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How to estimate left ventricular ejection fraction visually
Visual ("eyeball") EF is the first estimate of systolic function in nearly every echocardiogram. Experienced readers come close to quantitative methods, but only after reading many studies against a reference. This guide gives a systematic approach; the simulator gives you the reference.
1. Use all the views
Form your impression from the parasternal long axis, the short axis at papillary level and the three apical views together. A single view can mislead you: a foreshortened apical 4-chamber hides the apex, and a single short-axis level misses regional abnormalities elsewhere in the ventricle.
2. Look at the cavity, not only the walls
EF is a volume ratio. Compare the cavity area at end-diastole (just after the QRS) with end-systole (just before the mitral valve opens). Because volume changes faster than area, a cavity whose area roughly halves from end-diastole to end-systole in each view corresponds to an EF of about 55–65%. If the area shrinks by only a quarter, EF is around 35–40%; near-obliteration of the cavity suggests an EF above 70%.
3. Then check wall thickening and longitudinal motion
- Thickening: normal myocardium thickens by roughly 40% or more in systole. Global poor thickening means global dysfunction.
- Mitral annular motion (MAPSE): the base normally moves about 1.2–1.6 cm toward a near-stationary apex; below 10 mm suggests reduced longitudinal function, often before radial motion or EF falls.
- Regional abnormalities: add up. An akinetic apex and apical segments in an otherwise normal ventricle often brings EF down to the 40s.
4. Report in ranges and categories
Report visual EF in ranges, for example 50–55%, and map it to a category. The simulator uses the BSE thresholds:
| Category | EF |
|---|---|
| Normal | ≥55% |
| Borderline low | 50–54% |
| Impaired | 36–49% |
| Severely impaired | ≤35% |
5. Know the pitfalls
- Heart rate and rhythm: in atrial fibrillation EF varies from beat to beat. Average at least five beats, or use an index beat that follows two similar RR intervals.
- Small, thick ventricles (LVH, HCM) look hyperdynamic. EF may be normal even when stroke volume is low.
- Dyssynchrony (LBBB, pacing) makes the ventricle look chaotic and is easy to underestimate. Focus on the end-systolic cavity size.
- Image quality: near-field clutter at the apex and lateral-wall dropout hide the endocardium. Use every view, and contrast if it is available.
6. Calibrate yourself
Visual EF is a learned skill. The fastest way to improve is immediate feedback against a known answer. In Practice every simulated case has an exact EF calculated from its 3D ventricle, and your Progress page shows whether you systematically over- or under-estimate.
Practise visual EF now →