Summary of Cardiac and vascular function curves
The cardiac function curve or the Frank-Starling curve is a plot of the relationship between cardiac output of the left ventricle and right atrial pressure. An increase in venous return of the left ventricle will increase the right atrial pressure, end-diastolic volume and end-diastolic fiber length and therefore increase cardiac output. The vascular function curve is a plot of the relationship between the venous return and right atrial pressure. An increase in right atrial pressure will decrease the pressure gradient between the systemic arteries and the right atrium and would thereby decrease the amount of venous return to the right atrium.