Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. After going through the radiological findings, I m of the following opinion: i. Although median sternotomy is predominantly associated with cardiac surgery, it is a useful incision for a number of other operations, since it allows access to both pleural spaces, making it useful for some thoracic operations. ii. As hiatal hernia is an important extracardiac factor in patients presenting with chest pain, thus although it is important to repair the defect while performing a sternotomy, it was your attending physician decision to proceed with it. iii. Cardiomegaly means an enlarged heart and is a sign of heart-related condition [underlying conditon] and is caused either by ventricular hypertrophy or ventricular dilation, so you might have to see a Cardiologist to exclude factors of mild cardiomegaly with further tests like echocardiogram, chest X-ray, CT-Scan, a full physical examination, cardiac catherterization, stress test, blood test, after which he can accordingly advise you regarding medicine and lifestyle changes. Hope I have answered your query. Let me know if I can assist you further.