Background: Diastolic left ventricular (LV) abnormalities are sensitive early signs of myocardial ischemia. Ischemia-induced delay in the onset of regional relaxation has been demonstrated in the perfusion territory of the involved coronary artery in animal and clinical models. This study was designed to determine whether delayed regional relaxation is resolved after percutaneous intervention (PCI) in patients with stable angina. Methods: Thirty patients with stable angina going to PCI were involved. Two-dimensional speckle tracking echocardiographies were performed before and after PCI to evaluate regional myocardial tissue velocity and strain. We analyzed strain and tissue velocity of myocardium according to the territory of coronary arteries. Results: Sixteen patients were taken one vessel PCI and 14 patients were taken PCI at two vessels. Myocardial regions supplied by coronary artery with significant stenosis showed delayed onset of regional relaxation in strain (974 짹 436 ms vs. 725 짹 326 ms, p < 0.05) and tissue velocity (512 짹 352 ms vs. 386 짹 298 ms, p < 0.05) compared with normal myocardial regions. Post-PCI images showed significant shortness in the onset of regional relaxation after 24 hours from PCI (mean change 231 짹 195 ms, p < 0.05), but did not show the improvement in delayed relaxation immediately after PCI within 30 minutes. Conclusion: Delayed regional relaxation due to ischemia was not resolved within 30 minutes after PCI but resolved after 24 hours. Therefore the evaluation of diastolic function of ischemic myocardium to detect PCI effect should be performed after 24 hours from PCI due to diastolic stunning.