Elucidation of the natural history of ventricular septal defects by serial Doppler color flow mapping studies

Two-dimensional echocardiography has provided information to aid in the diagnosis and management of infants with ventricular septal defect, but its inability to resolve very small ventricular septal defects and problems with defining ventricular septal defect orifice size (because of overlying muscle or tricuspid tissue) have made it unsuitable as a standard for defining the natural history of ventricular septal defect. In this study, 114 serial two-dimensional Doppler color flow mapping studies were performed to define ventricular septal defect anatomy, location and color flow diameter as an indicator of shunt size in 66 patients (over a 40 month period). Twenty-five patients first studied at 6 months of age (mean age at most recent study 15.9 months) had congestive heart failure and 41 (mean age 45 months) did not. In the congestive heart failure group, there were 24 perimembranous and 1 muscular ventricular septal defect and aneurysm formation was present in 17. Mean (±SD) color flow diameter was 8.2 ± 1.9 mm and color flow diameter/aortic root diameter ratio was 0.63. In the 30 patients who underwent cardiac catheterization, color flow diameter bore a close relation to angiographic diameter (r = 0.96) and pulmonary/systemic flow ratio (Qp/Qs) (r = 0.88). In the patients with congestive heart failure, 4 of the 25 ventricular septal defects, all with aneurysm present or positioned adjacent to the tricuspid valve, became smaller but none closed. Of the 41 patients without congestive heart failure, 21 had a perimembranous defect (15 with aneurysm), 18 had a muscular ventricular septa) defect and 2 had a supracristal ventricular septal defect. Mean color flow diameter was 3.9 ± 1.7 mm, and color flow diameter/aortic root ratio was 0.27 (both p < 0.05 compared with values in the congestive heart failure group). Follow-up Doppler color flow map studies of the noncongestive heart failure group showed that 4 of 21 perimembranous defects and 6 of 18 muscular defects had closed, whereas 4 perimembranous and 3 muscular defects showed significant diminution in color flow diameter. Two-dimensional echocardiography and color flow mapping diameter observations aid in predicting which patients with a ventricular septal defect might develop congestive heart failure, and suggest which ventricular septal defects will become smaller or close spontaneously.