Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android

Key Features

Essentials of Diagnosis

  • Fixed, widely split S2, right ventricular (RV) heave

  • Grade I–III/VI systolic ejection murmur at the pulmonary area

  • Large shunts cause a diastolic flow murmur at the lower left sternal border (increased flow across the tricuspid valve)

  • ECG shows rsR´ in lead V1

  • Frequently asymptomatic

General Considerations

  • Defined as an opening in the atrial septum permitting the shunting of blood between the atria

  • There are three major types

    • Ostium secundum

    • Ostium primum

    • Sinus venosus

  • Ostium secundum

    • Most common type

    • Occurs in 10% of patients with congenital heart disease

    • Two times more common in females than in males

    • Represents an embryologic deficiency in the septum secundum or too large of a central hole in the septum primum

    • Most often sporadic but may be familial or have a genetic basis (Holt-Oram syndrome)

  • Ostium primum: associated with atrioventricular septal defects

  • Sinus venosus defect: frequently associated with abnormal pulmonary venous return

Clinical Findings

Symptoms and Signs

  • Most infants and children have no cardiovascular symptoms

  • Exercise intolerance, easy fatigability or, rarely, heart failure in older children

  • Cyanosis does not occur unless RV dysfunction occurs, usually as a result of pulmonary hypertension

  • Peripheral pulses are normal and equal

  • The heart is usually hyperactive, with an RV heave felt best at the mid to lower left sternal border

  • S2 at the pulmonary area is widely split and often fixed

  • In ostium secundum

    • Atrial arrhythmias or pulmonary vascular disease may develop after third decade

    • Irreversible pulmonary hypertension resulting in cyanosis

    • Right heart failure can occur and is a life-limiting process (Eisenmenger syndrome)



  • Radiographs

    • May show cardiac enlargement

    • In large defects,

      • The main pulmonary artery may be dilated

      • Pulmonary vascular markings may be increased

  • Echocardiography

    • Shows a dilated right atrium and RV

    • Direct visualization of the exact anatomic location and demonstration of a left-to-right shunt through the defect confirms the diagnosis and has eliminated the need for cardiac catheterization prior to surgical or catheter closure of the defect

    • Assessment of all pulmonary veins should be made to rule out associated anomalous pulmonary venous return

Diagnostic Procedures

  • Electrocardiography

    • Shows right axis deviation

    • In the right precordial leads, an rsR´ pattern is usually present

    • Atrioventricular block may be seen when a mutation in the cardiac homeobox gene (NKX2-5) is present

  • Cardiac catheterization: rarely needed for diagnostic purposes


  • Surgical or catheterization closure is generally recommended for symptomatic children with a large atrial level defect and associated right heart dilation

  • In the asymptomatic child with a large hemodynamically significant defect, closure is performed electively at age 1–3 years

  • Most defects are amenable to nonoperative device closure during ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.