Atrial Septal Defect

Amplatzer Septal Occluder Device

Atrial Septal Defect (ASD) is a common form of congenital heart disease. It is a defect involving the atrial septum which divides the two upper chambers (atria) of the heart. When a defect occurs, there is an abnormal connection which allows blood to flow abnormally between the left and right atriums. Over time, this can lead to enlargement of the right atrium and right ventricle with excessive blood flow into the lungs and pulmonary circulation. Symptomatic patients often report shortness of breath due to the development of heart failure , decreased exercise tolerance, palpitations and may have a heart murmur on exam with a 'fixed' second heart sound. Patients with ASD are at increased risk of stroke and may have a shortened life expectancy without corrective treatment. Many childhood ASDs are small and will not require any intervention. Because of the risk of developing heart failure later in life, most ASDs which produce right ventricular volume overload with shunts greater than 1.5:1 are candidates for closure.

Different types of ASDs occur. The commonest form is a Secundum ASD which involves a defect in the central portion of the atrial septum.

Secundum ASDs can be closed either surgically or with the aid of a transcatheter device. The Amplatzer Septal Occluder shown above is introduced through a small puncture in the groin and does not involve open heart surgery. This Septal occluder is a self expanding double disc device made from Nitinol wire mesh. Not all ASDs are ammenable to device closure. Some will require an open heart procedure for definitive treatment.