Atrioventricular valve orifice areas in normal subjects: determination by cross-sectional and Doppler echocardiography.

Mitral and tricuspid valve orifice areas were determined in 78 healthy subjects (age range, 2 months-50 years; mean, 20 +/- 13 years; 43 male, 35 female; body surface area, 0.25-1.9 m2; mean, 1.24 +/- 0.45 m2) by a combined echo-Doppler approach to establish normal values and their relationship with body surface area. Mitral valve orifice area by direct planimetry (3.37 +/- 1.13 cm2; range, 0.52-5.6 cm2) and by continuity equation (3.62 +/- 1.08 cm2; range, 0.66-5.4 cm2) were similar (r = 0.85, P < 0.0001). Tricuspid valve orifice area (4.07 +/- 1.5 cm2; range 0.62-7.2 cm2) by continuity equation had a close correlation with mitral valve orifice area (r = 0.76, P < 0.001). Mitral and tricuspid valve orifice areas were significantly correlated to body surface area (r = 0.85 and 0.77, respectively), left and right ventricular outflow tract diameters (r = 0.90 and 0.79, respectively) and age (r = 0.70 and 0.61, respectively). These data provide normal values for atrioventricular valve orifice areas in normal subjects with a wide range of body surface area and support the practice of indexing valve area by body surface area.