When is atrial septal defect surgery typically considered?

Atrial septal defect (ASD) surgery is generally considered when the QP/QS ratio exceeds 1:5. The QP/QS ratio is a measure of the amount of blood flow through the pulmonary circulation (QP) compared to the systemic circulation (QS). A ratio greater than 1:5 indicates that the left-to-right shunt caused by the ASD is significant enough to warrant surgical intervention. This ratio reflects the amount of overload on the right side of the heart and the pulmonary circulation, which can lead to complications such as right heart failure, pulmonary hypertension, and atrial arrhythmias if left untreated.

The decision for surgical repair is based not only on the QP/QS ratio but also on the presence of clinical symptoms and echocardiographic findings. When the ratio is excessively high, such as exceeding 1:5, it indicates substantial volume overload and increased pulmonary blood flow that can be harmful to the patient, making surgery a prudent corrective measure.

In contrast, a QP/QS ratio of 1:3 would not typically prompt surgical intervention as it indicates a lower level of shunt. Similarly, a normal QP/QS ratio suggests typical hemodynamics without significant shunting through the defect,