Aortopulmonary Septal Defect Clinical Presentation

Updated: Feb 01, 2021
  • Author: Barry A Love, MD; Chief Editor: Stuart Berger, MD  more...
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The clinical presentation of aortopulmonary septal defect (APSD) depends on the size of the defect, pulmonary vascular resistance (PVR), and associated anomalies.

In a large defect with falling PVR, aortopulmonary septal defect presents with typical signs and symptoms of congestive heart failure (CHF) indistinguishable from those of a large ventricular septal defect (VSD) or ductus arteriosus. Symptoms usually emerge between the second and eighth weeks of life. Caregivers typically report signs of CHF as tachypnea and diaphoresis (especially with feeds), poor feeding, and usually poor growth.

If aortopulmonary septal defect is associated with interrupted aortic arch or severe coarctation, the infant may present with signs and symptoms of shock in newborn period as the ductus arteriosus closes.

In less common scenarios (about 10% of patients), the defect is small and restrictive and presents as an asymptomatic murmur in the first weeks to months of life.

In presence of a large, nonrestrictive defect, PVR in some patients may not fall significantly, CHF does not develop, and the patients may be relatively asymptomatic. Because pulmonary and systemic resistances are comparable, some right-to-left shunting and mild cyanosis may be present yet not clinically apparent. Unfortunately, despite lack of symptoms, irreversible pulmonary vascular obstructive disease (PVOD) typically develops with time. At this stage, fatigue, exercise intolerance, and cyanosis may appear. Children with persistently elevated PVR are most difficult to identify clinically, and many years pass before diagnosis with serious heart disease.


Physical Examination

If a large, nonrestrictive defect with low pulmonary vascular resistance (PVR) is present, then physical examination findings are indistinguishable from those of a large patent ductus arteriosus (PDA). These findings include tachypnea, tachycardia, and increased work of breathing. Note the following:

  • Continuous run-off into the pulmonary circuit during diastole, in combination with an elevated stoke volume, causes a wide pulse pressure with bounding pulses.

  • Palpation reveals a hyperdynamic precordial impulse from increased volume load on the left ventricle.

  • Auscultation reveals a loud and single second heart sound with a continuous murmur at the left upper sternal border. Often, a gallop rhythm and an apical diastolic rumble from increased volume load are present.

  • Hepatic congestion and hepatomegaly develop in proportion to the degree of heart failure.

  • Failure to thrive is concomitant with the degree of heart failure.

In situations in which PVR fails to fall significantly after birth, findings may be subtler. The second heart sound is single, yet no murmur or only a soft systolic murmur may be observed. Pulses are not bounding; little diastolic run-off is noted. Subtle cyanosis may be present from a small amount of right-to-left shunt when pulmonary and systemic resistances are comparable. With irreversible pulmonary vascular changes and Eisenmenger syndrome, cyanosis may become more prominent. Cyanosis will be present if other cyanotic lesions are present (eg, transposition of the great vessels, tetralogy of Fallot).

A continuous murmur may be the only physical finding if the defect is small and restrictive.