Atrial Septal Aneurysms - A Clinically Relevant Enigma?

Atrial septal aneurysms (ASAs) are often seen during routine cardiac imaging, though their clinical relevance has been poorly defined. The aneurysmal, and often mobile, inter-atrial septum is frequently associated with other clinically relevant structural cardiac abnormalities, particularly patent foramen ovale (PFO). Whilst ASAs have previously been considered an incidental finding, a well-endowed atrial septum provides more than visual interest, including insights into atrial function and intra-atrial pressures, and has important clinical implications in PFO-associated stroke, migraines, and arrhythmias. This review outlines diagnostic challenges when assessing ASAs using all imaging modalities and the clinical implications of this common anatomical variant.