Does stroke volume matter?

I would seek another cardiology opinion

by Gemita - 2022-03-12 21:56:58

Mae,

I have sent a couple of links to you privately which may help.  I am so sorry to hear about your ongoing syncope, your frustration and concern that something is being missed.  The sooner you are able to get full autonomic function testing done under an expert neurologist at the Cleveland Clinic, the better for you. 

Reading your message, it seems to me that you no longer have confidence in your cardiology team and are questioning everything they are saying.  This is not a good sign, especially since you believe that your heart is in some way causing your symptoms and it may well turn out to be the case.  Any chance of getting another cardiology opinion before the neurology appointment at Cleveland Clinic or getting seen earlier than June at Cleveland?  I had two full days of autonomic testing some years ago and it provided lots of answers.  Hopefully it will for you too.

The assessment of cardiac ouput and stroke volume is not something that I fully understand Mae and I attach a link which might help explain the physiology.  There are some investigations including cardiac MRI and right sided heart catheterization which may better assess and measure cardiac function and calculate stroke volume and ejection fraction than an echocardiogram and you could always ask your doctors about these.  The right heart catheterisation procedure would be invasive though and only done if it is indicated.  Your question is an interesting and challenging one though and certainly warrants further discussion and thought

https://www.ncbi.nlm.nih.gov/books/NBK547686/

Thank you, Gemita!

by Mae11 - 2022-03-12 22:39:27

Thank you as always, Gemita. My cardiologist and EP are in the same network. I'm not necessarily saying they are flat out wrong or missing things, but possibly tiptoeing around it. 

It seems to make perfect sense to me. Low blood flow out of the heart=Low blood flow to the rest of the body. Which could explain the constant lightheadedness, weakness/exercise intolerance, and transient loss of consciousness.

As I said a few posts back, my e wave deceleration time is also prolonged, suggesting impaired diastolic relaxation. 

My episodes seem to be getting worse and more frequent, and honestly it's scaring the crap out of me..

Perhaps ask for Reveal Linq implant monitoring?

by Gemita - 2022-03-13 07:39:18

Mae, have they checked bloods recently to look for causes (like electrolyte abnormalities, thyroid problems, infection and so on).  They have clearly seen arrhythmias (tachy events as well as ectopics - PVCs) and these intermittently can really mess with blood flow.  My husband too has lost consciousness from his arrhythmias which were often caused by abnormal electrolytes (very low potassium and magnesium levels) as well as thyroid problems.

When I had round the clock arrhythmias (mainly frequent ectopics, with sudden bursts of tachycardia), I felt as though I was on my way out.  As well as autonomic function testing, long term Reveal Linq implant monitoring helped confirm the causes for my syncope.  Reveal Linq implant monitoring is so effective at finding the cause for syncope where shorter term monitoring may have failed.  I would ask whether this implant could be considered in view of your worsening symptoms?  In my opinion, Reveal Linq implant is indicated especially if recommended by your doctors and should be covered by your health insurance?  Perhaps Cleveland Clinic will recommend this implant in any event.  I feel permanent monitoring (implant lasts for up to three years) is now the way to go Mae.  There is nothing better than this and autonomic testing, to get to the bottom of your unexplained syncope.  I hope this is resolved quickly for you 

Stroke Volume Anxiety

by Selwyn - 2022-03-13 10:22:20

Ejection fraction %    = EDV-ESV        x        100    

                                        EDV           

( EDV-ESV  is the volume difference of the relaxed and contracted lower left heart chamber ie. the left ventricle). The lower limit of ejection fraction for white Europeans is 55%. If you get to 70% you are doing well.

Ejection fraction varies as to how it is tested as heart compliance ( ie. how much it stretches) becomes important, particularly for those of us with cardiomyopathy.  So, for 'getting warmed up' in exercise, the heart with start to stretch and the result is a larger stroke volume.  This is certainly my experience of exercise. 

Then we have to take into account heart rate, as the cardiac output is SV  x  HR. 

Sometimes, looking things up increases anxiety. I  think it would help to try and leave the physiology to the professionals and to try to concentrate on getting  an explanation of your symptoms from your physicians.  Your worries and doubts would be best shared with your health carers.  

There are many different conditions that affect the functioning of our hearts.  This is a life time of learning for those involved in care. I have looking after me an electrophysiology cardiologist, an interventionist cardiologist,  a cardiomyopathy cardiologist, and a pacemaker electrophysiologist.  I am sure that are many other cardiological specialities dealing with everything from coronary disease to  valve disease.  We have a whole hospital specialising with these heart  problems.  

What is important is your well being. 

Yes.

by crustyg - 2022-03-14 10:18:58

Stroke volume *does* matter.  You need a certain volume of oxygenated blood to be pumped into your aorta in order to maintain your BP - and hence deliver enough pressure to get some of that blood to your brain.

%LVEF (you wrote EF) is a useful marker of how well your heart is filling and contracting and it's very useful for patients with symptoms of heart failure.  If you had a child's heart *size* in your chest, you'd have a lovely efficiently pumping heart (high %LVEF), but a low BP as each beat/stroke would only push out a tiny amount of blood.  So a bigger heart, beating at the same rate, with the same %LVEF would pump more blood => increased BP, happy brain.  Heart size is expected to vary with body size: the conventional calculation requires an approximation for Body Surface Area, which is usually derived from sex/weight/height.  So while your Stroke Volume seems low, I have no idea how large/small you are.

So Stroke Volume absolutely *does* matter.  Selwyn has provided the full technical details about how our advisors calculate some of the more objective numbers that they use to track our heart health, and he and Gemita have warned that anxiety comes with its own problems.  Teasing apart the heart aspects of feeling faint when standing is not easy, and really does require someone who can see the big picture and not just focus on one aspect of you (e.g. your heart).  But be careful - this big-picture requirement applies to you too! If you focus only on your heart you may well miss other possibilities and not make the correct diagnosis.

Just as a thought experiment consider this: light-headedness or frank syncope on standing could be due to: heart problem(s), Addison's disease, Shy-Drager, POTS, micturition-syncope, severe kidney damage, salt-depletion due to fad-diets.... and that's just the first few that spring to mind (never was very good on the formal differential diagnosis).  Big picture - ask the experts.

UPDATE: I hadn't seen your earlier post from 6th March.  Lots of experts already involved in your case.  Possibly time to start with a fresh pair of eyes, and get a comprehensive history taken by someone who doesn't already know you.  Patients tell us the diagnosis in about 85% of cases - we just have to learn to listen and not project our pet diagnosis onto them.