title: Association of ventricular ectopy with nuclear scintigraphic perfusion defects during dipyridamole stress testing.
abstract: OBJECTIVE
  No information is available regarding the significance of ventricular ectopic activity induced during dipyridamole nuclear scintigraphic stress testing. This study tested the hypothesis that dipyridamole-induced ventricular ectopy predicts a thallium-201 or technetium-99m sestamibi perfusion defect.
  
  
  METHODS
  A group of 186 consecutive patients with premature ventricular contractions and/or couplets occurring during dipyridamole stress testing (ventricular tachycardia did not occur) was compared with a control group of 194 patients without ventricular ectopy during dipyridamole stress testing.
  
  
  RESULTS
  The results indicated that ventricular ectopy induced during dipyridamole infusion occurred more frequently in patients demonstrating either a fixed or reversible perfusion defect on scintigraphic imaging (p < 0.01). The higher frequency of perfusion defects in this group of patients was attributable to a higher frequency of "fixed" compared with "reversible" defects (p < 0.05). This finding is consistent with the additional observation that ventricular ectopy induced by dipyridamole was associated with the presence of Q waves on the resting ECG (p < 0.05). The positive and negative predictive values of the presence of ventricular ectopy in predicting a fixed myocardial perfusion defect were 59 and 54%, respectively.
  
  
  CONCLUSIONS
  Ventricular ectopy induced during dipyridamole infusion suggests the presence of a fixed myocardial perfusion defect.
authors.affiliation: Department of Medicine, Rush Medical College, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Rabin
authors.forename: A
authors.initials: A
authors.lastname: Ali
authors.forename: J T
authors.initials: JT
authors.lastname: Barron
mesh_terms: D000368:Aged; D004176:Dipyridamole / Q000008:administration & dosage / Q000009:adverse effects*; D004562:Electrocardiography; D005080:Exercise Test / Q000009:adverse effects / Q000379:methods; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000009:adverse effects*; D018879:Ventricular Premature Complexes / Q000139:chemically induced* / Q000503:physiopathology
chemical_list: D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D014665:Vasodilator Agents; D004176:Dipyridamole; D017256:Technetium Tc 99m Sestamibi