Canonical: https://echosuite.app/guides/lap-ee/

# Left atrial pressure calculator: E/e′ method

Review the E/e′ pressure-estimation method and its mitral inflow and tissue-Doppler measurement guidance.

Created by [Mohammed Kamareddine, MD](https://echosuite.app/about/) · [Sources & educational scope](https://echosuite.app/about/)

[Open interactive calculator →](https://echosuite.app/calculators/#lap-ee)

## Method

Average E/e′ = E ÷ [(septal e′ + lateral e′)/2]; historical PCWP regression uses lateral E/e′

Use the measurement units shown below. Some fields apply only to a selected method or condition; follow the interactive tool’s method choices. The interactive tool keeps missing measurements incomplete and provides its method-specific results and reference context.

## Measurements and acquisition

### Mitral E velocity  cm/s

PW Doppler at the mitral leaflet tips

- Place the PW sample between the mitral leaflet tips.
- Record at end-expiration with a clear E and A wave.
- Measure the requested peaks or trace the requested envelope.

### Septal e′  cm/s

PW tissue Doppler at the mitral annulus

- Place the sample at the septal or lateral mitral annulus.
- Use tissue-Doppler settings and align with annular motion.
- Measure the early diastolic e′ peak and average representative beats.

### Lateral e′  cm/s

PW tissue Doppler at the mitral annulus

- Place the sample at the septal or lateral mitral annulus.
- Use tissue-Doppler settings and align with annular motion.
- Measure the early diastolic e′ peak and average representative beats.

## Sources and method context

American Society of Echocardiography · 2025 · Evaluation of Left Ventricular Diastolic Function and HFpEF Diagnosis · Table 3 · PDF p. 5; Figure 3 · PDF p. 18

[Primary reference](https://www.asecho.org/wp-content/uploads/2025/07/Left-Ventricular-Diastolic-Function.pdf)

- Acquisition & average E/e′ · Table 3 · PDF p. 5

Tissue sample position and size, full spectral display, and E divided by average septal/lateral e′.

- Guided resting LAP reading · Figure 3 and adjacent text · PDF p. 18

General sinus-rhythm scope, PASP preference when RAP is available, pressure branches and grades.

- Historical regression is separate · Nagueh et al. JACC 1997;30:1527–1533 · PMID 9362412

The PCWP regression uses lateral annular e′ and does not directly measure pressure. The legacy E/e′ + 4 estimate remains separately labelled.

Catalogue review status: Exact guideline locator mapped · clinical sign-off pending

These pages describe the educational tool. Interpret measurements with the complete clinical context and the method’s acquisition limitations.

## Keep exploring

- [Apical four chamber acquisition guide](https://echosuite.app/guides/views/apical-four-chamber/) · [Open in Probe Lab](https://echosuite.app/#a4c)
- [Left atrial pressure calculator: mitral regurgitation velocity](https://echosuite.app/guides/lap-mr/)
- [Left atrial volume index calculator: LAVI](https://echosuite.app/guides/la-size/)
- [Left ventricular pressure calculator](https://echosuite.app/guides/lv-pressure/)
- [Diastolic function assessment: sinus rhythm](https://echosuite.app/guides/diastolic-sinus/)

[All echo guides](https://echosuite.app/guides/) · [Learning paths](https://echosuite.app/learn/)