Three-dimensional echocardiographic planimetry of maximal regurgitant orifice area in myxomatous mitral regurgitation: intraoperative comparison with proximal flow convergence.
OBJECTIVE
We sought to validate direct planimetry of mitral regurgitant orifice area from three-dimensional echocardiographic reconstructions.


BACKGROUND
Regurgitant orifice area (ROA) is an important measure of the severity of mitral regurgitation (MR) that up to now has been calculated from hemodynamic data rather than measured directly. We hypothesized that improved spatial resolution of the mitral valve (MV) with three-dimensional (3D) echo might allow accurate planimetry of ROA.


METHODS
We reconstructed the MV using 3D echo with 3 degrees rotational acquisitions (TomTec) using a transesophageal (TEE) multiplane probe in 15 patients undergoing MV repair (age 59 +/- 11 years). One observer reconstructed the prolapsing mitral leaflet in a left atrial plane parallel to the ROA and planimetered the two-dimensional (2D) projection of the maximal ROA. A second observer, blinded to the results of the first, calculated maximal ROA using the proximal convergence method defined as maximal flow rate (2pi(r2)va, where r is the radius of a color alias contour with velocity va) divided by regurgitant peak velocity (obtained by continuous wave [CW] Doppler) and corrected as necessary for proximal flow constraint.


RESULTS
Maximal ROA was 0.79 +/- 0.39 (mean +/- SD) cm2 by 3D and 0.86 +/- 0.42 cm2 by proximal convergence (p = NS). Maximal ROA by 3D echo (y) was highly correlated with the corresponding flow measurement (x) (y = 0.87x + 0.03, r = 0.95, p < 0.001) with close agreement seen (AROA (y - x) = 0.07 +/- 0.12 cm2).


CONCLUSIONS
3D echo imaging of the MV allows direct visualization and planimetry of the ROA in patients with severe MR with good agreement to flow-based proximal convergence measurements.
Cardiovascular Imaging Center, Department of Cardiology, The Cleveland Clinic Foundation, Ohio 44195, USA.
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CS
Breburda
B P
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Griffin
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Rodriguez
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Cosgrove
J D
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Thomas
D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D002306:Cardiac Volume / Q000502:physiology*; D004452:Echocardiography; D015150:Echocardiography, Doppler; D019560:Echocardiography, Three-Dimensional; D017548:Echocardiography, Transesophageal; D005260:Female; D006338:Heart Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D006349:Heart Valve Diseases / Q000150:complications / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D008945:Mitral Valve Prolapse / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D009232:Myxoma / Q000150:complications / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D016037:Single-Blind Method