The disorder seems to occur more often in women than men, has a particularly high incidence in Japanese males as well as females, and affects individuals who may smoke tobacco products but exhibit few other cardiovascular risk factors. However, individuals exhibiting angina symptoms that are associated with depressions in their electrocardiogram ST segments, that are triggered by exertion, and/or who have atherosclerotic coronary artery disease are still considered to have variant angina if their symptoms are caused by coronary artery spasms. Finally, rare cases may exhibit symptom-free coronary artery spasm that is nonetheless associated with cardiac muscle ischemia (i.e. restricted blood flow and poor oxygenation) along with concurrent ischemic electrocardiographic changes. The term vasospastic angina is sometimes used to include all of these atypical cases with the more typical cases of variant angina. Here, variant angina is taken to include typical and atypical cases. For a portion of patients, variant angina may be a manifestation of a more generalized episodic smooth muscle-contractile disorder such as migraine, Raynauds phenomenon, or aspirin-induced asthma. Variant angina is also the major complication of eosinophilic coronary periarteritis, an extremely rare disorder caused by extensive eosinophilic infiltration of the adventitia and periadventitia, i.e. the soft tissues, surrounding the coronary arteries. Variant angina also differs from the Kounis syndrome (also termed allergic acute coronary syndrome) in which coronary artery constriction and symptoms are caused by allergic or strong immune reactions to a drug or other substance. Treatment of the Kounis syndrome very much differs from that for variant angina.
Typically, these presentations reflect the development of a heart attack and/or a potentially lethal heart arrhythmia; they require immediate medical intervention as well as consideration for the presence of, and specific treatment regimens for, their disorder.Variant angina should be suspected by a cardiologist when a) an individuals symptoms occur at rest or during sleep; b) an individuals symptoms occur in clusters; c) an individual with a history of angina does not develop angina during treadmill stress testing (variant angina is exercise tolerant); d) an individual with a history of angina shows no evidence of other forms of cardiac disease; and/or e) an individual without features of coronary artery atherosclerotic heart disease has a history of unexplained fainting.Complaints of chest pain should be immediately checked for an abnormal electrocardiogram (ECG). ECG changes compatible but not indicative of variant angina include elevations rather than depressions of the ST segment or an elevated ST segment plus a widening of the R wave to create a single, broad QRS complex peak termed the "monophasic curve". Associated with these ECG changes, there may be small elevations in the blood levels of cardiac damage marker enzymes, especially during long attacks. Some individuals with otherwise typical variant angina may show depressions, rather than elevations in the ST segments of their ECGs during angina pain; they may also show new U waves on ECGs during angina attacks.A significant percentage of those with variant angina have symptom-free episodes of coronary artery spasm. These episodes may be far more frequent than expected, cause myocardial ischemia (i.e.