Mitral valve area (MVA) can be estimated using the pressure half-time (PHT) method, which relates the time it takes for the mitral valve pressure gradient to reduce by half during diastole. The formula used is:
MVA (cm²) = 220 / PHT (ms)
A PHT of 220 ms yields:
MVA = 220 / 220 = 1.0 cm²
However, this is a classic teaching; in actual practice, the formula is widely accepted and validated.
Given this, the options need to be reviewed carefully. Since the PHT is 220 ms, the MVA is approximately 1.0 cm², consistent with moderate mitral stenosis.
Therefore, the correct answer is B (1.0 cm²).
(Please note: Since your options may contain a typographical error—4,4 cm² instead of 4.4 cm²—and considering typical values, option B fits best.)
This method and interpretation are described in the "Textbook of Clinical Echocardiography, 6e", Chapter on Mitral Stenosis and Doppler Hemodynamics【20:385-390†Textbook of Clinical Echocardiography】.
