CARDIAC OUTPUT (CO)

SUMMARY

1. CO = Heart Rate (HR) x Stroke Volume (SV).

2. BP = CO x Systemic Vascular Resistance (SVR).

3. SV determined by: preload, contractility, after-load, HR.

4. Preload determined by: venous return to the heart; venous return = systemic filling pressure - CVP.

5. Myocardial contractility determined by: intrinsic factors (cardiac sympathetic stimulation), extrinsic factors (circulating catecholamines).

6. Afterload (ventricular wall tension that has to be generated in order to eject blood out of the ventricle, analogous to arterial pressure) determined by: SVR.

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.