Internal Medicine

P1: SBT

0521779407-05 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:49

196 Atrial Septal Defect (ASD)

➣Left-to-right shunt by color and Doppler flow or using saline

contrast; level of shunt readily identified in most cases

■Transesophageal echocardiography

➣Helps identify shunt level if not well visualized by surface echo

➣Sinus venosus: diagnosis often made by TEE (better visualization

of pulmonary veins)

■Cardiac catheterization

➣Required if magnitude of left-to-right shunt is uncertain or asso-

ciated coronary anomalies or disease are suspected

differential diagnosis

■Patent foramen ovale (present in 15–20% of normal adults)

management

■Endocarditis prophylaxis necessary in sinus venosus and ostium pri-

mum defects

■Risk of endocarditis is low in isolated ostium secundum defects and

routine prophylaxis is not recommended

specific therapy

■Operative repair (suture or patch closure) indicated in all patients

with significant left to right shunt (generally pulmonary to systemic

shunt ration greater than 1.7: 1) or if there is evidence of right ven-

tricular dilation

follow-up

■Leak of ASD patch may occur-detected by echocardiography

■Endocarditis prophylaxis for first 6 months after surgery

complications and prognosis

Complications

■Heart failure-due to chronic left-to-right shunting

■Atrial arrhythmias

■Cerebral vascular accidents from paradoxical emboli

■Pulmonary artery hypertension (occurs in 15% of patients)

■Eisenmenger’s syndrome: development of pulmonary hypertension

and subsequent reversal of shunt right-to-left (occurs in 5% of

patients)

Prognosis

■Repair in early adulthood (<24 years of age) have normal long-term

survival

■Later repair associated with an 85% 10-year survival