Transesophageal echocardiography for the detection of left atrial thrombus.

We performed transesophageal two-dimensional echocardiography (TEE) and compared its results with those of transthoracic echocardiography (TTE) in a series of 120 patients with rheumatic mitral stenosis (MS). The patients were selected from a pool of 2000 patients of rheumatic heart disease assessed earlier by clinical examination and TTE. The selection criteria for TEE included one or more of the following: 1. Atrial fibrillation, 2. Embolic episode, 3. Before closed mitral valvotomy or balloon mitral valvuloplasty, 4. Large left atrium (LA) and 5. Evidence of clot or spontaneous echo-contrast in LA. The aim was to study the usefulness of TEE as compared to TTE in the detection of thrombus in LA. LA thrombus was imaged in 34/120 TEE studies as compared to 21/120 TTE studies. In 12/13 patients in whom TTE failed, the clot was present in the left atrial appendage (LAA). In the remaining one patient, poor echo window for TTE was responsible. In 2/6 patients with embolic episode, neither TTE nor TEE could document the presence of clot in LA. The procedure of TEE was well tolerated and there were no complications. We conclude that TEE is a safe and valuable adjunct to TTE with better diagnostic ability for the detection of LA thrombus and should be performed in all patients with MS in whom a clot in LA is suspected or needs to be excluded.