Congenital Absence of Left Atrial Appendage Diagnosed by Multimodality Imaging.

A 70-years-old male with a history of hypertension and drug resistant paroxysmal atrial fibrillation (AF) presented to our hospital for catheter ablation to his symptomatic AF. He had no prior surgical or percutaneous procedure to close or exclude the left atrial appendage (LAA). A transesophageal echocardiography (TEE) was performed to rule out intra-cardiac thrombus prior to the ablation procedure. Although the TEE imaging at multiple acquisition angles was obtained, the LAA could not be visualized and an absence of the LAA was suspected. An absence of the LAA was confirmed using cardiac computed tomography (CT), which included 3D reconstruction. Additionally, the LAA was not visualized with left atrium (LA) angiography. During the ablation procedure, 3D voltage mapping in LA was created and no low voltage area or abnormal potential was recorded around the usual root location of the LAA. Successful electrical pulmonary vein isolation was achieved with no major complications. After six months of follow-up, the patient remained in sinus rhythm without any antiarrhythmic drugs and showed no related clinical symptoms. He stopped his anticoagulation therapy due to lack of evidence of AF recurrence and an absence of LAA. Multimodality imaging allowed us to identify the congenital absence of LAA.