Right atrial appendage: forgotten part of the heart in atrial fibrillation.

Atrial fibrillation (AF) is the most common clinically encountered arrhythmia in adults. Because it is associated with an increased risk of atrial thrombus formation and embolism, medical and/or electrical cardioversion is the preferred treatment method in the majority of clinics. Thrombus formation in the setting of AF most commonly occurs in the left atrial appendage (LAA), left atrium (LA), right atrial appendage (RAA), and right atrium in decreasing frequency. In routine transesophageal echocardiographic evaluation for AF, examination is generally limited to LA and LAA. Although relatively rare when compared with the left side, RAA thrombus has also the potential of embolism and should be screened. A case of RAA thrombus in which the LA and LAA were spared is described. The authors aimed to underline the importance of this rare but potentially dangerous complication of AF.