title: Regional blood flow, oxidative metabolism, and glucose utilization in patients with recent myocardial infarction.
abstract: BACKGROUND
  Metabolic imaging with positron emission tomography (PET) can detect tissue viability in clinical infarct regions. With appropriate tracer kinetic models and serial PET imaging, regional myocardial blood flow and rates of metabolism can now be quantified in patients with recent myocardial infarctions.
  
  
  RESULTS
  Serial PET imaging with [13N]ammonia, [11C]acetate, and 18F-deoxyglucose was performed in 22 patients with recent infarctions to measure regional blood flow (in milliliters per gram per minute), glucose metabolism (in micromoles per gram per minute), and oxidative metabolism (in clearance rate per minute). Hypoperfused clinical infarct regions were classified as "PET mismatch" if 18F was increased relative to 13N activity or "PET match" if 13N and 18F activities were reduced concordantly. Blood flows differed significantly between normal, mismatch, and match segments (0.83 +/- 0.20, 0.57 +/- 0.20, and 0.32 +/- 0.12 mL.g-1.min-1, respectively). The relation between oxidative metabolism and blood flow was piecewise linear and differed significantly between PET mismatch and PET match. Oxidative metabolism was less severely reduced than blood flow in mismatch regions but but reduced in proportion to blood flow in match regions. There was considerable overlap of blood flows between both types of PET segments.
  
  
  CONCLUSIONS
  Quantification of regional blood flow and substrate metabolism in postinfarction patients revealed alterations in the relation between substrate delivery and consumption demonstrated previously only in invasive animal experiments. The preserved oxidative metabolism in myocardium with PET mismatches may be ascribed to a regional increase in oxygen extraction. Such increase together with preserved glucose utilization may be the prerequisite for survival of ischemically injured myocardium.
authors.affiliation: Department of Radiological Sciences, UCLA School of Medicine 90024-1721.
authors.forename: J
authors.initials: J
authors.lastname: Czernin
authors.forename: G
authors.initials: G
authors.lastname: Porenta
authors.forename: R
authors.initials: R
authors.lastname: Brunken
authors.forename: J
authors.initials: J
authors.lastname: Krivokapich
authors.forename: K
authors.initials: K
authors.lastname: Chen
authors.forename: R
authors.initials: R
authors.lastname: Bennett
authors.forename: A
authors.initials: A
authors.lastname: Hage
authors.forename: C
authors.initials: C
authors.lastname: Fung
authors.forename: J
authors.initials: J
authors.lastname: Tillisch
authors.forename: M E
authors.initials: ME
authors.lastname: Phelps
mesh_terms: D017023:Coronary Angiography; D003326:Coronary Circulation / Q000502:physiology*; D004452:Echocardiography; D005947:Glucose / Q000378:metabolism*; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D014055:Tomography, Emission-Computed
chemical_list: D005947:Glucose