Spontaneous Closure of Secundum Atrial Septal Defect in Neonates: An Evaluation by Color Doppler Echocardiography and the Result s of a 1-Year Follow- Up

Background and Hypothesis: This is a follow-up study from 2005-2007 to know the natural course of the ostium secundum ASD including its rate of spontaneous closure in neonatal period. Patients and Methods: 45 patients enrolled in this study, defects of diameter between 4 to 5mm were considered to be small, and 33 patients had such defects. Medium sized defects were judged to be between 6 and 8mm, with 12 patients fulfilling this criterion. Results: 80% (n=16) of small ASD of 4mm in diameter, 46% (n=6) of 5mm ASD closed spontaneously, 6 out of 33 (18%) were completely closed in group one. Patients in group two, 17% (one out of 6) with 6mm in diameter closed spon- taneously, its size ≤3mm in diameter. Regarding to 7-8mm in diameter 50% remained the same size and 25% (n=3) increase in size, one of these increase ≥2mm in diameter. ASD enlarged in 3 cases, none of these three cases had small defect to begin with. Conclusions: We conclude that defects smaller than 6mm in diameter are very likely to close spontaneously although follow-up is necessary. Moderate size ASD had a lesser chance to close. Recommendations: Cases with ASD 3mm do need to be followed until the defect closes completely. Those with moderate sized ASD should be followed-up regularly, because these defects can remain open.