Three-dimensional echocardiographic assessment of annular shape changes in the normal and regurgitant mitral valve.
OBJECTIVE
To compare mitral annular shape and motion throughout the cardiac cycle in patients with normal hearts versus those with functional mitral regurgitation (FMR).


BACKGROUND
The causes of mitral regurgitation without valvular disease are unclear, but the condition is associated with changes in annular shape and dynamics. Three-dimensional (3D) imaging provides a more comprehensive view of annular structure and allows accurate reconstructions at high spatial and temporal resolution.


METHODS
Nine normal subjects and 8 patients with FMR undergoing surgery underwent rotationally scanned transesophageal echocardiography. At every video frame of 1 sinus beat, the mitral annulus was manually traced and reconstructed in 3D by Fourier series. Annular projected area, nonplanarity, eccentricity, perimeter length, and interpeak and intervalley spans were determined at 10 time points in systole and 10 points in diastole.


RESULTS
The mitral annulus in patients with FMR had a larger area, perimeter, and interpeak span than in normal subjects (P <.001 for all). At mid-systole in normal annuli, area and perimeter reach a minimum, nonplanarity is greatest, and projected shape is least circular. These cyclic variations were not significant in patients with FMR. Annular area change closely paralleled perimeter change in all patients (mean r = 0.96 +/- 0.07).


CONCLUSIONS
FMR is associated with annular dilation and reduced cyclic variation in annular shape and area. Normal mitral valve function may depend on normal annular 3D shape and dimensions as well as annular plasticity. These observations may have implications for design and selection of mitral annular prostheses.
Kaplan
S R
SR
Division of Cardiology, Department of Medicine, University of Washington, Seattle, WA 98195-6422, USA.
Bashein
G
G
Sheehan
F H
FH
Legget
M E
ME
Munt
B
B
Li
X N
XN
Sivarajan
M
M
Bolson
E L
EL
Zeppa
M
M
Arch
M Z
MZ
Martin
R W
RW
D000328:Adult; D000368:Aged; D003971:Diastole / Q000502:physiology; D019560:Echocardiography, Three-Dimensional; D017548:Echocardiography, Transesophageal; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging* / Q000502:physiology; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000601:surgery; D015588:Observer Variation; D012044:Regression Analysis; D012720:Severity of Illness Index; D013599:Systole / Q000502:physiology