How do coronary artery spasms relate to coronary heart disease?

Prinzmetal angina. Spasm can happen in any blood vessel including the coronaries. The inner lining of the arteries have ability to produce a relaxing factor now known to be nitric oxide. However, diseased arteries have dysfunctional inner lining cells that can't make the relaxing factor and thus can present with spasm also known as prinzmetal angina.