title: Provocation of microvessel spasm by low-dose acetylcholine in patients with suspected coronary artery disease--two case reports.
abstract: Endothelial dysfunction plays an important role in the pathogenesis of cardiac syndrome X, and intracoronary low-dose acetylcholine infusion is a widely used diagnostic modality for studying the coronary artery endothelial function. The authors herein report 2 cases of cardiac syndrome X with coronary artery endothelial dysfunction and microvessel spasm. The findings of non-invasive testing were positive for ischemia. Coronary angiograms appeared entirely normal in both cases. However, the intracoronary infusion of low-dose (1.5-15 microg/minute) acetylcholine demonstrated an impairment of the coronary blood flow response and consequently provoked an ST-segment elevation in an electrocardiogram. The coronary angiograms showed no spasm in the epicardial arteries. These patients are thus suggested to have cardiac syndrome X with microvessel spasms associated with coronary artery endothelial dysfunction.
authors.affiliation: The First Department of Internal Medicine, National Defense Medical College, Saitama, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Masaki
authors.forename: Bonpei
authors.initials: B
authors.lastname: Takase
authors.forename: Kimio
authors.initials: K
authors.lastname: Satomura
authors.forename: Takashi
authors.initials: T
authors.lastname: Akima
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matsushima
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Hosaka
authors.forename: Akira
authors.initials: A
authors.lastname: Hamabe
authors.forename: Akira
authors.initials: A
authors.lastname: Kurita
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Ohsuzu
mesh_terms: D000109:Acetylcholine; D001783:Blood Flow Velocity / Q000187:drug effects; D018678:Cholinergic Agents; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000187:drug effects / Q000502:physiology; D003327:Coronary Disease / Q000175:diagnosis* / Q000503:physiopathology; D003329:Coronary Vasospasm / Q000139:chemically induced* / Q000503:physiopathology; D003937:Diagnosis, Differential; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology; D005260:Female; D006801:Humans; D007269:Injections, Intra-Arterial; D018810:Magnetic Resonance Angiography; D008297:Male; D008833:Microcirculation / Q000187:drug effects / Q000503:physiopathology; D017566:Microvascular Angina / Q000175:diagnosis* / Q000503:physiopathology; D008875:Middle Aged
chemical_list: D018678:Cholinergic Agents; D000109:Acetylcholine