Figure 2.

The relationship between the steady state stroke volume (SV) as the dependent variable (DV) and the steady state right atrial pressure (RAP) as the independent variable (IV) during cardiac cycles. Based on the Frank-Starling mechanism, the greater the RAP (i.e., the preload), the greater the left ventricular pressure, thus the greater the SV. In order to show that the left atrial pressure (LAP) is slightly higher than that of the right atrial pressure (RAP), the drawing of the LAP from a to b, and c is exaggeratedly higher than their normal values.