Doppler echocardiographic atrial pacing stress tests were performed in 23 patients with coronary artery disease (CAD) and 35 normal subjects. It was found that the peak flow velocity (PFV) through the mitral valve decreased at 160 beats per minute (BPM) during pacing in the CAD group (P less than 0.01), but no significant variation was seen in the normal group. No differences between the two groups were observed in 1/3 filling fraction (1/3 FF), total diastolic filling period (DFP) and the ratio of early diastolic filling period (EDFP) to DFP before pacing. However, 1/3 FF and DFP decreased and EDFP/DFP increased immediately following rapid pacing in the CAD group but did not change in the normal group (P less than 0.05, 0.01, and 0.001 respectively). The peak flow velocity during atrial contraction (APFV), time velocity integral during atrial contraction (ATVI) and the ratio of ATVI to total TVI (ATVI/TTVI) increased immediately following pacing in the CAD group. Using two of three indices--ATVI/TTVI more than 0.35, ATVI increase and 1/3 FF decrease immediately following pacing--as diagnostic criteria for CAD, the sensitivity was 86% and the specificity was 77%. It may be concluded that the Doppler echocardiographic atrial pacing stress test is a feasible and reliable method for detecting CAD.