title: Clinical implications of isolated T wave inversion in adults: electrocardiographic differentiation of the underlying causes of this phenomenon.
abstract: OBJECTIVE
  This study aimed to assess the causes and clinical implications of isolated T wave inversion in adults and to evaluate electrocardiographic (ECG) differentiation of these causes.
  
  
  BACKGROUND
  There are few previous reports on isolated T wave inversion in adults, which is a paradoxic observation in normal adults and in those with severe coronary artery disease.
  
  
  METHODS
  We used echocardiography, stress thallium-201 scintigraphy and coronary angiography to determine the underlying causes and then used conventional electrocardiography and precordial ECG mapping to differentiate them. Eighty-six consecutive patients with isolated T wave inversion were classified as follows: group A included 23 asymptomatic patients; group B included 63 patients with chest pain.
  
  
  RESULTS
  In group A, isolated T wave inversion was found as a normal variant in 20 patients and was due to hypertrophic cardiomyopathy in 3. In group B, the cause was hypertrophic cardiomyopathy in 3 patients, pericarditis in 2, coronary artery disease (lesions of the proximal left anterior descending coronary artery) in 39 and a normal variant in 19. The causes of isolated T wave inversion were difficult to determine from 12-lead ECG findings alone. However, when the inverted T wave region extended into the upper part of the precordium, precordial ECG mapping demonstrated excellent detection of coronary artery disease, with a sensitivity, specificity and overall accuracy of 88%, 93% and 91%, respectively.
  
  
  CONCLUSIONS
  Isolated T wave inversion in asymptomatic adults is usually a normal variant. In patients with chest pain, isolated T wave inversions can develop in two different situations: a normal variant and severe coronary artery disease; these can be easily differentiated by precordial ECG mapping using conventional electrocardiography.
authors.affiliation: Second Department of Internal Medicine, School of Medicine, Kyorin University, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Okada
authors.forename: M
authors.initials: M
authors.lastname: Yotsukura
authors.forename: T
authors.initials: T
authors.lastname: Shimada
authors.forename: K
authors.initials: K
authors.lastname: Ishikawa
mesh_terms: D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000209:etiology; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000175:diagnosis; D003327:Coronary Disease / Q000150:complications / Q000175:diagnosis; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010493:Pericarditis / Q000150:complications / Q000175:diagnosis; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity