Model-based assessment of pressure and flow-dependent coronary responses following abrupt pressure drops

The response of the coronary vasculature to-an experimental manoeuvre of st ep-like decrease of the perfusion pressure has been investigated with a mod el. The coronary vasculature was simulated using a 'windkessel' scheme. Pro ximal resistance and compliance were assumed to be pressure-independent. Th e distal resistance, on the contrary, was controlled by a feed-back loop wh ich accounts for the smooth muscle activation induced by the pressure varia tion. Three more parameters were introduced, and namely the smooth muscle a ctivation time constant and the pressure-induced and flow-induced gains. Th e parameter values were assessed by comparing the model predicted coronary flow with the one actually measured in animals. (C) 2000 Elsevier Science L td. All rights reserved.