Can coronary artery spasm occur during exertion or during intercourse? or is it at rest only? can normal coronary arteries spasm or just the atherosclerosis arteries?

Mostly at rest: Coronary spams occur mostly at rest in contrast to classic exertional angina during activity (including intercourse). These spasms occur frequently in those people who share risk profile for coronary artery disease; for example-smokers, those with high cholesterol, cocaine users, and not infrequently among those with high emotional stress. Hope it answers your question.

Yes, exertional only: Coronary artery spasm usually occurs in normal coronary arteries, not atherosclerosis. Coronary artery spasm causes temporary blockage of the artery during periods of exertion (yes, even intercourse), leading to anginal pain or even an MI (heart attack). When at rest, the coronary artery is open with normal blood flow. A medication called "calcium channel blocker" is given daily as treatment.