Jack Lee
Posters-Accepted Abstracts: Biol Syst Open Access
Clinical diagnosis of coronary artery disease continues to be a subject of intense investigation. On one hand, questions remain regarding newer imaging technologies such as perfusion MRI due to the difficulties in relating the acquired data to the underlying physiological state. Meanwhile, enhanced invasive indices such as wave intensity analysis (WIA) which has the potential to offer broader diagnostic information on combined coronary and cardiac function, remains poorly understood. A common obstacle in these pursuits is the difficulty of addressing the physiological complexity, quantitatively. In this work, we present new methodological advances based on integrative computational modeling which aims to tackle these conventional limitations. Our framework comprises a multi-scale model of cardiac perfusion encompassing both macro and microcirculation. The varying flow regimes over these scales are addressed by heterogeneous mathematical models (one-dimensional elastic tube flow and poro mechanics) that are coupled together. The regional influence of cardiac motion on coronary flow is captured through actively contracting myocardium. Coronary anatomy and the compartment-averaged microvascular properties are derived from high-resolution imaging. The complete numerical model including systemic hemodynamics is solved via finite element method. The utility of the model is demonstrated through an in silico wave WIA, which is sensitive to both myocardial and coronary function. In particular the effects of QRS duration and aortic valve dynamics on major coronary waves are quantified. Furthermore, the calculated flow field forms the basis for simulation of transport phenomena, allowing in silico perfusion imaging based on the passage of contrast agent through the myocardium.
