Pressure Half-Time in Pulmonary Regurgitation

How to get PR Severity PHT.

1. Obtain a PWD or a CWD of the pulmonary valve. The flow profile of the aortic valve, in pulmonic regurgitation will show a diastolic flow profile that decays over the diastolic time period. Utilizing the caliper function, mark the Vmax and Vmin to calculate the slope and pressure half time of the diastolic flow profile. A steep slope and a short PHT will be indicative of severe pulmonic regurgitation. Note that mild or moderate pulmonic regurgitation are NOT holodiastolic, whereas severe pulmonic regurgitation IS holodiastolic. In aortic regurgitation, mild and moderate regurgitation IS holodiastolic, whereas, severe aortic regurgitation IS NOT holodiastolic. The differences in the two valve disorders occurs because of the pressure differential between the respective ventricular cavities and the great vessels.