Color Doppler Echocardiographic Study on the Incidence and Natural History of Early-Infancy Muscular Ventricular Septal Defect

Background: Most small muscular ventricular septal defect (M-VSD) types have been diagnosed using color Doppler echocardiography. The purpose of this study was to understand the incidence of small M-VSD in the neonatal period and analyze the natural history of these M-VSDs. Materials and Methods: All individuals in our study were neonates delivered at term who had a normal healthy appearance. Each accepted neonate had an examination with complete color Doppler echocardiography once before discharge. If the examination was confirmed for M-VSD, the study participants were then classified according to defect type. Further examination was arranged with color Doppler echocardiography at 1 month, 2 months, 4 months, 6 months, 9 months, and 12 months of age or until there was complete spontaneous closure. Results: Among 2891 neonates, we found that 72 (24.9/1000) were diagnosed with M-VSD. Among this group, 38 were male and 34 were female. Only six infants were lost to follow-up. Fifty-four of the 66 infants (81.8%) had M-VSD closed spontaneously at 12 months' follow-up. Significantly, 33 of 37 infants (89.2%) with mid-muscular type, the most common type of M-VSD, closed within the 1(st) year of life compared with apical type (17/24:70.8%). Four of the five infants (80%) had anterior type M-VSD closed. Infants with posterior type M-VSD were not seen during this study period. Conclusion: Although the incidence of M-VSD was common in the neonatal period, there was also a high rate of spontaneous closure. Therefore, comparison of M-VSD appearance with the incidence of congenital heart disease in neonates had a decisive influence on analysis. Copyright (C) 2011, Taiwan Pediatric Association. Published by Elsevier Taiwan LLC. All rights reserved.