Possible (Low-Flow) Low-Gradient Aortic Stenosis?

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Seaton

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I was introduced to a new term when seeing my surgeon (Mr Christopher Young) for the first time in August: Low-Flow,Low-Gradient Aortic Stenosis (LF-LG AS).

I went home and read some google:

http://circ.ahajournals.org/content/...AHA.113.005718
http://content.onlinejacc.org/articl...icleid=1377146


According to my surgeon there is discordance between my gradient readings (currently peak 41 mm/Hg, mean 25 mm/Hg) and my Effective Area Orifice (0.77cm²) of my aorta. I asked about my Ejection Fraction and he said that appears normal at 70%.

My combined gradients and EF readings seem to indicate a longer waiting time before surgical intervention. But my stenotic valve area suggests something else might be going on, unless the EOA echo readings are inaccurate (two recent echo readings have indicated 1.0 cm² and 0.77cm² respectively). It seems the surgeon is adhering to the 0.77cm² reading, as this is what he has written on my recent follow-up letter.

Mr Young said he needed to get to the bottom of the discrepancy in my readings and rule out Low-Gradient Aortic Stenosis (I’d never heard of this term). He would take my readings to an ‘echo conference’, where other valve/echo specialists would possibly offer alternative opinions that would maybe counter his analysis. From my current readings he felt it was too early to operate and that he would most likely want to see me in six months time (February) '... unless the feeling at the [echo] meeting is that this should have an earlier intervention'.

I had previously been booked to see a cardiologist in November but some weeks back received a call cancelling that appointment and instead was given an appointment in September with a consultant valve specialist. I was also being booked for an echo stress test.

I had the echo stress test on the cardiac treadmill last Wednesday at St Thomas’ Hospital in London. I lasted about 7 minutes. I think these tests often run for about 12 minutes. I was beginning to get winded by 7 and felt real resistance from my body and lungs. So I requested they stop (they’d previously said I could stop at any time if I felt like doing so). Whether the resistance was to do with my ‘Chronic Fatigue Syndrome’, my general lack of fitness, or something specifically heart related, I’'ve no idea.

Next day I saw the valve specialist for the first time, Dr Jane Hancock. She was excellent. Informative, down to earth, fully engaged (despite an obvious huge caseload).

She asked me why I had stopped at 7 minutes on the stress test. I explained I was becoming weary and a bit too winded.
She said from now on I would be under her care until further notice and she would be cancelling my appointments with other consultants. She felt it was better if there was consolidation of care at this stage to prevent confusion.

It appears my readings are in a ‘grey area’. She said there was perplexing discordance between my gradient readings and valve reading . One reading suggesting things were relatively steady, another that I was in severe stenosis with potential problems. Finding out exactly what was going on was a challenge that would need the collation of a variety of data sources so that a proper diagnosis could be made.

She then went off for 15 minutes to look at my previous echocardiogram results more closely. She came back and said at first glance it seems my valve area is more moderate than originally thought.
'Your valve area appears to be 1.08 cm² but I'll need to crunch a few more more numbers to be sure. I need to factor in your body surface area.'
She then did some complicated maths on her pad and I glimpsed the final figure she wrote: 0.5 cm².

Promptly she said: 'Hmmm … I think this is going to need much closer scrutiny. I need to discuss this with my team tomorrow and perhaps do a few further tests.’

She asked me to have a blood test straight after my appointment at the hospital. A routine NT-proBNP blood test.

She mentioned another possible stress test in the future, a dobutamine (stress) echocardiogram.

She would see me again in January unless she felt, after looking at all my results, that there was a more urgent need to see me sooner.

‘We will need to follow you closely from now on.'

I asked about lifting heavy weights.

‘No heavy weight lifting. Avoid for now.’

So that'’s where I am – awaiting confirmation of my readings and a definitive diagnosis.

So, do I have Low-Gradient Aortic Stenosis?
Am I in fact positively closer to 0.5cm² (critical) in my EOA reading than previously thought?
Or am I getting some kind of a pseudo-severe aortic stenosis reading and everything is relatively ok for now and we'll see you in four months?

http://www.cxvascular.com/cn-feature...ortic-stenosis
http://circ.ahajournals.org/content/124/23/e739.full


The truth will out, I'm sure.
 
