A routine electrocardiogram should not be used to determine the size of myocardial infarction in the rat

A. M.M. Bonilha, R. M. Saraiva, R. M. Kanashiro, L. A. Portes, E. L. Antonio, P. J.F. Tucci

Research output: Contribution to journalArticle

9 Scopus citations


Nine lead electrocardiograms of non-infarcted (N = 61) and infarcted (N = 71) female Wistar rats (200-250 g) were analyzed in order to distinguish left ventricle myocardial infarction (MI) larger than 40% (LMI) from MI smaller than 40% (SMI) . MI larger than 40% clearly caused a deviation of ÂQRS and ÂT from normal values of 270-360 degrees to 90-270 degrees. Infarcted rats showed Q wave in D1 larger than 1 mm with 94% sensitivity and 100% specificity. The sum of QRS positivity in V1, V2 and V6 lower than 10 mm identified MI with 82% sensitivity and 100% specificity. The data showed that MI can be easily and reliably diagnosed by electrocardiogram in the rat. However, contradicting what is frequently believed, when specificity and sensitivity were analyzed focusing on MI size, none of these current electrocardiographic indices of MI size adequately discriminates LMI from SMI.

Original languageEnglish (US)
Pages (from-to)615-619
Number of pages5
JournalBrazilian Journal of Medical and Biological Research
Issue number4
StatePublished - Apr 2005



  • Echocardiogram
  • Electrocardiogram
  • Myocardial infarction size
  • ROC curve
  • Rats

ASJC Scopus subject areas

  • Biophysics
  • Neuroscience(all)
  • Biochemistry
  • Physiology
  • Immunology
  • Pharmacology, Toxicology and Pharmaceutics(all)
  • Cell Biology

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