing sleep duration to lower beat-to-beat blood pressure – a pilot study

    OpenAIRE

    Haack, Monika; Serrador, Jorge; Cohen, Daniel; Simpson, Norah; Meier-Ewert, Hans; Mullington, Janet M.

    2012-01-01

    Strong evidence has accumulated over the last several years, showing that low sleep quantity and/or quality plays an important role in the elevation of blood pressure. We hypothesized that increasing sleep duration serves as an effective behavioral strategy to reduce blood pressure in pre-hypertension or type 1 hypertension.

  20. Novel Approach for Ensuring Increased Validity in Home Blood Pressure Monitoring

    DEFF Research Database (Denmark)

    Wagner, Stefan Rahr; Toftegaard, Thomas Skjødeberg; Bertelsen, Olav Wedege

    This paper proposes a novel technique to increase the validity of home blood pressure monitoring by using various sensor technologies as part of an intelligent environment platform in the home of the user. A range of recommendations exists on how to obtain a valid blood pressure...

  1. Propofol increases the Ca2+ sensitivity of BKca in the cerebral arterial smooth muscle cells of mice

    Institute of Scientific and Technical Information of China (English)

    Xue-ru LIU; Xiao-qiu TAN; Yan YANG; Xiao-rong ZENG; Xian-ling TANG

    2012-01-01

    Propofol has the side effect of hypotension especially in the elderly and patients with hypertension.Previous studies suggest propofol-caused hypotension results from activation of large conductance Ca2+-sensitive K channels (BKCa).In this study,the effects of propofol on the Ca2+ sensitivity of BKCa were investigated in mice cerebral arterial smooth muscle cells.Methods:Single smooth muscle cells were prepared from the cerebral arteries of mice.Perforated whole-cell recoding was conducted to investigate the whole-cell BKCa current and spontaneous transient outward K+ current (STOC).Inside-out patch configuration was used to record the single channel current and to study the Ca2+- and voltage-dependence of BKCa.Results:Propofol (56 and 112 μmol/L) increased the macroscopic BKCa and STOC currents in a concentration-dependent manner.It markedly increased the total open probability (Npo) of single BKCa channel with an EC50 value of 76 μmol/L.Furthermore,propofol significantly decreased the equilibrium dissociation constant (Kd) of Ca2+ for BKCa channel.The Kd value of Ca2+ was 0.881 μmol/L in control,and decreased to 0.694,0.599,and 0.177 μmol/L,respectively,in the presence of propofol 28,56,and 112 μmol/L.An analysis of the channel kinetics revealed that propofol (112 μmol/L) significantly increased the open dwell time and decreased the closed dwell time,which stabilized BKCa channel in the open state.Conclusion:Propofol increases the Ca2+ sensitivity of BKCa channels,thus lowering the Ca2* threshold of the channel activation in arterial smooth muscle cells,which causes greater vasodilating effects.

  2. Increased expression of endothelin ET(B) and angiotensin AT(1) receptors in peripheral resistance arteries of patients with suspected acute coronary syndrome

    DEFF Research Database (Denmark)

    Dimitrijevic, Ivan; Ekelund, Ulf; Edvinsson, Marie-Louise;

    2009-01-01

    group. There were no significant differences in AT(2) and ET(A) receptor expression between the groups. The results indicate that the expression of arterial smooth muscle ET(B) and AT(1) receptors are increased in patients with suspected but ruled out ACS. These receptor changes could be important...... of arterial vasoconstrictor endothelin (ET) and angiotensin (AT) receptors. Our aim was to investigate if the arterial expressions of these receptors are changed in patients with suspected but ruled out acute coronary syndrome (ACS). Small subcutaneous arteries (diameter of 100 microm) were surgically removed....... The control group (controls) consisted of eight healthy volunteers matched for age and sex with no previous cardiac illness or medication. The susp ACS group had an increased expression of ET(B) (by 94%) and AT(1) (by 34%) receptors in the smooth muscle cells of resistance arteries as compared to the control...

  3. Increased tea consumption is associated with decreased arterial stiffness in a Chinese population.

    Directory of Open Access Journals (Sweden)

    Chung-Hao Li

    Full Text Available BACKGROUND: Tea has attracted considerable attention for its potential cardioprotective effects. The primary chemical components of tea are thought to have a beneficial effect by reducing arterial stiffness. The objective of this study was to assess the association between tea consumption and brachial-ankle pulse wave velocity (baPWV in a relatively healthy Chinese population. METHODS: We enrolled 3,135 apparently healthy subjects from October 2006 to August 2009. Subjects taking medication for diabetes, hypertension, or hyperlipidemia, or with a history of cardiovascular disease, were excluded from the study. The subjects were categorized into three groups according to their tea-drinking habits: (1 none to low (n = 1615, defined as non-habitual tea drinkers, or drinking for 450 mL per day. Multiple logistic regression was used to determine whether different levels of consumption were independently associated with the highest quartile of baPWV values, defined as ≥1428.5 cm/s. RESULTS: Of the 3,135 subjects, 48.5% had drunk >150 mL of tea per day for at least 1 year. In multivariate regression analysis with adjustment for co-variables, including, age, sex, current smoking, alcohol use, habitual exercise, total cholesterol/high-density lipoprotein cholesterol (TC/HDL-C ratio >5, obesity, newly diagnosed hypertension and diabetes, subjects with high tea consumption had a decreased risk of highest quartile of baPWV by 22% (odds ratio = 0.78, 95% confidence interval = 0.62-0.98, p = 0.032, while subjects with moderate tea consumption did not (p = 0.742, as compared subjects with none to low tea consumption. CONCLUSIONS: High, but not moderate, habitual tea consumption may decrease arterial stiffness.

  4. Capabilities of Cluster Analysis in Interpretation of 24-Hour Blood Pressure Monitoring Data in Patients with Arterial Hypertension and Left Ventricular Remodeling

    Directory of Open Access Journals (Sweden)

    S.V. Samoyavcheva

    2015-12-01

    Full Text Available The aim of the investigation was to assess the potential of cluster analysis as an additional method of data analysis for 24-hour blood pressure monitoring (BPM in patients with both normal geometry and with various types and extents of remodeling of the left ventricle (LV. Materials and Methods. The investigation included 71 patients, ranging in age from 23 to 71. The inclusion criterion was significant arterial hypertension (AH, while exclusion criteria were symptomatic AH and severe co-morbidity. Body mass, height, waist measurement, body mass index, lipid profile, and glycemic level were determined for each subject in addition to carrying out echocardiography and conventional and cluster analysis of 24-hour BPM data of each. Results. In patient groups with different types of left ventricular hypertrophy (LVH, the conventional analysis demonstrated differences in the standard 24-hour BPM parameters. Development of concentric LVH is associated with the highest average day-time and average night-time blood pressure, pressure-induced loads and blood pressure variability. Eccentric LVH has a pathogenetic link to other factors and is formed under conditions of relatively low blood pressure. The use of cluster analysis allowed to reveal the increased occurrence of systolic-diastolic AH in concentric LVH, and isolated systolic AH and isolated diastolic AH in eccentric LVH. Conclusion. Such an integrated approach to the interpretation of 24-hour BPM results, comprising both conventional and cluster analysis, allows for objectification of the study results and reveals the significant features of AH in patients with different types of LV remodeling.

  5. Presence of anomalous coronary seen on angiogram is not associated with increased risk of significant coronary artery disease.

    Science.gov (United States)

    Suryanarayana, Prakash; Kollampare, Shubha; Riaz, Irbaz Bin; Lee, Justin; Husnain, Muhammad; Luni, Faraz Khan; Movahed, Mohammad Reza

    2014-12-01

    It is unclear if anomalous coronary arteries are at higher risk for atherosclerosis. The link between anomalous coronary artery and early coronary artery disease has been suggested. The aim of this study is to determine whether the coronary artery anomaly predisposes to development of significant coronary disease. Using retrospective chart review, patients with documented anomalous coronary arteries recognized during coronary angiography between years 2000 to 2007 were analyzed. Prevalence of significant atherosclerotic coronary artery disease (defined as more than 50% luminal narrowing) was compared between normal and anomalous coronaries. A total of 147 patients with anomalous coronary arteries were found. Right coronary artery was the most common anomalous artery 128 of 148 (86.5%) in our dataset. There was no difference in the occurrence of atherosclerosis between anomalous and nonanomalous coronaries. Significant atherosclerosis was present in 59 of the 148 anomalous coronary arteries (37.8%), and 112 of the 293 nonanomalous coronary arteries (38.2%, p = 0.9). On the basis of our study, there is no evidence that anomalous coronary arteries predispose to significant coronary artery disease in comparison to normal coronary arteries.

  6. Valores da pressão arterial em cães pelos métodos oscilométrico e Doppler vascular Arterial blood pressure in dogs by the oscilometric method and the Doppler ultrasonic

    Directory of Open Access Journals (Sweden)

    R.R. Cabral

    2010-02-01

    Full Text Available Foram comparados dois métodos não-invasivos de medida da pressão arterial, o Doppler vascular e o oscilométrico, com o objetivo de estabelecer parâmetros que possam auxiliar no diagnóstico seguro da hipertensão arterial. Para tal, foram utilizados 45 cães, machos e fêmeas, distribuídos em três grupos de acordo com o peso, pequeno, médio e grande porte. Em cada animal, procedeu-se a mensuração por meio do Doppler vascular e, em seguida, do oscilométrico. Na obtenção da pressão arterial sistólica, não houve diferença entre os métodos nos três grupos de animais, porém, na obtenção da pressão arterial diastólica, houve diferença estatística entre o Doppler vascular e o oscilométrico nos grupos de animais de pequeno e médio porte. Pôde-se concluir que valores confiáveis de pressão sistólica podem ser obtidos tanto por meio do Doppler vascular quanto do oscilométrico. Os valores da pressão arterial diastólica obtidos pelos dois métodos não se correlacionam, principalmente nos animais de pequeno e médio porte.Two noninvasive methods for blood pressure measurement, the oscilometric and the Doppler ultrasonic, were compaired aiming the establishment of parameters that can be helpful for the hypertension diagnosis. Forty-five dogs, males and females, were distributed in three groups, according to body weight: small, medium, and large sizes. In each animal, measurement of the blood pressure was performed, first by the Doppler ultrasonic, followed by the oscilometric method. No differences were observed in sistolic arterial pressure values obtained by both methods in none of the three animal groups. However, there was an important difference in diastolic arterial pressure values obtained by these methods, especially in small and medium size dogs. It was concluded that reliable results of sistolic blood pressure can be obtained both by the Doppler ultrasonic and the oscilometric method. Diastolic blood pressure

  7. Systolic blood pressure response after high-intensity interval exercise is independently related to decreased small arterial elasticity in normotensive African American women.

