FujiFilm SonoSite X-Porte User Manual page 198

Pressure Half Time (PHT) in msec
Oh, J.K., J.B. Seward, A.J. Tajik. The Echo Manual. 3rd ed., Philadelphia: Lippincott, Williams, and Wilkins,
(2007), p.73-74.
Reynolds, Terry. The Echocardiographer's Pocket Reference. 2nd ed., School of Cardiac Ultrasound,
Arizona Heart Institute, (2000), p. 391.
PHT = DT * 0.29 (time required for the pressure gradient to fall half its maximum level)
where:
DT = deceleration time
Proximal Isovelocity Surface Area (PISA) in cm
Oh, J.K., J.B. Seward, A.J. Tajik. The Echo Manual. 3rd ed., Philadelphia: Lippincott, Williams, and Wilkins,
(2007), p.74-76.
2
PISA = 2 π r
where:
r = aliasing radius
Qp/Qs
Oh, J.K., J.B. Seward, A.J. Tajik. The Echo Manual. 3rd ed., Philadelphia: Lippincott, Williams, and Wilkins,
(2007), p.70-72.
Qp/Qs = SV Qp site/SV Qs site = RVOT SV/LVOT SV
where:
RVOT SV = RVOT CSA* RVOT VTI = π/4 * RVOT diameter
LVOT SV = LVOT CSA * LVOT VTI = π/4 * LVOT diameter
Regurgitant Fraction (RF) in percent
Oh, J.K., J.B. Seward, A.J. Tajik.The Echo Manual. 3rd ed., Philadelphia: Lippincott, Williams, and Wilkins,
(2007), p.215-217.
RF = RV/ MV SV
where:
RV = Regurgitant Volume
MV SV = Mitral Stroke Volume (Mitral CSA * Mitral VTI)
Mitral CSA = cross-sectional area calculated using annulus diameter
Regurgitant Volume (RV) in cc
Oh, J.K., J.B. Seward, A.J. Tajik. The Echo Manual. 3rd ed., Lippincott, Williams, and Wilkins, (2007),
p.215-217.
RV = ERO * MR VTI/100
6-12
2
2
* RVOT VTI
2
* LVOT VTI
Measurement references