Septal thrombus in the left atrium: is the left atrial septal pouch the culprit?

A R D I O E M B O L I C S T R O K E S A R E R E S P O N S I B L E for more than 20% of all ischemic trokes. The examination of atrial sources of cardioembolic strokes has focused almost exclusively on he left atrial appendage (LAA) and the pathophysiology of thrombus formation at this site is well nderstood. However, especially in rheumatic heart disease, thrombi can occur in the left atrium (LA) utside the appendage a significant proportion of the time with poor understanding of the underlying echanism. We present 3 patients in whom a thrombus was seen adherent to the septal LA. The robable underlying pathophysiology and the relationship to a recently described novel atrial structure, he left atrial septal pouch (LASP) (Fig. 1) that has the potential to be a site of stasis with hromboembolic complications, is discussed (1).