Nowadays the anatomy and coronary flow can be evaluated by means of various methods requiring cardiac catheterization. Transesophageal echocardiography is a new diagnostic method with great potential (excellent technical quality, stable positioning of the transducer, no lung interposition). Because of its potential we have used transesophageal echocardiography on a number of patients undergoing coronary angiography in order to investigate its reliability in estimating the anatomy and coronary flow. From the anatomical point of view 3 aspects were identified: absence of alterations affecting the vessel being explored (Criterion A); presence of non-stenotic calcific wall plaques (Criterion B); presence of stenotic calcific plaques (Criterion C). The percentage of visualization of the left main artery, the left anterior descending and the circumflex was 87%, 78% and 76% respectively. The criteria described showed varying reliability depending on the coronary portion being considered. Using the pulsed Doppler, during the transesophageal study, we obtained an adequate recording of the velocity profile of the left anterior descending in 28/37 patients. After dipyridamole infusion all velocity parameters (diastolic and systolic mean and maximum velocities) increased significantly in those patients with left anterior descending without stenosis, while remaining practically constant in those patients with significant stenosis of the left anterior descending artery. In particular the ratio between the maximum diastolic velocity recorded after dipyridamole and the velocity recorded immediately before infusion was significantly greater in those subjects with normal left anterior descending than in those with significant stenosis of the left anterior descending artery.
Conclusions: transesophageal echocardiography offers new prospects in studying anatomic alterations and flow patterns of the proximal part of the left coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)