EchocardiographyExercise StressMiscExercise Stress
Duke Treadmill ScoreMaximum Predicted Heart Rate (DOB)Mets & VO2 (Treadmill)
Maximum Predicted Heart Rate (Age)Max. Predicted Heart Rate AchievedRate Pressure Product

PISA Method in Quantitating Mitral Stenosis


r cm
Vr cm/s
VMax m/s
α deg0

VFR cc
MVA cm2



Definition of Mitral Stenosis Severity

MVA (cm2)
Normal 4.0-5.0
Mild >1.5
Moderate 1.0-1.5
Severe <1.0

PISA (Mitral Stenosis)

Estimation of the mitral valve area using the principle of conservation of mass by analyzing the Proximal Isovelocity hemispheric Surface Area (PISA) of the flow convergence on the atrial side. Due to funnel shape of the proximal convergence, it is important to take into account the angle correction, α when the aliasing velocity (Vr <40 cm/s). If the aliasing velocity is high (Vr >40 cm/s), it is not as important since the PISA approximates a hemisphere.

2πr2 *

Variable Definition
2 × π × r2 Proximal isovelocity hemispheric surface area at a radial distance r from the orifice
Vr Aliasing velocity at the radial distance r (cm/s)
VMax Peak mitral stenosis velocity by CW (m/s)
α Angle between two mitral leaflets on the atrial side (degree0)
VFR Volume Flow Rate (cc)
MVA Mitral valve area (cm2)


Baumgartner H, et al. Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice. J Am Soc Echocardiogr. 2009 Jan;22(1):14, 17.
Rodriguez L., et al. Validation of the proximal flow convergence method. calculation of orifice area in patients with mitral stenosis. Circulation. 1993 Sep; 88(3):1157-65.


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