MR severity assessment

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]

Colour flow mapping

Size of flow recruitment is noted
Jet base width at the valve level
Intra atrial jet area if it is a central jet
Jet direction is usually away from a prolapsing leaflet and behind a restricted leaflet

Continuous wave doppler

Shape and density of signal - In severe Mitral regurgitation, the flow is dense and triangular
If as dense as forward flow, it is severe.

Pulse wave doppler(PW)

PW in apical-4-chamber view
E wave more than 1.2m/s indicates severe MR
Even minor mitral stenosis or hyperdynamic circulation can increase E wave
If A-wave dominant, severe MR is virtually ruled out.

vena contracta

vena contracta is the narrowest region of regurgitant jet (usually just below the valve in LA)
>0.7 cm - severe MR

Pulmonary Venous Flow

usually forward throughout cycle
systolic dominant
as MR worsens, there is a blunting of systolic flow
If severe MR - systolic flow reversal.

Regurgitant volume

Mitral regurgitant volume = Mitral inflow volume - LV outflow volume

Mitral inflow volume = Vti * Cross sectional area of mitral valve

LV outflow volume = Vti * Cross sectional area at LV outflow

Regurtitant volume - <20% - mild , >50% severe

PISA (Proximal isovelocity surface area)

The radius of Proximal isovelocity surface area or flow convergence zone which is a 3-dimensional surface area proximal to a narrowed orifice at which all the blood velocities are equal, can be used to calculate the severity of mitral regurgitation. The principle is that if the mitral regurgitation is mild, only the blood nearer to the valve orifice accelerates towards the atrium while in severe regurgitation, blood farther away from the valve moves back.

PISA radius

A simple method to determine severity of mitral regurgitation is to measure the PISA radius. Regurgitation is mild if radius is <0.4 cm and severe if >1 cm.