Doppler Echo Cardiac Output Calculator

cm
cm
bpm
Health

The Doppler Echo Cardiac Output Calculator estimates stroke volume and cardiac output from the LVOT diameter, LVOT velocity-time integral (VTI), and heart rate. For clinical education only.

Rates and fees change frequently. Always confirm the current figures with the official authority before relying on this result.

Formula

CSA = π(LVOT/2)²; SV = CSA × VTI; CO = SV × HR ÷ 1000
  • The LVOT is modelled as a circle to get its cross-sectional area.
  • Cardiac output is stroke volume times heart rate, converted to litres per minute.

LVOT 2 cm, VTI 20 cm, HR 70

Inputs
  • LVOT Diameter: 2 cm
  • LVOT VTI: 20 cm
  • Heart Rate: 70 bpm

CSA = 3.14 cm², SV = 62.8 mL, CO = 4.4 L/min.

Frequently asked questions

How is cardiac output measured on echo?
Stroke volume (LVOT area × VTI) is multiplied by heart rate. Small LVOT diameter errors have a large effect because the area uses the radius squared.