scholarly journals Computational Assessment of Blood Flow Heterogeneity in Peritoneal Dialysis Patients' Cardiac Ventricles

2018 ◽  
Vol 9 ◽  
Author(s):  
Sanjay R. Kharche ◽  
Aaron So ◽  
Fabio Salerno ◽  
Ting-Yim Lee ◽  
Chris Ellis ◽  
...  
Keyword(s):  
Blood Flow ◽  
Peritoneal Dialysis ◽  
Dialysis Patients ◽  
Flow Heterogeneity ◽  
Cardiac Ventricles ◽  
Blood Flow Heterogeneity

Blood flow distribution in working in situ canine muscle during blood flow reduction

1996 ◽  
Vol 80 (6) ◽  
pp. 1978-1983 ◽  
Author(s):  
S. S. Kurdak ◽  
B. Grassi ◽  
P. D. Wagner ◽  
M. C. Hogan
Keyword(s):  
Blood Flow ◽  
Muscle Blood Flow ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Strong Negative Correlation ◽  
Flow Heterogeneity ◽  
Blood Flow Reduction ◽  
Blood Flow Heterogeneity

The purpose of this study was to determine whether reduction in apparent muscle O2 diffusing capacity (Dmo2) calculated during reduced blood flow conditions in maximally working muscle is a reflection of alterations in blood flow distribution. Isolated dog gastrocnemius muscle (n = 6) was stimulated for 3 min to achieve peak O2 uptake (VO2) at two levels of blood flow (controlled by pump perfusion): control (C) conditions at normal perfusion pressure (blood flow = 111 +/- 10 ml.100 g-1.min-1) and reduced blood flow treatment [ischemia (I); 52 +/- 6 ml.100 g-1.min-1]. In addition, maximal vasodilation was achieved by adenosine (A) infusion (10(-2)M) at both levels of blood flow, so that each muscle was subjected randomly to a total of four conditions (C, CA, I, and IA; each separated by 45 min of rest). Muscle blood flow distribution was measured with 15-microns-diameter colored microspheres. A numerical integration technique was used to calculate Dmo2 for each treatment with use of a model that calculates O2 loss along a capillary on the basis of Fick's law of diffusion. Peak VO2 was reduced significantly (P < 0.01) with ischemia and was unchanged by adenosine infusion at either flow rate (10.6 +/- 0.9, 9.7 +/- 1.0, 6.7 +/- 0.2, and 5.9 +/- 0.8 ml.100 g-1.min-1 for C, CA, I, and IA, respectively). Dmo2 was significantly lower by 30-35% (P < 0.01) when flow was reduced (except for CA vs. I; 0.23 +/- 0.03, 0.20 +/- 0.02, 0.16 +/- 0.01, and 0.13 +/- 0.01 ml.100 g-1.min-1.Torr-1 for C, CA, I, and IA, respectively). As expressed by the coefficient of variation (0.45 +/- 0.04, 0.47 +/- 0.04, 0.55 +/- 0.03, and 0.53 +/- 0.04 for C, CA, I, and IA, respectively), blood flow heterogeneity per se was not significantly different among the four conditions when examined by analysis of variance. However, there was a strong negative correlation (r = 0.89, P < 0.05) between Dmo2 and blood flow heterogeneity among the four conditions, suggesting that blood flow redistribution (likely a result of a decrease in the number of perfused capillaries) becomes an increasingly important factor in the determination of Dmo2 as blood flow is diminished.

scholarly journals The mechanical and metabolic basis of myocardial blood flow heterogeneity

2001 ◽  
Vol 96 (6) ◽  
pp. 582-594 ◽  
Author(s):  
James B. Bassingthwaighte ◽  
Daniel A. Beard ◽  
Zheng Li
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Flow Heterogeneity ◽  
Metabolic Basis ◽  
Blood Flow Heterogeneity

scholarly journals Vascular tree structure affects lung blood flow heterogeneity simulated in three dimensions

1997 ◽  
Vol 83 (4) ◽  
pp. 1370-1382 ◽  
Author(s):  
James C. Parker ◽  
Chris B. Cave ◽  
Jeffrey L. Ardell ◽  
Charles R. Hamm ◽  
Susan G. Williams
Keyword(s):  
Blood Flow ◽  
Tree Structure ◽  
Three Dimensions ◽  
Vascular Tree ◽  
Tree Structures ◽  
Flow Heterogeneity ◽  
Blood Flows ◽  
Flow Gradients ◽  
Lung Blood Flow ◽  
Blood Flow Heterogeneity

Parker, James C., Chris B. Cave, Jeffrey L. Ardell, Charles R. Hamm, and Susan G. Williams. Vascular tree structure affects lung blood flow heterogeneity simulated in three dimensions. J. Appl. Physiol. 83(4): 1370–1382, 1997.—Pulmonary arterial tree structures related to blood flow heterogeneity were simulated by using a symmetrical, bifurcating model in three-dimensional space. The branch angle (Θ), daughter-parent length ratio ( rL ), branch rotation angle (φ), and branch fraction of parent flow (γ) for a single bifurcation were defined and repeated sequentially through 11 generations. With φ fixed at 90°, tree structures were generated with Θ between 60 and 90°, rL between 0.65 and 0.85, and an initial segment length of 5.6 cm and sectioned into 1-cm3 samples for analysis. Blood flow relative dispersions (RD%) between 52 and 42% and fractal dimensions ( D s) between 1.20 and 1.15 in 1-cm3samples were observed even with equal branch flows. When γ ≠ 0.5, RD% increased, but D s either decreased with gravity bias of higher branch flows or increased with random assignment of higher flows. Blood flow gradients along gravity and centripetal vectors increased with biased flow assignment of higher flows, and blood flows correlated negatively with distance only when γ ≠ 0.5. Thus a recursive branching vascular tree structure simulated D s and RD% values for blood flow heterogeneity similar to those observed experimentally in the pulmonary circulation due to differences in the number of terminal arterioles per 1-cm3 sample, but blood flow gradients and a negative correlation of flows with distance required unequal partitioning of blood flows at branch points.

Myocardial Blood Flow Heterogeneity In Highly Endurance-trained Athletes And Untrained Control Subjects

2014 ◽  
Vol 46 ◽  
pp. 341
Author(s):  
Ilkka Heinonen ◽  
Joonas Hakala ◽  
Dirk J. Duncker ◽  
Juhani Knuuti ◽  
Kari K. Kalliokoski
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Flow Heterogeneity ◽  
Control Subjects ◽  
Blood Flow Heterogeneity
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