CARDIAC CYCLE-PRESSURES

SUMMARY

1. Systolic pressure: peak pressure in ventricles during contraction
2. Diastolic pressure: lowest pressure in ventricles during relaxation
3. Isovolumetric contraction (lasts 0.05s): during this stage both AV and arterial valves are closed & the ventricle is a closed chamber. The onset of contraction causes a rapid rise in wall tension at a constant volume
4. This rapidity (dP/dt) is used to measure myocardial contractility

PRESSURES
5. Pulse pressure = systolic – diastolic pressure
6. MAP = diastolic + 1/3 pulse pressure

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.