Cardiac and vascular function curves

Cardiac and vascular function curves depict the functional relationship between the vascular system, the right atrial pressure, and the cardiac output. The vascular system is a network of arteries, veins, and capillaries that carry blood throughout the body. The arteries are the blood vessels that carry blood away from the heart, whereas veins are the blood vessels that carry blood back to the heart.

The capillaries are the small blood vessels that connect the arteries and veins. Right atrial pressure refers to the blood pressure in the right heart atrium. Blood in the right atrium reflects the amount of blood that's returned to the heart and can help assess the heart's ability to pump it in the arterial system. The cardiac output (CO) is the amount of blood that the heart pumps out in one minute. It is equal to the stroke volume times the heart rate.