How old is your brother? and exactly what kind of hole in the heart must be known to know about the prognosis. Commonly ASD and VSD( Atrial and Vetricular Septal defect) are referred as hole in the heart.
The patients of such defect have increased chances for Respiratory or chest infection
as compared to normal ones. Which may be the cause for his breathlessness and visit to hospital.
If size of hole is small it may close naturally but if age is more and hole is big then surgical repair is advised which can cure the patient. Be in follow up of your Cardiologist if surgery is required or not.