Cardiac Mechanics Simulator Tutorial

Exercise Set 1

II. Valve Pathologies

C. Aortic Regurgitation

When the leaflets of the aortic valve fail to create a fluid-tight seal, blood can leak back into the left ventricle during parts of the cardiac cycle. How will this affect the normally rectangular shape of the pressure-volume loop? After making your prediction, create a mild degree of aortic regurgitation in the program and check your prediction. Vary the degree of aortic regurgitation and see how the PV loop shape is affected.

Varying degrees of aortic disease can be encountered in clinical situations. The degree of cardiovascular compromise is generally related to the severity of regurgitation. Determine (make a plot of) how the severity of aortic regurgitation affects cardiac output, mean aortic pressure and mean left atrial pressure. In addition, what is the relationship between ventricular stroke volume determined from the PV loop and stroke volume measured from the actual cardiac output through the aortic valve with different degrees of aortic regurgitation. Explain the discrepancy.

Filling Pressure Threshold for Elastance/MAP effect is off. Was set to 50.0