CARDIAC CYCLE-VENTRICULAR VOLUMES

SUMMARY

1. EDV = 130 ml

2. SV = 70-90 ml

3. ESV = EDV – SV = 130-80 = 50 mls remain in each ventricle at end of systole.

4. EF = SV/EDV = ~65% (very important in evaluating index of ventricular function).

5. Starling’ s law of the heart: if there’s increased venous return, there is increased CO. Tension is increased optimally for the actin/myosin bonds to strengthen. Give it more, and it will pump more out!

6. Frank-starling curve looks at the relationship between EDV & SV: curve shift up & to the left with increased contractility (inotropes), shifts down & to right with decreased 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.