Background: Transthoracic Doppler echocardiography(TTDE) examination can detect coronary artery and can evaluate coronary circulation by analyzing coronary flow pattern. While previous studies reported use of TTDE in evaluating the distal coronary artery, few studies have evaluated the proximal coronary artery. Then, we applied the TTDE for evaluation of the proximal portion of left coronary artery in patients with angina pectoris(AP).
Methods: Eighty patients with AP were enrolled in this study, and they underwent both coronary angiography(CAG)and TTDE. A modified short-axis view was utilized to identify left main and proximal left anterior descending artery(LAD). After searching for localized aliasing with color Doppler echocardiography, coronary flow velocities were measured at the alias site or the normal site.
Results: Visualization of the left main and the proximal LAD was possible in 65(81%)of the 80 patients. Mean length 19mm of the proximal LAD could be recorded in 65 patients. Localized aliasing was detected in 14 patients. The diastolic peak flow velosity was significantly higher in the alias site than in the normal site(105±40 vs 35±15 cm/sec,p<0.001). Localized aliasing by TTDE had a sensitivity of 92% and a specificity of 94% for the detection of significant coronary artery stenosis(≧75%) by CAG.
Conclusion: TTDE could detect and evaluate proximal left coronary aretry stenosis directly. TTDE is a useful non-invasive tool for predicting proximal left coronary artery stenosis in patients with AP.