Dear Colleagues,

Coronary spasm is a condition in which the epicardial coronary artery undergoes transient vasoconstriction, leading to myocardial ischemia. This is thought to cause not only resting angina pectoris, but also exertional angina, acute coronary syndrome, and sudden cardiac death. The diagnosis of coronary spasm can be made by detecting transient ST changes in the electrocardiogram of patients with chest pain during evening or early morning rest periods. Due to the difficulty of detecting electrocardiographic changes, in clinical practice the diagnosis is often made by performing a coronary spasm provocation test (SPT). Treatment consists of lifestyle modification (mainly cessation of smoking) and the administration of coronary dilators, especially calcium channel blockers.

However, there is no consensus regarding the drugs and doses that are provocative in the SPT. Moreover, in recent years coronary microcirculatory dysfunction (CMD) often coexists with coronary spasms. Whether coronary spasm or CMD should be evaluated first is subject to debate. During the treatment of coronary spasms, medically refractory cases are sometimes encountered in which the chest pain is prolonged, even with the use of several coronary vasodilators. Several unresolved issues clearly remain regarding the diagnosis and treatment of coronary spasms.

This special issue will publish various articles on coronary spasms relating to their diagnosis and treatment, with the aim of improving our current understanding and highlighting future directions and issues in the field.

Dr. Hiroki Teragawa
Guest Editor