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