@vector2 I think we disagree here in some places but agree in others:
All mitral regurg measurements (qualitative and quantitative) are load-dependent: RVol/R% Regurgitant volume%, Vena Contracta (VC), EROA (Effective regurgitant orifice area), are all load-dependent. MR it self is load-dependent so it should follow that all measurements are load-dependent. EROA and VC are less theoretically less load-dependent because a small area change can mean a big change in flow, so it's harder to detect the change in a smaller dimension due to the margin of error.
Yea man, I agree, that's why I also said *theoretically* load independent (assuming we're not talking about rheumatic MS with concomitant MR where the regurgitant orifice is relatively fixed throughout the cardiac cycle).
According to the 2014 AHA/ACC guidelines, VC is only 1 of the quantitative measures that should be taken into account in the context of the big picture. I don't believe the 2017 guideline change any of the diagnostic criteria but i'd be happy to be corrected. I do agree with you that PISA isn't a hemisphere and prone to a lot of errors. Personally, I feel that VC is just as prone too error. It's about as user-dependent as Vp.
I disagree with the 2D VC measurement. The valve cordes do not read the text book, sometimes you have to sweep to the edge of A1 to get the MR. Also how do you know your VC is in line with the the actual direction of flow?? How do you know your LAX view is actually lined up perpendicular to A2-P2 commissure? How do you know the VC you get at 120 degree isn't foreshortened when you should be at 135 degrees? I don't like the VC measurement at all to be honest, but it's only my personal opinion.
Sorry, my fault, I was mixing up my guidelines. I was referring to the updated 2017 JASE
Recommendations for Noninvasive Evaluation of Native Valvular Regurgitation in which RVol and RF assumed more prominence, E Wave inflow changed to 1.2 from 1.5 m/s, cautioned that 2d EROA for secondary MR may be underestimating severity, emphasized CMR. You are correct that the algorithm from 2014 to 2017 ACC/AHA did not change significantly.
Let me clarify what was talking about when I said making sure your beam is ME-AVLAX and you are cutting through A2-P2 to use 2d VC. I specifically mean that your MR is
also coming through A2-P2 (which you have confirmed looking at the leaflets with a 3d surgeons view) because hopefully you are evaluating someone who has the most common primary lesion which is P2 prolapse. Obviously it's nonsensical to use 2d VC if your jet is eccentrically directed in a medial to lateral or lateral to medial or another oblique to the AVLAX orientation. Very specifically, to use 2d VC I think your 2d image with CFD needs to capture 1. flow acceleration 2. the VC 3. the main jet body in the same plane. If you don't have all those things in your picture then you are correct that 2d VC is probably garbage. And even if you have all those things, obviously you should never use just one measurement in one plane to make a diagnosis.
Now, you might ask why I am using VC if I have have the ability to use 3d to check my orientation and leaflet pathology. It's because frequently I don't have access to an epic 7 or GE vivid and I have to use a POS portable cx-50 that only has 3d zoom and goes to 2hz if I activate CFD with 3d on.
I like the 3D color EROA measurement but it also runs into problems of foreshortening and frame rate. (most X8-2t probes with Epic7C machines only gets like 8Hz frame rate if you do 3d with color). I am a HUGE fan of the 3D ejection volume to calculate the ERV, but a lot of electrocardiographers don't do this and it's never been "validated" by any study as far as I know. Still, i think this is the most reliable measure, but it still should be taken into the context of the big picture.
Even with poor frame rate, 3d EROA or VCA, 3d RVol (along with 3d volumetric [assuming good endocardial border definition], which I should've mentioned, which is just waiting for validation) are the likely gold standards for mitral regurg echocardiography if you look at their R coefficients compared to the true gold standard which is CMR.
AbstractAims. Vena contracta area (VCA3D), derived by 3D colour Doppler echocardiography, has already been validated against cardiac magnetic resonance ima
academic.oup.com
The aim of this study was to evaluate feasibility and accuracy of real-time 3-dimensional (3D) echocardiography for quantification of mitral regurgita…
www.sciencedirect.com
I used to be a big fan of the S wave reversal but then it was explained to me by an experienced cardiologist that it's merely a proxy measure of a previously not very sensitive finding during fluoroscopy - If they did an LV gram while doing a LHC, it would clue them in if they see the pulm vein tracing during the fluro shot. The S wave reversal was just an echography proxy measure for that but it's very non-sensitive
I don't understand how the anecdote about fluoro negates its utility since (in my amateur opinion) it seems that it's gotta be a significant volume of blood refluxing retrograde during an LV gram to be able to pick up angiographic pulmonary vein blush. Regardless though, the hallmark of holosystolic pulmonary vein flow reversal isn't that it's sensitive- it's that it's a pretty specific marker of severe mitral regurgitation.
To sum this up I am not sure if there is any set way to do it. It takes an experience person years to understand all the nuances and i still got a ways to go. The measurement of MR is not an exactly science either, because you have to then take into account if this is primary or secondary. The data and evidence on primary is overwhelming while secondary MR is still somewhat in a gray area.
Agree.
However, I do believe that we should account of the load conditions when doing the TEE. The most experienced cardiologists do this, e.g. we always do a phenylephrine challenge after the mitraclip if the BP is low - make sure the clip actually did something and not just the general anesthesia making it better.
I think you have to account for the load conditions within reason, especially if your post-clip deployments are like mine where post-clip severity is usually the cardiologist "eyeballing" jet areas etc. Stuff like VC and EROA are going to have a bit of a dynamic change during the cardiac cycle as well, but ime I've never noticed a significant change unless the pt's volume status/contractility changed
significantly or BP was 40+ points off the baseline.