EF and FS Percentages

[dave1726]

  I was just looking back at my echocardiogram results which supposedly ruled out any major structural abnormalities that are causing my infrequent palpitations, and I found something a little weird....My LV Diastolic and Systolic diameters were both normal (4.9cm and 3.8cm  respectively), but despite those values being used to calculate my FS%, my FS% came back as 22%. Although they didn't really mark this as abnormal or anything, I have found out that anything below 25% is considered a sign of mild heart failure problems. How can this be?
       Also, my diastolic and systolic volumes were both in the normal ranges (117 and 56.2 cm cubed respectively), yet they are used to calculate my EF%, which came to 52%. Once again, they didn't mark this as abnormal, but I have found out that anything below 55% is considered a bad sign. How can this be? I guess I just don't get how all my volume, diameter, and wall thickness values (IVS diastolic thickness was normal at .88, and LVPW diastolic thickness was normal at .82) and yet these two percentages that are calculated from these numbers are off. I also don't get how there could be some sort of mild failure going on in my heart if it is not enlarged or too thick as these tests seem to have ruled out.
       I probably wouldn't worry about it, but the fact that I feel palpitations makes me think that this is an indication of something. I also don't see how my stroke volume could be 60.2. I am a college runner, and although my value is considered normal, 70 is the average normal, so shouldn't I be more up there or at the high end of normal given that I can run faster than the average person over long distances?

[is_something_wrong]

Seems like you've read quite a bit about this ;)

High EF at rest is not necessarily better. Athletes often have a fairly low EF at rest, as the heart relax very well, but they are able to increase stroke volume and EF quite a bit with exercise.

What matters is that you are able to run, if you can run fast for a long distance without symptoms you don't have heart failure!

Your FS is 22,5% (4,9-3,8)/4,9 = 0,225

EF can be roughly estimated as FS x 2, but this formula will under-estimate EF at lower FS and over-estimate it at higher FS. If you had a FS of say 60%, your EF could not be 120%, if you see the point.

High blood pressure doesn't cause low EF, but it can cause thickened heart walls (not the case with you) and diastolic failure, though high EF.

Average EF at rest is NOT 70%. And it varies all the time. Anxiety can both make the EF higher and lower. What was your heart rate when they did the echo? To compare, one of my echos measured my EF to 56%, and another to 80% (at the last one I felt like the heart was about to jump out of my chest)..

If your cardiologist said you are OK, and you can run for long distances, forget your EF :)

[dave1726]

  Okay, thanks. That really does help me feel better about some of this. I guess the reason I worried so much is because I figured that since I'm so active, maybe I actually had a really weak baseline and my exercise and youth were the only things bringing me up to the low end of the normal range. But I guess the machine values do vary and since there are no structural problems it's not really a big deal.
    I guess my only other questions then would be that if I do just have this FS ad EF% with no structural abnormalities, do they seem low enough that they could cause a negative restructuring of my heart in the future if I don't monitor them well? Also, I know that high blood pressure runs in my family, and I have slightly high levels (usually around 140/90ish at doctor's office at check up's) so could high bp actually be the culprit of my slightly weaker heart contractions (as evidenced by the two percentages, if they were actually accurate)? I know I've heard that high bp can effect dystolic function, but I'm not aware if it could play any role in systolic function. Finally, I guess this is a good thing, since systolic heart failure usually comes with an enlarged LV mass, but mine only weighs 141g. I looked that up and the average for a male my age is more like 180-190. 140 is more like an average female heart for someone my age. Could this have anything to do with it being a little weaker?
        Thanks for reading and answering my first question. I appreciate it.

[ed34]

FS and EF on most echo machines are calculated automatically, and are not very accurate, but can be used as a guideline. If all other tolerances look fine, then a Cardiologist will ignore these if they look odd. As an example, my EF is measured at 60% on an echo, but in an angiogram it's revealed as 70%. An extra 10% of blood being ejected is a considerable amount of error. You are correct that the dimensions of your chambers are fine, so how can the Fractional shortening be so low. Probably why this was ignored.
The normal range for EF is anywhere between 50 and 75% but I don't believe the average would be 70%. I think it would be more like 50-55%. It would be very likely that if you had a more accurate test for EF, it would be up in the 70's. It is also important to remember that there are quite a number of things which can cause a Fractional shortening value to be incorrectly calculated. Even heart rate can affect this.