Figure 1.

Representative case documenting spasm by IC injection of 200 µg of ACh but not 100 µg in the LCA. Patient is an 84‐year‐old male with a chief complaint of chest pressure at rest beginning 6 months ago. Neither usual chest pressure/ischemic ECG changes nor positive spasm were observed by ACh 100 µg administration into the LCA (A), whereas usual chest pressure, ischemic ECG change (ST‐segment depression in V₄ through V₆), and subtotal spasm on the distal LAD were recognized by ACh 200 µg injection (B). His LCA (C) had no organic stenosis. We could diagnose CSA by the administration of ACh 200 µg in this case. Abbreviations: ACh, acetylcholine; CSA, coronary spastic angina; ECG, electrocardiogram; IC, intracoronary; ISDN, isosorbide dinitrate; LAD, left anterior descending artery; LCA, left coronary artery.