Clinical Course of the Ostium Secundum Atrial Septal Defect(ASD) and Its Rate of Spontaneous Closure

Kim, Dae Yong; Hyun, Myung Chul; Lee, Sang Bum

Abstract

PURPOSE
To know the natural course of the ostium secundum ASD including its rate of spontaneous closure.
METHODS
We studied 259 cases who were diagnosed as ostium secundum ASD by 2D-echocardiography at Department of Pediatrics, Kyungpook National University Hospital between Jan. 1985 and Dec. 1994. According to the age at diagnosis, we divided them into two groups, group I (those diagnosed before 1 month of age: 59 cases) and group II (those diagnosed after 1 month of age: 200 cases)
RESULTS
Mean age at first diagnosis was 2.6+/-4.6 years and mean defect size(diameter by 2D-echocardiography) was 9.9+/-8.0 mm. Cardiac murmur was the main reason to refer the patients to hospital, being in 50 cases(87%) in group I, 179 cases(90%) in group II. Defect sizes were significantly small in group I compared with group II (5.3+/-3.4 mm vs 11.1+/-6.9 mm, p<0.05). Symptoms corresponding to congestive heart failure were present in 16 cases of group I (27%)( isolated ASD: 8 cases, ASD accompanying with PDA: 5 cases, ASD accompanying with VSD: 2 cases, ASD accompanying both PDA and VSD : 1 case) and in 27 cases of group II(13.5%) (isolated ASD: 17 cases, ASD accompanying with VSD: 4 cases, ASD accompanying with PDA: 4 cases, ASD accompanying both PDA and VSD: 2 cases). Of total 139 cases, spontaneous closure of ostium secundum ASD was documented in 14 cases(10.1%) by follow up 2D-echocardiography. The rate of spontaneous closure was significantly high in group I compared with group II (6 cases: 37.5% vs 8 cases: 6.5%, p<0.05) Comparing with those cases without closure, there were no significant differences in defect size in group I but significant differences in group II(p<0.05), being 5.63 2.62 mm in cases with spontaneous closure and 12.82 7.09 mm in those cases without closure. Of the 9 cases with atrial septal septal aneurysm, 2D- echocardiographic follow ups were possible in 5 cases with spontaneous closure in 2 (40%).
CONCLUSIONS
Spontaneous closure was documented in 10.1% of all the patients with ostium secundum ASD. Especially the closure rate was significantly high in those cases their diagnosis was made before 1 month of age and with atrial septal aneurysm.