heart enlargement

My child is 5 year old. She went thru open heart surgery when she was 5 months old. The surgery went well and doctors said that she is as normal as other babies afterwards. She was normal for 5 years. Her heart was of normal size.

Recently, due to cough and cold we went to the doctor and he suggested to do X-ray. The x-ray result suggests to have her heart. I am really very worried. Dr. at GP suggested to see cardiologist in the hospital which could take around 2 months to get appointment. It is making me very tensed.

I would like to know if heart enlargement is very dangerous? What could be the reasons behind? How long it will take to come to normal size? Will it be treated through medication? Could there be connection with her previous operation? She looks quite normal except that she coughs sometimes in the night. What are dos and don'ts for child so that it does not harm her heart.

Look forward for respose.

worried mother