Last edited:
Hi Seaton - I can't begin to understand, but do you mean your peak gradient is 41 mm/Hg and your mean 25 mm/Hg rather than the other way round as above ? And because your gradients aren't "severe" that the stenosis therefore isn't so "bad" ? Is that what they're thinking ? How long will you have to wait for the confirmation of readings, diagnosis and prognosis of when you may need surgery ?
 
Oops. And aha.

Yes, I meant peak 41 mm/Hg, mean 25 mm/Hg. Thank you for pointing that out, Anne. I've corrected the post.

Even though my stenosis was in the ‘severe’ category, the surgeon would have waited a further six months before seeing me again if it wasn't for the discrepancy between my gradient/EOA readings. It seems he was considering my stenosis still relatively moderate based on my lower gradient readings and normal EF. Normally they would expect an EOA reading of 0.77cm² on a BAV to show substantially higher gradient readings, relatively. But mine aren't corresponding in such a way. My gradients are low comparatively. This is the paradox they’re trying to fathom.

It may mean I have Low-Gradient Aortic Stenosis, which seems a challenge to confirm, but a challenge that needs to be pursued because of the dangers of misdiagnosis and underestimating the true severity of the stenosis and staging. Hence my surprise (and I think the Dr’s, too) on seeing a reading of 0.5cm² when she worked out her numbers with her pen on her pad.

I said nothing on seeing that figure. I could tell from her reaction that it was of possible concern. It was only afterwards I wish I’d spoken up and asked her what she thought about such a reading and what she thought its implications were.

I did ask her about possible timing of surgery. Two years? Less? She said probably sooner rather than later, but that there was more work to be done to confirm a correct diagnosis.

Although I'm booked to see her again in January as a standard procedure, she said she may be in touch with me before that dependent on her echo conference (the next day), where my figures would be discussed. She asked for my email address, the first of the consultants to do that, and sent me a confirmation email as I sat there.

If I am Low Gradient AS then I am definitely severe and it might be time to act (assuming they can). If not, perhaps I am moderate/severe or just moderate and it’s a waiting game.

She said if there were any classic symptoms – breathlessness, angina or blacking out (she said fainting was definitely more concerning as a symptom) – then I was to contact her or the department immediately. For me, the biggest ‘symptom’ seems to be fatigue. Which may or may not be heart related. I’ve grown more fatigued these past 6 months.

You have these set moments with the specialists in which all your questions seem to morph into airy nothing because other, newer information is being presented and processed and its not until you’re walking alone down the South Bank beside the Thames heading for a coffee that you wished you’d asked this and this and probably that. I suppose it’s the nature of the beast.

Thanks for your reply Anne.
 
Seaton;n858745 said:
You have these set moments with the specialists in which all your questions seem to morph into airy nothing because other, newer information is being presented and processed and its not until you’re walking alone down the South Bank beside the Thames heading for a coffee that you wished you’d asked this and this and probably that. I suppose it’s the nature of the beast..
I know what you mean. I write down all the questions and issues I have BUT then the consultant comes up with the totally unexpected and it throws everything off and I can't even begin to think of what I should ask……...until I'm outside walking away. And it makes no difference having someone else there, in fact that makes it worse for me ! My only answer to this conundrum is to try and get another appointment asap. I do hope Dr Hancock gets back to you soon, even if it is only to say that it's fine and to see you in January. If you don't hear from her in a week or so maybe you can email her since she did a confirmation message to you - it's an awful stress for you being in the dark like this.
 
Seaton - My readings were very similar to yours. My gradients never got to the traditional "danger" zone, while my valve area became steadily smaller (down to about 0.7 cm2 at time of replacement). I never did present with any of the cardinal symptoms (shortness of breath, chest pain, fainting), and in fact was still going to the gym 5 days a week and jogging right up until the month prior to my surgery. I was instructed to stay away from heavy lifting and to be checked/monitored every 6 months. Never was the term "low gradient aortic stenosis mentioned. My cardio felt that I would tell him when I felt that it was time for surgery, and seemed to feel that I was in no more danger than any other patient in severe aortic stenosis. We were both quite calm and organized, as we had been watching my valve for nearly 10 years already. I finally "made the call" and had the surgery, and the rest, as they say, is history.
 
Thanks so much for that, Steve. It’s reassuring to hear your story.

