Prospective identification of ventricular septal defects in infancy using subxiphoid two-dimensional echocardiography.

The objective of this study was to establish a dependable technique for imaging the interventricular septum and ventricular septal defects in infants. Subxiphoid two-dimensional echocardiograms were performed on 81 infants who were 1 day to 12 months (median 43 days) old and weighed 1.6-8.6 kg (median 3.4 kg). A short-focus, 5-MHz crystal with a 13-mm active element diameter was used in all studies. The interventricular septum was visualized in 80 of 81 infants. Defects in the membranous, atrioventricular canal, conoventricular and muscular segments of the sentum were identified using three standard transverse subxiphoid projections. All defects in the membranous and atrioventricular canal segments, as well as malalignment type conoventricular communications, were correctly identified when compared with selective angled cineangiocardiography. Only two of the three subpulmonic and four of 11 muscular defects were identified successfully. Limitations in imaging defects in the muscular septum reflected the varied morphology of these interventricular communications and the tangential orientation of the echo beam to the extreme apical and anterior segments of the muscular septum.