ASD

• 5-10% of all CHD
• More common in females
• Ostium secundum most common type
• Usually asymptomatic with characteristic physical findings being picked up in the toddler/preschool age groups
• SEM with widely split and fixed S2; middiastolic murmur may be present with large shunt

Pathophysiology

• Left to right shunting at the atrial level throughout the entire cardiac cycle
• RA and RV volume overload
• Increased blood flow across functionally stenotic valves produce murmurs
• Widely split S2 due to delayed closure of the pulmonic valve

EKG Findings (EKG stuff)

• RAD with RVH
• RBBB

CXR

• Cardiomegaly with RAE and RVH
• Prominent MPA
• Increased pulmonary vascular markings

Management

• Spontaneous closure rate very low compared to VSD, but may occur in the first 4 years of life; surgically closure therefore usually delayed until 3-4 y.o.
• SBE prophylaxis not indicated for secundum ASD
• may develop pulm hypertension after age 20 if left untreated

CHLA Board Review 2005
Park MK. Pediatric Cardiology for Practictioners, 3rded. St. Louis,
Mosby, 1996.