title: Dobutamine stress electrocardiography-gated Tc-99m tetrofosmin SPECT for detection of viable but dysfunctional myocardium.
abstract: BACKGROUND
  Technetium-99m-labeled myocardial perfusion tracers allow simultaneous assessment of myocardial perfusion and left ventricular function by electrocardiography-gated scan. This study was performed to determine whether dobutamine stress electrocardiography-gated tetrofosmin single photon emission computed tomography (SPECT) can identify viable (as defined by positron emission tomography [PET]) but dysfunctional myocardium with contractile reserve.
  
  
  RESULTS
  Thirty-five patients with myocardial infarction underwent resting electrocardiography-gated SPECT and fluorodeoxyglucose (FDG) PET. The relative uptakes of tetrofosmin (%tetrofosmin) and FDG (%FDG) were calculated. Wall motion in 9 left ventricular segments was assessed at rest and during dobutamine stress on a 3-dimensional cine-mode display created with automatic left ventricular function analysis software. A total of 129 dysfunctional segments were analyzed. Forty-five (48.9%) of 92 segments with %tetrofosmin of 50% or greater and only 4 (10.8%) of 37 segments with %tetrofosmin less than 50% had contractile reserves (P <.0001). The sensitivity, specificity, and predictive accuracy of %tetrofosmin of 50% or greater for detecting %FDG of 50% or greater were 85.7%, 74%, and 82.9%, respectively. The incidence of the presence of contractile reserve rose with increasing magnitude of %FDG. The sensitivity, specificity, and predictive accuracy of the presence of contractile reserve for detecting %FDG of 50% or greater were 43.9%, 80.6%, and 52.7%, respectively.
  
  
  CONCLUSIONS
  Dobutamine stress electrocardiography-gated SPECT can identify viable (as defined by PET) but dysfunctional myocardium with contractile reserve.
authors.affiliation: First Department of Internal Medicine and Division of Nuclear Medicine, Osaka City University Medical School, 1-5-7 Asahi-machi, Abeno-Ku, Osaka 545-8586, Japan. hiroyuki@msic.med
authors.forename: H
authors.initials: H
authors.lastname: Yamagishi
authors.forename: K
authors.initials: K
authors.lastname: Akioka
authors.forename: K
authors.initials: K
authors.lastname: Hirata
authors.forename: Y
authors.initials: Y
authors.lastname: Sakanoue
authors.forename: I
authors.initials: I
authors.lastname: Toda
authors.forename: M
authors.initials: M
authors.lastname: Yoshiyama
authors.forename: M
authors.initials: M
authors.lastname: Teragaki
authors.forename: K
authors.initials: K
authors.lastname: Takeuchi
authors.forename: J
authors.initials: J
authors.lastname: Yoshikawa
authors.forename: H
authors.initials: H
authors.lastname: Ochi
mesh_terms: D000328:Adult; D000368:Aged; D004280:Dobutamine; D004562:Electrocardiography; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon; D016277:Ventricular Function, Left
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D004280:Dobutamine; C078700:technetium tc-99m tetrofosmin