Starling’s law of the heart
Starling pointed this out when he stated that the “energy of contraction is proportional to the initial length of the cardiac muscle fiber” (Starling’s law of the heart or the Frank–Starling law ).
For the heart, the length of the muscle fibers (ie, the extent of the preload) is proportional to the end-diastolic volume.
The relation between ventricular stroke volume and end diastolic volume is called the Frank–Starling curve.
Does not operate in the failing heart.
Does not operate during exercise.
Explains the increase in heart rate produced by exercise.
Explains the increase in cardiac output that occurs when venous return is increased.