“…Coronary artery spasm may be involved in the genesis of various cardiac disorders, such as acute coronary syndrome, unstable angina, serious fatal arrhythmia, sudden cardiac death, syncope, transient heart failure, and atypical chest pain . As clinical noninvasive methods, we employ 24‐hour Holter recording, exercise testing, the hyperventilation test, cold stress test, and cardiac scintigraphy .…”