    Science.gov (United States)

    Carter, Stephen J; Goldsby, TaShauna U; Fisher, Gordon; Plaisance, Eric P; Gower, Barbara A; Glasser, Stephen P; Hunter, Gary R

    2016-05-01

    Aerobic exercise transiently lowers blood pressure. However, limited research has concurrently evaluated blood pressure and small arterial elasticity (SAE), an index of endothelial function, among African American (AA) and European American (EA) women the morning after (i.e., ≈22 h later) acute bouts of moderate-intensity continuous (MIC) and high-intensity interval (HII) exercise matched for total work. Because of greater gradients of shear stress, it was hypothesized that HII exercise would elicit a greater reduction in systolic blood pressure (SBP) compared to MIC exercise. After baseline, 22 AA and EA women initiated aerobic exercise training 3 times/week. Beginning at week 8, three follow-up assessments were conducted over the next 8 weeks at random to measure resting blood pressure and SAE. In total all participants completed 16 weeks of training. Follow-up evaluations were made: (i) in the trained state (TS; 8-16 weeks of aerobic training); (ii) ≈22 h after an acute bout of MIC exercise; and (iii) ≈22 h after an acute bout of HII exercise. Among AAs, the acute bout of HII exercise incited a significant increase in SBP (mm Hg) (TS, 121 ± 14 versus HII, 128 ± 14; p = 0.01) whereas responses (TS, 116 ± 12 versus HII, 113 ± 9; p = 0.34) did not differ in EAs. After adjusting for race, changes in SAE were associated (partial r = -0.533; p = 0.01) with changes in SBP following HII exercise. These data demonstrate an acute, unaccustomed bout of HII exercise produces physiological perturbations resulting in a significant increase in SBP that are independently associated with decreased SAE among AA women, but not EA women.

  8. Blood pressure telemonitoring is useful to achieve blood pressure control in inadequately treated patients with arterial hypertension.

    Science.gov (United States)

    Neumann, C L; Menne, J; Rieken, E M; Fischer, N; Weber, M H; Haller, H; Schulz, E G

    2011-12-01

    Failing to reach blood pressure (BP) goals is one of the main problems in hypertension management. Especially in high-risk patients, intensive monitoring including frequently office visits or new techniques to monitor home BP is required. A total of 60 patients with uncontrolled hypertension were included and randomized into a group with telemetric BP monitoring (TBPM) (n=30) and a control group receiving standard care (n=30). During the 3-month study period, patients received in addition to their antihypertensive pre-treatment up to 2 × 300 mg irbesartan to achieve the required target BP. All patients were instructed to measure their BP once daily in the morning. In the TBPM group automatic alerts were generated by the central database server using pre-defined algorithms and patients were subsequently contacted by the physician. At baseline mean 24-h ambulant BP monitoring (ABPM) was 143.3±11.1/82.6±9.9 mm Hg in the TBPM group and 141.4±12.6/82.1±6.5 mm Hg in the standard care group. During treatment mean systolic BP showed a more intensive decrease in the TBPM vs control group (-17.0±11.1 mm Hg vs -9.8±13.7 mm Hg; P=0.032). Patients in the TBPM group had a more pronounced night dipping and a higher reduction of mean pulse pressure than controls (-8.1±5.9 mm Hg vs -2.8±7.4 mm Hg, P=0.004). After 3 months, TBPM-treated patients were given a higher mean daily dose of irbesartan (375±187 mg vs 222±147 mg in controls; P=titration of the antihypertensive agent is possible. The alarm criteria chosen were useful to improve BP control. PMID:21228822

  9. Pressão arterial elevada em escolares de Santos: relação com a obesidade High arterial pressure in school children in Santos: relationship to obesity

    Directory of Open Access Journals (Sweden)

    Paulo César Koch Nogueira

    2007-10-01

    Full Text Available OBJETIVO: O crescimento na prevalência da obesidade aumentou a freqüência de pressão elevada em crianças. O objetivo do presente trabalho é avaliar a relação da pressão arterial com a obesidade em escolares do município de Santos. MÉTODOS: Realizamos estudo transversal em duas etapas, sendo uma fase de triagem, envolvendo avaliação antropométrica e medida de pressão em 7.440 crianças (9,0 ± 1,1 anos, 3.891 ou 52% de meninas. Uma amostra de 1.713 indivíduos (9,7 ± 1,1 anos, 826 ou 48% de meninas dentre os que, na triagem, apresentaram a pressão arterial em nível igual ou superior ao percentil 90 foi revisitada um ano mais tarde e novas medidas foram realizadas. Nas duas fases do estudo, consideramos pressão elevada os valores iguais ou maiores que o percentil 95 de pressão para o sexo e a estatura. RESULTADOS: Na triagem 1.123/7.440 (15% crianças apresentaram pressão elevada; crianças obesas apresentaram pressão elevada mais freqüentemente (OR = 3,7 95% IC=3,2 a 4,3. Na segunda fase, 43/1.713 (2,7% apresentaram pressão elevada e novamente a presença de obesidade conferiu maior risco para pressão elevada (OR=1,5 95% IC=1,2 a 1,8. Além disso, observamos aumento da PA sistólica de acordo com a massa corporal na totalidade dos intervalos de IMC estudados e não apenas após a instalação da obesidade. CONCLUSÃO: Nosso estudo reforça os dados que sugerem aumento no risco de pressão elevada em crianças obesas. Para a pressão sistólica, o incremento de pressão parece ser cumulativo de acordo com o aumento do IMC, mesmo em crianças não obesas.OBJECTIVE: The escalating prevalence of obesity has led to an increase in the blood pressure of children and adolescents. This works aims to assess the relation between blood pressure and obesity in school children of Santos. METHODS: We performed a cross-sectional study in two phases. In a first screening we measured blood pressure and performed anthropometric evaluation

  10. Exercise training prevents increased intraocular pressure and sympathetic vascular modulation in an experimental model of metabolic syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Castro, E.F.S. [Unidade de Hipertensão, Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Mostarda, C.T. [Universidade Federal do Maranhão, São Luís, MA (Brazil); Rodrigues, B. [Laboratório do Movimento Humano, Universidade São Judas Tadeu, São Paulo, SP (Brazil); Moraes-Silva, I.C. [Unidade de Hipertensão, Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Feriani, D.J. [Laboratório do Movimento Humano, Universidade São Judas Tadeu, São Paulo, SP (Brazil); De Angelis, K. [Laboratório de Fisiologia Translacional, Universidade Nove de Julho, São Paulo, SP (Brazil); Irigoyen, M.C. [Unidade de Hipertensão, Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)

    2015-02-13

    The present study aimed to study the effects of exercise training (ET) performed by rats on a 10-week high-fructose diet on metabolic, hemodynamic, and autonomic changes, as well as intraocular pressure (IOP). Male Wistar rats receiving fructose overload in drinking water (100 g/L) were concomitantly trained on a treadmill for 10 weeks (FT group) or kept sedentary (F group), and a control group (C) was kept in normal laboratory conditions. The metabolic evaluation comprised the Lee index, glycemia, and insulin tolerance test (KITT). Arterial pressure (AP) was measured directly, and systolic AP variability was performed to determine peripheral autonomic modulation. ET attenuated impaired metabolic parameters, AP, IOP, and ocular perfusion pressure (OPP) induced by fructose overload (FT vs F). The increase in peripheral sympathetic modulation in F rats, demonstrated by systolic AP variance and low frequency (LF) band (F: 37±2, 6.6±0.3 vs C: 26±3, 3.6±0.5 mmHg{sup 2}), was prevented by ET (FT: 29±3, 3.4±0.7 mmHg{sup 2}). Positive correlations were found between the LF band and right IOP (r=0.57, P=0.01) and left IOP (r=0.64, P=0.003). Negative correlations were noted between KITT values and right IOP (r=-0.55, P=0.01) and left IOP (r=-0.62, P=0.005). ET in rats effectively prevented metabolic abnormalities and AP and IOP increases promoted by a high-fructose diet. In addition, ocular benefits triggered by exercise training were associated with peripheral autonomic improvement.

  11. Exercise training prevents increased intraocular pressure and sympathetic vascular modulation in an experimental model of metabolic syndrome

    International Nuclear Information System (INIS)

    The present study aimed to study the effects of exercise training (ET) performed by rats on a 10-week high-fructose diet on metabolic, hemodynamic, and autonomic changes, as well as intraocular pressure (IOP). Male Wistar rats receiving fructose overload in drinking water (100 g/L) were concomitantly trained on a treadmill for 10 weeks (FT group) or kept sedentary (F group), and a control group (C) was kept in normal laboratory conditions. The metabolic evaluation comprised the Lee index, glycemia, and insulin tolerance test (KITT). Arterial pressure (AP) was measured directly, and systolic AP variability was performed to determine peripheral autonomic modulation. ET attenuated impaired metabolic parameters, AP, IOP, and ocular perfusion pressure (OPP) induced by fructose overload (FT vs F). The increase in peripheral sympathetic modulation in F rats, demonstrated by systolic AP variance and low frequency (LF) band (F: 37±2, 6.6±0.3 vs C: 26±3, 3.6±0.5 mmHg2), was prevented by ET (FT: 29±3, 3.4±0.7 mmHg2). Positive correlations were found between the LF band and right IOP (r=0.57, P=0.01) and left IOP (r=0.64, P=0.003). Negative correlations were noted between KITT values and right IOP (r=-0.55, P=0.01) and left IOP (r=-0.62, P=0.005). ET in rats effectively prevented metabolic abnormalities and AP and IOP increases promoted by a high-fructose diet. In addition, ocular benefits triggered by exercise training were associated with peripheral autonomic improvement

  12. Exercise training prevents increased intraocular pressure and sympathetic vascular modulation in an experimental model of metabolic syndrome.

