If you have chest pain that doesn't go away, go to the emergency room right away. Variant angina pectoris is also called Prinzmetal's angina. Unlike typical angina, it nearly always occurs when a person is at rest. It doesn't follow physical exertion or emotional stress, either. Attacks can be very painful and usually occur between midnight and 8 a.m.
Variant angina is due to coronary artery spasm.
About two-thirds of people with it have severe coronary atherosclerosis in at least one major vessel. The spasm usually occurs very close to the blockage. A heart attack, in contrast to the partial blockage in angina, involves the complete blockage of a coronary artery. This can cause death of the heart cells in that area. Heart attack can be caused by a part of an atherosclerotic plaque that cracks off and is carried further along the coronary artery to a point where the artery narrows.