Paradoxical Brain Embolism in Elderly Subjects with Small Atrial Septal Defects.

BACKGROUND

Atrial septal defects have a low prevalence in the general population, and are recognized as a rare cause of paradoxical brain embolism.

METHODS

We extensively examined stroke causes in patients with acute stroke admitted to a single stroke center within 1 year.

RESULTS

Among 186 consecutive patients, transesophageal or transthoracic echocardiography revealed 5 cases of paradoxical brain embolism: 3 (1.6%) were related to atrial septal defects, whereas 2 were patent foramen ovale patients. Although right-to-left shunt may have occurred after the development of acute pulmonary embolism in atrial septal defects case #1, the Valsalva maneuver elicited right-to-left shunt in atrial septal defects cases #2 and #3. The 3 cases were elderly (>60 years old), harbored small defects with normal systemic hemodynamics, and had not experienced any clinical symptoms related to atrial septal defects.

CONCLUSIONS

Small atrial septal defect may cause paradoxical embolism as its initial related event, particularly in elderly subjects.