title: Repeatability of cold pressor test-induced flow increase assessed with H(2)(15)O and PET.
abstract: The aim of this study was to evaluate the repeatability of endothelium-related myocardial blood flow (MBF) responses to cold pressor testing (CPT) as assessed by PET.
  
  
  METHODS
  In 10 age-matched control subjects (26.6 +/- 3.4 y) and 10 tobacco smokers (24.9 +/- 3.3 y) MBF was assessed at rest and after repeated CPT (CPT1 and CPT2, 40 min apart) using PET with H(2)(15)O. CPT was performed by a 2-min immersion of the subject's foot in ice water. MBF values were corrected for cardiac workload (rate.pressure product), and the repeatability of CPT-related MBF values was assessed according to Bland and Altman.
  
  
  RESULTS
  Corrected MBF at CPT1 and CPT2 were comparable in control subjects (1.79 +/- 0.37 vs. 1.70 +/- 0.35 mL/min/g; P = not significant [NS]) and in smokers (1.97 +/- 0.42 vs. 1.80 +/- 0.41 mL/min/g; P = NS). Repeatability coefficients in control subjects and smokers were 0.46 mL/min/g (27% of the mean MBF) and 0.51 mL/min/g (27%), respectively. MBF increased significantly after CPT in both groups but tended to be lower in smokers (P = 0.08).
  
  
  CONCLUSIONS
  PET measured MBF combined with CPT is a feasible and repeatable method for the evaluation of endothelium-related changes of MBF.
authors.affiliation: Nuclear Cardiology, Cardiovascular Center, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Siegrist
authors.forename: Oliver
authors.initials: O
authors.lastname: Gaemperli
authors.forename: Pascal
authors.initials: P
authors.lastname: Koepfli
authors.forename: Tiziano
authors.initials: T
authors.lastname: Schepis
authors.forename: Mehdi
authors.initials: M
authors.lastname: Namdar
authors.forename: Ines
authors.initials: I
authors.lastname: Valenta
authors.forename: Floreana
authors.initials: F
authors.lastname: Aiello
authors.forename: Samuel
authors.initials: S
authors.lastname: Fleischmann
authors.forename: Hatem
authors.initials: H
authors.lastname: Alkadhi
authors.forename: Philipp A
authors.initials: PA
authors.lastname: Kaufmann
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D003080:Cold Temperature; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging; D005080:Exercise Test / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D010104:Oxygen Radioisotopes; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012907:Smoking / Q000503:physiopathology*; D014666:Vasomotor System / Q000503:physiopathology; D014867:Water
chemical_list: D010104:Oxygen Radioisotopes; D019275:Radiopharmaceuticals; D014867:Water