title: ST-segment depression during dipyridamole infusion, and its clinical, scintigraphic and hemodynamic correlates.
abstract: The goal of this study was to determine whether dipyridamole-induced ST-segment depression reflects more severe or extensive myocardial hypoperfusion than the absence of this electrocardiographic finding. The clinical, hemodynamic and scintigraphic correlates of ST-segment depression during intravenous dipyridamole infusion were studied in 204 consecutive patients undergoing dipyridamole stress thallium-201 (Tl-201) imaging for evaluation of coronary artery disease. Of 182 patients with a diagnostic baseline electrocardiogram, 28 (15%) developed ST depression after dipyridamole. Patients with ST depression, compared with those without, were older (64 +/- 1 vs 60 +/- 1 years; p less than 0.03) and had a higher frequency of chest pain (57 vs 23%; p less than 0.001) and a higher heart rate-blood pressure product (12.7 +/- 0.6 vs 11.2 +/- 0.2 x 10(3); p less than 0.008) after dipyridamole. Patients with ST depression were more likely to have Tl-201 redistribution (64 vs 38%; p less than 0.02) and a greater number of redistribution defects (2.3 +/- 0.04 vs 0.9 +/- 0.1, p less than 0.001) than were those without ST depression. By multivariate logistic regression analysis, the most powerful correlate of ST depression was the number of segments having Tl-201 redistribution (p less than 0.001). Other independent correlates were presence of chest pain, heart rate at Tl-201 injection, and age. Thus, the determinants of dipyridamole-induced ST-segment depression include the scintigraphic extent of reversible hypoperfusion, as well as indexes of myocardial oxygen demand.
authors.affiliation: Department of Internal Medicine, University of Virginia Health Sciences Center, Charlottesville 22908.
authors.forename: F S
authors.initials: FS
authors.lastname: Villanueva
authors.forename: W H
authors.initials: WH
authors.lastname: Smith
authors.forename: D D
authors.initials: DD
authors.lastname: Watson
authors.forename: G A
authors.initials: GA
authors.lastname: Beller
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001794:Blood Pressure / Q000187:drug effects; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004176:Dipyridamole; D004562:Electrocardiography / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007262:Infusions, Intravenous; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes
chemical_list: D013794:Thallium Radioisotopes; D004176:Dipyridamole