What Is Reduced Ejection Fraction?

Heart failure (HF) is a condition where your heart cannot pump blood through your body well enough. When the heart is strained, blood and fluid build up in the body. This can lead to a variety of symptoms. For example, HF may cause symptoms such as fatigue, shortness of breath, and irregular heartbeat.¹

HF can result from a range of health conditions that affect the heart, like coronary artery disease, high blood pressure, or diabetes. Depending on its cause, HF may get worse over time. One way doctors measure heart function and monitor for HF progression is with an ejection fraction (EF) test.^1,2

What is ejection fraction (EF)?

Along with assigning your HF a stage or class, your doctor may measure your ejection fraction (EF) to determine how well your heart is working. EF is a measurement of the amount of blood the ventricles of your heart push out with every beat.³

The heart has 4 chambers, 2 at the top called atria and 2 at the bottom called ventricles. The right atrium receives blood from the body and then the left ventricle pumps it into the lungs to get oxygen. Once the blood is oxygenated, it travels through the left atrium to the left ventricle, which pumps the blood into the rest of the body.^4,5

Doctors typically measure the EF of the left ventricle because left-sided HF is the most common type of HF. For this reason, EF is sometimes called left ventricular ejection fraction or LVEF.^6,7

Measuring heart function with EF

Most commonly, doctors measure EF with an echocardiogram. Other tests they can use to measure EF are:^6-8

• Magnetic resonance imaging (MRI)
• Computed tomography (CT) scan
• Cardiac catheterization
• Multigated acquisition (MUGA) scan
• Nuclear stress test

EF is reported as a percentage of the amount of blood the ventricle pumps out versus how much stays in. Usually, a higher EF measurement means your heart is working better. But the heart cannot pump out 100 percent of the blood it receives, so this measurement typically will not go above 70 percent.⁷

An EF measurement between 50 and 70 is considered normal or healthy. If your EF is under 50, your heart may not be functioning as well as it should. Between 40 and 49 is considered borderline, or mildly reduced, EF.⁸

An EF measurement of under 40 is considered reduced EF. Reduced EF indicates severe HF. Doctors also call reduced EF systolic heart failure or HFrEF. At this stage, the heart is not able to pump enough blood into the body to meet your other organs’ needs.⁸

Symptoms of reduced EF

If you have reduced EF, your HF symptoms may become persistent and eventually life-threatening. The lower your EF measurement, the worse your symptoms may be. Symptoms may include:^2,6

• Shortness of breath or cough
• Heart palpitations or changes in heart rhythm
• Nausea
• Extreme tiredness (fatigue)
• Muscle weakness
• Swelling in your belly, hands, or feet
• Confusion

How is reduced EF treated?

Your doctor will look at your health history, stage of HF, and EF measurement to determine the best treatment plan for you. The primary way to improve your heart’s function is to treat the underlying cause of your HF. Different causes of HF may require different treatments. In general, people with HF may need to:^6,9

• Take medicines that make it easier for the heart to pump blood
• Have a device implanted, such as a pacemaker or defibrillator
• Have surgery to replace or repair the heart valve
• Have a heart transplant

However, it is possible to improve your heart function and EF measurement by changing a few key lifestyle habits. Actions you can take include:^3,9

• Stop smoking if you smoke
• Limit the amount of alcohol you drink or stop drinking altogether
• Limit your salt (sodium) intake as your doctor instructs
• Ask your doctor about participating in a cardiac rehab program
• Reach and maintain a healthy weight with a nutritious diet and regular exercise
• Manage your stress levels

Remember that EF is just one way to measure your heart’s health. It is possible to have HF with a normal EF measurement. This is called heart failure with preserved ejection fraction, HFpEF, or diastolic heart failure.⁸

If you are at risk for or already in HF, your doctor will monitor your heart in several ways. This will help them treat your condition as effectively as possible.⁸