title: A numerical study of the effect of varied blood pressure on the stability of carotid atherosclerotic plaque.
abstract: BACKGROUND
  Blood pressure (BP) is associated with early atherosclerosis and plaque rupture because the BP variability can significantly affect the blood flow velocity and shear stress over the plaque. However, the mechanical response of BP variability to the plaque remains unclear. Therefore, we investigated the correlation between different maximum systolic blood pressure (SBP) and the stress distribution on plaque, as well as the stress over the plaque and blood velocity around the plaque using different BP variations, which are the BP variability in different phases during one cardiac cycle and beat-to-beat BP variability.
  
  
  METHODS
  We established a two-dimensional artery model with stenosis at the degree of 62.5%. Eight combinations of pulsatile pressure gradients between the inflow and outflow were implemented at the model. Three levels of fibrous cap thickness were taken into consideration to investigate the additional effect on the BP variability. Wall shear stress and stress/strain distribution over the plaque were derived as well as the oscillation shear index (OSI) to analyze the impact of the changing rate of BP.
  
  
  RESULTS
  The stresses at diastole were 2.5% ± 1.8% lower than that at systole under the same pressure drop during one cycle. It was also found that elevated SBP might cause the immediate increment of stress in the present cycle (292% ± 72.3%), but slight reduction in the successive cycle (0.48% ± 0.4%).
  
  
  CONCLUSIONS
  The stress/strain distribution over the plaque is sensitive to the BP variability during one cardiac cycle, and the beat-to-beat BP variability could cause considerable impact on the progression of atherosclerosis in long-term.
authors.forename: Huahua
authors.initials: H
authors.lastname: Xiong
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Tian
authors.forename: Lina
authors.initials: L
authors.lastname: Pu
authors.affiliation: Key Lab of Health Informatics of Chinese Academy of Sciences, Shenzhen, China. hy.zhang@siat.ac.cn.
authors.forename: Heye
authors.initials: H
authors.lastname: Zhang
authors.forename: Minhua
authors.initials: M
authors.lastname: Lu
authors.forename: Wenhua
authors.initials: W
authors.lastname: Huang
authors.forename: Yuan-Ting
authors.initials: YT
authors.lastname: Zhang
mesh_terms: D050197:Atherosclerosis / Q000503:physiopathology; D001794:Blood Pressure; D002340:Carotid Artery Diseases / Q000503:physiopathology*; D003198:Computer Simulation; D003251:Constriction, Pathologic / Q000503:physiopathology; D003971:Diastole; D006801:Humans; D008962:Models, Theoretical; D009991:Oscillometry; D058226:Plaque, Atherosclerotic / Q000503:physiopathology*; D018570:Risk Assessment; D033081:Shear Strength; D013314:Stress, Mechanical; D013599:Systole; D013816:Thermodynamics