Background: Intracardiac echocardiography (ICE) is a useful imaging modality that is now being used more widely to assist in the percutaneous closure of atrial septal defects (ASD) and patent foramen ovales (PFO).
Case presentation: A 42 year old lady with a history of transient ischaemic attacks and migraine underwent percutaneous closure of an ASD. Intraprocedural ICE demonstrated a mammoth billowing multiperforated interatrial septal aneurysm in association with a secondum ASD.
Conclusion: ICE provides excellent adjuvant imaging during percutaneous closure of intracardiac shunts, in this case demonstrating a 'mammoth' interatrial septal aneurysm.