Incidental Right Atrial Appendage Thrombosis in a Patient With a Left Atrial Appendage Occlusion Device

Right atrial appendage (RAA) thrombosis is exceedingly rare, is usually found incidentally on imaging, and carries a high thromboembolic risk.

An 83-year-old man with chronic atrial fibrillation complicated by previous bleeding episodes on anticoagulation and managed most recently with a WATCHMAN device presented after a mechanical fall. Imaging work-up revealed a new incidental finding of RAA thrombosis.

This case highlights an uncommon thrombotic finding and that atrial fibrillation is a biatrial disease. Occlusion of the left atrial appendage does not eliminate the risk of right-sided thrombosis.

Thromboembolic prevention in patients with chronic atrial fibrillation is challenging. Left atrial appendage occlusion devices, although effective, do not eliminate the risk of RAA thrombosis, as atrial fibrillation is a biatrial disease.