Canonical: https://echosuite.app/guides/la-size/

# Left atrial volume index calculator: LAVI

Review left atrial volume and indexing inputs, with acquisition guidance and independently browsable reference context in the interactive tool.

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

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

## Method

LAVi = biplane LA volume ÷ BSA

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

### Biplane LA volume  mL

Enter the measured value in the displayed unit

- Confirm the variable matches the selected formula.
- Use the unit displayed beside the field.
- Keep measurements from the same representative hemodynamic state.

### Body surface area  m²

Record the units, date and measurement source

- Use measured height and weight where feasible. Record the units, date and whether a value was reported or estimated.
- Fluid status and weight changes affect BSA. Document any substituted weight; do not silently replace measured weight with ideal or dry weight.
- Use the unit named by the field. BSA is in m²; height and weight can be converted in the Body surface area calculator. Keep the formula with serial indexed results.

### LAVi  mL/m²

Enter the measured value in the displayed unit

- Confirm the variable matches the selected formula.
- Use the unit displayed beside the field.
- Keep measurements from the same representative hemodynamic state.

## Sources and method context

American Society of Echocardiography / EACVI · 2015 · Recommendations for Cardiac Chamber Quantification by Echocardiography in Adults · LA volume: chamber-quantification recommendations and Supplemental Table 3. Technique: ASE 2019 pp. 30–32. Diastolic context: ASE 2025 update.

[Primary reference](https://www.asecho.org/wp-content/uploads/2025/04/2015_ChamberQuantificationREV.pdf)

- LA volume technique · ASE 2019 · p. 32 · V.C.2

Trace at maximum end-systolic volume; exclude appendage and pulmonary veins; disk summation preferred; index biplane volume to BSA.

- LAVi abnormal threshold · ASE 2025 diastolic-function update · LA volume as a structural/supplemental marker

LAVi >34 mL/m² remains the ASE abnormal threshold. The 2025 update did not replace the chamber-quantification mild–moderate–severe rows (16–34 / 35–41 / 42–48 / >48).

- LA remodeling context · ASE 2025 diastolic-function update · LA volume and special-population discussion

LAVi is a cumulative remodeling marker, not an instantaneous manometer. Rhythm, mitral valve disease, high-output states, and athletic remodeling can enlarge the chamber.

Catalogue review status: Source 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)
- [Apical two chamber acquisition guide](https://echosuite.app/guides/views/apical-two-chamber/) · [Open in Probe Lab](https://echosuite.app/#a2c)
- [Left atrial pressure calculator: E/e′ method](https://echosuite.app/guides/lap-ee/)
- [Left atrial pressure calculator: mitral regurgitation velocity](https://echosuite.app/guides/lap-mr/)
- [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/)