Absent left atrial appendage: case report and review of the literature

Congenital absence of left atrial appendage (LAA) is an extremely rare condition and is usually diagnosed incidentally in imaging intended for other purposes. Herein, we report a rare case of absent left atrial appendage in an 80-year-old gentleman who was candidate for radiofrequency catheter ablation procedure for atrial flutter rhythm in whom we observed the absence of left atrial appendage in echocardiographic examination. Computed tomography angiographic examination performed in the evaluation course of the patient was also confirmative of this finding. As there is no data on anticoagulating of patients with absent left atrial appendage, after successful radiofrequency catheter ablation procedure, we continued rivaroxaban per guidelines. The results of a second imaging modality and a thorough medical history are critical for diagnosis of absent left atrial appendage. These steps are required to rule out imitating conditions such as prior surgical/percutaneous exclusion, unusual anatomical features or flush thrombotic exclusion of left atrial appendage. In this case report, we also provide a brief review of the characteristics of 17 cases that have been reported in the literature so far.