Ejection Fraction Test
Overview
An ejection fraction test shows how well the heart pumps blood with each beat, giving important information about heart function. This test helps doctors find out if the heart is working normally or if there are problems like heart failure. The most common way to measure ejection fraction is through an echocardiogram, which uses sound waves to create images of the heart in action.
Understanding these test results can help patients know more about their heart health and discuss treatment options with their doctor. People who are worried about their heart or who have been told to get this test often want clear answers about what the numbers mean and what steps to take next.
What Is an Ejection Fraction Test?
An ejection fraction test measures how well the heart pumps blood out to the body. The test helps spot several heart conditions and guides treatment choices.
Purpose of Ejection Fraction Measurement
The main purpose of an ejection fraction (EF) test is to find out how much blood the left ventricle pumps out with each heartbeat. The left ventricle is the heart’s main pumping chamber. This measurement shows if the heart pushes out enough blood with each beat to supply the body’s organs and tissues.
Doctors use it to check heart strength, guide patient care, and monitor changes over time. Imaging tests such as echocardiograms, MRI, or nuclear tests measure ejection fraction. An EF test gives clear numbers that guide diagnosis and treatment.
Common Reasons for an Ejection Fraction Test
Doctors order an ejection fraction test when a person has symptoms like shortness of breath, fatigue, or swelling in the legs. These symptoms can suggest heart failure or other heart issues. Doctors also use the test after a heart attack to see if the heart muscle is damaged.
People with a history of heart disease, irregular heartbeat, or high blood pressure may also need this test. Doctors use the test to track the effects of heart medications or devices and before and after heart surgery to monitor changes in heart function.
What the Results Mean
Ejection fraction appears as a percentage. It shows how much blood leaves the heart’s left ventricle each time it beats.
- Normal EF: 50% to 70%
- Borderline or slightly below normal: 41% to 49%
- Low EF: 40% or less
A high EF does not always mean better health, as some heart problems cause the heart to overwork. Sometimes, a person can have a normal ejection fraction but still have heart failure, called HFpEF (heart failure with preserved ejection fraction).
Table: Example Ejection Fraction Ranges
| EF Range | What It Means |
|---|---|
| 55-70% | Normal |
| 41-54% | Below normal (borderline) |
| 40% or less | May show heart failure |
Conditions Detected or Monitored
Ejection fraction tests help detect and track several heart conditions. The most common is heart failure, which can develop when the heart cannot pump enough blood. A low ejection fraction may suggest heart muscle damage after a heart attack or cardiomyopathy.
The test also tracks changes in conditions like valve disease and arrhythmias. Doctors use this test to follow recovery after surgery and to check if heart treatments are working. The test is key for making treatment plans and monitoring how a heart condition changes over time.
Types of Ejection Fraction Tests
Several medical tests measure ejection fraction in the heart. Each test uses a different technique to look at heart function and blood flow.
Echocardiogram
An echocardiogram is the most common way doctors check ejection fraction. It uses sound waves to create live pictures of the heart as it beats. This test is non-invasive, meaning no surgery or needles are required.
A technician places a small device called a transducer on a patient’s chest. The device sends sound waves into the body, which bounce back to make images. Doctors look closely at the left ventricle, where most of the pumping happens. They can see how much blood the heart pushes out with each heartbeat.
The echocardiogram also shows the size and shape of the heart and if the valves work correctly. Doctors usually provide results from an echocardiogram within the same day. The test is safe, quick, and does not use radiation, making it a good option for many people.
Cardiac MRI
A cardiac MRI uses powerful magnets and radio waves to take clear, detailed pictures of the heart. This test helps doctors see both the structure and the function of the heart muscle. The person lies very still inside a large tube-shaped machine during the scan.
Sometimes a dye is injected into a vein to help highlight blood flow in the images. The test is painless but can take longer than other heart tests, usually around 30 to 60 minutes. Doctors often use this test when they need more detailed information than an echocardiogram can give.
A cardiac MRI is helpful for people who may have other heart conditions, scar tissue, or heart muscle diseases. This test does not use any radiation. The images can show even small areas of the heart that are not working properly. This allows for very accurate measurement of ejection fraction.
