Left atrial appendage septae not visualized with transesophageal echocardiography.

Left atrial appendage (LAA) filter implantation was attempted in an 89 year old male. The LAA size was estimated by transesophageal echocardiography (TEE). Complete LAA obliteration was not achieved. LAA angiography suggested that the LAA was multilobed, likely separated by a thin septae not seen with TEE. MRI or CT may be more appropriate imaging modalities to define LAA anatomy.