Preoperative risk evaluation by simulating extracorporeal circulation and its impact on aortic blood flow

2011 ◽  
Vol 59 (S 01) ◽  
Author(s):  
A Assmann ◽  
AC Benim ◽  
F Gül ◽  
P Akhyari ◽  
A Lichtenberg ◽  
...  
Keyword(s):  
Blood Flow ◽  
Extracorporeal Circulation ◽  
Risk Evaluation ◽  
Aortic Blood Flow ◽  
Preoperative Risk ◽  
Aortic Blood

COMPUTATIONS OF PULSATILE AORTIC BLOOD FLOW PROBLEMS ON PARALLEL COMPUTERS

2003 ◽  
Vol 15 (03) ◽  
pp. 109-114
Author(s):  
YANG-YAO NIU ◽  
SHOU-CHENG TCHENG
Keyword(s):  
Blood Flow ◽  
Stokes Equations ◽  
Computing Time ◽  
Time Integration ◽  
Parallel Computer ◽  
Aortic Blood Flow ◽  
Pc Cluster ◽  
Flow Problems ◽  
Aortic Blood ◽  
Speed Up

In this study, a parallel computing technology is applied on the simulation of aortic blood flow problems. A third-order upwind flux extrapolation with a dual-time integration method based on artificial compressibility solver is used to solve the Navier-Stokes equations. The original FORTRAN code is converted to the MPI code and tested on a 64-CPU IBM SP2 parallel computer and a 32-node PC Cluster. The test results show that a significant reduction of computing time in running the model and a super-linear speed up rate is achieved up to 32 CPUs at PC cluster. The speed up rate is as high as 49 for using IBM SP2 64 processors. The test shows very promising potential of parallel processing to provide prompt simulation of the current aortic flow problems.

S-nitroso-albumin carries a thiol-labile pool of nitric oxide, which causes venodilation in the rat

2005 ◽  
Vol 289 (2) ◽  
pp. H916-H923 ◽  
Author(s):  
Nelson N. Orie ◽  
Patrick Vallance ◽  
Dean P. Jones ◽  
Kevin P. Moore
Keyword(s):  
Nitric Oxide ◽  
Molecular Weight ◽  
Blood Flow ◽  
Vascular Function ◽  
Low Molecular Weight ◽  
Aortic Blood Flow ◽  
Hemodynamic Effects ◽  
Rapid Decomposition ◽  
Aortic Blood

It is now established that S-nitroso-albumin (SNO-albumin) circulates at low nanomolar concentrations under physiological conditions, but concentrations may increase to micromolar levels during disease states (e.g., cirrhosis or endotoxemia). This study tested the hypothesis that high concentrations of SNO-albumin observed in some diseases modulate vascular function and that it acts as a stable reservoir of nitric oxide (NO), releasing this molecule when the concentrations of low-molecular-weight thiols are increased. SNO-albumin was infused into rats to increase the plasma concentration from <50 nmol/l to ∼4 μmol/l. This caused a 29 ± 6% drop in blood pressure, 20 ± 4% decrease in aortic blood flow, and a 25 ± 14% reduction of renal blood flow within 10 min. These observations were in striking contrast to those of an infused arterial vasodilator (hydralazine), which increased aortic blood flow, and suggested that SNO-albumin acts primarily as a venodilator in vivo. This was confirmed by the observations that glyceryl trinitrate (a venodilator) led to similar hemodynamic changes and that the hemodynamic effects of SNO-albumin are reversed by infusion of colloid. Infusion of N-acetylcysteine into animals with artificially elevated plasma SNO-albumin concentrations led to the rapid decomposition of SNO-albumin in vivo and reproduced the hemodynamic effects of SNO-albumin infusion. These data demonstrate that SNO-albumin acts primarily as a venodilator in vivo and represents a stable reservoir of NO that can release NO when the concentrations of low-molecular-weight thiols are elevated.

Hepatosplanchnic Vasoregulation and Oxygen Consumption During Selective Aortic Blood Flow Reduction and Reperfusion

2011 ◽  
Vol 171 (2) ◽  
pp. 532-539 ◽  
Author(s):  
Ruy J. Cruz ◽  
Alejandra G. Garrido ◽  
Décio de Natale Caly ◽  
Mauricio Rocha-e-Silva
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Aortic Blood Flow ◽  
Flow Reduction ◽  
Aortic Blood ◽  
Blood Flow Reduction

Aortic blood flow subtraction: an alternative method for measuring total renal blood flow in conscious dogs

2002 ◽  
Vol 282 (5) ◽  
pp. R1528-R1535 ◽  
Author(s):  
N. C. F. Sandgaard ◽  
J. L. Andersen ◽  
N.-H. Holstein-Rathlou ◽  
P. Bie
Keyword(s):  
Blood Flow ◽  
Angiotensin Ii ◽  
Renal Blood Flow ◽  
Aortic Blood Flow ◽  
Excretory Function ◽  
Endothelin 1 ◽  
Arterial Blood ◽  
Aortic Blood ◽  
Bilateral Carotid ◽  
Total Renal Blood Flow

We have measured total renal blood flow (TRBF) as the difference between signals from ultrasound flow probes implanted around the aorta above and below the renal arteries. The repeatability of the method was investigated by repeated, continuous infusions of angiotensin II and endothelin-1 seven times over 8 wk in the same dog. Angiotensin II decreased TRBF (350 ± 16 to 299 ± 15 ml/min), an effect completely blocked by candesartan (TRBF 377 ± 17 ml/min). Subsequent endothelin-1 infusion reduced TRBF to 268 ± 20 ml/min. Bilateral carotid occlusion (8 sessions in 3 dogs) increased arterial blood pressure by 49% and decreased TRBF by 12%, providing an increase in renal vascular resistance of 69%. Dynamic analysis showed autoregulation of renal blood flow in the frequency range <0.06–0.07 Hz, with a peak in the transfer function at 0.03 Hz. It is concluded that continuous measurement of TRBF by aortic blood flow subtraction is a practical and reliable method that allows direct comparison of excretory function and renal blood flow from two kidneys. The method also allows direct comparison between TRBF and flow in the caudal aorta.

A simple module for on-line computation of stroke volume and cardiac output

1975 ◽  
Vol 38 (5) ◽  
pp. 927-929 ◽  
Author(s):  
G. Pinardi ◽  
A. Sainz ◽  
E. Santiago
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Data Analysis ◽  
Stroke Volume ◽  
Simple Module ◽  
Cardiovascular Responses ◽  
Aortic Blood Flow ◽  
Aortic Blood ◽  
On Line ◽  
Aortic Blood Flow Velocity

An easily constructed, low-priced, simple, and reliable module to obtain stroke volume and cardiac output by analog integration of aortic blood flow velocity signals is described. Rapid data analysis of physiologic and pharmacologic cardiovascular responses in dogs is greatly facilitated by on line computation of these parameters.

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