MUGA Scan
A MUGA scan stands for “multi-gated acquisition scan.” It is also known as a nuclear stress test. This test uses a small amount of radioactive material to track blood movement inside the heart. A technician injects the material into a vein, which then mixes with the blood.
Special cameras outside the body record images as the heart pumps. These pictures become moving images that show how well the heart chambers work with each beat. MUGA scans measure ejection fraction accurately and consistently. The test is safe, but there is low-level exposure to radiation.
Doctors may recommend a MUGA scan if other tests are unclear or if the person is being treated with medications that might impact heart function. The test usually takes about one hour to complete.
Cardiac Catheterization
Cardiac catheterization gives direct information about how the heart is working. Doctors insert a thin, flexible tube called a catheter into a blood vessel in the arm or leg and guide it to the heart.
Doctors inject a special dye through the catheter, which lets them see the heart and blood vessels on X-ray images. This procedure measures blood flow, pressure inside the heart, and ejection fraction. Cardiac catheterization is more invasive than other tests and may require a short stay in the hospital.
Risks include bleeding or infection, but the procedure provides very precise results. Doctors use this test when they need to get a close look at the heart or when other tests have not provided enough information. They also use it if there are signs of blocked arteries or other serious heart problems.
Preparing for an Ejection Fraction Test
Most people need little preparation for an ejection fraction test. Knowing what will happen and how to get ready can help reduce worry and make the process smoother.
What to Expect During the Test
Doctors can perform an ejection fraction test in several ways, including echocardiogram (ultrasound of the heart), MRI, CT scan, or nuclear medicine scan. Each test measures how much blood the heart pumps out with each beat. The test is painless and usually takes 30 to 60 minutes.
Doctors may ask patients to avoid eating or drinking for a short time before some tests. Patients should wear comfortable clothing and follow any directions from their doctor. Sometimes, a contrast dye is used to get clearer images, and patients should tell their care team if they have allergies. Doctors generally provide results soon after the test and review them with the patient.
Understanding Ejection Fraction Results
Ejection fraction (EF) is a percentage that shows how much blood the left ventricle pumps out with each heartbeat. This number helps doctors understand how well the heart is working. A normal ejection fraction usually falls between 55% and 70%. This means over half the blood in the left ventricle leaves the heart with each beat. Here is a quick guide:
| EF Range | Meaning |
|---|---|
| 50% to 70% | Normal |
| 41% to 49% | Mildly reduced |
| 40% or lower | Reduced |
Even if the ejection fraction is normal, people can still have heart failure. This is known as heart failure with preserved ejection fraction (HFpEF). Low ejection fraction can suggest weakened heart muscle.
This may lead to symptoms like shortness of breath, tiredness, and swelling. Doctors look at EF together with other test results. Ejection fraction is just one piece of information. Other factors, such as symptoms and other heart tests, are also important in determining heart health.
An ejection fraction of 60% means the heart pumps out 60% of the blood, which is considered healthy. For men and women, normal values range a little but generally fall within the 50–70% range.
Risks and Limitations of Ejection Fraction Testing
Ejection fraction (EF) tests, such as echocardiograms and cardiac CT scans, help check how well the heart pumps. While these tests are non-invasive or minimally invasive, they have some risks and limitations.
Possible Risks
- Cardiac catheterization, a test sometimes used to measure EF, can cause small risks like bleeding, infection, or allergic reaction to contrast dye.
- Non-invasive imaging, like echocardiograms and CT scans, usually carries very few risks, but CT scans expose patients to low levels of radiation.
Limitations of Ejection Fraction Testing
- EF measures only how much blood the left ventricle pumps out. It does not show how well all parts of the heart work.
- Some heart problems do not lower the ejection fraction. For example, people with heart failure with preserved ejection fraction (HFpEF) can have normal EF but still have symptoms.
Accuracy and Interpretation
- The type of test or the technician performing the test can affect results.
- Heartbeat irregularities may make results less reliable.
Table: Limitations of Common EF Tests
| Test Type | Limitation |
|---|---|
| Echocardiogram | Operator-dependent, image quality |
| Cardiac CT | Radiation exposure |
| Cardiac catheterization | Invasive procedure |
