DYNAMIC CURVATURE EFFECTS ON BIFURCATING CORONARY ARTERY FLOW

Cooperative study
TU-Graz, Inst. of Mathematics: M. Prosi, K. Perktold
Duke Univ., Durham, USA, Dept. of Biomed. Engineering: M.H. Friedman

The coronary arteries undergo large dynamic variations during each cardiac cycle due to their position on the beating heart. The local artery curvature varies significantly during myocardial contraction.

Computer simulation is carried out in an anatomically realistic model of the bifurcation of the left anterior descending coronary artery and its first diagonal branch, which is known to be atherosclerosis-prone.

The study applies a physiologic coronary flow wave and curvature history. The model permits one to separate the effects on the flow field and the shear field of flow division, out-of-plane curvature, and dynamic curvature.

The aim of the study is to analyze the effects of dynamic curvature on coronary artery hemodynamics and to compare these with the effects of vessel branching.

INPUT DATA: Geometry Dynamics: Flow, Curvature

Curvature history

• Coronary arteries move with the heartbeat
• The interaction of coronary artery dynamics and bifurcating flow is of interest
  ® Study the effects of changes in out-of-plane coronary curvature on the pulsatile flow field in the neighborhood of a branch.

Flow pulse wave Curvature history

• High shear stress variation
• Outer wall: Low shear region during the cycle
• Pericardial wall: Downstream increase of shear

• In the neighborhood of the branch ostium, the bifurcating flow generally dominates the effect of curvature.
• The relative effect of curvature increases distally.
• In systole, when curvature is greatest, its effect on wall shear stress is dominated by the flow wave.
• Dynamic curvature reduces the shear along the outer wall of the bifurcation.