From the Guidelines
The normal ejection fraction of a healthy individual is typically greater than 78%. This is based on the most recent and highest quality study available, which provides a comprehensive review of cardiovascular magnetic resonance normal values of cardiac chamber size and aortic root in adults 1. The study suggests that an ejection fraction (EF) of greater than 78% is considered normal, while values between 57-77% are considered mildly abnormal, and values below 57% are considered moderately to severely abnormal.
Key Points to Consider
- The ejection fraction is an important measurement of heart function that represents the percentage of blood that leaves the left ventricle when it contracts.
- Values below 57% may indicate heart failure or cardiomyopathy, while values above 78% can suggest hypertrophic cardiomyopathy or dehydration.
- The ejection fraction is commonly measured using echocardiography, cardiac MRI, or cardiac catheterization.
- It's essential to interpret ejection fraction alongside other clinical findings, as some individuals with heart failure may have preserved ejection fraction (HFpEF) despite having symptoms, while others may have reduced ejection fraction (HFrEF) with significant impairment in cardiac output.
Measurement and Interpretation
- Quantitative measurement of ejection fraction is preferred over qualitative measurement, with a hierarchy of modalities including radionuclide ventriculography, magnetic resonance imaging (MRI), and echocardiography 2.
- When multiple determinations are present, the most recent measurement is preferred.
- Ejection fraction should be enumerated as a percentage, with a range of 5% to 90% for left ventricle and right ventricle.
From the Research
Normal Ejection Fraction
The normal ejection fraction of a healthy individual is typically considered to be between 50% and 70% 3, 4.
Ejection Fraction Ranges
- An ejection fraction of 50% to 59% is often associated with heart failure with mildly reduced ejection fraction (HFmrEF) 4.
- An ejection fraction of 60% or higher is considered normal or even supranormal 3, 4.
- Some studies suggest that an ejection fraction above 65% to 70% may be associated with higher mortality in heart failure patients 3.
Factors Influencing Ejection Fraction
- Patient characteristics such as hypertrophic cardiomyopathy, hypertension, and valvular disease can influence ejection fraction 3.
- The use of medications and devices recommended for heart failure with reduced ejection fraction can also impact ejection fraction 3.
- Exercise capacity and haemodynamic responses to exercise can vary among patients with heart failure with preserved ejection fraction (HFpEF) 5.
Clinical Implications
- The diagnosis and treatment of heart failure with preserved ejection fraction (HFpEF) can be challenging due to the lack of clear risk factors and pathophysiological associations 6.
- The introduction of exercise diastolic stress tests may help improve diagnosis and monitoring of HFpEF 6.
- Implantable cardioverter-defibrillators (ICDs) may not reduce overall mortality in patients with acute myocardial infarction and reduced left ventricular ejection fraction 7.