Caliber and distribution of normal coronary arterial anatomya

Selective coronary arteriograms of 125 patients with normal coronary arteries were reviewed to establish the caliber and distribution of normal coronary arterial anatomy. Measurements established the following normal values for coronary arterial caliber in right (R), mixed (M), and left (L) inferior emphasis systems expressed in mm (± SEM): R M L Main left coronary artery 4.7 ± 0.1 5.2 ± 0.2 5.0 ± 0.2 Proximal left anterior descending artery 3.9 ± 0.1 4.1 ± 0.2 3.8 ± 0.2 Mid‐left anterior descending artery 2.3 ± 0.1 2.4 ± 0.1 2.5 ± 0.1 Left circumflex artery 3.2 ± 0.1 3.8 ± 0.2 4.0 ± 0.2 Proximal right coronary artery 4.1 ± 0.1 3.7 ± 0.1 2.7 ± 0.1 Mid‐right coronary artery 3.4 ± 0.1 2.7 ± 0.1 1.9 ± 0.1 S gnificant differences in the caliber of right coronary arterial systems and left circumflex coronary arterial systems validate the separation of coronary arterial anatomy into right, mixed, and left inferior emphasis systems, depending upon the blood supply to the inferior wall of the left ventricle. Classification of the anatomical pattern into right, mixed, and left inferior emphasis systems is useful in the cardiac catheterization laboratory at the time of selective coronary arteriography. If the expected distribution of the coronary vessels is not found, then missing vessels must be sought out. A knowledge of the range of normal size for the coronary arterial tree should be of value in defining the severity of coronary arterial narrowing.