A MODEL FOR GEOMETRIC AND MECHANICAL ADAPTATION OF ARTERIES TO SUSTAINED HYPERTENSION

This study aimed to model phenomenologically the dynamics of arterial wall remodeling under hypertensive conditions. Sustained hypertension was simulated by a step increase in blood pressure. The arterial wall was considered to be a thick-walled tube made of nonlinear elastic inc ompressible material. Remodeling rate equations were postulated for th e evolution of the geometric dimensions of the hypertensive artery at the zero-stress state, as well as for one of the material constants in the constitutive equations. The driving stimuli for the geometric ada ptation are the normalized deviations of wall stresses from their valu es under normotensive conditions. The geometric dimensions are modulat ed by the evolution of the deformed inner radius, which serves to rest ore the level of the flow-induced shear stresses at the arterial endot helium. Mechanical adaptation is driven by the difference between the area compliance under hypertensive and normotensive conditions. The pr edicted rime course of the geometry and mechanical properties of arter ial wall are in good qualitative agreement with publishes experimental findings. The model predicts that the geometric adaptation maintains the stress distribution in arterial wall to its control level, while t he mechanical adaptation restores the normal arterial function under i nduced hypertension.