Association of ventricular ectopy with nuclear scintigraphic perfusion defects during dipyridamole stress testing.
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.
Rabin
D L
DL
Department of Medicine, Rush Medical College, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612, USA.
Ali
A
A
Barron
J T
JT
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
D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D014665:Vasodilator Agents; D004176:Dipyridamole; D017256:Technetium Tc 99m Sestamibi