[The clinical significance of exercise-induced ST segment elevation in patients with previous myocardial infarction].

To define the clinical significance of exercise-induced ST-segment elevation, exercise thallium-201 scintigraphy (Ex-Tl), left ventriculography and coronary arteriography were performed in 19 patients with anterior infarction less than 3 months previously. Seven of the 19 patients showed redistribution by Ex-Tl and underwent percutaneous transluminal coronary angioplasty (PTCA). In these 7 patients, exercise-induced ST-segment elevation disappeared after successful PTCA. The average VO2 max was unchanged, but the pressure rate products improved from 270.8 +/- 83.2 to 314.8 +/- 51.4 x 10(2) (p less than 0.05). The defect score in Ex-Tl improved from 14.1 +/- 4.5 to 4.7 +/- 4.2 (p less than 0.01), but ejection fraction and segmental-area change were unchanged. These findings suggest that exercise-induced ST-segment elevation in patients with previous myocardial infarction showed re-distribution by Ex-Tl related directly to myocardial ischemia rather than to wall-motion abnormality.