Streamline pattern and velocity components of flow in a model of a branching coronary vessel--possible functional implication for the development of localized platelet deposition in vitro.
A simplified model of the left descending coronary artery was perfused with a suspension of tungstic acid particles in dimethyl sulfoxide/water solution. To visualize the streamline pattern within the main tube, flow was illuminated with laser light using the dark field technique. Moving particles appeared as points, or, when illuminated with pulsating light, as a series of points. They were photographed and evaluated with respect to the velocity vector normal (vl) and parallel (v =) to the vessel wall. Wall shear stress (tw) was calculated from (v =) and fluid viscosity. At Reynolds (Re) numbers comparable to the in vivo situation, defined flow disturbances were observed in the main tube: (i) Separation of the flow on the wall facing the opening of the side branch and (ii) development of a stagnation point flow at defined locations. Comparison of our results with experiments using platelet suspensions, allowed those hydrodynamic conditions to be determined which are responsible for the deposition of platelet microthrombi in vitro. These conditions were identified as being positive velocity components toward the wall (vl greater than 0).
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MA
Kratzer
J
J
Kinder
D001783:Blood Flow Velocity; D001792:Blood Platelets / Q000502:physiology*; D003331:Coronary Vessels / Q000033:anatomy & histology / Q000473:pathology / Q000502:physiology*; D005898:Glass; D006801:Humans; D007202:Indicators and Reagents; D007834:Lasers; D008953:Models, Anatomic
D007202:Indicators and Reagents