Mathematical model of pressure-related changes in stenosis cross-sectional area during the cardiac cycle

The purpose of this study was to investigate the effect of pressure losses during the cardiac cycle on the cross-sectional shape of a partially compliant coronary artery stenosis. A mathematical model of pulsatile flow through a partially collapsible stenosis was used to calculate changes in minimum stenosis diameter in response to changes in intraluminal pressure. Nine stenoses were simulated, ranging from 50 to 90% area reduction with different fractions of flexible wall circumference (1/4, 1/3, and 1/2). For typical flow rates during maximum vasodilation the minimum diameter of simulated severe stenoses decreased by over 50% from systole to diastole, thereby substantially altering the cross-sectional area of the stenosis. These results may explain some of the discrepancies that have been reported from pathologic and angiographie studies of coronary artery stenosis morphology.