    Science.gov (United States)

    Castro, E F S; Mostarda, C T; Rodrigues, B; Moraes-Silva, I C; Feriani, D J; De Angelis, K; Irigoyen, M C

    2015-04-01

    The present study aimed to study the effects of exercise training (ET) performed by rats on a 10-week high-fructose diet on metabolic, hemodynamic, and autonomic changes, as well as intraocular pressure (IOP). Male Wistar rats receiving fructose overload in drinking water (100 g/L) were concomitantly trained on a treadmill for 10 weeks (FT group) or kept sedentary (F group), and a control group (C) was kept in normal laboratory conditions. The metabolic evaluation comprised the Lee index, glycemia, and insulin tolerance test (KITT). Arterial pressure (AP) was measured directly, and systolic AP variability was performed to determine peripheral autonomic modulation. ET attenuated impaired metabolic parameters, AP, IOP, and ocular perfusion pressure (OPP) induced by fructose overload (FT vs F). The increase in peripheral sympathetic modulation in F rats, demonstrated by systolic AP variance and low frequency (LF) band (F: 37±2, 6.6±0.3 vs C: 26±3, 3.6±0.5 mmHg2), was prevented by ET (FT: 29±3, 3.4±0.7 mmHg2). Positive correlations were found between the LF band and right IOP (r=0.57, P=0.01) and left IOP (r=0.64, P=0.003). Negative correlations were noted between KITT values and right IOP (r=-0.55, P=0.01) and left IOP (r=-0.62, P=0.005). ET in rats effectively prevented metabolic abnormalities and AP and IOP increases promoted by a high-fructose diet. In addition, ocular benefits triggered by exercise training were associated with peripheral autonomic improvement. PMID:25714884

  13. Pressão arterial de adolescentes de escolas particulares de Fortaleza-CE Presión arterial de adolescentes de escuelas particulares en Fortaleza-CE Blood pressure of adolescents in private schools in Fortaleza-CE

    Directory of Open Access Journals (Sweden)

    Polyana Carina Viana da Silva

    2010-01-01

    Full Text Available OBJETIVO: Identificar a pressão arterial de adolescentes de escolas particulares da cidade de Fortaleza-CE. MÉTODOS: Estudo do tipo quantitativo com delineamento transversal no qual foram investigados 794 adolescentes, entre 12-17 anos de idade de 14 escolas privadas dessa cidade no período de março a setembro de 2007, mediante aplicação de um formulário que abrangeu o registro das características sóciodemográficas, pressão arterial, Índice de Massa Corporal (IMC, prática de atividade física e glicemia capilar. RESULTADOS: Verificou-se que 19,7% dos jovens apresentavam pressão arterial elevada. Os adolescentes do sexo masculino apresentaram pressão arteial sistólica (PAS e pressão arterial diastólica (PAD maiores do que a do sexo feminino (p=0,0001. A pesquisa constatou valores maiores de PAS e PAD naqueles com excesso de peso (p=0,0001. CONCLUSÃO: A pressão arterial foi influenciada sobretudo pelo sexo e IMC.OBJETIVO: Identificar la presión arterial de adolescentes de escuelas particulares en la ciudad de Fortaleza-CE. MÉTODOS: Se trata de un estudio cuantitativo con delineamiento transversal en el cual fueron investigados 794 adolescentes - entre 12 y 17 años de edad - de 14 escuelas privadas de esa ciudad, en el período de marzo a septiembre de 2007. Se utilizó un formulario que contempló el registro de las siguientes características: socio-demográficas, presión arterial, Índice de Masa Corporal (IMC, práctica de actividad física y, glucemia capilar. RESULTADOS: Se verificó que 19,7% de los jóvenes presentaban presión arterial elevada. Los adolescentes del sexo masculino presentaron presión arterial sistólica (PAS y presión arterial diastólica (PAD mayores que las del sexo femenino (p=0,0001. La investigación constató valores mayores de PAS y PAD en aquellos con exceso de peso (p=0,0001. CONCLUSIÓN: La presión arterial fue influenciada, sobre todo, por el sexo y el IMC.OBJECTIVE: To identify the

  14. Blood pressure

    Science.gov (United States)

    ... the walls of the arteries is called blood pressure. Blood pressure is measured both as the heart contracts, which ... as it relaxes, which is called diastole. Normal blood pressure is considered to be a systolic blood pressure ...

  15. Inferior Gluteal Artery Perforator Flap for Sacral Pressure Ulcer Reconstruction: A Retrospective Case Study of 11 Patients.

    Science.gov (United States)

    Lin, Chin-Ta; Ou, Kuang-Wen; Chiao, Hao-Yu; Wang, Chi-Yu; Chou, Chang-Yi; Chen, Shyi-Gen; Lee, Tzu-Peng

    2016-01-01

    Despite advances in reconstruction techniques, sacral pressure ulcers continue to present a challenge to the plastic surgeon. The flap from the gluteal crease derives blood supply from the inferior gluteal artery perforator (IGAP) and reliably preserves the entire contralateral side as a donor site. To incorporate the IGAP in the reconstruction of sacral pressure ulcers, a skin paddle over the gluteal crease was created and implemented by the authors. Data from 11 patients (8 men, 3 women; mean age 67 [range 44-85] years old) whose sacral ulcers were closed with an IGAP flap between June 2006 and May 2012 were retrieved and reviewed. All patients were bedridden; 1 patient in a vegetative state with a diagnosis of carbon monoxide intoxication was referred from a local clinic, 2 patients had Parkinson's disease, and 8 patients had a history of stroke. The average defect size was 120 cm(2) (range 88-144 cm(2)). The average flap size was 85.8 cm(2) (range 56-121 cm(2)). Only 1 flap failure occurred during surgery and was converted into V-Y advancement flap; 10 of the 11 flaps survived. After surgery, the patients' position was changed every 2 hours; patients remained prone or on their side for approximately 2 weeks until the flap was healed. After healing was confirmed, patients were discharged. Complications were relatively minor and included 1 donor site wound dehiscence that required wound reapproximation. No surgery-related mortality was noted; the longest follow-up period was 24 months. In this case series, flaps from the gluteal crease were successfully used for surgical closure of sacral pressure ulcers. This flap design should be used with caution in patients with hip contractures. Studies with larger sample sizes are needed to ascertain which type of flap is best suited to surgically manage extensive pressure ulcers in a variety of patient populations. PMID:26779702

  16. The 24 h pattern of arterial pressure in mice is determined mainly by heart rate‐driven variation in cardiac output

    OpenAIRE

    Kurtz, Theodore W.; Lujan, Heidi L.; DiCarlo, Stephen E.

    2014-01-01

    Abstract Few studies have systematically investigated whether daily patterns of arterial blood pressure over 24 h are mediated by changes in cardiac output, peripheral resistance, or both. Understanding the hemodynamic mechanisms that determine the 24 h patterns of blood pressure may lead to a better understanding of how such patterns become disturbed in hypertension and influence risk for cardiovascular events. In conscious, unrestrained C57BL/6J mice, we investigated whether the 24 h patter...

  17. The lingering dilemma of arterial pressure in CKD : what do we know, where do we go?

    NARCIS (Netherlands)

    Agarwal, Rajiv; Martinez-Castelao, Alberto; Wiecek, Andrzej; Massy, Ziad; Suleymanlar, Gultekin; Ortiz, Alberto; Blankestijn, Peter J.; Covic, Adrian; Dekker, Friedo W.; Jager, Kitty J.; Lindholm, Bengt; Goldsmith, David; Fliser, Danilo; London, Gerard; Zoccali, Carmine

    2011-01-01

    Despite many advances in the management of hypertensive chronic kidney disease (CKD) patients, both on and off dialysis, there exist several gaps in our knowledge. Although the modern techniques to measure blood pressure (BP) indirectly have been available for a long time, among those with CKD, how

  18. Pimecrolimus increases the expression of interferon-inducible genes that modulate human coronary artery cells proliferation.

    Science.gov (United States)

    Hussner, Janine; Sünwoldt, Juliane; Seibert, Isabell; Gliesche, Daniel G; Zu Schwabedissen, Henriette E Meyer

    2016-08-01

    The pharmacodynamics of the loaded compounds defines clinical failure or success of a drug-eluting device. Various limus derivatives have entered clinics due to the observed positive outcome after stent implantation, which is explained by their antiproliferative activity resulting from inhibition of the cytosolic immunophilin FK506-binding protein 12. Although pimecrolimus also binds to this protein, pimecrolimus-eluting stents failed in clinics. However, despite its impact on T lymphocytes little is known about the pharmacodynamics of pimecrolimus in cultured human coronary artery cells. We were able to show that pimecrolimus exerts antiproliferative activity in human smooth muscle and endothelial cells. Furthermore in those cells pimecrolimus induced transcription of interferon-inducible genes which in part are known to modulate cell proliferation. Modulation of gene expression may be part of an interaction between calcineurin, the downstream target of the pimecrolimus/FK506-binding protein 12-complex, and the toll-like receptor 4. In accordance are our findings showing that silencing of toll-like receptor 4 by siRNA in A549 a lung carcinoma cell line reduced the activation of interferon-inducible genes upon pimecrolimus treatment in those cells. Based on our findings we hypothesize that calcineurin inhibition may induce the toll-like receptor 4 mediated activation of type I interferon signaling finally inducing the observed effect in endothelial and smooth muscle cells. The crosstalk of interferon and toll-like receptor signaling may be a molecular mechanism that contributed to the failure of pimecrolimus-eluting stents in humans. PMID:27212382

  19. Genetic predisposition to higher blood pressure increases risk of incident hypertension and cardiovascular diseases in Chinese.

