title: How many electrocardiographic leads are required for exercise treadmill tests?
abstract: Forty-four consecutive patients who had perfusion defects on thallium-201 scanning and positive exercise treadmill tests were prospectively studied. Thirty-eight (86%) subjects had diagnostic ST segment changes in lead V5, 37 (84%) in lead V4, and 44 (100%) in either lead V4, V5 or both. Thirty patients had ST segment changes in the inferior leads, 20 in lead aVR, and only four in lead I and/or aVL. All of these latter subjects had diagnostic ST segments in lead V4 and/or V5. It is concluded that: combined electrocardiographic leads V4 and V5 detect the vast majority of ischemic changes during exercise treadmill testing, regardless of the site of perfusion defects detected by thallium-201 scanning; and monitoring the inferior and lateral leads rarely provides more diagnostic information.
mesh_terms: D003327:Coronary Disease / Q000175:diagnosis* / Q000503:physiopathology; D004562:Electrocardiography / Q000379:methods*; D004566:Electrodes; D005080:Exercise Test / Q000379:methods*; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D009203:Myocardial Infarction / Q000175:diagnosis; D011868:Radioisotopes; D013793:Thallium
chemical_list: D011868:Radioisotopes; D013793:Thallium