title: Patients with circumflex occlusions miss out on reperfusion:  how to recognize and manage them.
abstract: OBJECTIVE
  To review the diagnosis of circumflex occlusion, and why it is important for patient care.
  
  
  RESULTS
  The ECG is an essential tool for identifying patients who might benefit from reperfusion therapy with ST segment elevation being a requirement. However, circumflex occlusions are often not recognized. Patients with circumflex acute coronary syndromes (ACSs) often present without ST segment elevation even when there is a total occlusion causing a full-thickness inferobasal (previously called posterior) infarction. Recent registries and trials show overrepresentation of circumflex occlusions in non-ST elevation ACS and underrepresentation in ST elevation myocardial infarction populations. This is because usually only the 12-lead ECG has been recorded.Leads V7-V9 should be recorded if there is a clinical suspicion of circumflex territory involvement, such as ST depression in leads V1-V3, or presentation with a normal 12-lead ECG with hemodynamic compromise.
  
  
  CONCLUSIONS
  If ST elevation in the circumflex territory is not recognized, patients may be treated inappropriately as having a non-ST elevation ACS without having primary percutaneous coronary intervention or receiving early administration of fibrinolytic therapy. There is a large opportunity for saving thousands of lives worldwide if circumflex occlusions are recognized and treated appropriately.
authors.affiliation: Division of Cardiology, Department of Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
authors.forename: Cheuk-Kit
authors.initials: CK
authors.lastname: Wong
authors.forename: Harvey D
authors.initials: HD
authors.lastname: White
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D004562:Electrocardiography / Q000295:instrumentation; D005342:Fibrinolysis; D006439:Hemodynamics; D006801:Humans; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D015425:Myocardial Reperfusion / Q000379:methods*; D005791:Patient Care