Atrioventricular canal defect

At Children’s Hospital Boston, we know that the first step in treating your child is forming an accurate, complete and timely diagnosis.

Exams

If your newborn is exhibiting signs and symptoms that suggest a congenital heart defect, your pediatrician will refer you to a pediatric cardiologist, who will perform a physical examination. Your cardiologist will listen to your baby’s heart and lungs, measure the oxygen level in his blood (non-invasively) and make other observations that help to determine the diagnosis.

Your cardiologist will also investigate whether your baby has a heart murmur—a noise heard through the stethoscope that’s caused by the turbulence of blood flow. The location in the chest where the murmur is best heard, as well as the sound and character of the murmur itself, will give the cardiologist an initial idea of the kind of heart problem your baby may have.

Tests

Some combination (not necessarily all) of the following medical tests will also used to diagnose AV canal and its associated defects:

• electrocardiogram (EKG): An EKG is used to evaluate the electrical activity and rhythm of your child’s heart. An EKG is usually the initial test for evaluating the causes of symptoms and detecting heart abnormalities, including AV canal. The test is performed by placing electrodes on the arms, legs and chest to record the electrical activity. The test takes five minutes or less and involves no pain or discomfort.
   
• chest x-ray: A conventional chest x-ray will evaluate the size and spatial relationships of the heart within the child’s chest. It takes a few moments. There is no pain or discomfort.
   
• echocardiogram (cardiac ultrasound): An echocardiogram evaluates the structure and function of your child’s heart using electronically recorded sound waves that produce a moving picture of the heart and heart valves. No discomfort is involved. It takes 30-60 minutes.

Note: If, during your pregnancy, a routine prenatal ultrasound or other signs raise your obstetrician’s suspicion of a congenital heart defect in the fetus, a cardiac ultrasound (described in the paragraph above) of the baby in utero will usually be the next step. The cardiac ultrasound—focusing exclusively on the baby’s heart—can usually detect whether a congenital heart defect is present.

• cardiac magnetic resonance imaging (cardiac MRI): An MRI is a non-invasive test using 3-D imaging technology produced by magnets to accurately determine the size of the heart chambers, arteries and veins in the chest, as well as the blood flow and functioning of your child’s heart. No pain is involved, although an IV may be needed. It takes about an hour.

• cardiac catheterization: This invasive test performed under sedation provides detailed visual information and measurements about the structures inside the heart. Blood pressure and oxygen measurements are taken in the four chambers of the heart, as well as the pulmonary artery and aorta.