A curious case of an absent left atrial appendage.

The left atrial appendage (LAA) in the setting of non-valvular atrial fibrillation (NVAF) is the predominant location for intracardiac thrombus formation. An absent LAA is a very rare congenital cardiac anomaly. We present a case of a 79-year-old female with NVAF, high CHADS2VASC2 score, and high bleeding risk who presented for elective Watchman™ left atrial appendage closure device implant. A pre-procedural transesophageal echocardiography showed an absent LAA. This finding was confirmed with cardiac computed tomography and a left atrial angiogram. The patient was discharged on medical therapy with close outpatient follow-up.