Echocardiographic criteria for normal newborn infants.

Echocardiograms were obtained from 200 normal newborn infants ranging from 6 to 10 pounds in weight and from 10 to 72 hours in age. A continuous recording technique is described employing a 5 MHz transducer. Criteria have been established for a normal echocardiographic profile in the full-term neonate. This profile consists of obtaining quantitative measurements of mitral valve excursion and velocity, tricuspid valve excursion and velocity, pulmonary artery diameter, aortic root diameter, left atrial diameter, and interventricular septal thicknesses. In addition, qualitative assessment is made of the septal contour, position of the aortic root to pulmonary artery, continuity of mitral valve with posterior aortic root, and continuity of tricuspid valve with anterior aortic root. No correlation was found between the magnitude of any one parameter and either body surface area or weight. The establishment of normal echocardiographic criteria for the newborn may be expected to significantly facilitate application of this noninvasive technique to infants born with congenital heart disease.