Objectives: To describe the clinical and subclinical characteristics and evaluate the early results after simple atrial septal closure surgery in children weighing less than 10 kg at the Cardiovascular Centre – E Hospital.

Subjects   and   Methods: Retrospective descriptive study, from January 2015 to July 2020, we surgery closure of isolated ASD in children with procedural weight less than 10 kg for 50 patiens. Mean age 16.14 ± 8.35 months (3 – 38 months), average age 7.8 ± 1.73 kg (3.5 – 10 kg).The patient was evaluated clinically and subclinically (electrocardiogram (ECG), chest X-ray and echocardiography) upon admission to the hospital. At the time of hospital discharge, the child was evaluated for clinical, ECG and echocardiography return to assess the effectiveness of early post-closure of the ventricular fibrillation.

Results: History: slow weight gain (78.0%), fatigue on exertion (40.0%), recurrent pneumonia (36.0%), 16.0% of patients had no symptoms and the disease was detected only once. By chance; 14% of patients had congenital malformations other than heart, Down syndrome was the most common (8.0%). Preoperative clinical: 56.0% of patients are malnourished, mainly with mild malnutrition (36.0%); cardiac examination with asystolic murmur was the most common symptom (94.0%), strong T2 split (32.0%); heart failure degree: 52% of patients had heart failure, mild heart failure 46.0%. Subclinical: EGG shows increased right ventricular load (84.0%), right axis (68.0%) and incomplete right bundle branch block (50.0%); straight chest x-ray showed increased pulmonary circulation (90.0%), enlarged heart (48.0%), enlarged pulmonary artery arch (28.0%); Echocardiography: 100% EF normal; 100% large size vents (mean 15.8 ± 3.72 mm.); 96.0% secondary atrial septal defect; mean asystolic pulmonary artery pressure was 29.3 ± 12.88 mmHg, 38% increased slightly and moderately, 4.0% increased seriously; TP/TT diameter ratio increased by 98.0% (Mean: 0.84 ± 0.21), mainly slightly to moderate (60.0%). After the closure of the atrial septal defect, the clinical and laboratory symptoms improved almost completely compared with before surgery (p < 0.001). Complications: Two patients had the very small residual shunt. 2 patients had postoperative bleeding, no patient had arrhythmia, cerebrovascular accident and died.

Conclusion:   Although atrial septal defect is recognized as a congenital heart disease with slow progression, complications often occur late, but in fact we found that the disease can cause early complications such as slow weight gain, recurrent pneumonia. Chronic disease, malnutrition, heart failure, early pulmonary hypertension account for a large number and require early surgical intervention. Surgery to close the atrial septal defect in children under 10 kg is a safe and highly effective method. After closure of the stoma, especially at a young age, the early disease stage helps to reduce the rate and severity of complications as well as increase the effectiveness of clinical and subclinical improvement for children soon after surgery card.