MORPHOLOGICAL FEATURES OF THE LEFT ANTERIOR DESCENDING CORONARY-ARTERY AS REVEALED BY HIGH-FREQUENCY TRANSTHORACIC ECHOCARDIOGRAPHY IN NORMAL SUBJECTS

This report describes the normal echocardiographic coronary wall featu res of the mid and apical segments of the left anterior coronary arter y in 30 normal subjects as revealed by high-frequency transthoracic ec hocardiography. Both mid and apical segments were imaged in all subjec ts in short and long axis orientation. Their greatest length (as seen within the sector of a single frame) was respectively 21 +/- 6 and 17 +/- 5 mm, and the diameter and circumference were respectively 2.3 +/- 0.4 and 6.7 +/- 1 mm in the mid and 2.0 +/- 0.1 and 6.5 +/- 1 mm in t he apical segment. In all subjects, the arterial wall was imaged as a smooth and regular echoreflective linear structure. In the mid segment of the 16 most echogenic subjects (53%), we distinguished a three-lay ered wall with a very thin and apparently noncontinuous line adjacent to the lumen, which was separated from the more echoreflective linear echo by a hypoechogenic space. A homogeneous red color-coded flow, fil ling the arterial lumen, was found in 14 of the 30 subjects (46%), in 8 of whom a spectral flow signal was also detected. These preliminary findings indicate that, in the near future, this method could become a n effective part of the noninvasive armamentarium for the evaluation o f coronary vessels and with further technological advances (e.g. an in crease in carrier frequency) the quantitative noninvasive data concern ing the thickness of the coronary wall may become a real possibility.