[Transesophageal Doppler echocardiographic imaging and blood flow measurements for the diagnosis of stenotic left coronary arteries].

To evaluate the usefulness of transesophageal Doppler echocardiography (TEE) in diagnosing left coronary artery (LCA) stenosis, we studied 26 patients with 33 proximal LCA lesions, including 5 with lesions of the left main trunk (LMT), 21 proximal anterior descending arteries (LAD), 7 proximal circumflex arteries (LCx), and 20 with normal coronary arteries. We measured blood flow velocity along the LCA using the pulsed Doppler mode (PD) and obtained velocities at multiple neighboring sites in 13 normal coronary arteries and in 12 of 26 LMTs or LADs with lesions. In all 13 normals, peak velocity tended to decline towards the periphery. By contrast, in one LMT and 10 LADs with lesions, marked increase in peak velocity (1.7 to 3.9 times) was observed at the sites diagnosed as stenotic lesions by coronary angiography. Using two-dimensional echocardiography (2DE), 24 LMTs including 3 with lesions, 4 LADs including 3 with lesions and 13 LCxs including 4 with lesions were imaged. Among them, 3 LMT, one LAD and 2 LCx lesions were correctly diagnosed. The diagnostic ratio by both PD and 2DE was 60% for LMT (PD: 20%, 2DE: 60%), 48% for LAD (PD: 48%, 2DE: 5%) and 29% for LCx (PD: 0%, 2DE: 29%) lesions. In conclusion, TEE proved to be useful in diagnosing proximal LCA stenosis. The coronary flow measurement by PD especially has the potentiality for the diagnosis of proximal LAD stenosis.