ObjectiveTo investigate clinical outcomes of isolated atrial septal defect (ASD)repair on the beating or non-beating heart through minimally invasive right axillary approach. MethodsForty-five patients underwent isolated ASD repair through minimally invasive right axillary approach in Research Institute of Surgery, Daping Hospital of the Third Military Medical University from September 2009 to August 2011. According to different surgical techniques, all the patients were divided into a beating-heart group and a non-beating heart group. In the beating-heart group, there were 22 patients including 13 males and 9 females with their mean age of 3.2±2.1 years and body weight of 13.1±4.0 kg. There were 20 patients with ostium secundum ASD and 2 patients with ostium primum ASD. Mean ASD diameter in the beating-heart group was 12.2±5.1 mm. In the non-beating heart group, there were 23 patients including 14 males and 9 females with their mean age of 3.5±2.5 years and body weight of 12.9±3.3 kg. There were 18 patients with ostium secundum ASD, 3 patients with sinus venosus ASD, and 2 patients with ostium primum ASD. Mean ASD diameter in the non-beating heart group was 11.6±4.7 mm. Serum creatine kinase (CK), creatine kinase isoenzyme (CK-MB), aspartate aminotransferase (AST)and highly sensitive cardiac troponin I (cTnI)were examined preoperatively, after weaning from cardiopulmonary bypass (CPB), 6 hours and 24 hours postoperatively. ResultsThere was no in-hospital death. Postoperatively, 1 patient had right atelectasis and another patient had right pneumothorax. CPB time and operation time of the beating-heart group were significantly shorter than those of the non-beating heart group (P < 0.05). There was no statistical difference in intraoperative blood transfusion, mechanical ventilation time, length of postoperative ICU stay or hospital stay, chest drainage within 24 hours postoperatively, or postoperative cardiac function between the 2 groups (P > 0.05). Preoperative levels of CK, CK-MB, AST and cTnI were all within the normal limit, and there was no statistical difference between the 2 groups (P > 0.05). After CPB, CK, CK-MB, AST and cTnI levels increased in both groups, but increased significantly greater in the non-beating heart group (P < 0.05). Postoperative levels of CK, CK-MB, AST and cTnI of the beating-heart group were significantly lower than those of the non-beating heart group (P < 0.05). ConclusionIsolated ASD repair on the beating heart via minimally invasive right axillary approach is a safe and cosmetic procedure with shorter operation time and less myocardial injury.