Mild atrial septal defects generally permit a normal life and do not easily cause colds. However, when pulmonary hypertension and heart failure occur with an atrial septal defect, it can lead to pulmonary congestion. At this point, bacterial colonization occurs, making respiratory infections more likely to develop. However, the colds we often refer to are upper respiratory tract infections, and atrial septal defects generally do not cause a decrease in immune system function.

However, if the upper respiratory tract infection is not treated promptly, it can lead to bronchitis, lung infections, etc., often exacerbating heart failure associated with the atrial septal defect. Therefore, while an atrial septal defect does not cause colds, patients with an atrial septal defect should address colds early to prevent the onset of heart failure triggered by the cold.