A woman with sickle cell disease, CAD, and pulmonary hypertension came to the ED with dyspnea, and a focused cardiac ultrasound (FoCUS) was performed.
Ventricular function and dimensions were unremarkable, but a good view of the atria revealed an odd finding:
What the heck is that?
An atrial septal aneurysm (ASA). This is infrequently seen, and has been described as a benign congenital abnormality in the past. However, much like a PFO, there appears to be an association with cerebral emboli.
Criteria for ASA aren't completely clear, but a common definition requires ≥ 10 mm of atrial septal excursion. In the picture below(from an open-access article), the total excursion = a + b.
Emergency physicians have learned to recognize a number of cardiac conditions besides the 4 or 5 problems usually sought on a FoCUS. With increasing utilization, however, rare abnormalities will be increasingly identified in the ED.
An ASA found on FoCUS does not require urgent therapy, and outpatient referral to cardiology would most likely be appropriate. On the other hand, if an ASA is found in a patient being investigated for a suspected acute stroke, this finding should be discussed with cardiology, since specific echocardiographic testing (e.g. bubble test for PFO, a TEE for atrial thrombi) may be pursued.
Butterfield, Michael, Christine Riguzzi, Oron Frenkel, and Arun Nagdev. “From the Heart: Interatrial Septal Aneurysm Identified on Bedside Ultrasound.” Western Journal of Emergency Medicine 15, no. 6 (September 2014): 719–20. doi:10.5811/westjem.2014.7.22972.
Mügge, Andreas, Werner G. Daniel, Christiane Angermann, Christoph Spes, Bijoy K. Khandheria, Itzhak Kronzon, Robin S. Freedberg, et al. “Atrial Septal Aneurysm in Adult Patients A Multicenter Study Using Transthoracic and Transesophageal Echocardiography.” Circulation 91, no. 11 (June 1, 1995): 2785–92. doi:10.1161/01.CIR.91.11.2785.