What does the term "ejection fraction" mean? What does it measure?

Answer From Rekha Mankad, M.D.

Ejection fraction is a measurement of the percentage of blood leaving the heart each time it squeezes. When the heart squeezes, it's called a contraction. Ejection fraction is just one of many tests your health care provider may use to see how your heart works.

The heart contracts and relaxes. When the heart contracts, it pumps out — ejects — blood from the two lower heart chambers, called ventricles. When the heart relaxes, the ventricles refill with blood. No matter how forceful the contraction, the heart can never pump all the blood out of a ventricle. The term "ejection fraction" is the amount of blood — as a percentage — that's pumped out of a filled ventricle with each heartbeat.

The ejection fraction is usually measured only in the left ventricle. The left ventricle is the heart's main pumping chamber. It pumps oxygen-rich blood up into the body's main artery, called the aorta. The blood then goes to the rest of the body.

According to the American Heart Association:

  • A left ventricle (LV) ejection fraction of about 50% to 70% is categorized as normal.
  • A mildly reduced LV ejection fraction is usually between 41% and 49%.
  • A reduced LV ejection fraction is usually 40% or less.

Even if you have a normal ejection fraction, your overall heart function may not be healthy. Talk with your health care provider if you have concerns about your heart.

Some things that may cause a reduced ejection fraction are:

  • Weakness of the heart muscle, such as cardiomyopathy.
  • Heart attack that damaged the heart muscle.
  • Heart valve problems.
  • Long-term, uncontrolled high blood pressure.

Ejection fraction can be measured with imaging tests, including:

  • Echocardiogram. This is the most common test used to measure ejection fraction. An echocardiogram uses sound waves to create pictures of the beating heart. It shows how blood flows through the heart and heart valves.
  • Cardiac catheterization. A long, thin flexible tube called a catheter is inserted in a blood vessel, usually in the groin or wrist, and guided to the heart. Images taken during this test can measure the ejection fraction of your heart.
  • Magnetic resonance imaging (MRI). An MRI uses a magnetic field and radio waves to create cross-sectional images of specific parts of the body. When an MRI is used to study the heart, it's called a cardiac MRI.
  • Computerized tomography (CT). A CT scan uses X-rays to create cross-sectional images of specific parts of the body. When a CT scan is used to study the heart, it's called a cardiac CT.
  • Nuclear medicine scan. During a nuclear medicine scan, trace amounts of radioactive material are put into your bloodstream through an IV. Special cameras then track the radioactive material in your blood as it flows through your heart and lungs.

With

Rekha Mankad, M.D.

From Mayo Clinic to your inbox

Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Click here for an email preview.

To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and website usage information with other information we have about you. If you are a Mayo Clinic patient, this could include protected health information. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail.

