Mathematical Modeling of the Coronary Circulation During Cardiac Pacing and Tachycardia

In this work, we consider blood flow in the coronary arteries during the abnormal heart rhythm conditions due to the cardiac pacing and pathological type of the tachycardia. We adapt the ID model of haemodynamics to the coronary circulation conditions, which are characterized by the periodic vessels contraction. The range of the convergence of the Newton's method is studied for the boundary conditions at the outlets of the terminal vessels. Simulation of the cardiac pacing conditions supports the hypothesis, that right ventricle pacing produce the most pronounced effect to the coronary flow. We also observe, that 0.03 s delay during right ventricular pacing produce substantial increase of the systolic blood flow in the left coronary artery. Simulations of the tachycardia conditions show, that the ratio between systolic and diastolic phase is a critical parameter for the possible ischemia development. We also observe, that the supraventricular tachycardia in paediatric patients results in the distinctive decrease of the coronary flow at some heart rates.