How to measure LAVI - Left Atrial Volume Index

Here’s a simple, step-by-step guide to measuring Left Atrial Volume Index (LAVi) on echocardiography — clear enough for practical use and quick reporting 👇

---

🧭 Key Concept

LAVi = Left atrial volume (mL) ÷ Body Surface Area (BSA, m²)

→ Reported as mL/m²

Normal ≤ 34 mL/m²

---

🩺 Step-by-Step: How to Measure LAVi

1. Acquire the right views

Use apical 4-chamber (A4C) and apical 2-chamber (A2C) views.

Ensure:

LA is not foreshortened (true apex visible)

LV long axis is fully elongated

Endocardial borders are clearly seen

---

2. Select timing

Measure at end-systole (when LA is largest)

→ Just before mitral valve opening

---

3. Trace the LA area

Trace inner border of LA (exclude:

pulmonary veins

LA appendage

mitral annulus thickness)

Do it in both A4C and A2C.

---

4. Measure the LA length

Measure longest perpendicular line from mid-mitral annulus to superior wall (shorter of A4C/A2C).

---

5. Calculate LA Volume (Biplane Simpson / Area–Length method)

Biplane Method of Disks (Simpson’s):

use the machine’s auto-trace/volume function (most echo machines do this automatically).

---

6. Index to BSA

LAVi = \frac{LA\ Volume}{BSA}

---

📋 Reporting Format

Example report section:

Left Atrial Volume (Biplane Simpson): 58 mL

Body Surface Area: 1.8 m²

Left Atrial Volume Index (LAVi): 32 mL/m² (Normal)

or in summary line:

> LAVi: 32 mL/m² — within normal limits (≤34 mL/m²)

---

📊 Reference Ranges (ASE 2020)

Category Men (mL/m²) Women (mL/m²)

Normal ≤34 ≤34

Mild ↑ 35–41 35–41

Moderate ↑ 42–48 42–48

Severe ↑ >48 >48