CARDIAC OUTPUT (CO)-STARLING'S LAW

SUMMARY

1. Starling's law: the energy of contraction is proportional to the initial length of the cardiac muscle fiber.

2. For the heart: muscle fiber stretch (extent of preload) is proportional to end-diastolic volume (EDV).

3. The Frank-Starling relationship describes the ability of myocardium to increase its force of contraction in response to increased EDV.

4. Increased EDV, therefore preload leads to increased myocardial fiber stretch & sarcomere length, which leads to increased contractility.

Reference(s)

Barrett, K.E., Barman, S.M., Brooks, H.L., X, J. and Ganong, W.F. (2019). Ganong’s review of medical physiology. 26th ed. New York: Mcgraw-Hill Education