Following a mitral commissurotomy, the valve orifice can be accurately evaluated with the :
A.) Doppler, by estimating valve area using the pressure half-time formula.
B.) Doppler, by the velocity of the flow and Bernoulli's equation.
C.) Two-dimensional echodardiography, by imaging the actual orifice.
D.) M mode, by defining the leaflet separation.
A.) The surgeon distorts the valve at the time of commissurotomy, and the resultant morphology is not well visualized by two-dimensional echo. M mode has never been optimal for valve orifice determinations, and the bernoulli equation gives velocity information but not orifice size. The most accurate way to determine valve size is with the pressure half-time equation.
(this multiple choice question has been scrambled)