Which statement about PHT and MS severity classification is true?

Which statement about PHT and MS severity classification is true?

• A. PHT is not used to classify MS severity.
• B. PHT thresholds are identical for all etiologies.
• C. PHT is used to categorize MS severity with thresholds.
• D. PHT cannot be measured in MS.

Answer: (C)

In evaluating mitral stenosis, pressure half-time (PHT) is a Doppler parameter used to estimate mitral valve area and to classify severity. You measure the rate at which the transmitral gradient decays after the early diastolic peak; PHT is the time for that gradient to fall to half of its initial value. A longer PHT means a smaller valve area, which corresponds to more severe stenosis. Clinically, these PHT-derived values are mapped to severity thresholds to categorize mild, moderate, or severe MS. That’s why the true statement is that PHT is used to categorize MS severity with thresholds. The other ideas aren’t correct because PHT is indeed used for this purpose, thresholds are not universal across all etiologies, and PHT can be measured in MS.

In evaluating mitral stenosis, pressure half-time (PHT) is a Doppler parameter used to estimate mitral valve area and to classify severity. You measure the rate at which the transmitral gradient decays after the early diastolic peak; PHT is the time for that gradient to fall to half of its initial value. A longer PHT means a smaller valve area, which corresponds to more severe stenosis. Clinically, these PHT-derived values are mapped to severity thresholds to categorize mild, moderate, or severe MS. That’s why the true statement is that PHT is used to categorize MS severity with thresholds.

The other ideas aren’t correct because PHT is indeed used for this purpose, thresholds are not universal across all etiologies, and PHT can be measured in MS.