Do You Know Your Heart’s Ejection Fraction?

Today I ran into a young woman I assisted in Cardiac Rehabilitation after she had a heart incident. One of the first things she said to me with a smile on her face was that her ejection fraction had increased from 15% to 55%. This means her heart essentially is functioning within normal limits of 50%-70%  in it’s pumping ability. She went on to tell me she was off to go snowshoeing in the woods. I was so proud, as working with patients over time you learn and share a lot about your lives, and for her this was huge!

Ejection fraction is a measurement of the percentage of blood leaving your heart each time it contracts.

When the heart beats, it contracts or squeezes and then relaxes. During heart contraction, it pushes the blood within the pumping chamber  out. When your heart relaxes, the chambers or ventricles refill with blood. No matter how forceful the contraction, it doesn’t empty all of the blood out of a ventricle. The term “ejection fraction” refers to the percentage of blood that’s pumped out of a filled ventricle with each heartbeat.

A normal LV ejection fraction is 55 to 70 percent. The ejection fraction may decrease if:

  • A heart attack has damaged the heart muscle such that it cannot forcefully contract
  • The valves of the heart are not working properly
  • Blood pressure has been uncontrolled  for a long period of time
  •  Weakness of the heart muscle, such as dilated cardiomyopathy

I get great gratification in this patient announcing this for another reason. I have a history of arguing with cardiologist about teaching patients their heart’s condition by reading their medical reports with them. As part of the intake to cardiac rehabilitation the charts are reviewed so both the patients and the clinicians have a solid understanding of their heart condition and the plan to manage the heart condition. Many patients enter rehabilitation with their last echo cardiogram or other studies showing the patient has a severely reduced ejection fraction. Some people will always have a reduced ejection fraction and others will recover depending on the severity of condition. A late presenting large heart attack may have permanently reduced pumping ability of the heart, where as a stent placed early in a heart attack may improve within a very short time. Other conditions slowly change over time, getting better or worse these include hearts that have cardiomyopathy, or pacemakers.

I believe heart patient’s understanding of their ejection fraction an important part of managing their health. The cardiologist was worried I would scare his patients.  The cardiologist  felt people would psychologically not improve if they knew their ejection fraction was low.  Many people with a reduced ejection fraction will not have any significant functional limitations or symptoms. I have worked with people with ejection fractions in the 8-10% who can function pretty normal including performing weight or resistance training exercises. On the other hand some folks with an ejection fraction of 30-40% can feel symptoms of fatigue or shortness of breath with mild exertion.

For many through building structured exercise they can improve the muscular strength of their body thus reducing the effort the heart has to work to meet the demands for oxygenated blood. Exercise does improve the ejection fraction in many studies, but if it doesn’t it still  improves the functional ability and quality of life of most individuals. Cardiac Rehabilitation programs often will note  an improvement in patients  ejection fraction. It is typical to undergo echo cardiogram studies approximately three month post intervention or event. I believe it is more of an insurance reimbursement issue which makes  most scheduling occur at 3 months post, but also gives the heart time to recover and medical management to be fully effective, and this is typically how long a cardiac rehabilitation program lasts.

When the overeager patient comes in and wants to give themselves a workout equivalent to a stress test on their first few sessions  of cardiac rehabilitation to prove to themselves they are ok,  we will  use information such as their ejection fraction to determine  and educate how much effort they should safely perform.  Then there is the  scared patient who has been living with a reduced ejection fraction and had short of breath and  gets a bi-ventricular pacemaker  the cardiac rehabilitation staff encourages them to increase their workloads as their ejection fraction is likely much improved and now can feel safe pushing the intensity. Reviewing this information with you healthcare provider can help you to understand your heart and any limitations it may have.

Read more about ejection fraction here

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