Ejection fraction is a measurement doctors use to calculate the percentage of blood that leaves your heart each time it contracts.
As your heart beats, it pumps (ejects) blood into your body from the two lower muscular chambers, known as the left and right ventricles. Between beats, when your heart relaxes, the two ventricles fill up with blood.
However, it takes more than a single contraction to pump all the blood out of a ventricle. Ejection fraction is a test your doctor can use to determine the percentage of blood that leaves the left ventricle each time your heart beats, and to understand how well your heart works.
Ejection fraction can help diagnose heart failure.
Generally, your left ventricle is the one measured for ejection fraction. It does the heavy lifting in your body, pumping blood to almost all your major organs.
However, current research suggests that the right ventricle shouldn’t be ignored when determining ejection fraction of the right heart.
An accurate left ventricle ejection fraction (LVEF) reading can be measured through a variety of imaging techniques. The most common ejection fraction testing measures include:
- Echocardiogram. An echocardiogram uses sound waves to take images of your heart. A 2012 research article suggests that 3-D images provide the best and most accurate readings.
- Cardiac MRI (C-MRI). A C-MRI is an image-based test that uses a magnetic field, radio waves, and a computer to create detailed images of the inside of your heart.
- Cardiac catheterization. In this procedure, your doctor inserts a hollow tube into a large blood vessel to monitor your heart function. During the catheterization, a coronary angiography is also performed. A dye is injected into the catheter. Then, an X-ray monitors the blood flowing throughout your heart.
- Cardiac nuclear medicine scan. Trace amounts of radioactive materials are injected into your bloodstream. They’re then detected by cameras that produce images of your heart and its mechanisms.
- Cardiac CT scan. This X-ray procedure can give a representation of heart size and, with gated images, heart function.
|Mildly abnormal range||41–51%||41–53%|
|Moderately abnormal range||30–40%||30–40%|
|Severely abnormal range||less than 30%||less than 30%|
- High LVEF. An LVEF measurement that’s above 72 percent for men and above 74 percent for women may be an indication of a heart condition such as hypertrophic cardiomyopathy. This is when the heart muscle becomes thicker than normal and interferes with the heart’s pumping function. It’s a common cause of sudden cardiac arrest.
- Normal. Even if you have a normal range LVEF, it doesn’t necessarily mean your heart is “normal.” Some people can have heart failure with a condition that’s known as heart failure with preserved ejection fraction (HFpEF). See below for more details.
- Mildly reduced. An ejection fraction range between 41 and 51 percent for men and between 41 and 53 percent for women is classified as mildly reduced. It could be a sign of heart damage, perhaps from a heart condition or a previous heart attack.
- Sign of heart failure. An LVEF below 40 percent is heart failure with reduced ejection fraction (HFrEF). It can also be due to cardiomyopathy, which is when your heart muscle weakens, making your heart less effective at pumping blood to the rest of your body.
Heart failure with reduced left ventricular function (HFrEF)
An ejection fraction below 40 percent is classified as heart failure with a reduced ejection fraction (HFrEF). It occurs when one of your heart’s chambers isn’t able to contract properly. Medications can treat it.
Symptoms may include:
- shortness of breath
- heart palpitations
- dizziness, confusion, lightheadedness
- swelling in your ankles, legs, or abdomen
- exercise intolerance
You may also have a greater risk of irregular heart rates that can be life threatening.
If your ejection fraction is below 35 percent, your doctor will likely recommend other treatments, like an implantable cardioverter defibrillator or a pacemaker, to help regulate your heart rhythm.
Heart failure with preserved left ventricular function (HFpEF)
With this type of heart failure, you have a preserved, or normal, ejection fraction. It occurs when your left ventricle doesn’t relax properly.
This may be due to a thickened heart muscle or heart muscle stiffness. It can lead to less blood being pumped from your heart to the rest of your body.
Symptoms may include fatigue and shortness of breath during exercise. HFpEF can be the result of aging, diabetes, or high blood pressure.
As we age, our hearts do too. Heart walls thicken and lose some of their capacity to contract and relax as efficiently as they should.
But a low ejection fraction reading can also indicate some form of heart damage, including:
- Cardiomyopathy. Cardiomyopathy is a weakening of the heart muscle caused by thickening or dilation of the heart muscle. This makes it harder for your heart to pump properly.
- Heart attack and coronary artery disease. A heart attack occurs when one or more of your arteries become blocked, causing damage to the heart muscle. Coronary artery disease can narrow or block your heart’s left and right arteries, making it more difficult for blood to flow to your heart.
- Heart valve disease. This occurs when one or more of the valves in your heart don’t open or close properly. This can disrupt the blood flow through your heart and body.
A high ejection fraction reading can indicate a heart condition known as hypertrophic cardiomyopathy. This condition abnormally thickens parts of your heart muscle without an obvious cause.
Hypertrophic cardiomyopathy is often genetic. It’s tough for doctors to diagnose because many people don’t have symptoms.
For a small number of people, hypertrophic cardiomyopathy can cause serious abnormal heart rhythms (arrhythmias) that require treatment.
If you have a family history of hypertrophic cardiomyopathy, let your doctor know so they can monitor you over time.
There are a variety of treatment options for abnormal ejection fraction. Some of the most common treatments include:
- Angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), or beta-blockers. These medications can reduce the amount of hormones that weaken your heart muscle. They can also slow the progression of heart disease.
- Diuretics. These drugs can help get rid of excess fluid that’s causing swelling and shortness of breath.
- Eplerenone or spironolactone. These drugs help you eliminate excess fluid and can help decrease stiffening of your heart.
- Hydralazine/nitrate. These two drugs have been successful in lowering blood pressure in people who still have symptoms when taking ACE, ARBs, and beta-blockers.
- Angiotensin receptor-neprilysin inhibitor (ARNI). This drug combines two drugs (sacubitril and valsartan) that reduce blood pressure and the strain on your heart.
- Sodium-glucose cotransporter 2 (SGLT2) inhibitors. If you have type 2 diabetes, this type of drug may help reduce the risk of heart failure and serious kidney complications.
- Biventricular pacemaker. This pacemaker helps synchronize the contractions of your left and right ventricles so they’re working to their highest capacity.
- Implantable cardiac defibrillator. This device can be directly implanted into your chest. It sends small electrical triggers to your heart to keep it beating regularly.
Ejection fraction is a test your doctor can use to determine the percentage of blood that leaves a ventricle each time your heart beats, and to understand how well your heart works.
A normal ejection fraction range is between 52 and 72 percent for men and between 54 and 74 percent for women. An ejection fraction that’s higher or lower may be a sign of heart failure or an underlying heart condition.
In general, the outlook for people with an abnormal ejection fraction result is encouraging. In most cases, with diligent care, the right treatment and medications, and certain lifestyle changes, you can manage your symptoms and continue living a high-quality life.