Explaining the elusive concept known as “ejection fraction.”

​I knew my heart failure was serious when the cardiologist called me to advise that he wanted me to see a heart failure specialist who also performed heart transplants.  The reason for this referral was because my recent echocardiogram established that my ejection fraction had slipped from about 30 to 15. 
 
To be candid with you, I really didn’t have a freaking clue what the term ejection fraction meant.  But I do recall that I had been told that 55 to 75% was normal.  So I quickly concluded that to have a number that was at first 30 and then 15 was not a good thing.  In fact, I assumed it might even be an urgent medical issue.   This was a correct assumption, as the other thing the cardiologist strongly recommended was that my pacemaker be upgraded to include a defibrillator.  This was to avoid the strongly growing risk of cardiac arrest.
 

Since that time I have developed a better understanding both of the term “ejection fraction” and of the extent of the risk to me.  Thankfully, at the time of the conversation with my cardiologist, I was too much in shock to say “what in the freaking hell is an ejection fraction – sounds like a silly term to me!”  According to the Collins English Dictionary, the word eject (which forms the basis of ejection) is a transitive verb.  To eject something means to remove it or push it out forcefully.
 
I think most of us would take that to mean that the action of “ejection” is a fairly violent, maybe even vicious action.  This is not the image one wants to imagine about the heart.    One thinks of a cartoon heart calmly going “glub glub” as it pumps the blood from the heart.  One wants to continue seeing an image of blood peacefully and efficiently flowing throughout the circulation system.  One doesn’t want to think of blood being pushed forcibly out of the heart, like an unruly patron being thrown out of a bar or club by a bouncer.
 
But in my shock, my imagination was no longer running wild.  It was running scared, a concern fueled by the term “heart transplant.”  Happily, we now know that I am not yet a candidate, and maybe never will be a candidate, for a heart transplant.  So my ejection fraction while shockingly low, is not endangering my heart at this point.  More about why my low ejection fraction is not threatening to me later in this post.
 
After four years of seeing the cardiologist and a heart failure specialist, I now have an appreciation for the term ejection fraction.  But I also admit that I have not shared the basis for that appreciation.  Rather, I have thrown the term ejection fraction around like candy without defining the term.  As a result, when I use this term with friends and family, they look at me as though I have uttered a term that is vaguely obscene
 
So I have decided it is time to lift the veil on this mysterious medical term.  According to the American Heart Association, the ejection fraction is an important measurement in determining how well your heart is pumping out blood and in diagnosing and tracking heart failure.  It is a percent measurement of how much blood the left ventricle pumps out with each contraction.  So an ejection fraction of 60% would mean that 60% of the total amount of blood in the left ventricle is pushed out with each heartbeat.
 
I previously told you that doctors had advised me that 55% to 75% was a normal ejection fraction.  But what does that percentage mean?  I think the best explanation was the one I found on the Veterans Administration website (myhealthva.gov):  “The ejection fraction represents the amount of blood the heart pumps during each beat. It is the amount of blood in the heart at the end of the pumping cycle. This is compared to the amount of blood that is in the heart just before the heart beats, at the end of the filling cycle. Ejection fraction is then expressed as a ratio, or as a percentage. Here are some examples:

• The heart contains 100 cc of blood at the end of the filling cycle.
• The heart pumps 50 cc of blood with each beat, and it has 50 cc of blood in the heart at the end of the heartbeat. In this case the heart emptied 50% of the blood in the chamber. Using the equation below we determine the ejection fraction to be 50/100 = 0.50, so 50% is the ejection fraction.
• If only 40 cc of blood remains in the heart, the heart pumped out 60 cc of blood, and the ejection fraction is 60%
• If 70 cc of blood remains in the heart and only 30 cc of blood is pumped out, then the ejection fraction is 30%”

What test is used to figure out a patient’s ejection fraction?  According to the Cleveland Clinic, the echocardiogram is the most common way to determine your ejection fraction.  What is an echocardiogram?  The Cleveland Clinic describes this test as “an ultrasound to see how well your heart can pump and relax, to check your heart valves, measure your heart and check blood flow. Images are captured using an ultrasound wand that is moved around on the skin of your chest. 

An echo is often done with a Doppler test so your doctor can see changes in the pressure inside your heart chambers and in the way your blood flows across your heart valves.”  (Gosh - is this like the Doppler radar that I see on my local news weather forecast?  Have the weather forecasters issued a weather alert based on my low ejection fraction?)  
 
I have also told you that according to my last echocardiogram (and about 3 previous echos) my ejection fraction is about 15.  It was the initial echo showing an ejection fraction of 15 that led me to the heart failure doctor to determine if I was in immediate need of a heart transplant.  We know now that the answer was no.  And the answer is that with an exceedingly low ejection fraction I still am incredibly active.  It seems to me like my ejection fraction is the identical twin of my blood pressure – exceedingly low but exceedingly functional.  In other words, nothing here to cause concern as long as I’m not constantly fainting or sleeping all day.
 
It also was helpful when my sister gave me a medical advice column that she found in her local newspaper.  It discussed a man who also had an ejection fraction of 15 and like me was functional.  So it is possible for some of us to have a disappointing ejection fraction but still not be on the waiting list for a heart transplant – or in need of a ventricle assistive device.
 
How can this be?  I don’t have the medical knowledge to answer that question.  But I did find a September 2015 article in the European Heart Journal that seemed to put into perspective how challenging it can be to reliably measuring the ejection fraction through an echocardiogram: 

• Various technical limitations, partly inherent to echocardiography as a non-tomographic technique, hamper the calculated LVEF values: poor image quality, anatomy difficult to scan often leading to foreshortened ventricles, the tedious and time-consuming process of manual delineation of the endocardium with boundary continuity often out-of-plane, being prone to inter- and intra-observer variability as well as shortcomings of novel, semi-automatic delineation applications dealing with similar issues, in particular lack of standardization and reproducibility.  Moreover, as a volume-derived index, LVEF often relies on geometric assumptions (particularly in one- and two-dimensional echocardiography) and is extremely load-dependent. These limitations lead to substantial loss of reproducibility, and even repeated measures of ejection fraction in the same individual over a brief time period can result in a 5- to 7-point variability.

 
Of course, I understood about 10% of this quote.  But I did pick up on the phrases “poor image quality, anatomy difficult to scan”, and “boundary continuity often out-of-plane being prone to inter and intra-observer variability” and “shortcomings of novel semi-automatic delineation applications.”  These phrases led me to believe that there are challenges in using the echocardiogram to measure the ejection fraction.  Of course, a variability of 5 to 7 points would only raise me up to around an ejection fraction of 22.  But it would at least present a more optimistic picture.

Whatever the reason, my doctors and I have learned that there are other measures that are equally relevant indicators of the state of my heart health:  treadmill stress test, cardiac catheterizations, how I feel each day, the amount of exercise I perform each day, etc.  These factors and probably others I am not aware of demonstrate to my doctors that I am pretty darn compensated for someone who apparently will permanently live in zombie territory.

While I live in hope that my ejection fraction will rise with my next echocardiogram, I have learned to judge my daily heart health by how I feel.  And even though I have some fatigue that I suspect may be my companion for the rest of my life, I feel positive and I am phyiscally active. 

The bottom line is that for the time being I am happy with my well compensated state, and have trust in my doctors to tell me when it is time to worry.  But even then, I will strive not to be anxious.  I will just work with my doctors to figure out measures to assure that  my heart becomes well accommodated.