An atrial septal defect (ASD) is a hole between the upper heart chambers. It allows blood from the left sided heart chambers to cross back to the right sided heart chambers and then the blood is pumped back to the lungs. If an ASD is large enough, and the inefficient blood flow occurs for long periods of time, then the right sided heart chambers enlarge. In older children and adolescents with large ASDs (and 2.5 cm would be large) it is common for them to experience shortness of breath with activity, and exercise intolderance. Some patients get palpitations and tachycardia related to the stretched cardiac chambers. You are correct that chest pain is not typically associated with atrial septal defects. However, there are many causes of chest pain in children, most of which are not cardiac in nature, including musculoskeletal pain, exercise induced asthma and inflammation of the chest wall. So your child's chest pain may not even be due to the atrial septal defect. Some ASDs occur in conjunction with other structural abnormalities of the heart, so your child's cardiologist will need to check for other associated heart problems. If your child's chest pain mainly occurs with physical activity, then an exercise stress test may be indicated to try to reproduce your son's pain and see what the cause might be.
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