title: Stress test with dual isotope studies for the documentation of classical ischemic preconditioning.
abstract: OBJECTIVE
  We investigated whether myocardial perfusion imaging (MPI) can demonstrate the effect of classical preconditioning.
  
  
  METHODS
  21 patients with documented coronary artery disease (stenosis>or=70%) underwent two exercise stress tests (EST) with concomitant MPI, using TL-201 for the first and tetrofosmin-Tc-99m for the second. A third MPI was performed at rest, using Tc-99m. Total defect score was derived by summing tracer uptake in a 17 segments left ventricle model, graded on a 5-point scale. Tomographic images were also analyzed quantitatively, to derive the total defect size.
  
  
  RESULTS
  Maximum ST depression did not differ significantly between the two EST (2.2+/-1 vs 2.2+/-1 mm, p=NS), however in the second EST longer times for onset of ischemic changes (228+/-94 vs 265+/-103 s, p=0.01) and appearance of angina (282+/-153 vs 328+/-177 s, p=0.04) were observed. Exercise perfusion abnormalities were significantly lower in the second MPI, in terms of both total defect score (19.2+/-11.5 vs 10+/-10.4, p<0.0001) and total defect size (28.3+/-16.9 vs 13.8+/-15.8, p<0.0001).
  
  
  CONCLUSIONS
  Significant improvement in perfusion pattern was demonstrated in the second MPI, accompanied by delayed appearance of ischemic manifestations. The improvement in myocardial perfusion extends far beyond the changes that can be attributed to differences in myocardial uptake between tracers, reflecting the effect of classical preconditioning.
authors.affiliation: Nuclear cardiology department, Onassis Cardiac Surgery Center, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Koutelou
authors.forename: Athanasios
authors.initials: A
authors.lastname: Katsikis
authors.forename: Athanasios
authors.initials: A
authors.lastname: Theodorakos
authors.forename: Virginia
authors.initials: V
authors.lastname: Tsapaki
authors.forename: Anna
authors.initials: A
authors.lastname: Kouzoumi
authors.forename: Athanasios
authors.initials: A
authors.lastname: Dritsas
authors.forename: Dennis
authors.initials: D
authors.lastname: Cokkinos
mesh_terms: D000368:Aged; D003324:Coronary Artery Disease / Q000473:pathology*; D005080:Exercise Test; D005260:Female; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D007511:Ischemia / Q000473:pathology; D019194:Ischemic Preconditioning; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000473:pathology; D009943:Organophosphorus Compounds / Q000494:pharmacology; D015609:Organotechnetium Compounds / Q000494:pharmacology; D010477:Perfusion; D013997:Time Factors
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; C078700:technetium tc-99m tetrofosmin