Congenital Heart Disease

Atrial Septal Defect

Signs and Symptoms
Diagnosis
Treatment

Signs and Symptoms

Atrial septal defect (ASD) is an abnormal hole in the wall between the two upper chambers of the heart, called the right and left atria. When this hole occurs, too much blood flows from the left atrium to the right atrium and through the right side of the heart. This excess blood flows through the right ventricle, pulmonary artery and into the lungs making the heart work harder. The extra blood flowing to the lungs creates a noise called a murmur.

Small holes may close on their own by the time a child is 2 years old. In some people, the defect doesn't cause symptoms until middle age.

A large ASD causes several problems. The heart works harder because it pumps extra blood to the lungs, which may cause the right side of your heart to enlarge resulting in irregular heartbeats called arrhythmias. It also may cause congestive heart failure, usually in middle age. In addition, a large amount of extra blood flow damages the blood vessels in the lung. All ASDs larger than a few millimeters in diameter should be closed to prevent these problems.

Reviewed by health care specialists at UCSF Medical Center.
Last updated December 18, 2008