title: Usefulness of ECG to differentiate Takotsubo cardiomyopathy from acute coronary syndrome.
abstract: OBJECTIVE
  We aimed to describe the evolution of ECG changes in TC compared with MI, and evaluate ECG features which might help to distinguish between these conditions.
  
  
  BACKGROUND
  Takotsubo cardiomyopathy (TC) can mimic both ST-elevation (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) but management is different. Several electrocardiographic (ECG) abnormalities have been identified which might help to differentiate TC with and without ST-elevation, from STEMI and NSTEMI, respectively.
  
  
  METHODS
  We prospectively identified 100 consecutive patients with TC and 100 MI patients. They were divided into 2 groups according to the presence of ST-segment elevation (STE). Serial ECGs from admission to Day 2 were compared.
  
  
  RESULTS
  Thirty-five TC patients had STE on admission. Compared with STEMI patients they had less prominent STE (median peak elevation 2mm vs. 3mm, P<0.05), less reciprocal ST-segment depression and no abnormal Q-waves. By Day 2 all STEMI patients had pathological Q-waves but none of the TC patients. Compared with NSTE-TC patients, NSTEMI patients had more ST-segment depression (28.2% vs. 0%, P<0.05), but less T-wave inversion (33.8% vs. 11.3%, P<0.05) on admission. By Day 2 the ECG criterion which best distinguished NSTE-TC from NSTEMI was the presence of T-wave inversion in ≥6 leads (sensitivity 74%, specificity 92%).
  
  
  CONCLUSIONS
  ECG changes seen in TC within two days of presentation are distinctive and important clues for clinicians to suspect the diagnosis.
authors.affiliation: Department of Cardiology, Middlemore Hospital, Private Bag 93311, Otahuhu, Auckland, New Zealand. Electronic address: JenLi.Looi@middlemore.co.nz.
authors.forename: Jen-Li
authors.initials: JL
authors.lastname: Looi
authors.affiliation: Department of Cardiology, Middlemore Hospital, Private Bag 93311, Otahuhu, Auckland, New Zealand.
authors.forename: Chi-Wing
authors.initials: CW
authors.lastname: Wong
authors.affiliation: Department of Cardiology, Middlemore Hospital, Private Bag 93311, Otahuhu, Auckland, New Zealand.
authors.forename: Mildred
authors.initials: M
authors.lastname: Lee
authors.affiliation: Cardiovascular Division, North Shore Hospital, 124 Shakespeare Road, Takapuna, Auckland 0622, New Zealand.
authors.forename: Ali
authors.initials: A
authors.lastname: Khan
authors.affiliation: Green Lane Cardiovascular Service, Auckland City Hospital, 2 Park Road Grafton, Auckland 1023, New Zealand.
authors.forename: Mark
authors.initials: M
authors.lastname: Webster
authors.affiliation: Department of Cardiology, Middlemore Hospital, Private Bag 93311, Otahuhu, Auckland, New Zealand.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Kerr
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis* / Q000503:physiopathology; D000208:Acute Disease; D000368:Aged; D053840:Brugada Syndrome / Q000503:physiopathology; D000075224:Cardiac Conduction System Disease; D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology; D009520:New Zealand / Q000453:epidemiology; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D054549:Takotsubo Cardiomyopathy / Q000175:diagnosis* / Q000503:physiopathology
keywords: Acute coronary syndrome; Acute myocardial infarction; Apical ballooning syndrome; Electrocardiogram; Takotsubo cardiomyopathy