Three-dimensional echocardiography for assessment of mitral valve regurgitation

Estimation of severity has become a significant predictor of outcomes and a pivotal factor in the management of mitral regurgitation. The flow convergence formula has become one of the most important quantitative methods for valve regurgitation in echocardiography. Nevertheless, it has many assumptions leading to over or underestimations. With recent development of a much improved three-dimensional volumetric imaging, there have been efforts in trying to overcome these two-dimensional limitations using three-dimensional approaches. Hence, this review is mainly focused on three-dimensional color flow and techniques of quantifying the severity of mitral regurgitation using three-dimensional echocardiography.

Investigators have found that imaging the proximal flow convergence region (PFCR) and measuring the vena contracta area are highly feasible. The shape of the PFCR may vary, being a hemisphere, prolate or oblate hemispheroid, or hemi-ellipsoid, based on these findings; three-dimensional formulas have a stronger correlation, less underestimation and better accuracy than the two-dimensional proximal isovelocity surface area method. Direct measurements of the effective regurgitant orifice are also feasible and serve as an alternative to hemodynamic formulas.

Three-dimensional echocardiography has made major advances with the three-dimensional matrix transesophageal echo and will be a clinically viable tool as probe technology and software evolve.