Master Two-Step Test in Coronary Artery Disease

The Master two-step test is a standardized exercise that permits the making of an electrocardiogram immediately after the activity terminates. The main criterion of the result is the behavior of the S-T segment of the tracing; depression of more than 0.5 mm. in any lead is considered a positive result. The test was applied to 186 patients known to have either angina pectoris or a healed myocardial infarction. By the criterion of ischemic S-T segment depression alone the test was positive in 61.3%; when Master's other criteria were also imposed, the test was positive in 81.7%. The test was applied further to 108 normal persons. By the criterion of ischemic S-T segment depression alone the test was negative in all; when Master's other criteria were also imposed, the test was positive in 19.4%. While a negative result does not exclude coronary insufficiency, a positive one strengthens the diagnosis of suspected coronary disease. Although the only conclusive evidence of coronary insufficiency is believed to be ischemic S-T segment depression, fewer cases escaped detection when all of Master's criteria were utilized. When sound clinical judgment is employed in conjunction with the test, overdiagnosis is infrequent.