Feb. 17, 2023 See more Expert Answers

See also

  1. Acute coronary syndrome
  2. Angina
  3. Angina treatment: Stents, drugs, lifestyle changes — What's best?
  4. Anorexia nervosa
  5. Aortic calcification: An early sign of heart valve problems?
  6. Aortic valve regurgitation
  7. Aortic valve stenosis
  8. ARDS
  9. Arteriosclerosis / atherosclerosis
  10. Atrial fibrillation
  11. Atrial fibrillation and managing stress
  12. Atrial flutter
  13. Atrial septal defect (ASD)
  14. Automated external defibrillators: Do you need an AED?
  15. Blood tests for heart disease
  16. Mitral valve clip to treat mitral regurgitation: Bob's story
  17. Bradycardia
  18. Mitral valve overview
  19. Jack Long — Live LONG - Beat STRONG to find a cure
  20. A leaky tricuspid valve
  21. Leaky valve cone procedure
  22. Mayo Clinic offers congenital heart care: Marcus' story
  23. Mitral valve disease in children
  24. Video: Septal myectomy and apical myectomy
  25. Treating Pericarditis
  26. Valve problems in children with heart disease: What patients and families should know
  27. Broken heart syndrome
  28. Bulimia nervosa
  29. Bundle branch block
  30. Calcium supplements: A risk factor for heart attack?
  31. Can vitamins help prevent a heart attack?
  32. Cardiac asthma: What causes it?
  33. Cardiac MRI animation
  34. Cardiac sarcoidosis
  35. Cardiogenic shock
  36. Cardiomyopathy
  37. Kinser's story
  38. Caregiving for someone with atrial fibrillation
  39. Chagas disease
  40. Chelation therapy for heart disease: Does it work?
  41. Chest pain
  42. Coarctation of the aorta
  43. What are congenital heart defects? An expert explains
  44. Congenital heart defects in children
  45. Congenital heart disease in adults
  46. Congenital heart defects FAQs
  47. Coronary artery disease
  48. Coronary artery disease: Angioplasty or bypass surgery?
  49. What is coronary artery disease? A Mayo Clinic cardiologist explains.
  50. Coronary artery disease FAQs
  51. Coronary artery spasm: Cause for concern?
  52. Daily aspirin therapy
  53. Diabetic ketoacidosis
  54. Dilated cardiomyopathy
  55. Does atrial fibrillation run in families?
  56. Does older age increase the risk of atrial fibrillation?
  57. Dressler syndrome
  58. Drug-eluting stents
  59. Drummer Beats Heart Disease
  60. Ebstein anomaly
  61. Eisenmenger syndrome
  62. Electrocardiogram (ECG or EKG)
  63. Endocarditis
  64. Enlarged heart
  65. Fainting during urination (micturition syncope): What causes it?
  66. Fasting diet: Can it improve my heart health?
  67. Flu Shot Prevents Heart Attack
  68. Flu shots and heart disease
  69. Four Steps to Heart Health
  70. Genetics and Cardiomyopathy
  71. Grass-fed beef
  72. Healthy Heart for Life!
  73. Heart arrhythmia
  74. Heart attack
  75. Heart attack prevention: Should I avoid secondhand smoke?
  76. Heart attack symptoms
  77. Heart Attack Timing
  78. Heart disease
  79. Heart disease in women: Understand symptoms and risk factors
  80. Heart failure
  81. Heart failure and sex: Is it safe?
  82. Heart-healthy diet: 8 steps to prevent heart disease
  83. Heart murmurs
  84. Heart palpitations
  85. Holiday Heart
  86. Hyperparathyroidism
  87. Hypertrophic cardiomyopathy
  88. Hypoparathyroidism
  89. Mayo Clinic Minute: Identifying and treating atrial fibrillation
  90. Kawasaki disease
  91. Left ventricular hypertrophy
  92. Long QT syndrome
  93. Low blood pressure (hypotension)
  94. Menus for heart-healthy eating
  95. Mitral valve disease
  96. Mitral valve prolapse
  97. Mitral valve regurgitation
  98. Mitral valve stenosis
  99. Multiple system atrophy (MSA)
  100. Myocardial ischemia
  101. Myocarditis
  102. Nocturnal panic attacks: What causes them?
  103. Noonan syndrome
  104. NSAIDs: Do they increase my risk of heart attack and stroke?
  105. Nuts and your heart: Eating nuts for heart health
  106. Omega-3 in fish
  107. Omega-6 fatty acids
  108. Orthostatic hypotension (postural hypotension)
  109. Panic attacks and panic disorder
  110. Patent ductus arteriosus (PDA)
  111. Pectus excavatum
  112. Pectus excavatum
  113. Pericardial effusion
  114. Pericarditis
  115. Planning to travel with atrial fibrillation?
  116. Polypill: Does it treat heart disease?
  117. Pregnancy and atrial fibrillation
  118. Premature ventricular contractions (PVCs)
  119. Pulmonary atresia
  120. Pulmonary atresia with intact ventricular septum
  121. Pulmonary atresia with ventricular septal defect
  122. Pulmonary edema
  123. Pulmonary valve stenosis
  124. Red wine, antioxidants and resveratrol
  125. Rheumatic fever
  126. Robotic heart surgery treats mitral regurgitation: Ed's story
  127. Robotic or minimally invasive cardiac surgery for adult-adolescent congenital heart disease
  128. Secondary hypertension
  129. Should I make changes to my diet if I've been diagnosed with atrial fibrillation?
  130. Sick sinus syndrome
  131. Silent heart attack
  132. Heart disease prevention
  133. Sudden cardiac arrest
  134. Sudden death in young people: Heart problems often blamed
  135. Tachycardia
  136. Tetralogy of Fallot
  137. Tetralogy of Fallot
  138. Transposition of the great arteries
  139. Treatment of parathyroid disease at Mayo Clinic
  140. Tricuspid valve regurgitation
  141. Tuberous sclerosis
  142. Vasovagal syncope
  143. Ventricular fibrillation
  144. Ventricular septal defect (VSD)
  145. Ventricular tachycardia
  146. What is ventricular tachycardia?
  147. Cardiac ablation: treatment for ventricular tachycardia
  148. Video: Heart and circulatory system
  149. Mitral valve regurgitation
  150. Heart failure action plan
  151. Wolff-Parkinson-White (WPW) syndrome