Ejection fraction is a procedure that calculates the percentage of blood that leaves the heart every time it contracts. As the heartbeats, it pumps blood into the system from the two lower muscular chambers – left and right ventricles and between beats, when the heart relaxes, the two ventricles refill with blood.

The term ejection fraction refers to the percentage of blood that’s pumped out of a filled ventricle with each heartbeat. It is usually measured only in the left ventricle, as it’s the main pumping chamber. The left ventricle pumps oxygen-rich blood up into the body’s main artery-aorta to the rest of the system and normally takes more than a single contraction to pump all the blood out of a ventricle. This test helps the doctor to evaluate the percentage of blood leaving the left ventricle each time heartbeats, understand how effectively the heart functions, and diagnose heart failure.
Ejection Fraction

What Can Cause Reduced Ejection Fraction?

Generally, heart walls thicken and lose their capacity to contract and relax as efficiently as they should as you age. However, a low ejection fraction reading also means heart problem or damage, including:

Cardiomyopathy: It is a weakening of the heart muscle caused due to thickening or dilation of the heart muscle, which makes it difficult for the heart to pump well.

Heart Attack/ Coronary Artery Disease: A heart attack develops when one or more arteries are blocked resulting in damage to the heart muscle. Coronary artery disease can block or narrow the heart’s left and right arteries, making it hard for blood to flow to the heart.

Heart Valve Disease: This develops when one or more of the valves in the heart don’t open or close, which can hinder the blood flow through the heart and system.

Also Read: Heart Valve Disease: Causes, Symptoms And Treatment

What Can Cause A High Ejection Fraction?

Hypertrophic Cardiomyopathy: This condition abnormally thickens certain regions of heart muscle without can a clear cause and mostly it is genetic. For some people, hypertrophic cardiomyopathy can lead to abnormal heart rhythms that need immediate medical help.

How Is The Ejection Fraction Test Done?

Usually, the left ventricle is measured for ejection fraction, as it performs heavy lifting in the system, pumping the blood to almost all vital organs. But recent research suggests that the right ventricle shouldn’t be ignored when assessing the ejection fraction of the right heart.

An appropriate left ventricle ejection fraction (LVEF) reading can be assessed through several imaging techniques such as:

Echocardiogram: This procedure uses sound waves to get the images of the heart.

Cardiac MRI: this is an imaging procedure that uses a magnetic field, radio waves and a computer to produce complete images of the heart.

Cardiac Catheterization: In this procedure, a hollow tube is inserted into a large blood vessel to determine heart function. During this test, coronary angiography is also done, where a dye is injected into the catheter and an X-ray checks the blood flow via the heart.

Cardiac Nuclear Medicine Scan: A very minimal amount of radioactive elements are injected into the bloodstream, which is identified by cameras that produce images of the heart and its mechanisms.

Cardiac CT Scan: This procedure can give a detailed representation of the heat size, with gated images and heart function.

Also Read: Electrocardiogram (ECG) Test: Procedure, Results And Risks

What Does The Ejection Fraction Result Mean?

A normal left ventricular ejection fraction (LVEF) is 55-to 70%. The EF can go up or down based on the heart condition and how well the treatment works.

Ejection Fraction (EF): 55% to 70%

Pumping ability of the heart: Normal.

Level of heart failure: Heart function may be normal, or a person may have heart failure with preserved EF(HF-pEF).

Ejection Fraction (EF) %: 40% to 54%

Pumping Ability of the Heart: Slightly below normal.

Level of Heart Failure: Very less blood is available, thus minimal amount is ejected from the ventricles. There is a lower-than-normal amount of oxygenated blood available to the rest of the body. But person may not show any symptoms.

Ejection Fraction (EF) %: 35% to 39%

Pumping Ability of the Heart: Moderately below normal.

Level of Heart Failure: Mild heart failure with reduced EF (HF-rEF).

Ejection Fraction (EF) %: Less than 35%

Pumping Ability of the Heart: Severely below normal

Level of Heart Failure: Moderate-to-severe HF-rEF. Severe HF-rEF increases the risk of life-threatening heartbeats and cardiac desynchronization (right and left ventricles do not pump in unison).

What Are The Types Of Heart Failure?

Heart Failure With Reduced Left Ventricular Function (HFrEF)

An EF below 40% is categorised as heart failure with reduced ejection fraction (HFrEF) and develops when one of the heart’s chambers is not contracting well. However, medications can treat this condition.

Symptoms include:

  • Shortness of breath
  • Exhaustion
  • Heart palpitations
  • Dizziness, confusion,
  • Swelling in ankles, legs, or abdomen
  • Poor intolerance to exercise

Also, a person with this problem may have a greater risk of irregular heart rates that can be life-threatening. If a person's EF is below 35% then the doctor would recommend treatment options such as an implantable cardioverter-defibrillator or a pacemaker that may control heart rhythm.

Heart Failure With Preserved Left Ventricular Function (HFpEF)

In this type of heart failure, you may have a preserved or normal EF and it happens when the left ventricle doesn’t relax properly. This may be due to a thickened heart muscle or heart muscle stiffness, which leads to less blood being pumped from the heart to the rest of the body.

Fatigue and shortness of breath during workouts are some of the symptoms. HEpEF can also be due to ageing, diabetes, or high blood pressure.


There are several modes of treatment available for abnormal ejection fraction. Doctors may prescribe medications to treat this condition that include:

Angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), or beta-blockers – that help to decrease the level of hormones that weaken the heart muscle, and it eventually slows the progression of heart disease.

Diuretics - these drugs work to clear out excess fluid that’s causing swelling and shortness of breath.

A biventricular pacemaker helps to harmonize the contractions of the left and right ventricles so that they are working to their highest capability.

An implantable cardiac defibrillator is implanted into the patient’s chest that sends minute electrical triggers to the heart to keep it beating regularly.