persistent ostium secundum

Epidemiology

most common form of atrial septal defect

Pathology

• congenital defect at fossa ovalis
• atrial septal defect
• mitral regurgitation as late complication

Clinical manifestations

• may be asymptomatic
• dyspnea
• right ventricular precordial thrust
• systolic ejection murmur 2nd & 3rd intercostal space
  • never more than grade III/VI
• fixed & wide splitting of 2nd heart sound S2
• short diastolic murmur along left sternal border
• atrial fibrillation often develops in patients in the sixth decade of life
• may present with a neurological event

Diagnostic procedures

• electrocardiogram:
  • right axis deviation*
  • first degree AV block
  • late R' in right-sided leads
  • right bundle branch block is generally present
• right atrial enlargement
• echocardiogram:
  • 2-dimensional with doppler
    • generally shows defect
    • right ventricular enlargement
    • volume overload
  • transesophageal echocardiography may be necessary
• cardiac catheterization generally unnecessary

* distinguishing feature from persistent ostium primum

Radiology

chest X-ray

• enlargement of right ventricle
• enlargement of right atrium
• enlargement of pulmonary artery
  • increased pulmonary vascularity
• if chest x-ray (or EKG) shows left atrial enlargement, consider persistent ostium primum with mitral regurgitation

Complications

• right ventricular hypertrophy
• right atrial enlargement
• atrial fibrillation
• pulmonary hypertension (rare)

Management

• percutaneous device closure preferred
  • see atrial septal defect for indications & contraindications
• antibiotic prophylaxis for endocarditis
  • not needed prior to closure
  • required for 6 months after closure only

More general terms

• atrial septal defect (ASD)

Additional terms

• ostium secundum (interatrial foramen secundum)