And amazing you were still doing gym and jogging so close to your time! I’m sure a body in shape prior to surgery aids the whole post-op recovery process.

I love swimming for fitness and hill walking, but do little of these things of late due to the prolonged fatigue I suffer afterwards. Takes quite a few days to recover. This may be heart related (or maybe age!) – I’ve no idea. I’m sure I’ll discover the answer post surgery if all goes according to plan. Think I’ll steady walk (and talk!) until then.
 
Seaton - Don't write too much off to "getting older." Some doctors tell us to do this, but that is the very reason I pursued specialists until I was diagnosed at age 51 or 52. When I complained to my internist about declining exercise tolerance and accelerating general fatigue, she said "Get over it. You're getting older." She also totally missed my heart murmur. I pushed her and finally got a referral to an endocrinologist for an endo work-up to test thyroid, etc., and the endocrinologist asked me "How long have you had the heart murmur?" He referred me to a cardio consult, who diagnosed moderate-to-severe aortic stenosis. It turns out that one of the early signs of advancing aortic stenosis is general fatigue, then reduced exercise tolerance. (I thought my internist should have known all this, so I fired her. . . )

A lot has to do with your general level of physical conditioning prior to the onset of the valve disease. My current cardio and I believe that by being a runner for all those years (over 30), I managed to delay the onset of symptoms severe enough to have me call for surgery. At least, that was my plan - delay as long as safely possible to maximize the chances of one tissue valve lasting the remainder of my lifespan. I've got the tissue valve, now we have to wait to see whether I outlast it or not.
 
Seaton

Thank you for your really informative post which addresses many of my own queries,

I've been prompted to study the forum recently as I'm due a 6th month echo since my MRI scan back in September.

So out came my notes and I started number crunching, I discovered the Paradoxical Low Flow - Low Gradient as perhaps an explanation for my own .8cm2 GOA/AVA with 67% ejection fraction and 3.1m/s peak aortic jet velocity. I've duly noted a question to ask my cardiologist/radiologist John Paul Carpenter, Poole General Hospital, tomorrow - theory sound but in practice could well be forgotten!

What I really want to do is share this link I've found, dating back to 2006, but explaining fairly clearly the different points of measurement for AVA used and the associated maths.

http://biomecardio.com/pageshtm/publi/jhvd06.pdf

I hope that you will find this helpful and wish you very well in your Comfy Chair in the Waiting Room.
 
Alchemist;n863184 said:
I hope that you will find this helpful and wish you very well in your Comfy Chair in the Waiting Room.
Hahaha ... Thank you Alchemist. Lovely to read your words.

And thank you for the link. I will most definitely read that later.

According to my consultant late September last year, my detailed readings are suggesting I don't have Low Flow. She said in her follow-up letter:

He has a functionally bicuspid aortic valve. The peak gradient is 41 mmHg with a mean of 25 mmHg. Doing some further calculations on his echocardiogram today, the dimensionless velocity index is 0.26, which is just outside the severe range. The indexed stroke volume is 41.2 ml/m² suggesting that he does not have low flow [my empasis]. His aortic valve area is 1.08cm², but the indexed aortic valve area, therefore, comes out at 0.5cm²/m², which would be in the severe range ...

So my indexed aortic valve area is in the severe range.

I saw my consultant again in January where I did slightly worse on a echo treadmill stress test using the Bruce Protocol. She booked another echo.

I had the echocardiogram recently and she has emailed me to say she'd be discussing the results at the department's specialist weekly echo meeting and would get back to me immediately.

Must say, I've been feeling a little bit more labored in my breathing of late. Subtle but noticeable (by me!).

I wish you the best for your appointment tomorrow. I'd be interested to know how it goes. We seem to have similar readings. Please keep us updated.

Best.
 
Hi

being a "Pythonist" from way back ...
Alchemist;n863184 said:
I hope that you will find this helpful and wish you very well in your Comfy Chair in the Waiting Room.

I was unable to resist this Cardinal Fang



because Nooooobody expects the Spanish Inquistion
 
Seaton

I'm hoping this post finds you well, especially in the sense that your concerns have been satisfactorily addressed by your consultant and her team?

One of the greatest benefits of this excellent forum is to force me to address my own health with the same acuity that I would any other feature of my life. The sand in my eyes is annoying and forum reminds me that it's over 2 weeks since I went for the echo with my consultant...

