Utility of three-dimensional echocardiography during balloon mitral valvuloplasty

We investigated the role of three-dimensional echocardiography in assessing mitral valve anatomy in greater detail in patients immediately before and after balloon mitral valvuloplasty (BMV).

Three-dimensional echocardiography is a recently developed, evolving imaging technique that allows visualization of intracardiac structures from any perspective.

We studied 19 patients undergoing BMV using transesophageal echocardiography (TEE) (Chicago, Illinois) to image the mitral valve. The TEE was interfaced to a TomTec three-dimensional workstation that allows electrocardiographic and respiratory cycle gated image acquisition. The acquired images are digitized, and after postprocessing a three-dimensional image is reconstructed. The mitral valve was viewed "en-face" as if looking up from the left ventricle.

The mean mitral valve area (by pressure half-time from the Doppler of the two-dimensional echocardiogram) increased after BMV from 0.86+/-0.06 cm2 to 2.07+/-0.10 cm2, p < 0.0001. This was similar to the mitral valve areas obtained by planimetry from the three-dimensional images. The three-dimensional reconstructions showed a complete commissural split in 10 patients and partial splitting in 9 patients. In three of the eight patients who had an increase in the amount of mitral regurgitation secondary to BMV, the three-dimensional reconstructions were able to detect tears within the valve leaflet. One leaflet tear actually extended up to the mitral valve annulus and was associated with the only case of severe mitral regurgitation.

The three-dimensional echocardiographic reconstruction enabled visualization of the mitral valve so that commissural splitting and leaflet tears not seen on the two-dimensional echocardiogram became visible.