ST segment depression with near-maximal exercise: its modification by physical conditioning.

Three hundred nine male insurance underwriters had near-maximal treadmill exercise tests following clinical evaluation. Thirty of the subjects developed ischemic type ST segment depression during or after exercise not associated with anginal pain. Thirteen of the ischemic responders participated in a supervised physical training program which led to increased exercise capacity. Four of these had reversion of the ischemic exercise ECG patterns to normal. Among those ischemic responders who did not train there was no improvement of exercise capacity yet two of these had reversion of ischemic ECG patterns to normal.