title: Relationship between strain rate imaging and coronary flow reserve in assessing myocardial viability after acute myocardial infarction.
abstract: OBJECTIVE
  To evaluate the relationship between strain rate (SR) imaging and coronary flow reserve (CFR) in assessing viability of akinetic myocardium after acute myocardial infarction (MI).
  
  
  METHODS
  Forty patients with acute first ST-elevation MI were analyzed. SR imaging and CFR by intracoronary flow measurement were obtained on the same day, 3~5 days after primary percutaneous coronary intervention. Viability of the akinetic myocardium was determined on 6-week echocardiography.
  
  
  RESULTS
  Systolic SR (SRs, -0.42 ± 0.10 vs. -0.35 ± 0.11 per second, P = 0.03), early diastolic SR (SRe, 0.68 ± 0.31 vs. 0.41 ± 0.22 per second, P = 0.003), and systolic strain (Ss, -5.9 ± 3.4 vs. -2.5 ± 4.0%, P = 0.04) were greater in akinetic, but viable myocardium of 21 patients than in akinetic and nonviable myocardium of 19 patients. CFR was also higher in patients with akinetic, but viable myocardium (2.0 ± 0.5 vs. 1.5 ± 0.5, P < 0.001). SRs, SRe, and Ss were significantly related to CFR (r =-0.50, r = 0.58, r =-0.56, respectively, all P ≤ 0.001) and SRe was most related to CFR (P < 0.001). The sensitivity and specificity to predict myocardial viability were 85.7% and 68.4% for CFR (cutoff = 1.75), and 90.5% and 57.9% for SRe (cutoff = 0.37 per second), respectively.
  
  
  CONCLUSIONS
  The degree of myocardial deformation determined by SR imaging was related to the degree of microvascular integrity determined by CFR, and can be used as a noninvasive method to predict myocardial viability after acute MI.
authors.affiliation: Division of Cardiology, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Seong-Mi
authors.initials: SM
authors.lastname: Park
authors.forename: Soon-Jun
authors.initials: SJ
authors.lastname: Hong
authors.forename: Jae-Suk
authors.initials: JS
authors.lastname: Park
authors.forename: Sang-Yup
authors.initials: SY
authors.lastname: Lim
authors.forename: Chul-Min
authors.initials: CM
authors.lastname: Ahn
authors.forename: Do-Sun
authors.initials: DS
authors.lastname: Lim
authors.forename: Wan-Joo
authors.initials: WJ
authors.lastname: Shim
mesh_terms: D000465:Algorithms; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000000981:diagnostic imaging*; D017682:Myocardial Stunning / Q000000981:diagnostic imaging* / Q000209:etiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014022:Tissue Survival