Normal Left Ventricular Ejection Fraction (LVEF)
A normal left ventricular ejection fraction (LVEF) ranges from 50% to 70%, with a midpoint of 60% according to current American College of Cardiology/American Heart Association guidelines 1.
LVEF Classification
LVEF is a critical measure of cardiac systolic function that guides diagnosis, prognosis, and treatment decisions in cardiovascular medicine. Current guidelines classify LVEF as follows:
- Hyperdynamic: Greater than 70% 1
- Normal: 50% to 70% 1
- Mildly diminished/reduced: 40% to 49% 1
- Moderately diminished/reduced: 30% to 39% 1
- Severely diminished/reduced: Less than 30% 1
Clinical Significance and Heart Failure Classification
LVEF is used to categorize heart failure into distinct types, which have different treatment approaches:
- HFrEF (Heart Failure with reduced EF): LVEF ≤40% 1
- HFmrEF (Heart Failure with mildly reduced EF): LVEF 41%-49% 1
- HFpEF (Heart Failure with preserved EF): LVEF ≥50% 1
- HFimpEF (Heart Failure with improved EF): Previous LVEF ≤40% with follow-up measurement >40% 1
Measurement Considerations
- LVEF is calculated as: (EDV-ESV)/EDV × 100, where EDV is end-diastolic volume and ESV is end-systolic volume 2
- Quantitative measurement of LVEF is preferred over qualitative assessment 1
- When multiple measurements are available, the hierarchy for preferred modality is:
- Radionuclide ventriculography
- Magnetic resonance imaging (MRI)
- Echocardiography (2D or 3D)
- Contrast ventriculography
- Technetium myocardial perfusion imaging 1
Important Clinical Considerations
- LVEF has considerable variability over time (within-person variance SD of 7.4%), which should be considered when making treatment decisions 3
- Patients with LVEF ≤55% may be at higher risk of progression to HFmrEF in the future (sensitivity 90.9%, specificity 97.7%) 4
- Low normal LVEF (50-55%) in asymptomatic individuals is associated with a 3.64-fold increased risk of developing heart failure compared to those with LVEF ≥55% 5
- Global longitudinal strain (GLS) measurement can provide additional information about LV function beyond LVEF and may detect subtle dysfunction even when LVEF appears normal 6
Pitfalls and Caveats
- LVEF measurement varies between imaging modalities and interpreters 2
- A single LVEF measurement at one time point may not be adequate, particularly for values in the mildly reduced range (41-49%), as these patients often show dynamic changes in LVEF over time 1, 3
- Patients with HFmrEF have a probability of <25% of remaining in that category after one year, highlighting the dynamic nature of LVEF 3
- LVEF may appear normal in certain pathophysiological conditions despite impaired myocardial function, such as in some cases of HFpEF 7