The coronary bed and its role in the cardiovascular system: a review and an introductory single-branch model

Mantero, Sara; Pietrabissa, Riccardo; Fumero, R.

doi:10.1016/0141-5425(92)90015-d

Cited by 63 publications

(40 citation statements)

References 32 publications

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“…For our 7 patients, we found a mean value of Q t = 76.9 ± 12.7 mL/min and literature data indicate a range of normal coronary flow around 200-300 mL/min (4% of the cardiac output). 16,21 …”

Section: Case (0g): No Graft Working (Pathological Situation)mentioning

confidence: 98%

Analog Electrical Model of the Coronary Circulation in Case of Multiple Revascularizations

Maasrani

Verhoye²,

Drochon³

2008

Ann Biomed Eng

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In this work, we propose an analog electrical model of the coronary circulation for patients with obstructive disease undergoing revascularization. In this clinical situation, the collateral circulation to the occluded artery is difficult to ascertain via preoperative measurements and well-developed collaterals might induce long-term restenosis of the revascularized artery due to flow competition mechanisms. The proposed model allows an original biomechanical analysis of per-operative hemodynamic data in order to assess quantitative evaluation of pressures and flows inside the native stenosed arteries, the collateral network and the bypass grafts. Average cardiac cycle values are analysed. In the case of 3-vessel disease and chronic occlusion of the right coronary artery, the quantitative results confirm the protective effects of the collateral flows in the pathological situation, but also show that the revascularization of the occluded right artery is fully justified since the collateral flows remain low, even when the left territory is revascularized. The model thus provides a computational tool to evaluate therapeutic strategies for each patient.

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Section: Case (0g): No Graft Working (Pathological Situation)mentioning

confidence: 98%

Analog Electrical Model of the Coronary Circulation in Case of Multiple Revascularizations

Maasrani

Verhoye²,

Drochon³

2008

Ann Biomed Eng

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“…The lumped parameter model of coronary vascular beds coupled to each coronary outlet surface is based on a model developed by Mantero et al 15 (Fig. 1).…”

Section: The Lumped Parameter Model Of Downstream Coronary Vascular Bedsmentioning

confidence: 99%

“…11 For the coronary outlets, we assigned lumped parameter coronary vascular models. 15 For the upper branch vessels and the descending thoracic aorta, we assigned three-element Windkessel models (Fig. 1).…”

Section: Simulation Detailsmentioning

confidence: 99%

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

et al. 2010

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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.

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“…This choice is motivated by the fact that the physiological mean coronary flow is about 5% of the aortic flow [17]; therefore, we expect that the capacitive and inertial effects of the coronary network are negligible with respect to the complete system considered (aortic root and main coronary channels). Moreover, the effect of the coronary system on the main aortic flow is not relevant, as also indicated by the lumped model in Mantero et al [32], where the addition of the coronary model does not modify or compromise the operation of the initial model of the cardiovascular system. At this level, the correctness of our model can be guided by a comparison of the results of the model in terms of flow rate with direct measurements available: The forcing was then tuned to reproduce a typical coronary flow rate extracted from echo-cardiographic imaging in a healthy young man.…”

Section: Discussionmentioning

confidence: 75%

“…One should consider the inertia of the fluid of all the neglected parts of the network, combined with the fact that the coronary arteries have a considerable degree of compliance. Based on an analogy between electrical and hydraulic nets, several models of the coronary circulation have been developed (see the work of [8,25,32] and references therein), including also autoregulation mechanisms which operate when the equilibrium of the biological system is disturbed, giving results in good agreement with the behavior of the natural system. Zero-dimensional and one-dimensional models cannot account for the fluid dynamics of the system in terms of local quantities, but they can provide the boundary conditions for the limited three-dimensional domain considered.…”

Section: Discussionmentioning

confidence: 81%

On the effect of aortic root geometry on the coronary entry-flow after a bileaflet mechanical heart valve implant: a numerical study

2010

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The simultaneous replacement of a diseased aortic valve, aortic root and ascending aorta with a prosthesis is known as Bentall procedure (Bentall and De Bono in Thorax 23:338, 1968). This is a nowadays standard surgical approach in which the Valsalva sinuses of the aortic root are sacrificed and the coronary arteries are reconnected directly to the graft. The important function of the natural sinuses in the presence of the natural valve is well established; however, very little information is available about whether or not their presence can affect the functioning of a prosthetic bi-leaflet valve and the coronary flow. In the present work, we study the effect of the aortic root geometry on the blood flow through such devices, focusing the attention on the coronary entry-flow. Three root geometries have been considered, two mimicking the prostheses used in practice by surgeons (a straight tube, and the more recent tube with a circular pseudo-sinus), and a third maintaining the natural shape with three sinuses, obtained by Reul et al. (J Biomech 23:181–191, 1990) by averaging numerous angiographies of the aortic root in healthy patients. Direct numerical simulations of the flow inside the three prostheses, assumed as undeformable, under physiological pulsatile inflow conditions are presented. The dynamics of the valvular leaflets is obtained by a fully-coupled fluid–structure-interaction approach and the coronary perfusion is reproduced by modulating in time an equivalent porosity, an thus the resistance, of the coronary channels. The results indicate that the sinuses do not significantly influence the coronary entry flow, in agreement with the in vivo observations of De Paulis et al. (Eur J Cardio-thorac Surg 26:66–72, 2004). Nevertheless, the peak pressure at the joints of the coronary arteries is smaller in the natural-like aortic root geometry. The latter also produces a further beneficial effect of a reduction in the leaflets’ angular velocity at the closure onto the valvular ring. These phenomena, if confirmed in more realistic clinical conditions, suggest that the use of a prothesis with physiologic sinuses would potentially reduce the local pressure peak, with the associated risk of post-operative bleeding and pseudo-aneurysm formation. It would also reduce the haemolysis effects caused by the red blood cells squashing between impacting solid artificial surfaces

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The coronary bed and its role in the cardiovascular system: a review and an introductory single-branch model

Cited by 63 publications

References 32 publications

Analog Electrical Model of the Coronary Circulation in Case of Multiple Revascularizations

Analog Electrical Model of the Coronary Circulation in Case of Multiple Revascularizations

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

On the effect of aortic root geometry on the coronary entry-flow after a bileaflet mechanical heart valve implant: a numerical study

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