Points
PW Doppler of pulmonary venous flow is performed in the apical 4-chamber view and aids in the assessment of LV diastolic function. Color flow imaging is useful for the proper location of the sample volume in the right upper pulmonary vein.
Doppler recordings are obtained by angulating the transducer superiorly such that the aortic valve is seen. A 2-mm to 3-mm sample volume is placed 0.5 cm into the pulmonary vein for optimal recording of the spectral waveforms. Wall filter settings must be low enough to display the onset and cessation of the atrial reversal (Ar) velocity waveform. It is recommended that spectral recordings be obtained at a sweep speed of 50 to 100 mm/s at end-expiration and that measurements include the average of ≥3 consecutive cardiac cycles.
Measurements include peak S and D velocities, the S/D ratio, systolic filling fraction (Stime-velocity integral/[Stime-velocity integral + Dtime-velocity integral]), and peak Ar velocity in late diastole. Another measurement is the time difference between Ar duration and mitral A-wave duration (Ar - A).
With increased LVEDP, Ar velocity and duration increase, as well as the Ar -A duration.
In patients with depressed EFs, reduced systolic filling fractions (<40%)are related to decreased LA compliance and increased mean LA pressure.