Dear scottishmum: If your son has been acting well and growing appropriately , the chances of him having a congenital heart abnormality that would result in him turning blue at times is extremely small. It is particularly consoling that he seems unaffected by these episodes. Most likely these are acrocyanotic spells (blueness of the extremities) that do not represent a true drop in oxygen level in the blood stream. Occasionally there are unusual conditions that do cause a true drop in oxygen level, even at this age. That is why it is important to have him evaluated by a physician, and have a pulse oximetry level checked (to assess the amount of oxygen in his blood at rest). The echocardiogram is probably a good idea to rule out a structural heart defect. If your son was admitted to the hospital, they probably did check his oxygen level with pulse oximetry. Do you know if that was done, and if the result was considered normal or not? If it was abnormal, then he needs a thorough evaluation by both a pediatric cardiologist and a pediatric pulmonologist. If the oxygen level was normal, then it would support the likelihood of these episodes being benign in nature.