Ostium Primum Atrial Septal Defects Clinical Presentation

Updated: Oct 12, 2020
  • Author: Shannon M Rivenes, MD; Chief Editor: Syamasundar Rao Patnana, MD  more...
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Children with smaller ostium primum atrial septal defects (ASDs) and little or no mitral regurgitation or left ventricle-to-right atrium shunting are usually asymptomatic. Those with significant pulmonary overcirculation and/or significant mitral regurgitation tend to present in infancy with congestive heart failure (CHF). Tachypnea and tachycardia are noted at rest and are exacerbated with crying or exertion. Feeding is accompanied by dyspnea, diaphoresis, and an increased work of breathing. The combination of feeding difficulties and increased metabolic demands results in failure to thrive, which may be severe and/or intractable.


Physical Examination

Characteristic features of trisomy 21 may be detected, such as hypotonia and hyperflexibility, and include the following:

  • Short, flat nose with a flat nasal bridge

  • Oblique palpebral fissures

  • Abundant neck skin

  • Large and protuberant tongue

  • Short, broad hands with a shorter fifth finger (clinodactyly)

  • Simian crease

  • Inner epicanthal fold extending onto the lower lid

  • Brushfield spots (speckled iris)

Infants and children with partial atrioventricular (AV) septal defects and significant mitral regurgitation have poor development and are tachypneic and tachycardic at rest. A hyperinflated thorax, bulging precordium, and Harrison grooves are often present. Most children, however, have a milder degree of mitral regurgitation and, in general, appear normally developed and thriving on examination.

The cardiac examination in isolated ostium primum atrial septal defects (ASDs) or partial AV septal defects with minimal mitral regurgitation is similar to that in other forms of ASDs. Patients typically have an increased right ventricular impulse secondary to volume overload. The first heart sound is normal. The second heart sound is fixed or at least widely split. A systolic ejection murmur is heard loudest at the upper left sternal border, with radiation to both lung fields. A click is not present. A tricuspid mid-diastolic rumble is present in children with larger shunts (pulmonary-to-systemic flow ratio >2:1) and is appreciated at the lower left sternal border.

The murmur of mitral insufficiency is typically high pitched, holosystolic, and loudest at the apex. The murmur usually radiates to the axilla but may sometimes radiate preferentially to the sternal edge secondary to streaming of the regurgitant flow across the atrial septum.

If pulmonary hypertension is present, significant changes are noted in the physical examination. The pulmonary component of the second heart sound becomes loud. The splitting of the second heart sound narrows and eventually may become single. The diastolic tricuspid rumble disappears. A holosystolic murmur of tricuspid regurgitation becomes noticeable as the right ventricle dilates. This murmur is usually loudest at the lower left sternal border and becomes higher pitched as the right ventricular pressure increases. A short midsystolic murmur may be present secondary to flow into a dilated pulmonary artery. A Graham-Steell pulmonary insufficiency murmur may be appreciated as an early diastolic decrescendo murmur at the mid left sternal border.