ASD (Atrial Septal Defect) refers to congenital holes in the heart walls. Sometimes this may be one hole, sometimes it may be two holes. It is the failure of the heart to close completely during its formation in the womb and as a result, the hole remains in the middle. It means the heart hole between the atria. Atrium is the atrium, septal is the wall. Atrial septal defect is the hole between the atria that is present from birth. This heart hole may not cause any complaints, but sometimes it may cause a lot of complaints. Sometimes it can occur until the age of 50s or 60s without causing any complaints, and it can be found by chance. In these cases, this heart hole is closed with minimally small incisions using minimally invasive surgical techniques. Sometimes it is closed with a patch, sometimes it is closed by erecting opposite walls. As a result, all the patient's complaints will disappear and there will be no tearing or opening in the future.