Abstract
Previously we validated the direct measurement of the regurgitant orifice area (ROA) using 3-D echo for the assessment of the severity of mitral regurgitation, in comparison with the flow convergence method, but the relationship between prolapse geometry and ROA is unknown. Method: To test the hypothesis that the 3-D extent of prolapse might predict ROA and thus the severity of mitral regurgitation, we reconstructed the mitral valve using 3D echo (30 rotational acquisitions, TomTec, HP 2500) with a multiplane transesophageal probe in 14 pts undergoing mitral valve repair (age 59 ± 11 yrs, 9 M) The area of prolapse was directly planimetered in 3D echo from a left atrial view and the volume of prolapse was manually traced with paraplane echo (1 mm slices), these were compared to the directly planimetered ROA. Results: All pts had prolapse of the posterior leaflet. 12 pts had a flail portion. 3D echo reconstruction was accomplished in all 14 pts. Maximal ROA by 3D echo correlated significantly with area of prolapse with r = 0.58, p < 0.04, SEE 0.35 with the regression line equation of y = 0.07x + 0.4. Mean maximal ROA was 0.78 ± 0.4 cm2 and maximal area of prolapse was 4.87 ± 3 cm2 Maximal volume of prolapse was 48 ± 3.7 ml and did not correlate with ROA. Prolapse with a small volume extending mainly along the leaflet edge let to a large ROA. Conclusion: Severity of MR as defined by maximal size of ROA is predicted by maximal area but not volume of prolapse using direct planimetry by 3D echo.