What is an atrial septal defect?

In this defect there is a hole between the top chambers (receiving chambers or atria). Due to the higher pressure in the left side of the heart, this allows oxygenated blood to flow through the hole from the left to the right side of the heart, and back to the lungs, in addition to the normal flow. There are three types of Atrial Septal Defect, the most common is where the hole is in the middle of the atrial septum (central heart wall) called the secundum defect. Holes in the lower part of the septum, called the primum defect (partial atrioventricular septal defect), are often associated with an abnormality of the mitral valve (resulting in a leak). Less common are holes in the top of the septum which are associated with abnormality of the right upper lung vein, called the sinus venosus defect. The amount of blood flow from the left to right atria is dependent on the size of the hole and on the pressure difference between the atria. The higher the rate of flow, the more strain that is placed on the heart.

Symptoms

Generally patients with an ASD defect will exhibit no symptoms (they are asymptomatic) and the problem is only found when a routine clinical examination detects a heart murmur. Occasionally a patient will exhibit poor weight gain and a failure to thrive, and if there is mitral valve leakage there may be early symptoms of breathlessness.

Treatment

Small holes which allow little blood flow from left to right generally cause no problems, and if they are located in the middle read more