title: Do mechanical markers of myocardial ischaemia predict the transmural extent of myocardial infarction in man?
abstract: BACKGROUND
  The present study aimed to explore the relationship between the transmural extent of myocardial necrosis and mechanical markers of myocardial ischaemia in man.
  
  
  METHODS
  A group of 40 patients with previous Q-wave myocardial infarction and a left ventricular ejection fraction (LVEF) of 27 +/- 11% was studied by cine and contrast-enhanced magnetic resonance imaging.
  
  
  RESULTS
  Necrotic areas of delayed contrast enhancement were present in every patient and involved 20 +/- 8% of left ventricular myocardium. In involved segments, the transmural extent of contrast enhancement varied from 5% to 100%, being on average 38 +/- 25% of the wall thickness. End-diastolic left ventricular wall thickness and systolic wall thickening were lower in contrast-enhanced segments than in the other segments (P < 0.001). Furthermore, although left ventricular wall thickness and systolic wall thickening decreased as the transmural extent of contrast enhancement increased, the correlations were weak (r = -0.382 and -0.45, respectively). Finally, a delayed contrast enhancement was present in 89% of akinetic and in 94% of dyskinetic segments; however, contrast enhancement was also present in 18% of the segments with normal wall motion and in 56% of hypokinetic segments.
  
  
  CONCLUSIONS
  Although mechanical markers of myocardial ischaemia substantially reflect the transmural extent of myocardial infarction, none of them can be considered as a substitute for the direct observation of necrotic tissue and its transmural extent, as provided by contrast-enhanced magnetic resonance imaging.
authors.affiliation: CNR Clinical Physiology Institute, Pisa, Italy. pingi@ifc.cnr.it
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pingitore
authors.forename: Daniele
authors.initials: D
authors.lastname: Rovai
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Positano
authors.forename: Gianluca
authors.initials: G
authors.lastname: Di Bella
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Strata
authors.forename: Daniele
authors.initials: D
authors.lastname: De Marchi
authors.forename: Mirko
authors.initials: M
authors.lastname: Passera
authors.forename: Giovanni D
authors.initials: GD
authors.lastname: Aquaro
authors.forename: Massimo
authors.initials: M
authors.lastname: Lombardi
mesh_terms: D000704:Analysis of Variance; D016009:Chi-Square Distribution; D003287:Contrast Media; D004562:Electrocardiography; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000473:pathology / Q000503:physiopathology*; D017202:Myocardial Ischemia / Q000503:physiopathology*; D009336:Necrosis; D011237:Predictive Value of Tests
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA