The intracoronary
acetylcholine (ACh) and
ergonovine (ER) test is employed as a pharmacological
spasm provocation test. ACh causes vasoconstriction in patients with coronary endothelial dysfunction such as
coronary atherosclerosis, while ER induces coronary vasoconstriction through the activation of coronary smooth muscle.
CASE SUMMARY: An 84-year-old Japanese man was admitted to our hospital due to resting angina and
syncope. Computed tomography coronary angiography (CTCAG) revealed severe proximal left anterior descending (LAD)
coronary artery stenosis, but hybrid images of CTCAG and
thallium-
adenosine myocardial scintigraphy revealed no ischaemia. During
syncope, inverted T waves on V5, V6 leads were recognized. After coronary arteriography, mild atherosclerotic
stenosis (50%) was found at the proximal LAD artery, and we administered intracoronary ER 104 µg and 80 µg into the left and right coronary arteries because of suspected coronary
spasm. However, no provoked
spasm was obtained in either vessel. We administered 20, 50, and 100 µg intracoronary ACh into the left coronary artery (LCA) for 30 s without a pacemaker, because neither
bradycardia nor
cardiac arrest has occurred. Diffuse distal
spasm was provoked after the administration of 100 µg ACh and the patient complained of typical
chest pain and prodrome before
syncope. The patient was diagnosed with coronary
spastic angina by the ACh test but not the ER test.
DISCUSSION: