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Updated: Jul 29, 2026

Ultrasound Assessment of Endothelial-Dependent Flow-Mediated Vasodilation of the Brachial Artery in Clinical Research
Published on: October 22, 2014
Normal left main coronary artery diameter can be predicted from diameters of its branch vessels
1Division of Cardiovascular Medicine, School of Medicine, University of California, Davis, Sacramento 95817, USA.
Abstract:
An uncommon though vexing problem exists when the left main coronary artery appears subjectively to be diffusely stenotic relative to its branch vessels, but the severity of such stenosis cannot be determined because of the lack of a normal reference. To overcome this problem, 20 coronary angiograms demonstrating no evidence of disease were quantitatively analyzed to determine the normal ratio of left main diameter to the sum of the diameters of its immediate branches. For bifurcating left mains, the mean ratio of diameter of left main to sum of diameters of its two immediate branches was 0.65 +/- 0.04; for trifurcating left mains, the mean ratio of diameter of left main to sum of diameters of its three immediate branches was 0.56 +/- 0.02. Thus, it appears feasible and practical to predict the normal diameter of the left main from the measured diameters of its immediate branches.
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