In AFib, why should a Doppler assessment of MS sample multiple waveforms?

• A. To average the deceleration times only
• B. To derive the average velocity and PHT from multiple waveforms
• C. To determine E velocity
• D. To select the waveform with the highest velocity

Answer: (B)

In AFib the heart rate is irregular, so the mitral Doppler signal varies from beat to beat. Mitral stenosis assessment relies on the early diastolic E wave velocity and its deceleration time to estimate the pressure half-time and thus the mitral valve area. Because each beat can produce a different E velocity and deceleration time, sampling only one waveform may give a misleading result. By recording several consecutive beats and deriving an average velocity and PHT from those waveforms, you obtain a more stable and representative measurement of diastolic flow, leading to a more accurate MVA calculation. Averaging both velocity and PHT accounts for beat-to-beat variability, whereas focusing on the highest velocity or on deceleration times alone would not provide the proper, balanced assessment.