A heart attack can also occur less frequently by a spasm of a coronary artery. During coronary spasm, the coronary arteries constrict or spasm on and off, causing lack of blood supply to the heart muscle (ischemia). It may occur at rest and can even occur in people without significant coronary artery disease. If coronary artery spasm occurs for …
https://my.clevelandclinic.org/health/diseases/16818-heart-attack-myocardial-infarction