title: Paradoxical scintigraphic pattern in regions with myocardial necrosis on myocardial perfusion gated SPECT with ⁹⁹mTc-tetrofosmin.
abstract: OBJECTIVE
  To assess the significance of a paradoxical pattern (PP) (greater tracer uptake during stress than at rest) on gated myocardial perfusion SPECT in myocardial regions with myocardial necrosis.
  
  
  METHODS
  A review of 1,764 consecutive stress-rest myocardial perfusion SPECT studies in patients with prior myocardial infarction (MI) was conducted. Of these, 117 patients (6.6%) with a PP corresponding to a region with myocardial necrosis were identified. An assessment of perfusion, contractility, wall thickening, scintigraphic criteria for viability, and the characteristics of the culprit artery in regions with a PP was performed.
  
  
  RESULTS
  Of the 160 regions with necrosis, 125 (75%) had a PP: 67 in the anterior region and 58 in the inferior-lateral region. In the PP group, the average tracer activity of defects during stress was significantly higher than at rest (P < .0001). Ninety-three (86.6%) out of 110 PP segments without scintigraphic criteria of viability at rest met viability criteria on stress imaging. The artery supplying regions with a PP was patent in 88% of cases. In the remaining patients it was occluded, although collateral circulation was always present.
  
  
  CONCLUSIONS
  In scintigraphic segments corresponding to regions with infarction and PP, a mixture of viable and well perfused myocardium was observed. In most cases, the vessel that supplied the region with PP was either patent, or when the artery was occluded, there was evident collateral circulation.
authors.affiliation: Cardiology Department, Institut de Recerca, Hospital Universitari Vall d'Hebron (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d'Hebron 119-129, 08035 Barcelona, Spain. nachi_pizzi@yahoo.com.ar
authors.forename: María Nazarena
authors.initials: MN
authors.lastname: Pizzi
authors.forename: Mónica
authors.initials: M
authors.lastname: Sabaté-Fernández
authors.forename: Santiago
authors.initials: S
authors.lastname: Aguadé-Bruix
authors.forename: Guillermo
authors.initials: G
authors.lastname: Romero-Farina
authors.forename: Gemma
authors.initials: G
authors.lastname: Cuberas-Borrós
authors.forename: Gustavo
authors.initials: G
authors.lastname: de León
authors.forename: Joan
authors.initials: J
authors.lastname: Castell-Conesa
authors.forename: David
authors.initials: D
authors.lastname: García-Dorado
authors.forename: Jaume
authors.initials: J
authors.lastname: Candell-Riera
mesh_terms: D000368:Aged; D055424:Cardiac-Gated Imaging Techniques / Q000706:statistics & numerical data*; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000453:epidemiology*; D055414:Myocardial Perfusion Imaging / Q000706:statistics & numerical data*; D009336:Necrosis / Q000000981:diagnostic imaging; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D015995:Prevalence; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013030:Spain / Q000453:epidemiology; D015899:Tomography, Emission-Computed, Single-Photon / Q000706:statistics & numerical data*
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin