This study investigated the effects of percutaneous coronary intervention (PCI) on global and regional left ventricular diastolic function, as assessed by strain rate (SR) imaging. In 27 patients with coronary artery disease, we performed echocardiography before and after PCI to obtain segmental peak systolic SR and peak early diastolic SR (E(SR)). PCI did not significantly change peak systolic SR in the ischemic (1.59 +/- 0.59-1.66 +/- 0.52/s) and nonischemic (1.64 +/- 0.59-1.61 +/- 0.53/s) segments. E(SR) in the ischemic segments was significantly smaller than that in the nonischemic segments at rest (1.82 +/- 0.71 vs 2.03 +/- 0.64/s, P < .01). PCI caused a significant increase in E(SR) from 1.82 +/- 0.71 to 2.29 +/- 0.92/s in the ischemic (P < .001), but not in the nonischemic, segments. The peak early diastolic transmitral flow velocities after PCI were improved in patients with greater extent of improvement of E(SR) in the ischemic segments. These findings suggest that the improvement in left ventricular early diastolic filling after PCI may be associated with the degree of improvement in impaired regional myocardial relaxation.