Adult human valve dimensions and their surgical significance

After cardiac valve replacement, some patients may show little improvement in functional status, in part because their prosthesis is restrictive. Guidelines were sought for valve replacement from measurements of valve circumference and calculated circularized orifice area in 160 postmortem hearts from adults with and without congestive cardiac failure. Multivariate analysis was used to relate valve area to age, sex, height, body surface area and cardiac failure. Only sex and cardiac failure were significantly related to valve area. Body surface area and other variables were poorly related to valve area. The mean (+/- standard deviation) circularized orifice area for adult male (M) and female (F) heart valves in the absence of cardiac failure were: Aortic, M 4.81 +/- 1.30, F 3.73 +/- 0.98; pulmonary, M 4.88 +/- 1.25, F 4.32 +/- 1.03; mitral, M 8.70 +/- 2.08, F 6.94 +/- 1.41; and tricuspid, M 11.9 +/- 2.72, F 9.33 +/- 2.02. In cardiac failure, atrioventricular valves enlarge (p less than 0.004). Guided by these dimensions, the surgeon can aim to insert a prosthesis of appropriate size. Comparison of these sizes with the manufacturer's calculated area for current prostheses shows that most mechanical valves and bioprostheses are potentially restrictive at rest. Improved prosthestic design, valve repair whenever possible, and anular enlargement procedures would be required to eliminate this size disparity.