    Science.gov (United States)

    Lu, Xiangfeng; Huang, Jianfeng; Wang, Laiyuan; Chen, Shufeng; Yang, Xueli; Li, Jianxin; Cao, Jie; Chen, Jichun; Li, Ying; Zhao, Liancheng; Li, Hongfan; Liu, Fangcao; Huang, Chen; Shen, Chong; Shen, Jinjin; Yu, Ling; Xu, Lihua; Mu, Jianjun; Wu, Xianping; Ji, Xu; Guo, Dongshuang; Zhou, Zhengyuan; Yang, Zili; Wang, Renping; Yang, Jun; Yan, Weili; Gu, Dongfeng

    2015-10-01

    Although multiple genetic markers associated with blood pressure have been identified by genome-wide association studies, their aggregate effect on risk of incident hypertension and cardiovascular disease is uncertain, particularly among East Asian who may have different genetic and environmental exposures from Europeans. We aimed to examine the association between genetic predisposition to higher blood pressure and risk of incident hypertension and cardiovascular disease in 26 262 individuals in 2 Chinese population-based prospective cohorts. A genetic risk score was calculated based on 22 established variants for blood pressure in East Asian. We found the genetic risk score was significantly and independently associated with linear increases in blood pressure and risk of incident hypertension and cardiovascular disease (P range from 4.57×10(-3) to 3.10×10(-6)). In analyses adjusted for traditional risk factors including blood pressure, individuals carrying most blood pressure-related risk alleles (top quintile of genetic score distribution) had 40% (95% confidence interval, 18-66) and 26% (6-45) increased risk for incident hypertension and cardiovascular disease, respectively, when compared with individuals in the bottom quintile. The genetic risk score also significantly improved discrimination for incident hypertension and cardiovascular disease and led to modest improvements in risk reclassification for cardiovascular disease (all the Pblood pressure is an independent risk factor for blood pressure increase and incident hypertension and cardiovascular disease and provides modest incremental information to cardiovascular disease risk prediction. The potential clinical use of this panel of blood pressure-associated polymorphisms remains to be determined.

  20. Daily liquorice consumption for two weeks increases augmentation index and central systolic and diastolic blood pressure.

    Directory of Open Access Journals (Sweden)

    Miia H Leskinen

    Full Text Available Liquorice ingestion often elevates blood pressure, but the detailed haemodynamic alterations are unknown. We studied haemodynamic changes induced by liquorice consumption in 20 subjects versus 30 controls with average blood pressures of 120/68 and 116/64 mmHg, respectively.Haemodynamic variables were measured in supine position before and after two weeks of liquorice consumption (daily glycyrrhizin dose 290-370 mg with tonometric recording of radial blood pressure, pulse wave analysis, and whole-body impedance cardiography. Thirty age-matched healthy subjects maintaining their normal diet were studied as controls.Two weeks of liquorice ingestion elevated peripheral and central systolic and diastolic blood pressure (by 7/4 and 8/4 mmHg, 95% confidence intervals [CI] 2-11/1-8 and 3-13/1-8, respectively, P<0.05, and increased extracellular volume by 0.5 litres (P<0.05 versus controls. Also augmentation index adjusted to heart rate 75/min (from 7% to 11%, 95% CI for change 0.3-7.5, P<0.05 and aortic pulse pressure (by 4 mmHg, 95% CI 1-7, P<0.05 were elevated indicating increased wave reflection from the periphery. In contrast, peripheral (-3/-0.3 mmHg and central blood pressure (-2/-0.5 mmHg, aortic pulse pressure (-1 mmHg, and augmentation index adjusted to heart rate 75/min (from 9% to 7% decreased numerically but not statistically significantly without changes in extracellular volume in the control group. Heart rate, systemic vascular resistance, cardiac output, and pulse wave velocity did not differ between the groups.Two weeks of daily liquorice consumption increased extracellular volume, amplified pressure wave reflection from the periphery, and elevated central systolic and diastolic blood pressure.EU Clinical Trials Register EudraCT 2006-002065-39 ClinicalTrials.gov NCT01742702.

  1. Increased expression of endothelin ET(B) and angiotensin AT(1) receptors in peripheral resistance arteries of patients with suspected acute coronary syndrome

    DEFF Research Database (Denmark)

    Dimitrijevic, Ivan; Ekelund, Ulf; Edvinsson, Lars

    2009-01-01

    Patients who experience chest pain, in which ischemic heart disease has been ruled out, still have an increased risk of future ischemic cardiac events and premature death, possibly due to subclinical endothelial dysfunction. A feature of endothelial dysfunction is an increased expression...... of arterial vasoconstrictor endothelin (ET) and angiotensin (AT) receptors. Our aim was to investigate if the arterial expressions of these receptors are changed in patients with suspected but ruled out acute coronary syndrome (ACS). Small subcutaneous arteries (diameter of 100 microm) were surgically removed....... The control group (controls) consisted of eight healthy volunteers matched for age and sex with no previous cardiac illness or medication. The susp ACS group had an increased expression of ET(B) (by 94%) and AT(1) (by 34%) receptors in the smooth muscle cells of resistance arteries as compared to the control...

  2. Liver cirrhosis and arterial hypertension

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik; Møller, Søren

    2006-01-01

    Characteristic findings in patients with cirrhosis are vasodilatation with low overall systemic vascular resistance, high arterial compliance, increased cardiac output, secondary activation of counter-regulatory systems (renin-angiotensin-aldosterone system, sympathetic nervous system, release...... blood pressure. This review considers the alterations in systemic hemodynamics in patients with cirrhosis in relation to essential hypertension and arterial hypertension of the renal origin. Subjects with arterial hypertension (essential, secondary) may become normotensive during the development...... of cirrhosis, and arterial hypertension is rarely manifested in patients with cirrhosis, even in cases with renovascular disease and high circulating renin activity. There is much dispute as to the understanding of homoeostatic regulation in cirrhotic patients with manifest arterial hypertension. This most...

  3. Prognostic Significance of Central Pulse Pressure for Mortality in Patients With Coronary Artery Disease Receiving Repeated Percutaneous Coronary Intervention.

    Science.gov (United States)

    Lin, Mao-Jen; Chen, Chun-Yu; Lin, Hau-De; Lin, Chung-Sheng; Wu, Han-Ping

    2016-03-01

    Coronary artery disease (CAD) is a life-threatening medical emergency which needs urgent medical attention. Percutaneous coronary intervention (PCI) is common and necessary for patients with CAD, but it has not completely evaluated in cases with repeated PCI. Therefore, the aim of this study was to examine the risk factors and prognosis in patients with CAD requiring repeated PCI. This is a prospective observational study. A total of 1126 patients with CAD requiring PCI took part in this study. Clinical parameters including baseline characteristics, hemodynamic data, location of vascular lesions, SYNTAX score, left ventricular ejection fraction, central pulse pressure (CPP), central aortic systolic pressure (CSP), risk factors, and invasive strategies were analyzed to identify the risk factors for patients requiring repeated PCI. We further analyzed the prognosis, including risk for myocardial infarction (MI), cardiovascular (CV) mortality, and all-cause mortality, in patients with repeated PCI. Among patients with PCI, 276 received repeated PCI. Patients in the repeated PCI group had a higher CPP (66.7 vs 62.5 mm Hg; P = 0.006), CSP (139.9 vs 135.9 mm Hg; P = 0.017), and male preponderance (P = 0.012). Drugs including diuretics, beta-blockers (BBs), angiotensin-converting enzyme inhibitors (ACEIs), and aspirin were all used more frequently in the repeated PCI group (all P patients with CAD after performing repeated PCI. PMID:27043689

  4. Assessment of renal artery stenosis using both resting pressures ratio and fractional flow reserve: relationship to angiography and ultrasonography.

    Science.gov (United States)

    Kadziela, Jacek; Witkowski, Adam; Januszewicz, Andrzej; Cedro, Krzysztof; Michałowska, Ilona; Januszewicz, Magdalena; Kabat, Marek; Prejbisz, Aleksander; Kalińczuk, Lukasz; Zieleń, Piotr; Michel-Rowicka, Katarzyna; Warchoł, Ewa; Rużyłło, Witold

    2011-08-01

    BACKGROUND. Clinical benefit from renal artery revascularization remains controversial, probably because of inaccurate stenosis severity assessment. Objective. The aim of the study was to evaluate resting translesional pressures ratio and renal fractional flow reserve (rFFR) in relation to angiography and Doppler duplex ultrasonography in patients with at least moderate renal artery stenosis (RAS). METHODS. 44 hypertensive patients (48% of males, mean age 65 years) with at least moderate RAS were investigated. Translesional systolic pressure gradient (TSPG), resting Pd/Pa ratio (the ratio of mean distal to lesion and mean proximal pressures) and hyperemic rFFR - after intrarenal administration of papaverine - were evaluated. Quantitative angiographic analysis of stenosis severity was performed including minimal lumen diameter (MLD) and percent diameter stenosis (DS) assessment. Renal/aortic ratio (RAR), resistive index (RI) and deltaRI (side-to side difference) were obtained in Doppler-duplex ultrasonography. The predictive value of selected variables was calculated using receiver-operating characteristics curves. RESULTS. Mean Pd/Pa ratio was 0.86 ± 0.12 and decreased to 0.79 ± 0.13 after papaverine administration. Both Pd/Pa ratio and rFFR strongly correlated with TSPG (r = -0.92, p < 0.0001 and r = -0.88, p < 0.0001, respectively) and moderately with MLD (r = 0.62, p < 0.0001 and r = 0.66, p < 0.0001) and DS (r = -0.63, p < 0.0001 and r = -0.70, p < 0.0001). To identify more than 70% RAS, considered severe, the most predictive cut-off values were 0.93 for Pd/Pa ratio and 0.80 for rFFR. CONCLUSIONS. Mean Pd/Pa ratio and rFFR strongly correlated with angiographic data and in less pronounced manner with ultrasound parameters reflecting intrarenal blood flow. The best accuracy cut-off points for severe RAS predicting were 0.93 and 0.80, respectively. PMID:21309656

  5. Creation of prompt and thin-sheet splashing by varying surface roughness or increasing air pressure

    CERN Document Server

    Latka, Andrzej; Driscoll, Michelle M; Stevens, Cacey S; Nagel, Sidney R

    2012-01-01

    A liquid drop impacting a solid surface may splash by emitting a thin liquid sheet that subsequently breaks apart or by promptly ejecting droplets from the advancing liquid-solid contact line. Using high-speed imaging, we show that air pressure and surface roughness influence both splash mechanisms. Roughness increases prompt splashing at the advancing contact line but inhibits the formation of the thin sheet. If the air pressure is lowered, droplet ejection is suppressed not only during thin-sheet formation but for prompt splashing as well. The threshold pressure depends on impact velocity, liquid viscosity and surface roughness.

  6. Increased oxidative stress and severe arterial remodeling induced by permanent high-flow challenge in experimental pulmonary hypertension

    Directory of Open Access Journals (Sweden)

    Fadel Elie

    2011-09-01

    Full Text Available Abstract Background Involvement of inflammation in pulmonary hypertension (PH has previously been demonstrated and recently, immune-modulating dendritic cells (DCs infiltrating arterial lesions in patients suffering from idiopathic pulmonary arterial hypertension (IPAH and in experimental monocrotaline-induced PH have been reported. Occurrence of perivascular inflammatory cells could be linked to local increase of oxidative stress (OS, as it has been shown for systemic atherosclerosis. The impact of OS on vascular remodeling in PH is still to be determined. We hypothesized, that augmented blood-flow could increase OS and might thereby contribute to DC/inflammatory cell-recruitment and smooth-muscle-cell-proliferation. Methods We applied a monocrotaline-induced PH-model and combined it with permanent flow-challenge. Thirty Sprague-Dawley rats were assigned to following groups: control, monocrotaline-exposure (MCT, monocrotaline-exposure/pneumonectomy (MCT/PE. Results Hemodynamic exploration demonstrated most severe effects in MCT/PE, corresponding in histology to exuberant medial and adventitial remodeling of pulmonary muscular arteries, and intimal remodeling of smaller arterioles; lung-tissue PCR evidenced increased expression of DCs-specific fascin, CD68, proinflammatory cytokines (IL-6, RANTES, fractalkine in MCT/PE and to a lesser extent in MCT. Major OS enzyme NOX-4 was maximal in MCT/PE. Antioxidative stress enzymes Mn-SOD and glutathion-peroxidase-1 were significantly elevated, while HO-1 showed maximal expression in MCT with significant decrease in MCT/PE. Catalase was decreased in MCT and MCT/PE. Expression of NOX-4, but also of MN-SOD in MCT/PE was mainly attributed to a highly increased number of interstitial and perivascular CXCR4/SDF1 pathway-recruited mast-cells. Stress markers malonedialdehyde and nitrotyrosine were produced in endothelial cells, medial smooth muscle and perivascular leucocytes of hypertensive vasculature

  7. The pharmacist and the management of arterial hypertension: the role of blood pressure monitoring and telemonitoring.

    Science.gov (United States)

    Omboni, Stefano; Sala, Elisa

    2015-02-01

    Randomized controlled trials have documented that a team of health care professionals which includes a physician, a nurse and a community pharmacist may improve the benefit and adherence of anti-hypertensive therapy. If such a health care model relies on blood pressure telemonitoring, it can promote a stronger relationship between health care professionals and patients, and further improve BP control of hypertension. The major benefit of this collaborative approach is to center the patient's management in a tailored way, providing comprehensive and preventive care based on health information technologies. In this review, the authors summarize recent clinical studies that evaluate the role of the community pharmacist in BP measurements, and in hypertension screening and control. The authors also describe the advantages of using blood pressure telemonitoring in home and ambulatory settings to evaluate potential alternatives to primary care in hypertension management.

  8. Impact of sudarshan kriya yoga on mean arterial blood pressure and biochemical parameters in medical students

    Directory of Open Access Journals (Sweden)

    Nisar Ahmad

    2016-06-01

    Conclusions: Living a happy and healthy life on all planes is possible through the unified practice of sudarshan kriya yoga (SKY along with asana and pranayam. The practice of SKY seems to be beneficial on mean blood pressure and biochemical parameters in normal healthy individuals. This unique breathing practice is a potent energizer. [Int J Res Med Sci 2016; 4(6.000: 2150-2152

  9. Insulin resistance reduces arterial prostacyclin synthase and eNOS activities by increasing endothelial fatty acid oxidation

    OpenAIRE

    DU, XUELIANG; Edelstein, Diane; Obici, Silvana; Higham, Ninon; Zou, Ming-Hui; Brownlee, Michael

    2006-01-01

    Insulin resistance markedly increases cardiovascular disease risk in people with normal glucose tolerance, even after adjustment for known risk factors such as LDL, triglycerides, HDL, and systolic blood pressure. In this report, we show that increased oxidation of FFAs in aortic endothelial cells without added insulin causes increased production of superoxide by the mitochondrial electron transport chain. FFA-induced overproduction of superoxide activated a variety of proinflammatory signals...

  10. Carbogen inhalation increases oxygen transport to hypoperfused brain tissue in patients with occlusive carotid artery disease: increased oxygen transport to hypoperfused brain

    DEFF Research Database (Denmark)

    Ashkanian, Mahmoud; Gjedde, Albert; Mouridsen, Kim;

    2009-01-01

    Hyperoxic therapy for cerebral ischemia reduces cerebral blood flow (CBF) principally from the vasoconstrictive effect of oxygen on cerebral arterioles. Based on a recent study in normal volunteers, we now claim that the vasodilatory effect of carbon dioxide predominates when 5% CO(2) is added...... to inhaled oxygen (the mixture known as carbogen). In the present study, we measured CBF by positron emission tomography (PET) during inhalation of test gases (O(2), carbogen, and atmospheric air) in healthy volunteers (n = 10) and in patients with occlusive carotid artery disease (n = 6). Statistical...... comparisons by an additive ANOVA model showed that carbogen significantly increased CBF by 7.51 + or - 1.62 ml/100 g/min while oxygen tended to reduce it by -3.22 + or - 1.62 ml/100 g/min. A separate analysis of the hemisphere contralateral to the hypoperfused hemisphere showed that carbogen significantly...

  11. Increased prevalence of coronary artery disease risk markers in patients with chronic hepatitis C – a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Roed T

    2014-01-01

    .7, difference of means 0.5; 95% CI 0.3–0.8, and a higher prevalence of metabolic syndrome (28% versus 18%, PR 1.6; 95% CI 0.8–3.0. Increased carotid intima media thickness above the standard 75th percentile was seen more frequently in chronic hepatitis C (9% versus 3%, PR 1.7; 95% CI 0.4–6.7, though difference of means was only 0.04 mm (95% CI 0.00–0.10. Patients with chronic hepatitis C had increased hsCRP (high-sensitivity C-reactive protein, sICAM-1 (soluble intercellular adhesion molecule-1, sVCAM-1 (soluble vascular cell adhesion molecule-1, and soluble E-selectin, but lower levels of tPAI-1 (tissue-type plasminogen activator inhibitor-1, MMP9 (matrix metallopeptidase 9, and MPO (myeloperoxidase than their comparisons.Conclusion: Our findings indicate that patients with chronic hepatitis C have increased prevalence of several coronary artery disease risk markers. These results may be important when evaluating the appropriateness of screening for coronary artery disease and its risk factors in chronic hepatitis C.Keywords: risk factors, atherosclerosis, endothelial dysfunction, biomarkers, metabolic syndrome, intima media thickness

  12. Pivotal Role of Mediterranean Dietary Regimen in the Increase of Serum Magnesium Concentration in Patients with Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    Nimah Bahreini

    2013-01-01

    Full Text Available Background. Recent studies confirmed cardioprotective role of intravenous magnesium for the prevention of cardiac events, but effect of dietary intake of this mineral via recommended dietary regimens on control and inhibition of coronary artery disease (CAD risk factors has been questioned. The aim of the present study was to determine effect of Mediterranean dietary approach on serum magnesium concentration among Iranian patients with CAD. Method. Baseline characteristics and clinical data of 102 consecutive patients with the diagnosis of CAD and candidates for isolated coronary artery bypass surgery were entered into the study. Laboratory parameters especially serum magnesium concentration were measured after 12–14 h of overnight fasting and before operation. Nutritional status was assessed by food frequency questionnaire and the diet score was calculated on the basis of Mediterranean diet quality index (Med-DQI. Results. No significant differences were found in the concentrations of albumin, last fasting blood sugar, last creatinine, and lipid profiles between the groups with Mediterranean dietary score < 5 and the group with higher dietary score; however, serum magnesium concentration in the first group was higher than that in the group with higher dietary score. Linear multivariate regression analysis showed that the lower Mediterranean dietary score was a predictor for serum magnesium concentration after adjusting for confounders. Conclusion. Taking Mediterranean dietary regimen can be associated with increased level of serum magnesium concentration, and thus this regimen can be cardioprotective because of its effects on serum magnesium.

  13. Association of Inter-arm Blood Pressure Difference with Asymptomatic Intracranial and Extracranial Arterial Stenosis in Hypertension Patients

    Science.gov (United States)

    Wang, Yan; Zhang, Jin; Qian, Yuesheng; Tang, Xiaofeng; Ling, Huawei; Chen, Kemin; Li, Yan; Gao, Pingjin; Zhu, Dingliang

    2016-01-01

    Inter-arm blood pressure (BP) difference has been associated with ischemic stroke. Local atherosclerosis of stroke differ among vulnerable individuals, whereas intracranial arterial stenosis (ICAS) is more frequently affected Asians, and extracranial arterial stenosis (ECAS) is more prevalent among whites. We hereby sought to explore the association of inter-arm BP difference with ICAS and ECAS in stroke-free hypertensive patients in Chinese population. All the 885 subjects were evaluated of ICAS and ECAS through computerized tomographic angiography. Both arm BP was measured simultaneously by Vascular Profiler-1000 device. In the continuous study, ICAS was significantly associated with age, male, average brachial SBP, diabetes, anti-hypertensive treatment and inter-arm DBP difference. ECAS was associated with age, inter-arm SBP and LDL. In the categorical study, subjects with the top quartile of inter-arm DBP difference (≥4 mmHg) showed significantly higher risk of ICAS (OR = 2.109; 95% CI, 1.24–3.587). And the participants with the top quartile of inter-arm SBP difference (≥6 mmHg) showed significantly higher risk of ECAS (OR = 2.288; 95% CI, 1.309–3.998). In conclusion, we reported a diverse association of inter-arm SBP/DBP difference with the ICAS/ECAS. Inter-arm DBP difference might be the early symbol of ICAS in Chinese population, which need further verification in long-term cohort study. PMID:27412818

  14. Technology and application of pressure relief and permeability increase by jointly drilling and slotting coal

    Institute of Scientific and Technical Information of China (English)

    Lin Baiquan; Zhang Jianguo; Shen Chunming; Zhang Qizhi; Sun Chen

    2012-01-01

    Difficulties with soft coal seams having a high gas content and high stress levels can be addressed by a technology of pressure relief and permeability increase.Slotting the seam by auxiliary drilling with a water jet that breaks the coal and slots the coal seam during the process of retreat drilling achieves pressure relief and permeability increase.Improved efficiency of gas extraction from a field test,high gas coal seam was observed.Investigating the theory of pressure relief and permeability increase required analyzing the characteristics of the double power slotting process and the effects of coal pressure relief and permeability increase.The influence of confining pressure on coal physical properties was examined by using FLAC3D software code to simulate changes of coal stress within the tool destruction area.The double power joint drilling method was modeled.Field experiments were performed and the effects are analyzed.This research shows that there is an "islanding effect" in front of the joint double power drill and slotting equipment.The failure strength of the coal seam is substantially reduced within the tool destruction area.Drilling depths are increased by 72% and the diameter of the borehole is increased by 30%.The amount of powdered coal extracted from the drill head increases by 17 times when using the new method.A 30 day total flow measurement from the double power drilled and slotted bores showed that gas extraction increased by 1.3 times compared to the standard drilled bores.Gas concentrations increased from 30% to 60% and were more stable so the overall extraction efficiency increased by a factor of two times.

  15. Middle cerebral artery blood velocity during rowing

    DEFF Research Database (Denmark)

    Secher, Niels Henry; Pott, F; Knudsen, L.;

    1997-01-01

    original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler......original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler...

  16. Optimal blood pressure in patients with peripheral artery disease following endovascular therapy.

    Science.gov (United States)

    Sasaki, Haruki; Ura, Nobuyuki; Hata, Shinya; Moniwa, Norihito; Hasegawa, Koichi; Takizawa, Hideki; Tanaka, Shigemichi

    2016-01-01

    This study examined the associations between blood pressure (BP) and event incidence to define optimal BP after endovascular therapy (EVT) in patients who underwent EVT. BP was monitored every 6 months for 5 years, and the patients were divided into two groups by average BP: ≥ 140/90 mmHg and  7.0% was significantly higher among those who did not achieve target BP in the restenosis group (42.9%) than in the other group (10.8%) (p EVT. PMID:26440772

  17. The influence of tobacco smoking on the relationship between pressure and flow in the middle cerebral artery in humans.

    Directory of Open Access Journals (Sweden)

    Karen C Peebles

    Full Text Available BACKGROUND: Cigarette smoking is associated with an increased risk of stroke but the mechanism is unclear. The study examined whether acute and chronic cigarette smoking alters the dynamic relationship between blood pressure and cerebral blood flow. We hypothesised that acute and chronic smoking would result in a cerebral circulation that was less capable of buffering against dynamic fluctuations in blood pressure. Further, these changes would be accompanied by a reduction in baroreflex sensitivity, which is reduced after smoking (acute smoking. METHODS: We recruited 17 non-smokers and 15 habitual smokers (13 ± 5 pack years. Continuous measurements of mean cerebral blood flow velocity (transcranial Doppler ultrasound, blood pressure (finger photoplethysmography and heart rate enabled transfer function analysis of the dynamic relationship between pressure and flow (gain, normalised gain, phase and coherence and baroreflex sensitivity during supine rest before and after smoking a single cigarette (acute smoking. RESULTS: There were no between-group differences in gain, phase or coherence before acute smoking. However, both groups showed a reduction in gain and coherence, associated with a reduction in baroreflex sensitivity, and increase in phase after acute smoking. CONCLUSIONS: Contrary to our hypothesis, these findings suggest that in the face of a reduction in baroreflex sensitivity acute smoking may potentially improve the ability of the cerebral circulation to buffer against changes in blood pressure. However, chronic smoking did not alter the dynamic relationship between blood pressure and cerebral blood flow velocity. These results have implications on understanding mechanisms for attenuating stroke risk.

  18. Hydrostatic Pressure Affects In Vitro Maturation of Oocytes and Follicles and Increases Granulosa Cell Death

    Directory of Open Access Journals (Sweden)

    Isac Karimi

    2013-01-01

    Full Text Available Objective: This study examines the effects of hydrostatic pressure on in vitro maturation (IVM of oocytes derived from in vitro grown follicles.Materials and Methods: In this experimental study, preantral follicles were isolated from 12-day-old female NMRI mice. Each follicle was cultured individually in Alpha Minimal Essential Medium (α-MEM under mineral oil for 12 days. Then, follicles were induced for IVM and divided into two groups, control and experiment. In the experiment group follicles were subjected to 20 mmHg pressure for 30 minutes and cultured for 24-48 hours. We assessed for viability and IVM of the oocytes. The percentage of apoptosis in cumulus cells was determined by the TUNEL assay. A comparison between groups was made using the student’s t test.Results: The percentage of metaphase II oocytes (MII increased in hydrostatic pressure-treated follicles compared to controls (p<0.05. Cumulus cell viability reduced in hydrostatic pressure-treated follicles compared to controls (p<0.05. Exposure of follicles to pressure increased apoptosis in cumulus cells compared to controls (p<0.05.Conclusion: Hydrostatic pressure, by inducing apoptosis in cumulus cells, participates in the cumulus oocyte coupled relationship with oocyte maturation.

  19. Efeitos do treinamento resistido sobre a pressão arterial de idosos Efectos del entrenamiento de resistencia sobre la presión arterial de añosos Effects of resistance training on blood pressure in the elderly

    Directory of Open Access Journals (Sweden)

    Andréia Cristiane Carrenho Queiroz

    2010-07-01

    de presión arterial de reposo, siendo importante analizar los efectos del ejercicio de resistencia sobre la presión arterial de individuos añosos. El objetivo de este estudio es evaluar el conocimiento científico existente sobre la respuesta de la presión arterial a los ejercicios de resistencia y sus mecanismos en añosos. Para esto, se realizó una revisión bibliográfica basada en la literatura portuguesa e inglesa relacionadas al tema. Con base en los estudios encontrados, el corpus actual, a pesar de ser escaso y controvertido, sugiere que, de forma crónica, los ejercicios de resistencia pueden tener efecto hipotensor en individuos añosos. Entre tanto, este efecto ocurre, principalmente en añosos normotensos y con entrenamiento de baja intensidad. Los mecanismos envueltos en esa respuesta hipotensora todavía precisan ser elucidados. Aunque el entrenamiento con resistencia esté siendo recomendado para añosos y haya algunos indicativos de que pueda tener efecto hipotensor crónico, todavía hay carencia de datos científicos y muchas controversias en el asunto, lo que evidencia que éste todavía es un campo abierto a la investigación.The aging process drastically reduces muscle mass, strength and power, decreasing the capacity to perform the activities of daily living. The practice of resistance exercises can reverse this picture, helping to maintain the muscular mass and improving muscular strength and resistance. However, the aging process causes cardiovascular alterations, which can result in increased blood pressure levels at rest and it is important to analyze the effects of resistance exercises on the blood pressure of elderly individuals. The objective of this study is to evaluate the current scientific knowledge on the responses of the blood pressure to resistance exercises and their mechanisms in elderly individuals. In order to do that, we carried out a literature review related to the theme, in both Portuguese and English. Based on the

  20. Hypoxia activates NADPH oxidase to increase [ROS]i and [Ca2+]i through mitochondrial ROS–PKCε signaling axis in pulmonary artery smooth muscle cells

    OpenAIRE

    Rathore, Rakesh; Zheng, Yun-Min; Niu, Chun-Feng; Liu, Qing-Hua; Korde, Amit; Ho, Ye-Shih; Wang, Yong-Xiao

    2008-01-01

    The importance of NADPH oxidase (Nox) in hypoxic responses in hypoxia-sensing cells including pulmonary artery smooth muscle cells (PASMCs) remains uncertain. In this study, using Western blot analysis we found that the major Nox subunits Nox1, Nox4, p22phox, p47phox, and p67phox were equivalently expressed in mouse pulmonary and systemic (mesenteric) arteries. However, acute hypoxia significantly increased Nox activity and translocation of p47phox protein to the plasma membrane in pulmonary,...

  1. Ultrasound-assessed perirenal fat is related to increased ophthalmic artery resistance index in HIV-1 patients

    Directory of Open Access Journals (Sweden)

    Chiavaroli Roberto

    2010-06-01

    Full Text Available Abstract Background The introduction of highly active antiretroviral therapy (HAART has dramatically changed the prognosis of human immunodeficiency virus (HIV infection, with a significant decline in morbidity and mortality. Changes in body fat distribution are a common finding in individuals with HIV infection being treated with antiretrovirals, and this condition (collectively termed lipodystrophy syndrome is associated with depletion of subcutaneous fat, increased triglycerides and insulin resistance. Obesity, particularly visceral obesity, is associated with increased risk of cardiovascular disease. Therefore, estimating visceral fat distribution is important in identifying subjects at high risk for cardiovascular disease. The aim of our study was to evaluate whether perirenal fat thickness (PRFT, a parameter of central obesity, is related to ophthalmic artery resistance index (OARI, an index of occlusive carotid artery disease in HIV-1 infected patients. Methods We enrolled 88 consecutive HIV-1-infected patients receiving highly active antiretroviral therapy for more than 12 months, in a prospective cohort study. Echographically measured PRFT and OARI, as well as serum metabolic parameters, were evaluated. PRFT and OARI were measured by 3.75 MHz convex and 7.5 MHz linear probe, respectively. Results The means of PRFT and OARI in HIV-1-infected patients with visceral obesity was considerably higher than in patients without it (p 0.74 (sensitivity 78.9%, specificity 82.8%. Conclusions Our data indicate that ultrasound assessment of PRFT may have potential as a marker of increased endothelial damage with specific involvement of the ocular vascular region in HIV-1-infected patients.

  2. Artificial reproduction of magnetic fields produced by a natural geomagnetic storm increases systolic blood pressure in rats

    Science.gov (United States)

    Martínez-Bretón, J. L.; Mendoza, B.; Miranda-Anaya, M.; Durán, P.; Flores-Chávez, P. L.

    2016-04-01

    The incidence of geomagnetic storms may be associated with changes in circulatory physiology. The way in which the natural variations of the geomagnetic field due to solar activity affects the blood pressure are poorly understood and require further study in controlled experimental designs in animal models. In the present study, we tested whether the systolic arterial pressure (AP) in adult rats is affected by simulated magnetic fields resembling the natural changes of a geomagnetic storm. We exposed adult rats to a linear magnetic profile that simulates the average changes associated to some well-known geomagnetic storm phases: the sudden commencement and principal phase. Magnetic stimulus was provided by a coil inductor and regulated by a microcontroller. The experiments were conducted in the electromagnetically isolated environment of a semi-anechoic chamber. After exposure, AP was determined with a non-invasive method through the pulse on the rat's tail. Animals were used as their own control. Our results indicate that there was no statistically significant effect in AP when the artificial profile was applied, neither in the sudden commencement nor in the principal phases. However, during the experimental period, a natural geomagnetic storm occurred, and we did observe statistically significant AP increase during the sudden commencement phase. Furthermore, when this storm phase was artificially replicated with a non-linear profile, we noticed a 7 to 9 % increase of the rats' AP in relation to a reference value. We suggested that the changes in the geomagnetic field associated with a geomagnetic storm in its first day could produce a measurable and reproducible physiological response in AP.

  3. Temporal and Spatial Properties of Arterial Pulsation Measurement Using Pressure Sensor Array

    Directory of Open Access Journals (Sweden)

    Chung-Shing Hu

    2012-01-01

    Full Text Available Conventionally, a pulse taking platform is based on a single sensor, which initiates a feasible method of quantitative pulse diagnosis. The aim of this paper is to implement a pulse taking platform with a tactile array sensor. Three-dimensional wrist pulse signals are constructed, and the length, width, ascending slope, and descending slope are defined following the surface of the wrist pulse. And the pressure waveform of the wrist pulse obtained through proposed pulse-taking platform has the same performance as the single sensor. Finally, the results of a paired samples t-test reveal that the repeatability of the proposal platform is consistent with clinical experience. On the other hand, the results of ANOVA indicate that differences exist among different pulse taking depths, and this result is consistent with clinical experience in traditional Chinese medicine pulse diagnosis (TCMPD. Hence, the proposed pulse taking platform with an array sensor is feasible for quantification in TCMPD.

  4. Increased discordance between HeartScore and coronary artery calcification score after introduction of the new ESC prevention guidelines

    DEFF Research Database (Denmark)

    Diederichsen, Axel C P; Mahabadi, Amir-Abbas; Gerke, Oke;

    2015-01-01

    -contrast Cardiac-CT scan was performed to detect coronary artery calcification (CAC). RESULTS: Agreement of HeartScore risk groups with CAC groups was poor, but higher when applying the algorithm for the low-risk compared to the high-risk country model (agreement rate: 77% versus 63%, and weighted Kappa: 0.......22 versus 0.15). However, the number of subjects with severe coronary calcification (CAC score ≥400) increased in the low and intermediate HeartScore risk group from 78 to 147 participants (from 2.7 % to 4.2 %, p = 0.001), when estimating the risk based on the algorithm for low-risk countries. CONCLUSION...

  5. Transient pool boiling heat transfer due to increasing heat inputs in subcooled water at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, K. [Kobe Univ. of Mercantile Marine (Japan); Shiotsu, M.; Sakurai, A. [Kyoto Univ. (Japan)

    1995-09-01

    Understanding of transient boiling phenomenon caused by increasing heat inputs in subcooled water at high pressures is necessary to predict correctly a severe accident due to a power burst in a water-cooled nuclear reactor. Transient maximum heat fluxes, q{sub max}, on a 1.2 mm diameter horizontal cylinder in a pool of saturated and subcooled water for exponential heat inputs, q{sub o}e{sup t/T}, with periods, {tau}, ranging from about 2 ms to 20 s at pressures from atmospheric up to 2063 kPa for water subcoolings from 0 to about 80 K were measured to obtain the extended data base to investigate the effect of high subcoolings on steady-state and transient maximum heat fluxes, q{sub max}. Two main mechanisms of q{sub max} exist depending on the exponential periods at low subcoolings. One is due to the time lag of the hydrodynamic instability which starts at steady-state maximum heat flux on fully developed nucleate boiling (FDNB), and the other is due to the heterogenous spontaneous nucleations (HSN) in flooded cavities which coexist with vapor bubbles growing up from active cavities. The shortest period corresponding to the maximum q{sub max} for long period range belonging to the former mechanism becomes longer and the q{sub max}mechanism for long period range shifts to that due the HSN on FDNB with the increase of subcooling and pressure. The longest period corresponding to the minimum q{sub max} for the short period range belonging to the latter mechanism becomes shorter with the increase in saturated pressure. On the contrary, the longest period becomes longer with the increase in subcooling at high pressures. Correlations for steady-state and transient maximum heat fluxes were presented for a wide range of pressure and subcooling.

  6. Differential effects of the changes of LDL cholesterol and systolic blood pressure on the risk of carotid artery atherosclerosis

    Directory of Open Access Journals (Sweden)

    Chien Kuo-Liong

    2012-08-01

    Full Text Available Abstract Background The effects of baseline and changes in blood pressure and low density lipoprotein (LDL cholesterol on the carotid intima media thickness (IMT have not been well documented. Methods A total of 2572 adults (mean age 53.8 years, 54.6% women in a Taiwanese community undertook three blood pressure and LDL cholesterol examinations over 6 years. Latent growth curve modeling was used to investigate the effects of baseline and change in blood pressure and LDL cholesterol on IMT. Results Greater baseline LDL and blood pressure were associated with an increase in IMT (0.005 ± 0.002 mm per 1 mg/dL [p = 0.006] and 0.041 ± 0.004 mm mmHg [p Conclusions Carotid IMT was associated with baseline blood pressure and LDL cholesterol, yet only changes of blood pressure, not LDL cholesterol, were related to carotid IMT during the 6-year observation.

  7. Increased prevalence of coronary artery disease risk markers in patients with chronic hepatitis C

    DEFF Research Database (Denmark)

    Roed, Torsten; Kristoffersen, Ulrik Sloth; Knudsen, Andreas;

    2014-01-01

    /high-density lipoprotein ratio), higher glycosylated hemoglobin level (mean 6.2 versus 5.7, difference of means 0.5; 95% CI 0.3-0.8), and a higher prevalence of metabolic syndrome (28% versus 18%, PR 1.6; 95% CI 0.8-3.0). Increased carotid intima media thickness above the standard 75th percentile was seen more frequently...

  8. Increased arterial vascular tone during the night in patients with essential hypertension

    DEFF Research Database (Denmark)

    Scholze, A; Burkert, A; Mardanzai, K;

    2007-01-01

    and normotensive control subjects. Vascular tone was continuously quantified by the reflective index obtained by non-invasive digital photoplethysmography and an algorithm for continuous, investigator-independent, automatic analysis of digital volume pulse. During the first half of the night, the reflective index...... was significantly higher in 31 patients with essential hypertension compared to 30 normotensive control subjects (30.0+/-0.2 vs 28.8+/-0.2; P=0.001). In patients with essential hypertension, the reflective index significantly increased from 30.0+/-0.2 in the first half (from 2301 to 0230) to 30.......7+/-0.2 in the second half (from 0231 to 0600) of the night (n=31; P=0.027). In normotensive control subjects the reflective index also significantly increased from 28.8+/-0.2 in the first half of the night to 30.2+/-0.2 in the second half of the night (n=30; P=0.001). An increase of the reflective index tone indicated...

  9. Arterial hypertension and cancer.

    Science.gov (United States)

    Milan, Alberto; Puglisi, Elisabetta; Ferrari, Laura; Bruno, Giulia; Losano, Isabel; Veglio, Franco

    2014-05-15

    Arterial hypertension and cancer are two of the most important causes of mortality in the world; correlations between these two clinical entities are complex and various. Cancer therapy using old (e.g., mitotic spindle poisons) as well as new (e.g., monoclonal antibody) drugs may cause arterial hypertension through different mechanisms; sometimes the increase of blood pressure levels may be responsible for chemotherapy withdrawal. Among newer cancer therapies, drugs interacting with the VEGF (vascular endothelial growth factors) pathways are the most frequently involved in hypertension development. However, many retrospective studies have suggested a relationship between antihypertensive treatment and risk of cancer, raising vast public concern. The purposes of this brief review have then been to analyse the role of chemotherapy in the pathogenesis of hypertension, to summarize the general rules of arterial hypertension management in this field and finally to evaluate the effects of antihypertensive therapy on cancer disease.

  10. Increasing preservation efficiency and product quality through control of temperature distributions in high pressure applications

    NARCIS (Netherlands)

    Heij, de W.; Schepdael, van L.; Berg, van den R.; Bartels, P.

