Atrial Septal Defect — ASD

·        4:1 ratio of females to males

·        The most frequent congenital heart lesion initially diagnosed as an adult

·        Frequently associated with Ellis-van Creveld and Holt-Oram syndromes

·        Associated with prolapsing mitral valve

 Four Major Types 

• Most common is ostium secundum (60%) located at fossa ovalis

o       High association with prolapse of the mitral valve

• Ostium primum type is usually part of an endocardial cushion defect

o       It tends to act like a VSD physiologically

• Sinus venosis type lies high in the interatrial septum

o       90% association of anomalous drainage of R upper pulmonary vein with SVC or Right atrium

• Most rare type is posteroinferior ASD

o       Associated with absence of the coronary sinus and a left SVC emptying into LA

 * Pulmonary hypertension is rare in ostium secundum variety of ASD (<6%);                                                                 

 X-RAY:

o       Enlarged pulmonary vessels

o       Normal-sized left atrium

o       Normal to small aorta

 

• With large shunts, pulmonary infections and cardiac arrythmias are common

• There is a higher incidence of pericardial disease with ASD than other CHD

• Bacterial endocarditis is rare

 

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