RESUMEN
A 64-year-old African American woman presented for defibrillator threshold testing (DFTs) after a recent hospitalization for ventricular fibrillation terminated by her ICD. She had a known history of non-ischemic cardiomyopathy, atrial fibrillation, rheumatic mitral valve disease s/p mitral valve replacement and a redo after subsequent endocarditis. In preparation for the DFTs, the patient underwent a transesophageal echocardiogram (TEE) to rule our left atrial (LA) or LA appendage thrombus. Patient was found to have a surgically closed appendage. Within the body of the closed appendage, a mobile thrombus was seen with clot free areas surrounding the thrombus. Doppler and contrast studies confirmed that there was no communication between the LA and the appendage. The patient underwent DFTs without complication and a follow-up TEE confirmed the presence of the clot in the non-communicating LA appendage.