title: Influence of exercise intensity on the presence, distribution, and size of thallium-201 defects.
abstract: The effects of two levels of exercise intensity on the size and location of thallium-201 defects were compared in 22 patients with known ischemic coronary artery disease. A symptom-limited incremental exercise test was performed followed (greater than 48 hours) by submaximal steady-state exercise at 70% of the peak heart rate achieved during the incremental test. Planar thallium-201 myocardial scans obtained after each protocol were analyzed by means of both visual qualitative and computerized quantitative methods. After incremental exercise all patients exhibited reversible thallium-201 defects, and submaximal exercise still resulted in reversible defects in 20 (91%) patients. However, the size of the ischemic area and the degree of ischemia were significantly reduced by both qualitative and quantitative criteria after submaximal exercise. Therefore interpretation of thallium-201 scans with regard to severity of disease and prognosis should take into account exercise intensity.
authors.affiliation: Department of Medicine (Division of Cardiology, Human Performance Laboratory), Memorial Hospital of Rhode Island, Pawtucket 02860.
authors.forename: G V
authors.initials: GV
authors.lastname: Heller
authors.forename: I
authors.initials: I
authors.lastname: Ahmed
authors.forename: P L
authors.initials: PL
authors.lastname: Tilkemeier
authors.forename: M M
authors.initials: MM
authors.lastname: Barbour
authors.forename: C E
authors.initials: CE
authors.lastname: Garber
mesh_terms: D001794:Blood Pressure; D003327:Coronary Disease / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D004562:Electrocardiography / Q000706:statistics & numerical data; D005080:Exercise Test / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006339:Heart Rate; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D015999:Multivariate Analysis; D010100:Oxygen / Q000502:physiology; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes
chemical_list: D013794:Thallium Radioisotopes; D010100:Oxygen