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Particle depositions and related hemodynamic parameters in the multiple stenosed right coronary artery.

Bernad SI, Bernad ES, Craina M, Sargan I, Totoran A, Brisan C - J Clin Med Res (2012)

Bottom Line: Energy loss associated with such flow expansion after each constriction will be large and consequently the pressure drop will be higher.Overall pressure drop increased from 1700 Pa (12.75 mmHg) at the end diastole to 11000 Pa (82.5 mmHg) at the peak systole.However at the end of one cardiac cycle a percent of 1.4% (15 from 1063 particles release at the inlet section) remain inside the stenosed RCA.

View Article: PubMed Central - PubMed

Affiliation: Centre for Fundamental and Advanced Research, Romanian Academy - Timisoara Branch, Timisoara, Romania.

ABSTRACT

Background: Blood flow analysis of the human right coronary artery (RCA) has been carried out to investigate the effects of serial stenosis on coronary hemodynamics. A 3-D model of a serial stenosed RCA was reconstructed based on multislice computerized tomography images.

Methods: A velocity waveform in the proximal RCA and a pressure waveform in the distal RCA of a patient with a severe stenosis were acquired with a catheter delivered wire probe and applied as boundary conditions. The numerical analysis examines closely the effect of a multiple serial stenosis on the hemodynamic characteristics such as flow separation, wall shear stress (WSS) and particle depositions.

Results and conclusions: Energy loss associated with such flow expansion after each constriction will be large and consequently the pressure drop will be higher. Overall pressure drop increased from 1700 Pa (12.75 mmHg) at the end diastole to 11000 Pa (82.5 mmHg) at the peak systole. At the peak systole the WSS values reached 110 Pa in the stenosis with 28% diameter reduction and 210 Pa in the stenosis with 54% diameter reduction, which is high enough to damage the endothelial cells. However at the end of one cardiac cycle a percent of 1.4% (15 from 1063 particles release at the inlet section) remain inside the stenosed RCA.

No MeSH data available.


Related in: MedlinePlus

Computational geometry used for code validation [26].
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Figure 3: Computational geometry used for code validation [26].

Mentions: Before presenting the main findings, we first validate our numerical tool against the problem investigated experimentally by Banerjee et al [26]. The case considered is the unsteady pulsatile flow, incompressible, Navier-Stokes flow through an axisymmetric moderate restenosis after percutaneous transluminal balloon coronary angioplasty (PTCA). The geometry model, has a stenosis length of ten times the arterial radius (Rp = Rd = 3 mm, see Fig. 3) and a diameter reduction of 40% (64% area reduction). In the Reynolds number, a kinematic viscosity of 0.035 cm2/s was used, a value nears the asymptote in the Carreau model for blood. Zero velocity was specified on the plaque wall. A stress free boundary condition was specified at the outlet. Adequate distal length was ensured for accurate determination of pressure drops due to the lesion and for the convergence of the calculations. The calculations were done at the mean flow rate Q = 50 mL/min (typical of basal physiological values in a coronary vessel of 3 mm size [26]). Heart rate was 75 beats/min and blood density was 1050 kg/m3 [26].


Particle depositions and related hemodynamic parameters in the multiple stenosed right coronary artery.

Bernad SI, Bernad ES, Craina M, Sargan I, Totoran A, Brisan C - J Clin Med Res (2012)

Computational geometry used for code validation [26].
© Copyright Policy - open access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376876&req=5

Figure 3: Computational geometry used for code validation [26].
Mentions: Before presenting the main findings, we first validate our numerical tool against the problem investigated experimentally by Banerjee et al [26]. The case considered is the unsteady pulsatile flow, incompressible, Navier-Stokes flow through an axisymmetric moderate restenosis after percutaneous transluminal balloon coronary angioplasty (PTCA). The geometry model, has a stenosis length of ten times the arterial radius (Rp = Rd = 3 mm, see Fig. 3) and a diameter reduction of 40% (64% area reduction). In the Reynolds number, a kinematic viscosity of 0.035 cm2/s was used, a value nears the asymptote in the Carreau model for blood. Zero velocity was specified on the plaque wall. A stress free boundary condition was specified at the outlet. Adequate distal length was ensured for accurate determination of pressure drops due to the lesion and for the convergence of the calculations. The calculations were done at the mean flow rate Q = 50 mL/min (typical of basal physiological values in a coronary vessel of 3 mm size [26]). Heart rate was 75 beats/min and blood density was 1050 kg/m3 [26].

Bottom Line: Energy loss associated with such flow expansion after each constriction will be large and consequently the pressure drop will be higher.Overall pressure drop increased from 1700 Pa (12.75 mmHg) at the end diastole to 11000 Pa (82.5 mmHg) at the peak systole.However at the end of one cardiac cycle a percent of 1.4% (15 from 1063 particles release at the inlet section) remain inside the stenosed RCA.

View Article: PubMed Central - PubMed

Affiliation: Centre for Fundamental and Advanced Research, Romanian Academy - Timisoara Branch, Timisoara, Romania.

ABSTRACT

Background: Blood flow analysis of the human right coronary artery (RCA) has been carried out to investigate the effects of serial stenosis on coronary hemodynamics. A 3-D model of a serial stenosed RCA was reconstructed based on multislice computerized tomography images.

Methods: A velocity waveform in the proximal RCA and a pressure waveform in the distal RCA of a patient with a severe stenosis were acquired with a catheter delivered wire probe and applied as boundary conditions. The numerical analysis examines closely the effect of a multiple serial stenosis on the hemodynamic characteristics such as flow separation, wall shear stress (WSS) and particle depositions.

Results and conclusions: Energy loss associated with such flow expansion after each constriction will be large and consequently the pressure drop will be higher. Overall pressure drop increased from 1700 Pa (12.75 mmHg) at the end diastole to 11000 Pa (82.5 mmHg) at the peak systole. At the peak systole the WSS values reached 110 Pa in the stenosis with 28% diameter reduction and 210 Pa in the stenosis with 54% diameter reduction, which is high enough to damage the endothelial cells. However at the end of one cardiac cycle a percent of 1.4% (15 from 1063 particles release at the inlet section) remain inside the stenosed RCA.

No MeSH data available.


Related in: MedlinePlus