Echocardiographic image from subcostal four chamber view showing the atrial septal defect (ASD). Subcostal view is the ideal view for imaging atrial septal defect to exclude false echo dropouts which may be seen in apical four chamber view. This is because the imaging ultrasound beam is perpendicular to the septum in subcostal view while it is parallel the to the atrial septum in apical four chamber view. This ASD has good rims above and below, and could be suitable for device closure, which has to be decided after a trans oesphageal echocardiogram to assess all the rims.
Colour Doppler flow mapping showing the red coloured flow across the atrial septum from left atrium (LA) to the right atrium (RA). The flow is red coloured because it is towards the echo transducer in this view. RV: right ventricle; LV: left ventricle. The flow reversal (blue colour and jet moving from RA to LA) can occur when there is severe pulmonary hypertension. Reverse flow across the atrial septal defect (right to left) can also be seen in total anomalous pulmonary venous connection.