title: The use of perfusion scintigraphy to differentiate proximal right coronary artery stenosis from distal right coronary artery stenosis in patients with inferior left ventricular ischaemia.
abstract: OBJECTIVE
  The identification of patients with a significant proximal right coronary artery (RCA) is of clinical relevance since it may direct diagnostic and therapeutic strategies. This study was performed to determine parameters of (201)Tl RV perfusion SPECT which can be used to discriminate between proximal and distal RCA stenosis in patients with inferior left ventricular (LV) ischaemia. In addition, feasibility and reproducibility of a new semi-quantitative method for the assessment of RV perfusion were evaluated.
  
  
  METHODS
  Inferior LV ischaemia was due to a single distal RCA stenosis in 10 (group I) and proximal RCA stenosis in 27 patients (group II). Twenty patients with normal (201)Tl myocardial perfusion scintigraphy and low likelihood of cardiovascular disease were used as a reference (group III).
  
  
  RESULTS
  RV (201)Tl stress uptake did not differ between the three groups. However, group II showed a significantly higher (201)Tl rest uptake indicating RV redistribution whereas in group I and III tracer washout was shown. Extent and severity of LV inferior ischaemia was not different between groups I and II. RV redistribution has a sensitivity of 0.74, a specificity of 0.80, and an overall agreement of 0.76 for detecting proximal RCA stenosis. The feasibility of the assessment of RV (201)Tl perfusion was 94%. Inter-observer and intra-observer coefficients of variation for RV (201)Tl perfusion assessment were 1.5 and 2.4%, respectively.
  
  
  CONCLUSIONS
  RV (201)Tl perfusion scintigraphy is feasible and reproducible. RV (201)Tl redistribution can be used to discriminate between proximal and distal RCA stenosis in patients with inferior LV ischaemia.
authors.affiliation: Department of Nuclear Medicine, F2-238 Academic Medical Center, 1100-DE Amsterdam, the Netherlands. h.j.verberne@amc.uva.nl
authors.forename: Hein J
authors.initials: HJ
authors.lastname: Verberne
authors.forename: Eric
authors.initials: E
authors.lastname: Fleury
authors.forename: Alberto
authors.initials: A
authors.lastname: Righetti
authors.forename: G Aernout
authors.initials: GA
authors.lastname: Somsen
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000473:pathology*; D003331:Coronary Vessels / Q000473:pathology; D005260:Female; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D007511:Ischemia / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D010477:Perfusion; D011877:Radionuclide Imaging / Q000379:methods*; D013794:Thallium Radioisotopes / Q000494:pharmacology; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D013794:Thallium Radioisotopes