title: Planar myocardial perfusion imaging for evaluation of patients with acute chest pain.
abstract: BACKGROUND
  Rest single-photon emission computed tomographic (SPECT) perfusion imaging identifies acute myocardial ischemia in patients with chest pain in the emergency department; however, the costs are high and radioisotopic services are usually not available 24 h a day. Planar imaging through a portable gamma camera may be useful in this setting. However, planar imaging might be associated with less predictive values in comparison with a gated SPECT imaging. We sought to evaluate rest planar myocardial perfusion imaging for evaluation and triage of patients with suspected acute cardiac ischemia.
  
  
  METHODS
  Patients within 6 h of chest pain onset and nondiagnostic electrocardiograms (ECGs) underwent planar myocardial perfusion imaging. Studies showing perfusion defects were considered suggestive of acute coronary syndromes. The results of planar scintigraphy were compared with the clinical diagnosis and outcomes. All patients were followed up and monitored for the occurrence of major cardiac events 120 days after hospital discharge.
  
  
  RESULTS
  71 patients underwent scintigraphy. Twenty-one (30%) patients had acute coronary syndromes, 15 (21%) had major cardiac events (8 had myocardial infarction and 7 underwent myocardial revascularization). Planar scintigraphy demonstrated perfusion defects in 21 patients, 16 (76%) patients with acute coronary syndromes, 12 (80%) patients who had major cardiac events and in 7 (88%) patients with myocardial infarction. The negative predictive value of planar scintigraphy was 90% for diagnosis of acute coronary syndromes and 94% for detecting major cardiac events.
  
  
  CONCLUSIONS
  Early planar myocardial perfusion imaging allowed rapid and accurate risk stratification of emergency departments patients with possible myocardial ischemia and nondiagnostic ECGs.
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, Av. Dr. Eneas de Carvalho Aguiar, 44, São Paulo 05403-000, Brazil. alice.yamada@incor.usp.br
authors.forename: Alice Tatsuko
authors.initials: AT
authors.lastname: Yamada
authors.forename: José
authors.initials: J
authors.lastname: Soares
authors.forename: José Claudio
authors.initials: JC
authors.lastname: Meneghetti
authors.forename: Fernando
authors.initials: F
authors.lastname: Araújo
authors.forename: José Antonio Franchini
authors.initials: JA
authors.lastname: Ramires
authors.forename: Alfredo José
authors.initials: AJ
authors.lastname: Mansur
mesh_terms: D002637:Chest Pain / Q000175:diagnosis*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D017256:Technetium Tc 99m Sestamibi
chemical_list: D017256:Technetium Tc 99m Sestamibi