<P> The arteries , when healthy , are capable of autoregulation to maintain coronary blood flow at levels appropriate to the needs of the heart muscle . These relatively narrow vessels are commonly affected by atherosclerosis and can become blocked , causing angina or a heart attack . The coronary arteries that run deep within the myocardium are referred to as subendocardial . </P>
<P> The arteries , when healthy , are capable of autoregulation to maintain coronary blood flow at levels appropriate to the needs of the heart muscle . These relatively narrow vessels are commonly affected by atherosclerosis and can become blocked , causing angina or a heart attack . The coronary arteries that run deep within the myocardium are referred to as subendocardial . </P>
when does blood flow occur through the coronary circulation
when does blood flow occur through the coronary circulation
when healthy
when healthy