title: The percent change of strain and strain rate under dobutamine stress echocardiography predicts viability following myocardial infarction.
abstract: OBJECTIVE
  The aim of the present study was to explore the accuracy of the dobutamine-induced percent change of myocardial deformation indices to detect viability following myocardial infarction.
  
  
  METHODS
  We enrolled 60 consecutive patients presenting for myocardial viability assessment at least 4 weeks following ST-segment-elevation myocardial infarction. Strain (S) and strain rate (SR) were individually measured for all myocardial segments, both at rest and during low-dose dobutamine stress echocardiography. The percent change of S and SR from baseline to dobutamine-induced values (at a dose of 20 µg/kg/min) was calculated individually for each segment. Patients underwent myocardial viability assessment with resting 99mTc-sestamibi scintigraphy. Based on the results of scintigraphy, the percent change of S and SR was compared between viable and non-viable segments.
  
  
  RESULTS
  For all segments, the percent change of both S and SR was significantly higher in viable as compared with non-viable segments (P<0.05 for all). Receiver-operating characteristics curve analysis identified the optimal cut-off value for the percent change of both S and SR that best discriminates viable from non-viable segments in the range of 20-25% with a sensitivity range from 95% to 100%, and a specificity range from 85% to 100%.
  
  
  CONCLUSIONS
  In patients undergoing viability assessment following ST segment elevation myocardial infarction, the percent change of both S and SR (from baseline to dobutamine-induced values) was significantly higher in viable versus non-viable segments. A cut-off value of 20-25% of the percent change for both S and SR reliably identified viable from non-viable segments with a high sensitivity and specificity for both.
authors.affiliation: El Demerdash Hospital, Cardiology Department, Faculty of medicine Ain Shams University, Cairo, Egypt - Mohamedismail1973@hotmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Ismail
authors.forename: S
authors.initials: S
authors.lastname: Khalid
authors.forename: S
authors.initials: S
authors.lastname: Eldemerdash
authors.forename: W
authors.initials: W
authors.lastname: Elmallal
authors.forename: H
authors.initials: H
authors.lastname: Bahy
authors.forename: W
authors.initials: W
authors.lastname: Nammas
mesh_terms: D004280:Dobutamine; D025401:Echocardiography, Stress / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011877:Radionuclide Imaging / Q000379:methods; D000072657:ST Elevation Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi
chemical_list: D004280:Dobutamine; D017256:Technetium Tc 99m Sestamibi