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