    2002-01-01

    The effectiveness of HP sterilisation is a function of both temperature and pressure. As during pressurisation the product temperature increases, heat transfer to the colder HPP vessel wall occurs and the product fraction near the vessel wall will be colder than the product in the middle of the vess

  11. Predictors of Subclinical Cardiovascular Disease in Women with Polycystic Ovary Syndrome: Interrelationship of Dyslipidemia and Arterial Blood Pressure

    Directory of Open Access Journals (Sweden)

    Djuro Macut

    2015-01-01

    Full Text Available Background. Women with polycystic ovary syndrome (PCOS could develop subclinical atherosclerosis during life. Purpose. To analyze cardiovascular risk (CVR factors and their relation to clinical markers of cardiovascular disease (CVD in respect to their age. Material and Methods. One hundred women with PCOS (26.32±5.26 years, BMI: 24.98±6.38 kg/m2 were compared to 50 respective controls. In all subjects, total cholesterol (TC, HDL-C, LDL-C, triglycerides, TC/HDL-C and TG/HDL-C ratios, glucose, insulin and HOMA index, waist-to-hip ratio (WHR, systolic and diastolic blood pressure (SBP and DBP, resp., and carotid intima-media thickness (CIMT were analyzed in respect to their age and level of androgens. Results. PCOS over 30 years had higher WHR (P=0.008, SBP (P<0.001, DBP (P<0.001, TC (P=0.028, HDL-C (P=0.028, LDL-C (P=0.045, triglycerides (P<0.001, TC/HDL-C (P<0.001, and triglycerides/HDL-C (P<0.001 and had more prevalent hypertension and pronounced CIMT on common carotid arteries even after adjustment for BMI (P=0.005 and 0.036, resp.. TC/HDL-C and TG/HDL-C were higher in PCOS with the highest quintile of FAI in comparison to those with lower FAI (P=0.045 and 0.034, resp.. Conclusions. PCOS women older than 30 years irrespective of BMI have the potential for early atherosclerosis mirrored through the elevated lipids/lipid ratios and through changes in blood pressure.

  12. Role of the Renin-Angiotensin-Aldosterone System beyond Blood Pressure Regulation: Molecular and Cellular Mechanisms Involved in End-Organ Damage during Arterial Hypertension

    Directory of Open Access Journals (Sweden)

    Natalia Muñoz-Durango

    2016-06-01

    Full Text Available Arterial hypertension is a common condition worldwide and an important predictor of several complicated diseases. Arterial hypertension can be triggered by many factors, including physiological, genetic, and lifestyle causes. Specifically, molecules of the renin-angiotensin-aldosterone system not only play important roles in the control of blood pressure, but they are also associated with the genesis of arterial hypertension, thus constituting a need for pharmacological interventions. Chronic high pressure generates mechanical damage along the vascular system, heart, and kidneys, which are the principal organs affected in this condition. In addition to mechanical stress, hypertension-induced oxidative stress, chronic inflammation, and the activation of reparative mechanisms lead to end-organ damage, mainly due to fibrosis. Clinical trials have demonstrated that renin-angiotensin-aldosterone system intervention in hypertensive patients lowers morbidity/mortality and inflammatory marker levels as compared to placebo patients, evidencing that this system controls more than blood pressure. This review emphasizes the detrimental effects that a renin-angiotensin-aldosterone system (RAAS imbalance has on health considerations above and beyond high blood pressure, such as fibrotic end-organ damage.

  13. Role of the Renin-Angiotensin-Aldosterone System beyond Blood Pressure Regulation: Molecular and Cellular Mechanisms Involved in End-Organ Damage during Arterial Hypertension.

    Science.gov (United States)

    Muñoz-Durango, Natalia; Fuentes, Cristóbal A; Castillo, Andrés E; González-Gómez, Luis Martín; Vecchiola, Andrea; Fardella, Carlos E; Kalergis, Alexis M

    2016-01-01

    Arterial hypertension is a common condition worldwide and an important predictor of several complicated diseases. Arterial hypertension can be triggered by many factors, including physiological, genetic, and lifestyle causes. Specifically, molecules of the renin-angiotensin-aldosterone system not only play important roles in the control of blood pressure, but they are also associated with the genesis of arterial hypertension, thus constituting a need for pharmacological interventions. Chronic high pressure generates mechanical damage along the vascular system, heart, and kidneys, which are the principal organs affected in this condition. In addition to mechanical stress, hypertension-induced oxidative stress, chronic inflammation, and the activation of reparative mechanisms lead to end-organ damage, mainly due to fibrosis. Clinical trials have demonstrated that renin-angiotensin-aldosterone system intervention in hypertensive patients lowers morbidity/mortality and inflammatory marker levels as compared to placebo patients, evidencing that this system controls more than blood pressure. This review emphasizes the detrimental effects that a renin-angiotensin-aldosterone system (RAAS) imbalance has on health considerations above and beyond high blood pressure, such as fibrotic end-organ damage. PMID:27347925

  14. Role of the Renin-Angiotensin-Aldosterone System beyond Blood Pressure Regulation: Molecular and Cellular Mechanisms Involved in End-Organ Damage during Arterial Hypertension.

    Science.gov (United States)

    Muñoz-Durango, Natalia; Fuentes, Cristóbal A; Castillo, Andrés E; González-Gómez, Luis Martín; Vecchiola, Andrea; Fardella, Carlos E; Kalergis, Alexis M

    2016-06-23

    Arterial hypertension is a common condition worldwide and an important predictor of several complicated diseases. Arterial hypertension can be triggered by many factors, including physiological, genetic, and lifestyle causes. Specifically, molecules of the renin-angiotensin-aldosterone system not only play important roles in the control of blood pressure, but they are also associated with the genesis of arterial hypertension, thus constituting a need for pharmacological interventions. Chronic high pressure generates mechanical damage along the vascular system, heart, and kidneys, which are the principal organs affected in this condition. In addition to mechanical stress, hypertension-induced oxidative stress, chronic inflammation, and the activation of reparative mechanisms lead to end-organ damage, mainly due to fibrosis. Clinical trials have demonstrated that renin-angiotensin-aldosterone system intervention in hypertensive patients lowers morbidity/mortality and inflammatory marker levels as compared to placebo patients, evidencing that this system controls more than blood pressure. This review emphasizes the detrimental effects that a renin-angiotensin-aldosterone system (RAAS) imbalance has on health considerations above and beyond high blood pressure, such as fibrotic end-organ damage.

  15. Sustained Improvement of Arterial Stiffness and Blood Pressure after Long-Term Rosuvastatin Treatment in Patients with Inflammatory Joint Diseases: Results from the RORA-AS Study.

    Directory of Open Access Journals (Sweden)

    Eirik Ikdahl

    Full Text Available Patients with inflammatory joint diseases (IJD have a high prevalence of hypertension and increased arterial stiffness. The aim of the present study was to evaluate the effect of long-term rosuvastatin treatment on arterial stiffness, measured by augmentation index (AIx and aortic pulse wave velocity (aPWV, and blood pressure (BP in IJD patients with established atherosclerosis.Eighty-nine statin naïve IJD patients with carotid atherosclerotic plaque(s (rheumatoid arthritis n = 55, ankylosing spondylitis n = 23, psoriatic arthritis n = 11 received rosuvastatin for 18 months to achieve low-density lipoprotein cholesterol goal ≤1.8 mmol/L. Change in AIx (ΔAIx, aPWV (ΔaPWV, systolic BP (ΔsBP and diastolic BP (ΔdBP from baseline to study end was assessed by paired samples t-tests. Linear regression was applied to evaluate associations between cardiovascular disease (CVD risk factors, rheumatic disease specific variables and medication, and ΔAIx, ΔaPWV, ΔsBP and ΔdBP.AIx, aPWV, sBP and dBP were significantly reduced from baseline to study end. The mean (95%CI changes were: ΔAIx: -0.34 (-0.03, -0.65% (p = 0.03, ΔaPWV: -1.69 (-0.21, -3.17m/s2 (p = 0.03, ΔsBP: -5.27 (-1.61, -8.93mmHg (p = 0.004 and ΔdBP -2.93 (-0.86, -5.00mmHg (p = 0.01. In linear regression models, ∆aPWV was significantly correlated with ΔsBP and ΔdBP (for all: p<0.001.There is an unmet need of studies evaluating CVD prevention in IJD patients. We have shown for the first time that long-term intensive lipid lowering with rosuvastatin improved arterial stiffness and induced a clinically significant BP reduction in patients with IJD. These improvements were linearly correlated and may represent novel insight into the pleiotropic effects by statins.ClinicalTrials.gov NCT01389388.

  16. Infections Increase Risk of Arterial and Venous Thromboses in Danish Patients with Systemic Lupus Erythematosus

    DEFF Research Database (Denmark)

    Baronaite Hansen, Renata; Jacobsen, Søren

    2014-01-01

    OBJECTIVE: Infections and thromboses are known complications of systemic lupus erythematosus (SLE). We investigated if infectious episodes in patients with SLE were followed by an increased risk of thrombotic events. METHODS: A cohort of 571 patients with prevalent or incident SLE was followed......, and ever-presence of antiphospholipid antibodies, thrombotic events were classified as occurring during the time at risk of 1 year after an infection or during the remaining control observation time. RESULTS: Of 271 infections identified, 104 were respiratory, 41 cutaneous herpes zoster, and 126 others...

  17. Incapacidade para atividades habituais: relação com pressão arterial e terapêutica anti-hipertensiva Incapacidad para actividades habituales: relación con presión arterial y tratamiento antihipertensivo Temporary limitations in daily routine activities: association with arterial pressure and antihypertensive therapy

    Directory of Open Access Journals (Sweden)

    Gilberto Senechal de Goffredo Filho

    2010-04-01

    individuos. OBJETIVO: Verificar si la elevación de los valores tensionales o el tratamiento farmacológico antihipertensivo determinan incapacidad temporaria para actividades habituales. MÉTODOS: Análisis de datos seccionales de 2.953 participantes, en 1999-2001, de cohorte de funcionarios de universidad en Rio de Janeiro (Estudio Pró-Saúde. La ocurrencia y duración de la incapacida