Atrial Septal Defect

Click here to listen over the pulmonic area

Click here for the phonocardiogram

Click here for the Echocardiogram


Atrial septal defect (secundum type) is a common congenital heart disease in the adult, and often remains asymptomatic until the fourth decade when a significant number of patients develop atrial arrhythmias, pulmonary arterial hypertension, bidirectional and then right-to-left shunting of blood, and cardiac failure.

The main clue to the diagnosis on physical examination is a wide fixed split of the second heart sound over the pulmonic area. Consequences of right ventricular volume overload (i.e., RVH with a parasternal thrust & retrosternal dullness) and pulmonary hypertension (loud S2P, systolic ejection murmur over pulmonic area) may also be present.

On the left side of this document, the phonocardiogram best demonstrates the fixed split of S2; the echocardiogram illustrates bidirectional flow using bubbles (CO2)