The principles of the HART scan are that PCWP does not tell you the emptiness status of the ventricle because an LV with diastolic dysfunction will be empty.

So, if you have someone with a low CI (normal=2.5-4.2 L/min/m sq) then you still need to visualize their ventricle to see their ventricular filling pressure.

The working model is that if you are under 2.3cm for your LVEDD (taken when the LV is biggest...or in the frame after the mitral/inflow valve has closed) you are dry, and if you are over 5.5 then you are dilated.

Most people will be between 4 and 5.5cm, which is because the true indexed values are 2.3-3.1cm/m sq.

So, if it's under 2.3 then there's your answer...unless there is a inferobasolateral wall abnormality because then the measurement will be wide, and you will be fooled into thinking the patient is not undervolume.

Alternatively, you could convert this EDD into a volume with Teichholtz - however, you're assuming that all the dimensions will be the same!
How do you do that conversion?
It's VOLUME= 7/(2.4+D)DDD....effectively 7/Dimension cubed.

The only other alternative is if you can't get any good dimensions because you're foreshortening all of the views or because there's WMA, is to do DP/DT using the MR wave.
The formula is 32/time to get from 1m/sec to 3m/sec.
Once again, 800mmHg/sec means dysfunction is severe, and 1200 means OK.

...actually the same can be done for the RV, except that because the TR velocity is lower, you take




Otherwise, you could try and come up with a volume using biplane Simpson's - take the 2C ES and ED tracings, and the 4C ES and ED tracings, and the computer will do the rest.

Normal volumes are:
Men: 67-155ml (th:65+90)
Women: 56-104ml (th:56 +50)
...which comes out to 35-75 ml/m sq for both sexes!

Another alternative is if you can only get images from the apex:- then you use the area-length method:
Volume=85% of AA/L.... you measure the area in the 4 or 2C and then the long axis length in the 4C.



Finally, the last thing you can do is get out a TEE probe and measure the mid-level transgastric short axis. If this area is <8cm>14 there is wetness. So, the computer spits out the area, you just do the tracing, EXCLUDING the papp muscles from the blood pool - therefore get not a circular trace but a batman-shaped trace.

So, having decided upon ventricular volume, you look at ventricular contractility.
With a TEE you do this through the Fractional Area Change= EDA-ESA/EDA
Normal is 50-65%

If you are using a TTE, then you do Fractional Shortening: EDD-ESD/EDD.
It's useless to use this if there is a wall motion abnormality of the posterior wall, and it tends to be inaccurate in paradoxical septal motion or with RV overload.
Normal is >28% (i.e the dimension of the heart changes by 1/3 from 5cm to 3.5cm).