Evaluation of left coronary artery anatomy in vitro by cross-sectional echocardiography.

This study was undertaken to provide a better anatomic description of the location and course of the left coronary artery within a commonly used ultrasonic tomographic plane. Twenty-three hearts were excised at autopsy and scanned in vitro. The locations of the left main (LMCA), left anterior descending (LAD), and left circumflex (LCCA) coronary arteries were confirmed by direct cannulation, by Cardio-Green injection, and by subsequent dissection. While the proximal LMCA was recorded in all specimens, the entire LMCA was visible in only 70%. Proximal portions of the LAD and LCCA were also identifiable in 70% of examinations, and their spatial positions were defined. In most recordings, the first branch of the LAD OR LCCA arose distal to the segment seen echocardiographically. The spatial orientation of the ultrasonic beam relative to the LAD and LCCA and the presence of other overlying cardiac structures limit the imaging of these vessels by cross-sectional echocardiography to only their most proximal portions.