Siemens ACUSON Cypress Operator's Manual page 165

Doppler Formulas (Cardiac)
TABLE 31.
Type Formula
Stroke Volume
SV
TVI is the time velocity integral (m).
Flow Area is derived from the flow diameter (cm
Aortic:
Mitral:
Pulmonic: PV TVI
Tricuspid: TV TVI
Cardiac Output
CO
SV is Stroke Volume (ml).
HR is Heart Rate (bpm).
Cardiac Index
CI
CO is cardiac output (l/min).
BSA is body surface area (m
Pressure Half
Time
(PHT)
PHT
Vmax is Maximum Velocity (m/s).
Deceleration Slope (m/s
Valve Area by
Valve Area
PHT
PHT is Pressure Half Time (msec).
Aortic Valve
AVA
Area by the
Continuity
Equation using
AVA is Aortic Valve Area (cm
V
max
CSA
Vmax
Vmax
(m/s).
LVOT is Left Ventricular Outflow Tract.
ACUSON Cypress™ Operator's Manual
• •
= TVI Flow Area 100
TVI FLOW AREA
AoV TVI LVOT Flow Area
MV TVI Mitral Flow Area
Pulmonic Flow Area
Tricuspid Flow Area
( • )
SV HR
= ------------------------- -
1000
CO
= ---------- -
BSA
2
).
⎛ ⎞
1
⎛
•
Vmax 1 – ------ -
⎝ ⎠
⎜
2
⎜
= --------------------------------------------------- -
⎜
Deceleration Slope
⎝
2
).
220
= ----------- -
PHT
Vmax
•
LVOT
= ----------------------- -
CSA
LVOT
Vmax
AoV
2
).
is Cross-sectional Area of LVOT (cm
LVOT
is the maximum velocity in the LVOT (m/s).
LVOT
is the maximum velocity across the aortic valve
AoV
Cardiac Formulas and References
2
).
⎞
⎟
•
⎟
1000
⎟
⎠
2
).
Units
ml
l/min
2
l/min/m
ms
2
cm
2
cm
6-21