To ensure the myocardium is appropriately perfused, the coronary arteries just vasodilate
The smooth muscle in the wall structure relaxes, which increases the size of the arterial lumen and increases the volume of blood that can pass through the arteries to be delivered to the myocardium
In addition, the endothelium lining the coronary arteries produce nitric oxide which is a very powerful local vasodilator
To produce nitric oxide, an individual has to have an intact and healthy endothelium, which is not always the case in those with cardiovascular disease
