What is ejection fraction?

As your heart beats, it pumps blood out into your body with two lower muscular chambers. These chambers are called the left and right ventricles.

It takes more than a single contraction to pump all of the blood out of your heart. Ejection fraction (EF) is a measurement doctors use to calculate the percentage of blood flowing out of these ventricles with each contraction.

Generally, your left ventricle is the one measured for EF. 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 EF.

An accurate left ventricle EF (LVEF) reading can be measured through a variety of imaging techniques. The most common EF testing measures are:

  • Echocardiogram. An echocardiogram uses sound waves to take images of your heart. Current research suggests that 3-D images provide the best and most accurate readings.
  • Cardiac magnetic resonance imagining (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 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 is fast and usually used when other tests are inconclusive.

A normal LVEF reading for adults over 20 years of age is 53 to 73 percent. An LVEF of below 53 percent for women and 52 percent for men is considered low. An RVEF of less than 45 percent is considered a potential indicator of heart issues. Two common issues include:

  • HFrEF (systolic dysfunction). This is heart failure with a reduced ejection fraction. This occurs when one of your heart’s four chambers can’t contract properly. Symptoms might include shortness of breath, exhaustion, or heart palpitations.
  • HFpEF (diastolic dysfunction). This is heart failure with a preserved, or normal, ejection fraction. This occurs when your ventricles don’t relax. This makes less blood flow from your heart and into your body. Symptoms for HFpEF often include shortness of breath during exercise or exertion and fatigue. HFpEF can be the result of aging, diabetes, or hypertension.

As we age, our hearts do too. Heart walls thicken and lose some of their capacity to contract and relax as the years go on. But, a low EF reading can also indicate some form of heart damage, including:

  • Cardiomyopathy. This condition thickens your heart tissues.
  • Heart attack. This occurs when your heart muscle’s damaged when one or more of your arteries become blocked.
  • Coronary artery disease. This condition narrows or blocks your heart’s left and right arteries, making blood flow to the heart very difficult.
  • Systolic heart failure. This occurs when your left ventricle cannot pump enough blood to your body.
  • Heart valve disease. This occurs when your heart’s valves can’t open and close properly and blood can’t flow into your heart normally.

A high EF reading can indicate a heart condition known as hypertrophic cardiomyopathy (HC). This condition abnormally thickens parts of your heart muscle without an obvious cause. HC is often genetic. It’s tough to diagnose because many people can live a symptom-free life.

For a small number of people, HC can cause serious abnormal heart rhythms (arrhythmias) that require treatment. If you have a family history of HC, let your doctor know so they can monitor you over time.

There are a variety of treatment options for abnormal EF, including:

  • 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 agents help you eliminate excess fluid and can help decrease stiffening of your heart.
  • Biventricular pacemaker. This pacemaker helps to 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.
  • 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.

In general, the outlook for an abnormal EF is encouraging. In most cases, with diligent care and medications, you can manage your symptoms and continue living a normal life.

Remember to pay attention to your body. Try to eat a balanced, low-fat diet with plenty of leafy green vegetables. Get daily exercise and maintain a regular sleep schedule.