Ischemic preconditioning during successive exercise testing.

It was suggested recently that ischemic preconditioning can occur in clinical practice. We investigated this hypothesis in 26 patients with old myocardial infarction (MI) or stable angina pectoris, subjected to two successive exercise testings at 1 hour interval. The ST depression was significantly lesser during the second exercise testing (1.83 +/- 0.12 mm, vs 1.02 +/- 0.14 mm p < 0.01) at the same double product (DP) (24.877 +/- 1206 vs 24.711 +/- 1152 p > 0.05) and peak effort (76.92 +/- 6.63 w vs 75.96 +/- 6.27 w p > 0.05). The improvement was attributed to ischemic preconditioning.