A low ejection fraction is always something to be taken seriously. 50-70% is considered 'normal'.
More information is needed for a discussion. Is this involving you or someone else? How was the low ejection fraction determined, and what is the brief history of the person with the low ejection fraction? Let us know.
Low ejection fraction is basically a low volume of blood being pushed out of the heart with each beat. The heart will try to compensate for this, usually by enlarging the left ventricle, but this causes other problems in itself such as making the wall thinner and weaker. If the cause of low EF is treated, then in most cases an enlarged ventricle will eventually return to its normal size. Sometimes low EF can be caused because the tissue of the heart muscle is damaged, so the ventricle cannot squeeze properly. Sometimes it can be due to a damaged or malfunctioning valve, allowing too much blood to leak back into the chamber. It can also be due to a restriction in the Aorta. There are more reasons than this, but I don't really want to write a book on here. The heart obviously has to pump oxygen and nutrients to all living tissue, all over the body. It also has to return waste gases and chemicals to be filtered out. So the left side of the heart has a huge job to do, compared with the right side which only has to push blood through the lungs. A low EF obviously means there is more restriction on the amount of oxygen getting to that body tissue. In most people, symptoms are not noticed when taking things easy, or walking slowly. The times when higher exercise levels are require is when the symptoms really start to present themselves.
The significance of a low EF indicates there is an underlying cause that effects the heart's left ventricle's contractility (pumping chamber). There can be present or past bacteral/virus disease that has damaged the heart muscle, and this condition's prognosis is not very good.
There can be a birth defect of the heart structually that impairs contractility. If the heart is overworked due to a defect such as heart valve insufficiency (leakage or narrowed orifice) or a blood circulation imbediment problem, etc...often these conditions can be successfully treated.
If you have improved your EF from 25 to 60, by various means, primarily a successful AV node ablation and a pacemaker, do you need to take any medication for the problem?