Exercise stress testing in the patient with coronary artery disease. Part I

Treadmill cardiac stress tests have a number of well known, identifiable criteria for positivity. One that is less known and thus often not appreciated, is the appearance of an inverted U wave in the left chest leads at the peak of exercise. This, even as an isolated finding, indicates a positive test. Of clinical significance is that this electrocardiographic response to a stress test is associated with an isolated lesion of the left anterior descending coronary artery.