Coarctation of the aorta is often detected during a newborn’s first physical examination. Sometimes it is not noticed until the natural closure of the ductus arteriosus, a temporary blood vessel that connects the aorta and pulmonary artery before birth. Blood pressure measurements in the arms and legs may be slightly or significantly different from each other, and the parents may have noticed that the child is breathless and failing to thrive. A physician may also detect a heart murmur by listening to the patient’s heart using a stethoscope.

The physician may also be able to detect signs of a narrowed and/or leaky aortic valve or left-sided heart failure. Coarctation of the aorta may occur with other congenital (from birth) heart diseases, such as an atrial septal defect, ventricular septal defect or various valvular heart diseases.

In many cases, the absence of the femoral (groin) pulse may be the only detectable sign immediately after birth. Diagnosis may be confirmed by any of these following tests:

• Electrocardiogram (EKG). A recording of the heart’s electrical activity as a graph on a moving strip of paper or video monitor. The highly sensitive electrocardiograph machine can indicate an enlargement (hypertrophy) of the left ventricle, which can be a sign of disease and overwork.
  
  
• Echocardiogram. A test that uses sound waves to visualize the structures and functions of the heart. A moving image of the patient’s beating heart is played on a video screen, where a physician can study the heart’s thickness, size and function. The image also shows the motion pattern and structure of the four heart valves, revealing any potential leakage (regurgitation) or narrowing (stenosis). During this test, a Doppler ultrasound may also be done to evaluate blood flow in the coronary arteries, the blood vessels of the arms and legs and the carotid arteries in the neck.
  
  
• Chest x-ray. A radiation-based test that produces a picture of the general size, shape and structure of the heart and lungs. It may show abnormal rib structure, or “notched” ribs.
  
  
• CAT scan (computed tomography or CT scan). An x-ray that creates a three-dimensional or cross-sectional image through computer technology.
  
  
• MRI (magnetic resonance imaging test). An imaging test that uses magnetic fields and a computer to produce high-resolution cross-sectional or three-dimensional images of the heart.
  
  
• Cardiac catheterization. This test includes an aortic angiogram to visualize the location and severity of blockages in the aorta. It uses a special dye administered through a thin tube called a catheter. This dye is visible under x-ray. It is less frequently used than other imaging studies.