Structural Heart Abnormalities

The heart is a muscular pump with four chambers. The two atria on top and the two ventricles below are separated by dividing walls (septa), four valves keep blood flowing in one direction, and great vessels such as the aorta and the pulmonary artery carry blood out of the heart. Structural heart abnormality is an umbrella term for changes in these physical parts. It is different from disease of the coronary arteries that supply the heart muscle, and from disorders of the electrical system that controls the heart rhythm.

Congenital or Acquired

Some abnormalities form while the fetal heart develops in the womb, for example a hole in a dividing wall, a narrowed valve, or an unusual position of the great vessels. This group is covered on the Congenital Heart Disease page. Others develop later, for example valves that calcify with age or are damaged by rheumatic fever, ventricle walls that thicken or enlarge because of heart muscle disease, and tears or bulges in the heart wall after a heart attack. Valve disorders are covered on the Heart Valve Disease page, while heart muscle disease is covered on the Cardiomyopathy page.

From Mild to Severe

Many structural abnormalities are mild. A small gap between the two atria, called a patent foramen ovale, is found in about one in four adults and generally does not need treatment. Small holes in the wall between a baby's ventricles often close on their own. In contrast, large abnormalities make the heart work harder or mix oxygen-rich blood with oxygen-poor blood, so they need early treatment.

How Abnormalities Are Found

Structural abnormalities are often first suspected from a heart murmur, an extra sound heard through a stethoscope, or from oxygen level screening in newborns. Echocardiography is the main test because it shows the shape and movement of each part of the heart without pain. In adults, congenital abnormalities are sometimes only discovered years later, and acquired abnormalities are found more often after the age of 65. Treatment options in adulthood, including catheter-based procedures, are covered on the Adult Structural Heart Disease page.

In babies, a severe structural abnormality may be suspected from oxygen level screening with a pulse oximeter before leaving the birthing facility, or from a heart murmur during a routine examination. In children and adults, the first clue is often a heart murmur, shortness of breath, or unusual findings on an ECG or chest X-ray.

Echocardiography is the next step because it shows the shape of the dividing walls, valves, and ventricle walls, as well as the direction of blood flow, without pain. If the images are not clear enough, the doctor may perform echocardiography through the esophagus. Cardiac MRI and CT give more detailed images of the anatomy, especially for complex congenital abnormalities or before a procedure. Cardiac catheterization is used when the pressures inside the heart and lungs need to be measured directly. From these results, the doctor determines the type of abnormality, its severity, and whether it can simply be monitored or needs treatment.

Mild structural abnormalities often cause no symptoms, so a heart murmur or an unusual test result should be followed up with a cardiologist. If severe shortness of breath, fainting, or severe chest pain appears, or a baby looks very blue and limp, go to the nearest emergency room right away.

Make an appointment with a cardiologist if:

• A doctor hears a heart murmur in you or your child.
• Your baby tires easily while feeding, sweats a lot, or has poor weight gain.
• You are starting to get short of breath, tire quickly, or have palpitations during activities that used to be easy.
• You had heart surgery as a child and have not had a follow-up as an adult.
• You have a heart abnormality and are planning a pregnancy.