Diagnosis

Hearing a heart murmur during a checkup might cause your or your child's doctor to suspect an atrial septal defect or other heart defect. For a suspected heart defect, your doctor might request one or more of the following tests:

• Echocardiogram. This is the most commonly used test to diagnose an atrial septal defect. Sound waves are used to produce a video image of the heart. It allows your doctor to see your heart's chambers and measure their pumping strength.

  This test also checks heart valves and looks for signs of heart defects. Doctors can also use this test to evaluate your condition and determine your treatment plan.

• Chest X-ray. This helps your doctor see the condition of your heart and lungs. An X-ray can identify conditions other than a heart defect that might explain your signs or symptoms.
• Electrocardiogram (ECG). This test records the electrical activity of your heart and helps identify heart rhythm problems.

• Cardiac catheterization. A thin, flexible tube (catheter) is inserted into a blood vessel at your groin or arm and guided to your heart. Through catheterization, doctors can diagnose congenital heart defects, test how well your heart is pumping, check heart valve function and measure the blood pressure in your lungs.

  However, this test usually isn't needed to diagnose an atrial septal defect. Doctors might also use catheterization techniques to repair heart defects.

• MRI. This uses a magnetic field and radio waves to create 3D images of your heart and other organs and bodily tissues. Your doctor might request an MRI if echocardiography can't definitively diagnose an atrial septal defect or related conditions.
• CT scan. This uses a series of X-rays to create detailed images of your heart. It can be used to diagnose an atrial septal defect and related congenital heart defects if echocardiography hasn't definitely diagnosed an atrial septal defect.