Patient-Specific Modeling of Blood Flow and Pressure in Human Coronary Arteries

Abstract

Coronary flow is different from the flow in other parts of the arterial system because it is influenced by the contraction and relaxation of the heart. To model coronary flow realistically, the compressive force of the heart acting on the coronary vessels needs to be included. In this study, we developed a method that predicts coronary flow and pressure of three-dimensional epicardial coronary arteries by considering models of the heart and arterial system and the interactions between the two models. For each coronary outlet, a lumped parameter coronary vascular bed model was assigned to represent the impedance of the downstream coronary vascular networks absent in the computational domain. The intramyocardial pressure was represented with either the left or right ventricular pressure depending on the location of the coronary arteries. The left and right ventricular pressure were solved from the lumped parameter heart models coupled to a closed loop system comprising a three-dimensional model of the aorta, three-element Windkessel models of the rest of the systemic circulation and the pulmonary circulation, and lumped parameter models for the left and right sides of the heart. The computed coronary flow and pressure and the aortic flow and pressure waveforms were realistic as compared to literature data.

A non-discrete method for computation of residence time in fluid mechanics simulations

“…A boundary condition that is specifically designed for the coronary arteries was used and an implicit method was used to couple boundary conditions to the 3D domain. 44 Flow simulation was continued for six cardiac cycles, with a time step size of 1 ms.…”

Diagnostic accuracy and discrimination of ischemia by fractional flow reserve CT using a clinical use rule: Results from the Determination of Fractional Flow Reserve by Anatomic Computed Tomographic Angiography study

“…In addition, owing to safety concerns, it was not feasible to mandate 3-vessel FFR as part of the trial design. To eliminate ascertainment bias, we used predefined criteria similar to those used in the FAME studies 20 in which mild disease is assigned a negative FFR and severe stenosis a positive one and limited vessel inclusion to clinically relevant vessels !2 mm in diameter. Importantly, this clinical use rule was prespecified during the trial design and is in line with other clinical trials previously performed in this field.…”

“…Threedimensional models of the coronary tree and ventricular myocardium were reconstructed using custom methods applied to blinded CT data for simulation of coronary flow and pressure 20 and as previously published. 8 FFR CT was modeled for conditions of adenosine-induced hyperemia; an FFR CT 0.80 was considered diagnostic of lesion-specific ischemia.…”

“…As per protocol, all vessels with a maximal stenosis (as determined by Quantitative coronary angiography) 30% were assigned a default value of 0.9, and vessels with a maximal stenosis !90% were considered positive and assigned an FFR value of 0.5 in accordance with the prespecified clinical use rule and prior multicenter randomized trials. 20 …”

Magnetic resonance imaging-based computational modelling of blood flow and nanomedicine deposition in patients with peripheral arterial disease

“…Once again, flow-coupled particle transport simulations were carried out for 10 cardiac cycles. The resulting spatial distribution of NPs in terms of particle surface density (cm 22 ) is presented in figure 9a,b for the baseline and 24-month post-intervention cases, respectively. In addition to local haemodynamics, receptor surface density rsif.royalsocietypublishing.org J. R. Soc.…”