Atrial Septal Defect (ASD)

• • A congenital heart lesion that increases pulmonary artery (PA) blood flow

  • Causes left to right shunt, results in lung infection, pulmonary vascular congestion, PA hypertension, right heart failure, pulmonary vasoconstriction, pulmonary vascular obstructive disease

  • Eisenmenger syndrome: Increased pulmonary hypertension to such extent that left to right shunt ceases and shunt becomes right to left, requiring heart-lung transplant

  • Inhaled nitric oxide, oxygen, or IV tolazoline reverses PA vasoconstriction

  • PA band is palliative and can reduce PA flow to alleviate RV failure and progression of pulmonary hypertension

Epidemiology

• • Ostium secundum type: Most common and largest of ASDs

  • Defects high in atrial septum, associated with partial anomalous pulmonary venous return, termed "sinus venosus defects"

  • Reduced life expectancy because of RV failure, arrhythmias, pulmonary vascular disease

  • Pulmonary vascular disease rare

Symptoms and Signs

• • Acyanotic, asymptomatic often

  • RV lift

  • S2 widely split and fixed

  • Pulmonary systolic ejection murmur

  • Diastolic flow murmur at left lower sternal border

  • Heart failure may occur in kids, rare in adults

  • Atrial dysrhythmias increase with age

Imaging Findings

• • Echocardiography: Diagnostic

• • Evaluate for other associated cardiac or extracardiac anomalies

• • Echocardiography

• • Most should be closed

  • Optimal time debated

  • Paradoxic embolism and endocarditis associated with delaying repair

  • Open surgery is performed to close if patient is 1 or 2 years old

  • Many now are closed percutaneously (patient must weigh > 10 kg)

Surgery

Indications

• • Presence of ASD in low- to moderate- risk patient

Prognosis

• • Excellent

References