title: Differential incidence and type of spasm according to coronary arterial location.
abstract: BACKGROUND
  We encounter a less provoked spasm in the left circumflex artery (LCX) by acetylcholine (ACh) testing compared with left anterior descending artery and right coronary artery (RCA) in the real world.
  
  
  OBJECTIVE
  We investigated the clinical characteristics of provoked spasm in the LCX by ACh testing.
  
  
  METHODS
  We retrospectively analyzed consecutive 1392 ACh testing over 20 years (1991-2011). The maximal ACh dose was 100 μg into the left coronary artery and 80 μg into the RCA. Positive spasm was defined as transient of more than or equal to 90% narrowing and usual chest symptoms or ischemic ECG changes.
  
  
  RESULTS
  Positive provoked spasm was recognized in 622 patients (44.7%) including 456 RCA spasms, 448 left anterior descending artery spasms, and 176 LCX spasms. LCX-provoked spasm was significantly lower than other vessels (P<0.001). LCX-provoked spasm was observed in 176 patients, of whom 113 patients (64.2%) had triple-vessel spasm, 46 patients (26.1%) had double-vessel spasm, and 17 patients (9.7%) had single-vessel spasm. More than 90% patients with LCX-provoked spasm had multiple spasms. Of 17 patients with LCX single-vessel spasm, 15 patients (88.2%) had focal spasm.
  
  
  CONCLUSIONS
  Under a maximal ACh dose of 100 μg into the left coronary artery, LCX-provoked spasm was significantly lower than other vessels and more than 90% of patients had multiple spasms.
authors.affiliation: aDepartment of Cardiology, Ehime Niihama Prefectural Hospital Niihama, Ehime Prefecture bDepartment of Cardiology, Tsukazaki Hospital, Himeji, Hyogo Prefecture, Japan.
authors.forename: Shozo
authors.initials: S
authors.lastname: Sueda
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kohno
mesh_terms: D000109:Acetylcholine / Q000008:administration & dosage; D000368:Aged; D000788:Angina Pectoris, Variant / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D003329:Coronary Vasospasm / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000008:administration & dosage
chemical_list: D014662:Vasoconstrictor Agents; D000109:Acetylcholine