Secundum Atrial Septal Defects

Secundum atrial septal defects are often not identified in childhood and can present with non specific symptoms such as lethargy. The first heart sound is often split but equally may be normal. The definitive investigation is transthoracic echocardiography. This will demonstrate first of all the anatomy and secondly using doppler indicate any significant shunting.

Ostium secundum defects are more midseptal and by far more common than primum defects which are more inferiorly displaced towards the AV valve. Primum defects are often associated with anomalies of the mitral and/or tricuspid valve, and as such patients more commonly present in childhood.

It is clear from the clinical picture that this is not a patent ductus arteriosus. Patent foramen ovale (PFO) is a common condition and generally benign. There may be some left to right flow on doppler imaging but this will not be significant. The harsh pansystolic murmur of a ventricular septal defect is usually obvious unless the defect is very large. In this case the patient would be likely to have more pronounced symptoms.