We report a case of left atrial myxoma simulating a thrombus on transthoracic echocardiography, but correctly diagnosed using transesophageal echocardiography. As this tumor is usually fatal unless surgically resected, a correct diagnosis is essential. Myxomas which do not prolapse between the mitral valve leaflets and coexist with mitral stenosis may be difficult to diagnose accurately using transthoracic echocardiography. The advantages of transesophageal compared with transthoracic echocardiography in the diagnosis of nonclassical left atrial myxoma are discussed.

To determine if aortic stenosis severity could be accurately measured by two-dimensional transesophageal echocardiography (TEE), 62 adult subjects (mean age 66 +/- 12 years) with aortic stenosis had their aortic valve area (AVA) determined by direct planimetry using TEE, and with the continuity equation using combined transthoracic Doppler and two-dimensional echocardiography (TTE). Eighteen subjects had AVA calculated by the Gorlin method during catheterization. An excellent correlation (r = 0.93, SEE = 0.17 cm2) was found between AVA determined by TEE (mean 1.24 +/- 0.49 cm2; range 0.40 to 2.26 cm2) and TTE (mean 1.23 +/- 0.46 cm2; range 0.40 to 2.23 cm2). The absolute (0.13 +/- 0.12 cm2) and percent (10.8 +/- 8.9%) differences between AVA determined by TEE versus TTE were small. Excellent correlations between AVA by TEE and TTE were also found in subjects with normal systolic function (r = 0.95, SEE = 0.14 cm2; n = 38) and impaired function (r = 0.91, SEE = 0.21 cm2; n = 24). AVA determined by catheterization correlated better with AVA measured by TEE (r = 0.91, SEE = 0.15 cm2) than AVA measured with TTE (r = 0.84, SEE = 0.19 cm2). These data demonstrate that AVA can be accurately measured by direct planimetry using TEE in subjects with aortic stenosis. TEE may become an important adjunct to transthoracic echocardiography in the assessment of aortic stenosis severity.