Cardiac output calculation with TEE

Steps for CO calculation:
(A) Midesophageal AV long-axis view with AV open in systole is used to measure the LVOT diameter. (Note that the LVOT radius is ½ the LVOT diameter.)
(B) Deep transgastric view through the LVOT and AV is used to measure the LVOT VTI. The pulsed-wave Doppler sample volume is positioned in the LVOT 1 cm proximal to the AV annulus.
(C) The LVOT VTI is measured by tracing the pulsed-wave Doppler spectral waveform.
(D) Machine-derived calculations of the SV and CO from the SV and HR.
Echocardiography systems commonly include software packages incorporating these formulas to automatically calculate CO from the measured parameters.