Clinical features of secundum defect

Patients are usually asymptomatic throughout infancy and childhood, often presenting in the third or fourth decades of life. Rarely the symptoms include:

• breathlessness on exertion
• recurrent chest infections

On examination:

• the child is pink with normal pulses
• there is a right ventricular heave
• there is a murmur in the 2nd intercostal space in the left parasternal region - this is usually a flow murmur across a normal valve
• if the ASD is large there may be a similar murmur across the tricuspid valve
• the second sound is split because the over-filled right atrium takes longer to empty
• the splitting is fixed because the atria act as a single unit and therefore inspiration affect them both equally
• mitral valve prolapse has been demonstrated in up to 30% of patients with ostium secundum ASD