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., Boitano, S., Brooks, H.L., Weitz, M., Brian Patrick Kearns, Ganong, W.F. and Mcgraw-Hill Education (Firm (2016). Ganong’s review of medical physiology. 25th ed. New York: Mcgraw Hill Education.
Hall, J.E. and Hall, M.E. (2020). Guyton And Hall Textbook Of Medical Physiology. 14th ed. S.L.: Elsevier - Health Science.
West, J.B. and Luks, A.M. (2021). West’s Pulmonary Pathophysiology. Lippincott Williams & Wilkins.