Which method uses the deceleration time of the mitral inflow (pressure half-time) to estimate the mitral valve area?

Which method uses the deceleration time of the mitral inflow (pressure half-time) to estimate the mitral valve area?

• A. Planimetry
• B. Pressure half time
• C. Continuity equation
• D. Mean gradient

Answer: (B)

The idea being tested is how the rate at which the transmitral pressure difference decays after the early filling peak relates to how wide the mitral valve is. In Doppler, we measure the time from the peak of the E wave until the pressure gradient across the valve falls to half of its peak value. That time is the pressure half-time. A smaller valve area (more severe stenosis) means the gradient decays more slowly, so the pressure half-time is longer; a larger valve area yields a shorter pressure half-time. By using the relationship MVA ≈ 220 / PHT (with PHT in milliseconds), you convert the measured deceleration time into an estimated mitral valve area. This approach is specifically about the speed of pressure equilibration across the mitral valve, not about tracing the actual orifice size (planimetry), calculating flow-based volumes (continuity equation), or using mean gradients with a formula like Gorlin. It’s also worth noting that certain conditions (abnormal LV compliance, very high heart rate, significant regurgitation) can affect accuracy, so in those cases other methods may be considered.

The idea being tested is how the rate at which the transmitral pressure difference decays after the early filling peak relates to how wide the mitral valve is. In Doppler, we measure the time from the peak of the E wave until the pressure gradient across the valve falls to half of its peak value. That time is the pressure half-time. A smaller valve area (more severe stenosis) means the gradient decays more slowly, so the pressure half-time is longer; a larger valve area yields a shorter pressure half-time. By using the relationship MVA ≈ 220 / PHT (with PHT in milliseconds), you convert the measured deceleration time into an estimated mitral valve area.

This approach is specifically about the speed of pressure equilibration across the mitral valve, not about tracing the actual orifice size (planimetry), calculating flow-based volumes (continuity equation), or using mean gradients with a formula like Gorlin. It’s also worth noting that certain conditions (abnormal LV compliance, very high heart rate, significant regurgitation) can affect accuracy, so in those cases other methods may be considered.