What is the PHT range for moderate mitral stenosis?

What is the PHT range for moderate mitral stenosis?

• A. 60-120 ms
• B. 90-150 ms
• C. 60-90 ms
• D. 150-219 ms

Answer: (D)

Pressure half-time measures how quickly blood flows decelerates across the mitral valve after the onset of diastole. The slower that deceleration (the longer the PHT), the smaller the mitral valve area, and thus the more severe the stenosis. In this question’s scheme, moderate mitral stenosis is defined by a PHT range of about 150 to 219 ms, which corresponds to a reduced valve area in the roughly 1.0–1.5 cm² range. So a PHT in this higher, 150–219 ms window fits the moderate category as used in this test. Keep in mind that different sources may use slightly different cutoffs, and factors like heart rate, rhythm, and left ventricular compliance can affect PHT. When in doubt, corroborate with direct measurements of mitral valve area or planimetry.

Pressure half-time measures how quickly blood flows decelerates across the mitral valve after the onset of diastole. The slower that deceleration (the longer the PHT), the smaller the mitral valve area, and thus the more severe the stenosis. In this question’s scheme, moderate mitral stenosis is defined by a PHT range of about 150 to 219 ms, which corresponds to a reduced valve area in the roughly 1.0–1.5 cm² range. So a PHT in this higher, 150–219 ms window fits the moderate category as used in this test.

Keep in mind that different sources may use slightly different cutoffs, and factors like heart rate, rhythm, and left ventricular compliance can affect PHT. When in doubt, corroborate with direct measurements of mitral valve area or planimetry.