A syndrome typically consisting of angina (cardiac chest pain) at rest that occurs in cycles. It is caused by vasospasm, a narrowing of the coronary arteries caused by contraction of the smooth muscle tissue in the vessel walls rather than directly by atherosclerosis (buildup of fatty plaque and hardening of the arteries). For a portion of patients Prinzmetal's angina may be a manifestation of vasospastic disorder and is associated with migraine, Raynaud's phenomenon or aspirin-induced asthma. The disease is Monarch Disease Ontology id MONDO_0006021 (Prinzmetal angina). Also known as: Prinzmetal's angina, Prinzmetal's variant angina, angina inversa, variant angina, variant angina pectoris.