title: Estimation of hydrogen peroxide plasma levels in patients evaluated for coronary heart disease using dipyridamole infusion followed by SPECT.
abstract: BACKGROUND
  Prolonged ischemia leads to myocardial infarction and increased formation of toxic oxygen radicals. These substances exert deleterious effects on myocardial cells, contributing to reperfusion injury and generation of arrhythmia. Little information is available, however, concerning the toxic oxygen species generated during transient ischemia. The purpose of our study was to estimate hydrogen peroxide plasma levels in patients subjected to short-lasting ischemia induced by a dipyridamole stress test used for the diagnosis of coronary artery disease. Evaluation of the performed test was carried out with 99mTc-SestaMIBI followed by single photon emission computed tomography (SPECT).
  
  
  METHODS
  Blood was obtained from peripheral veins of 53 patients (37 men and 16 women, mean age 49 +/- 11 years). Plasma hydrogen peroxide levels were estimated by spectrophotometric methods: immediately before a dipyridamole challenge and after drug infusion.
  
  
  RESULTS
  Hydrogen peroxide plasma levels in patients with a negative SPECT test were 23.5 +/- 3.0 mumol/l (mean +/- SEM) and 21.0 +/- 2.9 after the dipyridamole infusion (P = 0.474). Plasma concentrations of hydrogen peroxide in patients with a positive SPECT test were 30.5 +/- 4.6 and increased after dipyridamole challenge to 50.3 +/- 5.4 (P = 0.004). Further analysis revealed that the observed difference cannot be attributed to previous history of myocardial infarction.
  
  
  CONCLUSIONS
  Even transient myocardial ischemia can generate toxic oxygen derivatives. Evaluation of plasma levels of hydrogen peroxide may be of clinical relevance in patients with suspected coronary artery disease.
authors.affiliation: Department of Intensive Therapy, University School of Medicine, Poznan, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Kazmierczak
authors.forename: H
authors.initials: H
authors.lastname: Wysocki
authors.forename: A
authors.initials: A
authors.lastname: Wykretowicz
authors.forename: A
authors.initials: A
authors.lastname: Minczykowski
mesh_terms: D003327:Coronary Disease / Q000097:blood / Q000000981:diagnostic imaging*; D004176:Dipyridamole; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D006861:Hydrogen Peroxide / Q000097:blood*; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D004176:Dipyridamole; D017256:Technetium Tc 99m Sestamibi; D006861:Hydrogen Peroxide