title: QRS prolongation measured by a new computerized method: a sensitive marker for detecting exercise-induced ischemia.
abstract: This study compared thallium stress testing and exercise changes in QRS duration using a computerized 'optic scanner' in three groups. Group 1 consisted of 108 subjects with positive exercise ECG tests by ST-T segment criteria and with proven coronary artery disease. Group 2 included 19 subjects with nondiagnostic exercise ECG ST-T changes and with proven coronary artery disease. Group 3 was formed by 38 healthy controls. Group 1: Mean increase in exercise QRS width of 12.4 +/- 14 ms. Group 3: Mean decrease in exercise QRS width of 4.9 +/- 9.3 ms (p < 0.0001). Group 2: Mean QRS prolongation of 7.8 +/- 9.2 ms, which was significantly different from the controls (p < 0.0001) but not from group 1. When compared to thallium stress testing, exercise QRS prolongation had a sensitivity of 93%, specificity of 71%, relative risk of 5, and positive predictive value of 86%. QRS duration measurement can improve the diagnostic accuracy of the exercise ECG stress test.
authors.affiliation: Exercise Testing Unit, Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Cantor
authors.forename: B
authors.initials: B
authors.lastname: Goldfarb
authors.forename: A
authors.initials: A
authors.lastname: Aszodi
authors.forename: A
authors.initials: A
authors.lastname: Battler
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017023:Coronary Angiography; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D011237:Predictive Value of Tests; D011877:Radionuclide Imaging; D011897:Random Allocation; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted; D013794:Thallium Radioisotopes
chemical_list: D013794:Thallium Radioisotopes