Cardiac output (echo LVOT method)

SV = LVOT area × LVOT VTI. CO = SV × HR. CI/SVI use BSA (Mosteller).

Inputs

LVOT diameter

LVOT VTI

Heart rate

bpm

Height

Weight

Tip: LVOT diameter is squared in the formula, so small measurement differences can noticeably change SV/CO.

LVOT area

Area = π × (d/2)²

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Stroke volume (SV)

SV = LVOT area × LVOT VTI

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Cardiac output (CO)

CO = SV × HR

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Body surface area (BSA)

Mosteller: √(height×weight/3600)

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Cardiac index (CI)

CI = CO / BSA

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Stroke volume index (SVI)

SVI = SV / BSA (low-flow often < 35)

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