The clinical implication of the lack of hyperkinesis during dobutamine stress echocardiography (DSE) has not been determined. We hypothesized that a lack of hyperkinesis during graded doses of dobutamine infusion would reflect the severity of coronary flow abnormality distal to the stenosis and provide the functional significance of coronary arterial stenosis. The aim of the present study was to investigate the prevalence of the lack of hyperkinesis in patients with normal coronary arteries and to determine its value in patients with single-vessel disease. A total of 63 consecutive patients who subsequently revealed angiographically normal coronary arteries underwent DSE. Thirty-one consecutive patients with angina and single-vessel disease also underwent both DSE and exercise thallium single-photon emission computed tomography (SPECT). According to the response of wall motion during low and peak doses of dobutamine infusion, patients were divided into three groups (group A, hyperkinesis was present during both low dose and peak stress; group B, hyperkinesis was present only during low dose; group C, no hyperkinesis). SPECT images were divided into 16 segments, and thallium uptake at each segment was scored from 0 (normal) to 3 (severe defect). Thallium uptake score index (TSI) was calculated as total thallium score divided by 16 at stress and delayed image. The prevalence of group A, B and C was 56 (89%), 3 (5%), and 4 (6%) in patients with normal coronary arteries. The corresponding values were 11 (35%), 8 (26%), and 12 (39%) in patients with single-vessel disease (P < 0.0001). In patients with single-vessel disease, there was no significant difference in percent diameter stenosis (group A, 59% +/- 8%; group B, 69% +/- 16%; group C, 67% +/- 13%) and the prevalence of proximal stenosis (45%, 25%, and 42%) among three groups. However, TSI at stress image was significantly lower in group A (0.21 +/- 0.14) than in group B (0.45 +/- 0.20, P < 0.05) and group C (0.53 +/- 0.27, P < 0.01). TSI at delayed image was also significantly lower in group A (0.07 +/- 0. 11) than in group C (0.18 +/- 0.15, P < 0.05). Because the lack of hyperkinesis during DSE was observed in 11% of patients with normal coronary arteries, it does not always predict the presence of significant coronary artery stenosis. However, this finding related to the severity of perfusion abnormality by exercise thallium SPECT in patients with single-vessel disease. These results suggest that the lack of hyperkinesis during dobutamine infusion would predict functional significance of coronary arterial stenosis and provide myocardial perfusion status distal to the stenosis in patients with single-vessel disease.