Chest pain that results from the spasm of coronary arteries rather than from exertion or other increased demands on the heart. The pain typically occurs at rest. During coronary catheterization the spasm is usually found near an atherosclerotic plaque, often in the right coronary artery. Infusions of ergonovine may provoke it. On the electrocardiogram, the diagnostic hallmark is elevation of the ST segments during episodes of resting pain. Treatments include nitrates and calcium channel blocking drugs. Beta blocking drugs, frequently used as first line therapy in typical angina pectoris, are often ineffective in this form of angina.
Variant angina, also known as Prinzmetal’s angina, is a type of chest pain due to inadequate blood flow to the heart muscle that occurs even when at rest, often during sleep. The pain may be accompanied by shortness of breath and heart palpitations. This form of angina is believed to be caused by muscle spasms that narrow the coronary arteries. Treatment typically involves calcium channel blockers or nitrate medications, which are generally effective.