Cor triatriatum sinister: assessment by live/real time three-dimensional transthoracic echocardiography.

We report a 49-year-old morbidly obese female with a poor acoustic window in whom live/real time three-dimensional transthoracic echocardiography was able to make a confident diagnosis of cor triatriatum sinister. En face views of the membrane facilitated accurate assessment of the size and shape of the large nonobstructing opening in the membrane. Maximum dimensions of the opening were 3.06 x 1.03 cm and area was 2.3 cm(2).