Atrial septal defects

There are 4 types of atrial septal defect (ASD): ostium secundum, ostium primum, sinus venosus, and unroofed coronary sinus. Secundum defects are the most common.

Most patients are asymptomatic. Untreated defects can produce right atrial enlargement, cardiac arrhythmias, and heart failure over time.

Secundum, primum, and coronary sinus defects with small shunts (ratio of pulmonary flow to systemic flow, Qp:Qs, <1.5) do not require treatment. Corrective closure is required if the shunt is larger (Qp:Qs ratio ≥1.5), there is right atrial enlargement, or the patient has a sinus venosus defect.

Corrective closure, if required, is usually performed at 2 to 4 years of age but can be performed at a younger age in symptomatic patients.

Percutaneous device closure is the preferred treatment for secundum defects, and surgical closure is reserved for larger secundum defects, technically challenging cases, and other defects.

If right-to-left shunting (Eisenmenger syndrome) occurs, the ASD is operable if the shunt is reversible with pulmonary vasodilators. If the shunt is irreversible, the treatment is largely supportive.

An atrial septal defect (ASD) is an opening in the atrial septum, excluding a patent foramen ovale.[1]Driscoll DJ. Fundamentals of pediatric cardiology. Philadelphia, PA: Lippincott Williams & Wilkins; 2006:73-8. There are 4 types of ASD: ostium secundum, ostium primum, sinus venosus, and unroofed coronary sinus.