Xiong H, Liu X, Tian X, Pu L, Zhang H, Lu M, Huang W, Zhang YT. A numerical study of the effect of varied blood pressure on the stability of carotid atherosclerotic plaque.
Biomed Eng Online 2014;
13:152. [PMID:
25413300 PMCID:
PMC4277844 DOI:
10.1186/1475-925x-13-152]
[Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 10/22/2014] [Indexed: 12/18/2022] Open
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.
Method
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.
Result
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%).
Conclusion
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.
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