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Doppler echo cardiac output calculator

Calculate Doppler stroke volume and cardiac output from LVOT diameter, VTI and heart rate, with body surface area and cardiac index.

For feet, enter decimal feet: 5 ft 6 in is 5.5 ft.

For feet, enter decimal feet: 5 ft 6 in is 5.5 ft.

For feet, enter decimal feet: 5 ft 6 in is 5.5 ft.

Cardiac output
4.712
Stroke volume
62.83
LVOT cross-sectional area (cm²)
3.142
Mosteller BSA (m²)
2.000
Cardiac index (L/min/m²)
2.356
LVOT diameter (cm)
2.000
LVOT VTI (cm)
20.00
Heart rate (beats/min)
75.00

Estimates for information only. Not financial, medical, legal or engineering advice. See the Terms.

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How this calculator works

The LVOT is modelled as a circular opening. Multiplying its area by the Doppler velocity-time integral estimates forward stroke volume, then heart rate converts it to flow. Use aligned Doppler sampling and diameter at the appropriate measurement site. Irregular beats require representative averaging. Diameter error is amplified because area depends on its square. The result is an estimate for information only and is not medical advice.

Formula

LVOT area = πD²/4. SV = area × VTI. CO = SV × HR. CI = CO/BSA; Mosteller BSA = √[height(cm) × weight(kg)/3600].

Worked example

With diameter 2 cm and VTI 20 cm, area is 3.1416 cm² and SV is 62.8319 mL. At 75 beats/min, output is 4.7124 L/min.

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Frequently asked questions

Is VTI a velocity?

No. VTI is velocity integrated over time and has units of length, such as cm.

Why can small errors matter?

Diameter is squared in the area calculation.

What does cardiac index add?

It divides the output by body surface area to describe flow relative to body size.

Sources

Written byAmira MansourCalculator writer. Builds and tests Mathulate calculators against published sources.
Reviewed byPriya Natarajan, RDRegistered dietitian. Checks health calculators against public health guidance.

Last updated .

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