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Systemic Blood Flow (systemic + blood_flow)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Lower Cardiac Output Is Associated with Greater White Matter Hyperintensities in Older Adults with Cardiovascular Disease

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 7 2007
Angela L. Jefferson PhD
OBJECTIVES: To preliminarily examine the association between cardiac output, a measure of systemic blood flow, and structural brain magnetic resonance imaging indices of white matter hyperintensities (WMHs). DESIGN: Cross-sectional. SETTING: University medical setting. PARTICIPANTS: Thirty-six older adults without dementia with prevalent cardiovascular disease (aged 56,85). MEASUREMENTS: Cardiac output, WMHs. RESULTS: Partial correlations, adjusting for age and history of hypertension, yielded an inverse relationship between WMHs adjacent to subcortical nuclei and cardiac output (correlation coefficient=,0.48, P=.03); as cardiac output decreased, WMHs increased significantly. No significant associations were found between cardiac output and total WMHs or periventricular WMHs. CONCLUSION: These preliminary data suggest that systemic blood flow, measured according to cardiac output, is inversely associated with WMHs adjacent to the subcortical nuclei. Cerebrovascular degeneration and the chronicity of hypoperfusion may exacerbate the susceptibility of white matter integrity to alterations in blood flow in older adults. [source]

Clinical significance of reduced systemic Windkessel size in severe ventricular septal defect patients

PEDIATRICS INTERNATIONAL, Issue 3 2008
Keiko Kamisaka
Abstract Background: Large-shunt ventricular septal defect (VSD) infants manifest varied serious symptoms resulting from peripheral arterial constriction to compensate for increased pulmonary blood flow (Qp) and concomitantly decreased systemic blood flow (Qs). The aim of the present paper was therefore to estimate the whole arterial space proximal to arterioles as the systemic Windkessel size (WS) in these infants and compare it with aortic volume (AV) estimated angiographically. Method: Subjects were divided into three groups. Group 1a consisted of the so-called balanced-pressure VSD infants; group 1b consisted of those with normal or moderately increased pulmonary artery pressure (PAP) and highly augmented Qp; and group 2 consisted of those with a history of mucocutaneous lymph node syndrome as controls for Qp and pulmonary artery pressure. WS was computed from the Windkessel model, while the AV was calculated from the angiogram. Maximal systolic (WSs), mean (WSm), and minimum diastolic (WSd) WS were defined, computed, and compared. Result: All WS were significantly smaller in group 1a; those of group 1b were between group 1a and group 2, with Qs-dependent reduction of WS throughout all these three groups. WSs, WSm, and WSd had negative correlations with right ventricular systolic pressure/left ventricular systolic pressure in group 1a and group 1b. WSm, or the time averaged size, proved to be larger than the corresponding AV in all patients. The ratio of WSm/AV was significantly reduced in group 1a compared to group 1b and group 2, indicating that systemic arterial Windkessel space in severe VSD infants is significantly small, especially so in terms of space distal to aortic valve and proximal to arterioles. Conclusion: In severe VSD infants the whole systemic arterial space proximal to arterioles (WS) is reduced in size according to severity. [source]

Emergency Use of Extracorporeal Membrane Oxygenation in Cardiopulmonary Failure

ARTIFICIAL ORGANS, Issue 9 2009
Matthias Arlt
Abstract Severe pulmonary and cardiopulmonary failure resistant to critical care treatment leads to hypoxemia and hypoxia-dependent organ failure. New treatment options for cardiopulmonary failure are necessary even for patients in outlying medical facilities. If these patients are in need of specialized center treatment, additional emergency medical service has to be carried out quick and safely. We describe our experiences with a pumpless extracorporeal lung assist (PECLA/iLA) for out-of-center emergency treatment of hypercapnic respiratory failure and the use of a newly developed hand-held extracorporeal membrane oxygenation (ECMO) system in cardiac, pulmonary, and cardiopulmonary failure (EMERGENCY-LIFE Support System, ELS System, MAQUET Cardiopulmonary AG, Hechingen, Germany). Between March 2000 and April 2009, we used the PECLA System (n = 20) and the ELS System (n = 33) in adult patients. Cannulation was employed using percutaneous vessel access. The new hand-held ELS System consists of a centrifugal pump and a membrane oxygenator, both mounted on a special holder system for storing on a standard patient gurney for air or ground ambulance transfer. Bedside cannulation processes were uneventful. The PECLA System resulted in sufficient CO2 removal. In all ECMO patients, oxygen delivery and systemic blood flow could be restored and vasopressor support was markedly down. Hospital survival rate in the PECLA group was 50%, and 61% in the ECMO group. Out-of-center emergency treatment of hypercapnic pulmonary failure with pumpless extracorporeal gas exchange and treatment of cardiac, pulmonary, and cardiopulmonary failure with this new hand-held ECMO device is safe and highlyeffective. Patient outcome in cardiopulmonary organ failure could be improved. [source]

Initial transcatheter palliation of hypoplastic left heart syndrome

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 5 2006
FACC, K.C. Chan MBBS
Abstract Initial percutaneous transcatheter palliation of hypoplastic left heart syndrome is now feasible. The primary procedures for palliation include stenting of the ductus arteriosus with a self expanding nitinol stent to secure an adequate systemic blood flow, placement of an internal pulmonary arterial band to protect the pulmonary vascular bed and to prevent pulmonary overcirculation, and widening of the interatrial communication by blade and balloon septostomy or static balloon dilation to decompress the left atrium. Anatomic variations of the ductus arteriosus have important implications for technical success with ductal stenting. Patients who have undergone complete transcatheter palliation with the internal pulmonary band appear to have less immediate morbidity at the time of transplant, with preserved integrity and growth of the branch pulmonary arteries at one year follow-up. © 2006 Wiley-Liss, Inc. [source]

2151: Interaction of vascular and biomechanical aspects of glaucoma

ACTA OPHTHALMOLOGICA, Issue 2010
M LESK
Purpose In an attempt to understand some of the reasons why some optic nerves appear to be sensitive to IOP and others not, I will review studies describing the interaction between vascular and biomechanical factors in open angle glaucoma. Methods Studies using biomechanical modelling, epidemiologic data, measurements of ocular or systemic blood flow, measurment of peripheral vasospasticity, and measurement of ocular biomechanical parameters will be reviewed. Hypotheses will be presented regarding the interpretation of these data. Results Studies suggest that the optic nerves of vasospasctic patients may be more IOP-sensitive than those of non-vasospastic patients. Non-invasive measurements of ocular blood flow suggest that this pressure-sensitivity may be related to IOP-sensitive optic nerve blood flow. Biomechanical modelling suggests that scleral and lamina cribrosa elasticity, axial length, and eye wall thickness contribute to optic nerve head stress and strain. Cross-sectional clinical data supports the role of increased ocular elasticity in the susceptibilty of the optic nerve to glaucoma damage, especially in vasospastic patients. Some promising new avenues for research in this area will be presented. Conclusion There is increasing evidence that biomechanical and vascular ocular factors interact leading to an elevated susceptibilty of the optic nerve to glaucomatous optic nerve damage. Commercial interest [source]