Law of the Heart

The ‘Law of the Heart’ as it is known—the volume of blood that is ejected by the heart is related to the initial filling of the heart (i.e., muscle length)—is widely attributed to Otto Frank and Ernest Starling, and eponymously known as the Frank-Starling Law of the Heart. However, the origin of this ‘Law’ owes much to the physiologists at the Carl Ludwig Physiological Institute at the University of Leipzig. This chapter will discuss the origin of this ‘Law’, the subsequent work by Guyton and colleagues, most notably the superimposition of the cardiac function and venous return curves (and the debates that followed), and to the elastance model that is widely adopted in contemporary depiction of cardiovascular physiology in the form of pressure–volume loops.