CORONARY ARTERIES-CONDITIONS WITH NO OR LOW FLOW

SUMMARY

1. No flow occurs during systole in thesubendocardial portion of LV, thus is prone to ischemia & most common site for MI.

2. Since diastole is shorter in tachycardia, this leads to reduction in coronary flow.

3. Decreased flow in aortic stenosis as LV pressure is higher, thus the coronary vessels are more compressed. The myocardium also requires more O2.

4. Rise in venous pressure in CCF reduces coronary flow because it decreases effective coronary perfusion 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.