Duly inspired by previous posts, my opening gambit was to ask him why he didn't note an AVA in his letter to my GP after my echo in August 2015 (my prior history was a 'funny turn' that ended up in a French A&E, July 2015, whereupon a veteran Cardiologist swore that I had a BAV but couldn't for the life of him capture it on echo so challenged a English cardiologist to do so!) my consultant, who performed the 'tricky' echo, admitted that he disbelieved his own readings hence his omission in that letter.

My subsequent MRI showed an AVA of .8cm2 GOA planimetry plus the other data I posted earlier. I also had a CT scan as I was experiencing intermittent left side chest pain, the results of which were fortunately all good.

Which brings me to my most recent readings, consultant's diagnosis and my slight bemusement on the subject of ever moving AVA goal posts...

My AVA now reads .95cm2 by Continuity Equation, which I take to be an indexed version using my BSA of 1.6m2, whilst my AVA (V,D) is 0.83cm2.

You quoted your Indexed Stroke Volume from your consultant's readings, I note mine is 73ml (45mL/m2 indexed for BSA). My Mean Gradient is now 29mmHg up from 19mmHg in September 2015 with Peak Velocity 3.4m/s and LVEF noted as Normal.

My consultant is putting me into a Moderate category, this obviously helps with travel insurance but what I really would like to know, from either yourself or other members is the anticipated rate of progress/deterioration. My biggest concern, since having this 'out of the blue' diagnosis - having so far enjoyed amazing health and fitness to the age of 56 - is my ability to achieve my life's planned sailing ambitions during the twilight period pending 'symptoms' and 'waiting room' ? My consultant says Ocean crossings are a tad ambitious but anything 48 hours from land OK...?

It looks like the low flow - low gradient thesis has been shelved (though I admit I didn't mention it ) but I'm still confused with the anomalies in my readings and the insistence of my cardiologist to just wait for further symptoms. My next appointment is in 6 months which should hopefully shed some light on the rate of AS progress.

Just to add, following a post by Paleogirl, I too read 'The Calcium Paradox' and in conjunction with many Pubmed articles on the subject, started taking vitamin K2 in November 2015. When I mentioned this nutritional 'supplement' to my consultant, just to re-emphasise my proactive approach to my well-being, he immediately filed it under 'snake oil' so I hate to think where that's put me...

Your shared wisdom and personal experiences are extremely welcome and most valued.
 
Hello Alchemist - I've just got to join in here since your consultant filed your vitamin K2 under 'snake oil' ! Both my cardiologist and endocrinologist have been really interested in the K2 I take, they don't think it's snake oil ! When I was in hospital having the valve replaced I handed in the K2 along with my medications to the nursing staff and, at medication time I was duly handed my daily dose of K2, so even there it was respected.

Anyway - it's good you're seeing the 'snake oil' man in six months for your follow up. It's very difficult to gauge the rate of progression/deterioration in this business, but regular echos are the best way. My pressure gradient rose steadily over the years and then suddenly did a sharp rise - it was that that indicated that surgery would be coming soon. But I never had any symptoms at all, even when it came to the time for surgery, I was very fit, but it definitely was time by all accounts.
 
Greetings, Alchemist!

Apologies for the slow reply. I just found your recent post.

It seems the consensus for me is that I, too, watch and wait. No symptoms as such, other than persistent fatigue.

I note your Mean Gradient’s increased since last September. More significantly than mine over a similar period. As Paleogirl says, hers suddenly leapt up after a steady increase. I’ll be interested to see what happens to mine eventually (if anything!).

I’m in my second year now since diagnosis. I’ve no idea where that year went!

My cardiologist wants to continue to wait and watch. In the meantime, I'll be having a Dobutamine Test in April. This is to help clarify what happens to my gradients under controlled (chemical) conditions. My physical treadmill stress echoes weren’t giving enough info, it seems. Due mainly, I think, to my inability to maintain a sustained test period on the treadmill.

With regards to sailing and your AVA being below 1.0 CM², I imagine there is some hefty lifting and things while on the high seas? I wonder what your consultant says about that under your present readings. Might be worth asking. But I can’t see how post surgery, an eventual return to a full and active life wouldn’t be possible. That seems the way with a great many valvers here - which is tremendously encouraging.

Please let us know how it all goes!
 
