Ejection fraction (EF) is a unit of measurement that reflects how much blood the left ventricle of your heart pumps with each heartbeat. A person whose left ventricle pumps 60 percent of its blood with each heartbeat has an EF of 60 percent.
EF is an important measurement for monitoring and diagnosing heart problems, including heart failure. The hearts of people with very low EF struggle to pump blood throughout their bodies, which can result in many serious side effects and complications.
How Is Ejection Fraction Measured?
An echocardiogram, which uses sound waves to create an image of a person’s heart and how blood is pumping through it, can measure heart ejection fractions.
Other tests for EF include cardiac catheterization, MRI, CT and nuclear medicine scans.
What Are the Different Levels of EF?
A healthy ejection fraction is between 50 and 70 percent. When a person’s EF is below 50, it means that their heart is struggling to pump enough blood to meet their body’s needs. People with low EFs may have cardiomyopathy, a condition where the heart becomes enlarged, thickened, or rigid and can no longer pump as effectively as it should. This can lead to heart failure.
What Is the Lowest EF You Can Live With?
People with EFs under 50 percent often experience symptoms related to their hearts not pumping enough blood. Symptoms of a low EF, heart failure or cardiomyopathy include fatigue, shortness of breath and swelling in the feet and legs. However, many people can live for a long time with some degree of heart failure and lower-than-normal ejection fractions.
But when EFs become very low, patients become more at risk of serious health problems, including sudden cardiac arrest, or SCA. During SCA, your heart stops beating suddenly, and your brain and other vital organs stop receiving blood. If you aren’t treated immediately, SCA can cause death in a matter of minutes. Beta-blocker medications are the most important treatment to prevent SCA. Most patients with low ejection fractions will require long-term medications which will help the EF improve or at least stabilize. Rarely, patients with very low EFs may require a mechanical pump or heart transplant to regain their heart function.
Can a Person’s EF Be Too High?
When it comes to EF, a bigger number isn’t necessarily better. Although doctors are often concerned about raising patients’ EFs, this is done to get them as close as possible to the healthy range of 50 to 70 percent. When a person’s EF exceeds 75 percent, they may have a heart condition called hypertrophic cardiomyopathy (HCM).
HCM is often a benign condition, but it can also be associated with sudden cardiac death, especially in adolescents and young adults. Patients with high EFs and HCM may need cardioverter-defibrillators implanted in their chests to help reduce the risks associated with the condition.
Does a Pacemaker Increase Ejection Fraction?
A pacemaker is a small electric device that helps regulate your heartbeat. A temporary pacemaker is placed outside of a patient’s body, while a permanent pacemaker is implanted inside the chest. Both types of pacemakers are connected to the heart, and they send electrical pulses to the heart to help them beat at a normal rate and rhythm.
Standard pacemakers do not increase ejection fraction. In certain patients with low ejection fraction, a biventricular pacemaker may help to increase ejection fraction. These types of pacemakers are only effective for patients who also have a condition called Left Bundle Branch Block (LBBB).
Some patients with low EF may require a device called an implantable cardioverter defibrillator (ICD). This device is similar to a pacemaker but it helps to prevent and treat sudden cardiac arrest. ICDs do not change or improve heart function, but they are a very important lifesaving device for patients with EF of 30 percent or less. It watches the heart 365 days a year and revives the heart if SCA occurs.
People with pacemakers or defibrillators can return to regular activities within a few days, but they need regular follow-up visits to ensure that their pacemakers are working correctly.
What Conditions Require the Monitoring of Your EF?
Heart failure is the most common condition associated with the monitoring of a person’s EF. According to a study published in American Family Physician, reduced EF caused by heart failure can be brought about by many conditions, including:
- Arrhythmia
- Atrial fibrillation
- Coronary artery disease
- Hypertension
- Idiopathic cardiomyopathy
- Valvular heart disease
Any condition that affects heart function and the ability of the left ventricle to pump blood can affect EF. When EF drops below 50 percent, it needs to be monitored.
Is It Possible to Improve Your EF?
According to the American Heart Association, it is possible for people to increase a low EF by taking a few important steps towards improving their heart and overall health.
- Talk to your doctor about your diagnosis of low EF and what your treatment plan is for managing your condition and improving it.
- Treat your heart failure. If your EF is caused by heart failure, it’s important to treat it as best you can. This can involve treating high blood pressure through medications and lifestyle changes. If you have additional conditions, like diabetes and/or metabolic syndrome, manage or treat them effectively.
- Start a safe exercise program. Almost everyone can benefit from exercise, including people with heart failure. Talk to your doctor before beginning an exercise program and work your way up until you can sustain 20 to 30 minutes of cardiovascular exercise five days a week.
- Achieve a healthy BMI. Being overweight or obese makes your heart work harder, and when your heart’s function is already diminished, it can further reduce your EF.
- Reduce sodium and salt intake. Eating foods high in sodium can cause you to retain fluids. This puts an added strain on your heart and can impact your EF.
- Cut out alcohol and cigarettes. Both alcohol and cigarettes can make heart damage worse. You should also avoid drugs, such as cocaine or amphetamines, which are strongly associated with the development and worsening of heart failure.
- Reduce stress levels. High stress levels can increase heart rate and blood pressure, which can impact your EF and make your heart work harder than it has to. Check out this chart from the American Heart Association to find your target heart rate zone and average maximum heart rate.
More to Read
- How to Tell if You Have Edema
- Heart Fluid Retention
- Congestive Heart Failure: What You Need to Know
- COPD or Heart Failure? The Heart-Lung Health Connection
Medically reviewed by Asghar Fakhri, MD.
