Application of the vena contracta method for the calculation of the mitral valve area in mitral stenosis.
OBJECTIVE
The vena contracta is the narrowest region of the regurgitant or stenotic jet just downstream the orifice and reflects the size of that orifice. This study was performed to assess the accuracy of the vena contracta width (VCW) in evaluating the severity of mitral stenosis (MS) and to compare the mitral valve area (MVA) determined by VCW with MVAs obtained by other more traditional echocardiographic methods.


METHODS
We studied 59 patients (43 females, 42 +/- 14 years) with MS. VCW was measured in the apical four chamber view by Doppler color flow mapping. The largest diameter of the VCW during diastole was measured for at least three cardiac cycles and averaged. MVA was calculated from the following equation: pir(2), where r = VCW/2. MVA was also determined by planimetry, the pressure half-time method, and by the Gorlin formula.


RESULTS
In this study, the width of the vena contracta ranged from 0.89 to 1.73 cm (mean 1.30 +/- 0.21). MVA, calculated based on the VCW, ranged from 0.63 to 2.35 cm(2) (mean 1.36 +/- 0.41). MVA by VCW (1.36 +/- 0.41 cm(2)) showed good correlations with three comparative techniques: (1) the cross-sectional area by planimetry (1.35 +/- 0.36 cm(2), mean difference = 0.21 +/- 0.16 cm(2), y = 0.91x + 0.14, r = 0.79, SEE = 0.26 cm(2), p < 0.001); (2) the area derived from the Doppler pressure half-time (1.27 +/- 0.32 cm(2), mean difference = 0.22 +/- 0.19 cm(2), y = 0.97x + 0.13, r = 0.76, SEE = 0.27 cm(2), p < 0.001), and (3) the area derived from the Gorlin equation in the 18 patients who underwent catheterization (1.27 +/- 0.35 cm(2), mean difference = 0.19 +/- 0.16, y = 0.98x + 0.05, r = 0.81, SEE = 0.26 cm(2), p < 0.001).


CONCLUSIONS
These findings suggest that Doppler color flow imaging of the MS jet in the vena contracta can provide an accurate estimation of MVA and appears to be potentially applicable in the assessment of the severity of MS.
Abaci
Adnan
A
Department of Cardiology, Erciyes University School of Medicine, Kayseri, Turkey. abacia@hotmail.com
Oguzhan
Abdurrahman
A
Unal
Sükrü
S
Kiranatli
Burhanettin
B
Eryol
Namik Kemal
NK
Basar
Emrullah
E
Ergin
Ali
A
Cetin
Servet
S
D000328:Adult; D000368:Aged; D018618:Echocardiography, Doppler, Color / Q000379:methods; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008297:Male; D008875:Middle Aged; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology*; D015588:Observer Variation; D012044:Regression Analysis; D012720:Severity of Illness Index; D013223:Statistics as Topic