Greetings Paleogirl and Seaton

Thank you both for sharing your wisdom and personal experiences.

I'm trying to get a feel for how long I will be in the 'waiting room' so how much I should modify my activities, I'm loath to wrap myself in cotton wool but equally don't want to be a third world medical emergency for my husband to deal with.

So to that end I've tracked down a piece of research dated 1993 on the 'Rapidity of progression of aortic stenosis in patients with congenital bicuspid aortic valves'
http://www.ajconline.org/article/000...?showall=true=

I need to 'buy' this article so I wondered if anyone had read it? I gather from my research that data is predominantly concerned with AS in Tricuspid valves, often citing the caveat that in the case of BAV the stenotic progression is 'faster'. I've found figures for an annual AVA decrease of 0.12 - 0.19cm2 and an increase of 7mmHg per year mean pressure gradient and and increase of Aortic Jet Velocity of 0.32m/sec per year.

You are both right to point to the increase in my Mean Gradient, I think I need to be looking at a pattern before making any decisions and the lack of data given by my Cardiologist at my first echo means I don't have a year's worth of figures to get a feel for the rate of change.

Please keep us up dated with your Dobutamine Test this month, Seaton. It sounds pretty definitive and will clarify a lot of issues for you and your cardiology team.

All the best.
 
Greetings

I've tracked down free access to the literature review of another article covering the progression of Valvular Stenosis by the same authors of the original article I wanted to find concerning 'The Rapidity of Progression of Aortic Stenosis in Patients with congenital Bicuspid Aortic Valves' as mentioned in my last post. I note that whilst sourcing both these articles I discovered how referenced they are since their publication in the 1990's.

http://www.academia.edu/19034140/Pro...sis_in_adults_ Literature_review_and_clinical_implications

Currently I'm still asymptomatic, happily taking Vitamin K2 and D3 daily, I'll have another echo test at the start of August, be armed with plenty of questions and hoping for some stable results.

On reading more enlightening posts by Pellicle I do now have a greater understanding the medical profession's own perception of 'high risk' activity, conservative to a fault and unsupported by empirical data. We each take responsibility for how we live our lives based on our personal informed experience, to allow us to maximise the quality of our existence and not rule out more challenges... So there's no 'For Sale' sign on the boat yet!
 
Hi Alchemist again - I wasn't able to read that article, but from what I was told by my cardiologist and from my own experiences, it's impossible to tell in advance the rate of progression of aortic stenosis with bicuspid aortic valve. From when I started having yearly echos, seven years prior to surgery, I made a graph so I could see the 'progression' of the peak gradient and ejection fraction. The cardiologist I had at the time would always write in his reports "there has been little change". My gradient at that time was increasing by about 4 mmHg a year and I noted wryly to one of my other consultants that I would reach the time of aortic valve replacement as a Zeno's paradox - going all the way to severe with "little change". Umm. Anyway, suddenly two years before surgery the gradient incerased sharply so that at that point the cardiolologist was able to predict that in about two years I would probably need surgery. He was right, the last six months the peak gradient rose even more sharply indicating the time was very near and I was referred for surgery. I never got my valve area recorded until near the end when it was 0.9cm2. My ejection fraction always stayed good at around 77 to 79%.

Now post op I am carrying on with the graph, recording the pressure gradient (now 42 mmHg so not so good imho) and the ejection fraction, plus I now have mild left ventricular hypertrophy which I never had any of prior to surgery so they are now doing six monthly echos again. It's nice that I'm the kind of person that likes making graphs, and, in fact my cardiologist asked me for a copy of my graph last week.

But back to your original query - I would be very surprised if there is a known standard progression of stenosis - it rises steadily at whatever rate and then, from my understanding and experience, rises sharply which is the sign that something needs to be done. I don't know if that report suggested that ?

I did not make any lifestyle adjustments prior to surgery except once I'd been referred for surgery when I cut down some of the weights I lifted, but I still did six mile walks most days, even the day before surgery when I took great pains to do my last good walk and lift some heavy weights as I knew that post op I'd have to wait awhile. I don't have any weight or exercise restrictions now and, in fact, my cardiologist was clear to me that I should exercise as much as I could. At the stress/exercise echo I had the week before last I reached 100% maximum heart rate and I could have happily carried on with the test as it was an inclining treadmill and I love walking uphill, but the cardiologist didn't need me to !
 
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