Sudden death after myocardial infarction and T-wave changes in connection with exercise testing

Exercise testing-induced T-wave changes in lead CH6 were analysed after acute myocardial infarction. In 21 patients with subsequent sudden death the mean +/- SD T-wave amplitude at supine rest 5 minutes after exercise was -2.74 +/- 2.37, in 26 patients with non-sudden death -1.08 +/- 2.67, and in 23 patients who survived +0.44 +/- 2.26 mm. Differences between groups were statistically significant. Within the sudden death group and in patients who survived the T-wave was lower (p less than 0.05) after exercise than before exercise. In the non-sudden death group, however, the T wave depth was about the same before and after exercise. The pattern of T-wave changes in the sudden death group was similar to the primary, "vasoregulatory" T-wave changes in young men and, accordingly, enhanced sympathoadrenal activity could be involved.