title: Detection of regional myocardial ischaemia by a novel 80-electrode body surface Delta map in patients presenting to the emergency department with cardiac-sounding chest pain.
abstract: BACKGROUND
  Presentation with acute chest pain is common, but the conventional 12-lead ECG has limitations in the detection of regional myocardial ischaemia. The previously described method of the body surface mapping system (BSM) Delta map, derived from an 80-electrode BSM, as well as a novel parameter total ischaemic burden (IB), may offer improved diagnostic sensitivity and specificity in patients with myocardial ischaemia.
  
  
  METHODS
  The feasibility of using the novel BSM Delta map technique, and IB, for transient regional myocardial ischaemia was assessed in comparison with 12-lead ECG in 49 patients presenting to the emergency department (ED) with cardiac-sounding chest pain.
  
  
  RESULTS
  The sensitivity and specificity of 12-lead ECG for the diagnosis of acute coronary syndrome (ACS) was 67 and 55%, respectively, positive likelihood ratio (+LR) 1.52 [95% confidence interval (CI) 0.86, 2.70] and negative likelihood ratio (-LR) 0.58 [95% CI 0.30, 1.12]. The sensitivity and specificity of the BSM Delta map for the diagnosis of ACS was 71 and 78%, +LR 3.19 [95% CI 1.31, 7.80], -LR 0.37 [95% CI 0.20, 0.68]. There was a significantly positive correlation between peak troponin-I concentration and IB (r=0.437; P<0.002).
  
  
  CONCLUSIONS
  This pilot study confirms the feasibility of using the Delta map for the diagnosis of ACS in patients presenting to the ED with cardiac-sounding chest pain and suggests that it has promising diagnostic accuracy and has superior sensitivity and specificity to the 12-lead ECG. The novel parameter of IB shows a significant correlation with troponin-I and is a promising tool for describing the extent of ischaemia. The use of the BSM Delta map in the ED setting could improve the diagnosis of clinically important ischaemic heart disease and furthermore presents the result in an intuitive manner, requiring little specialist experience. Further larger scale study is now warranted.
authors.affiliation: aWessex Cardiac Unit bDepartment of Emergency, Southampton University Hospitals NHS Trust cDepartment of Cardiovascular Medicine, Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Mehmood
authors.initials: M
authors.lastname: Zeb
authors.forename: Michael
authors.initials: M
authors.lastname: Mahmoudi
authors.forename: Florence
authors.initials: F
authors.lastname: Garty
authors.forename: Clare
authors.initials: C
authors.lastname: Bannister
authors.forename: Richard
authors.initials: R
authors.lastname: Reddiar
authors.forename: Zoe
authors.initials: Z
authors.lastname: Nicholas
authors.forename: Robert
authors.initials: R
authors.lastname: Crouch
authors.forename: John
authors.initials: J
authors.lastname: Heyworth
authors.forename: Nicholas
authors.initials: N
authors.lastname: Curzen
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis / Q000503:physiopathology; D018780:Body Surface Potential Mapping / Q000379:methods*; D002637:Chest Pain / Q000209:etiology* / Q000503:physiopathology; D004562:Electrocardiography / Q000379:methods; D004566:Electrodes; D004636:Emergency Service, Hospital; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D012680:Sensitivity and Specificity; D019210:Troponin I / Q000097:blood
chemical_list: D019210:Troponin I