Morphometry of coronary arteries: its use in children 1 year of age or older.

Coronary arteries from 52 children were cross-sectioned semiserially at 0.2-mm intervals. The sections that showed the greatest intimal thickening were chosen for morphometric analysis, which was performed with the aid of a coordinate digitizer. The size of the arteries, the thickness of the arterial media and intima, and the cross-sectional areas of the arterial layers correlated closely with the patient's age with various body measurements, and with the anatomic dimensions of the arteries. The variation in the cross-sectional area of the media in the left anterior descending branch was almost completely explained by a stepwise regression model; the fraction explained by the model (ie, multiple correlations squared) was 0.96, which means that very little variability was due to other factors, eg, methodologic errors. This suggests that the method is reliable. With an exact method, a smaller sample is adequate, which will ease obtaining normal growth curves for coronary arteries.