Interatrial septal aneurysm or atrial septal aneurysm (ASA) is defined as an abnormal protrusion of the interatrial septum. The exact length of the protrusion that defines an interatrial septal aneurysm varies in the literature, ranging from >11 mm to >15 mm beyond normal excursion in adults 4,5 and 5 mm in children.
It can be limited to the fossa ovale or involve the entire interatrial septum.
It is encountered in approximately 1% of the paediatric population.
Interatrial septal aneurysm is associated with an increased incidence of peripheral arterial embolism and increased stroke risk.
It is known to be associated with the following:
- some consider an aneurysm of more than 10 mm excursion to be associated with markedly increased risk (odds ratio 8) 8
- the concurrent presence of a patent foramen ovale is thought to have a synergistic effect on stroke 8.
On imaging consider
- 1. Giannopoulos A, Gavras C, Sarioglou S et-al. Atrial septal aneurysms in childhood: prevalence, classification, and concurrent abnormalities. Cardiol Young. 2013;: 1-6. doi:10.1017/S1047951113000607 - Pubmed citation
- 2. Demirkol S, Balta S, Unlü M et-al. Case Images: Huge interatrial septal aneurysm associated with a multiple atrial septal defect evaluated by transesophageal echocardiography. Turk Kardiyol Dern Ars. 2013;41 (1): 88. Turk Kardiyol Dern Ars (link) - Pubmed citation
- 3. Mattioli AV, Aquilina M, Oldani A et-al. Atrial septal aneurysm as a cardioembolic source in adult patients with stroke and normal carotid arteries. A multicentre study. Eur. Heart J. 2001;22 (3): 261-8. doi:10.1053/euhj.2001.2293 - Pubmed citation
- 4. Hanley PC, Tajik AJ, Hynes JK et-al. Diagnosis and classification of atrial septal aneurysm by two-dimensional echocardiography: report of 80 consecutive cases. J. Am. Coll. Cardiol. 1986;6 (6): 1370-82. Pubmed citation
- 5. Mas JL, Arquizan C, Lamy C et-al. Recurrent cerebrovascular events associated with patent foramen ovale, atrial septal aneurysm, or both. N. Engl. J. Med. 2001;345 (24): 1740-6. doi:10.1056/NEJMoa011503 - Pubmed citation
- 7. Mügge A, Daniel WG, Angermann C et-al. Atrial septal aneurysm in adult patients. A multicenter study using transthoracic and transesophageal echocardiography. Circulation. 1995;91 (11): 2785-92. doi:10.1161/01.CIR.91.11.2785 - Pubmed citation
- 8. Cabanes L, Mas JL, Cohen A et-al. Atrial septal aneurysm and patent foramen ovale as risk factors for cryptogenic stroke in patients less than 55 years of age. A study using transesophageal echocardiography. Stroke. 1994;24 (12): 1865-73. Pubmed citation
- 9. Wahl A, Krumsdorf U, Meier B et-al. Transcatheter treatment of atrial septal aneurysm associated with patent foramen ovale for prevention of recurrent paradoxical embolism in high-risk patients. J. Am. Coll. Cardiol. 2005;45 (3): 377-80. doi:10.1016/j.jacc.2004.10.043 - Pubmed citation