Abstract

BACKGROUND Atrial septal defect (ASD) is a common congenital heart disease. OBJECTIVES The aim of this study was to assess the clinical course of ASD, as well as its frequency of spontaneous closure and regression of diameter. METHODS In a study conducted from 2000 to 2011, 192 consecutive patients with an isolated ASD were followed up regularly with periodic echocardiographic evaluations according to a standardized protocol. The study was conducted in two series of patients: infants and children and adults. Infants were classified into three groups based on ASD diameter: small (≤ 5 mm), medium (6 - 9 mm), and large (> 9 mm). In the same manner, the ASD size in children and adults was categorized into three groups: small (≤ 10), medium (10 - 20 mm), and large (> 20 mm). RESULTS The patients consisted of 76 (39.6%) males and 116 (60.4%) females. The mean age of patients at diagnosis was 16.12 ± 15.66 years (range 1 week - 75 years). The mean follow-up duration was 70 ± 9 months (range: 25 - 119 months). The most prevalent age group was adult patients (> 20 years), and most ASDs were of medium size (1 - 2 cm). The most common complication was mild pulmonary hypertension (31 cases, 16.2%), and Eisenmenger phenomenon was the rarest complication (2 cases, 1%). Overall spontaneous closure of ASD occurred in 42 (21.9%) cases. Spontaneous closure in cases with small defects occurred in 18 of 22 (81%) infants and 24 of 81 children > 1 years of age. Regression of ASD size occurred in 2 (9.5%) infants and 3 (3.7%) children. No spontaneous closure was observed in cases with a defect size > 10 mm, and no spontaneous occlusion was detected in adolescents or adults. Seventy-two percent (n = 139) of patients needed surgical repair or transcatheter closure of the ASD. CONCLUSIONS It is concluded that atrial septal defects < 6 mm typically close spontaneously, and ASDs measuring 6 - 9 mm may regress in infants and children. An ASD > 1 cm has little chance of spontaneous closure and may need surgical or device closure. ASD diameter and age at diagnosis are the most important predictors of spontaneous closure and the need for possible surgical or device closure.