Uses of Cardiac Catheterization in Acquired Heart Disease

Abstract

Pressure Gradients and ResistancesExperimental demonstration of a pressure gradient can be made easily if a constricting band is placed on the aorta or the pulmonary artery. When the degree of constriction exceeds a certain critical level, the pressure rises proximally to the constriction and falls distally to it; a difference in systolic pressure has been caused by the introduction of a resistance to the flow of blood. Thus a pressure gradient is caused by loss of pressure energy consumed in overcoming the resistance. Pressure gradients in the circulatory system can be divided into two types: a physiologic pressure gradient . . .