title: Diagnosis of coronary artery disease by exercise thallium-201 tomography in patients with a right ventricular pacemaker.
abstract: OBJECTIVE
  We sought to study the accuracy of exercise perfusion scintigraphy in patients with an implanted apical right ventricular pacemaker.
  
  
  BACKGROUND
  The specificity of exercise perfusion scintigraphy is decreased in patients with a left bundle branch block. Patients with a permanent ventricular pacemaker have a similar conduction abnormality that may also potentially result in similar false positive perfusion defects.
  
  
  METHODS
  One hundred five patients with a right ventricular pacemaker underwent exercise thallium-201 tomography and coronary angiography within 7 days of each other. Patients with a previous myocardial infarction were excluded.
  
  
  RESULTS
  Patients were classified into four groups according to the agreement or disagreement between the thallium tomographic and coronary angiographic results. Only 8% of patients with normal results by both techniques were continuously paced during exercise, compared with 78% of patients with normal angiographic results but abnormal scintigraphic results. The mean defect size was 12% in the latter group. Most of the false positive defects were localized to the inferoposterior (71%), apical (50%) and inferoseptal (28%) walls.
  
  
  CONCLUSIONS
  Patients who are paced in the right ventricular apex and who continue to be paced throughout exercise have a high incidence of false positive thallium-201 single-photon emission computed tomographic defects.
authors.affiliation: Department of Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: N M
authors.initials: NM
authors.lastname: Lakkis
authors.forename: Z X
authors.initials: ZX
authors.lastname: He
authors.forename: M S
authors.initials: MS
authors.lastname: Verani
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000503:physiopathology / Q000628:therapy; D016022:Case-Control Studies; D015331:Cohort Studies; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004562:Electrocardiography; D005080:Exercise Test; D005189:False Positive Reactions; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon; D016277:Ventricular Function, Left / Q000502:physiology
chemical_list: D013794:Thallium Radioisotopes