DUCTUS VENOSUS INDEX (DVI)

Angle independent index of ductus venosus hemodynamics, which is considered an expression of RV preload.

DVI = ventricular systole - atrial systole / ventricular systole.

S/A RATIO

Ductus venosus S/A ratio – Rizzo et.al. 1994

Ductus venosus S/A ratio – Rizzo et.al. 1994

The ductus venosus waveform has a triphasic flow pattern.

• Wave I or S = The first peak corresponding to systole.
• Wave II or D = The second peak or diastole.
• Wave III or A = The nadir during atrial contraction.

S/A ratio is an angle-independent parameter that describes ductus venosus hemodynamics (1).

REFERENCES

1. Rizzo G, Capponi A, Arduini D et.al. Ductus venosus velocity waveforms in appropriate and small for gestational age fetuses. Early Hum Dev 1994;37: