Pulmonary Question

[salley]

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Hi there. I having a little trouble finding information on TR velocity. While I know it's the pressure difference between the right atrium and ventricle, I am still confused. When exactly do we use it- and why can we not simply use RVSP when looking for pulmonary arterial hypertension/ pulmonary hypertension with an echo? What extra piece of information does using TR velocity give us? Thank you for your time.

 

[evilbooyaa]

TR Velocity? A quick google search states that this apparently means 'Tricuspid Regurgitation Velocity'. Is that's what you mean?

Can you define what TR is?
RVSP = Right Ventricle Systolic Pressure in my head, so correct that as well if need be.

 

[salley]

Yes, that is correct. I do understand what it means. I was just wondering when we would use it instead of RVSP as an estimation for Pulmonary Artery Pressure. I know a TR velocity of above 2.8 correlates with a RVSP of above 35, but where and why do we use it? Is it only in certain circumstances? Thank you.

 

[VisionaryTics]

An echo is not a catheterization. It is impossible to directly measure PASP using the echo, so you infer it by measuring tricuspid regurg velocity (you can measure flows with an echo by duplex mode).

The gold standard for PHTN would by a right-heart catheterization which allows us to directly measure pressures using a pressure transducer. An echo is a cheap, non-invasive substitute.

 

[evilbooyaa]

Yes, that is correct. I do understand what it means. I was just wondering when we would use it instead of RVSP as an estimation for Pulmonary Artery Pressure. I know a TR velocity of above 2.8 correlates with a RVSP of above 35, but where and why do we use it? Is it only in certain circumstances? Thank you.

Ah okay then.

Like VT posted above, you cannot measure a pressure (RSVP) with an echo. I don't know much more than that, but correlating a velocity to pressure seems like something that could be something that you could extrapolate from a velocity.

 

[salley]

On an echo, you can measure both TR velocity AND the RVSP, and you do so to estimate the PAP before performing the RHC to determine if it is necessary. But basically what you're all saying is it doesn't matter if you do the RVSP or the TR velocity to estimate the PAP on the echo- there is no real difference, correct?

 

[23 from me]

TRV is the measured value from echo, while RVSP is calculated. RVSP = 4(TRV)squared + RAP. RVSP roughly correlates with PASP assuming no pulmonary stensosis.

Echo has limitations for estimating PASP, and it tends to overestimate RVSP. RAP estimates are subjective.

A percentage of echos will have an unmeasurable TRV, and no RVSP estimate can be obtained from these studies. Generally, a TRV of 3 or higher is a good threshold for PH screening. If there are PH symptoms or other suspicious signs, neither an unmeasured TRV nor a TRV less than 3 rule out PH. Right heart cath is the gold standard to measure mean PAP and diagnose PH.