Siemens ACUSON Cypress

Cardiac Calculations
6-22 ACUSON Cypress™ Operator’s Manual
Aortic Valve
Area by the
Continuity
Equation using
TVI
AVA is Aortic Valve Area (cm
2
).
CSA
LVOT
is cross-sectional Area of LVOT (cm
2
).
TVI
LVOT
is the Time Velocity Interval in the LVOT (m).
TVI
AoV
is the Time Velocity Interval across the aortic valve
(m).
LVOT is Left Ventricular Outflow Tract.
cm
2
Flow Area from
Diameter
d is diameter (cm).
cm
2
Mitral Valve
Area by the
Continuity
Equation using
LVOT
MVA is Mitral Valve Area (cm
2
).
CSA
LVOT
is cross-sectional Area of LVOT (cm
2
).
TVI
LVOT
is the Time Velocity Integral of LVOT (m).
TVI
MV
is the Time Velocity Integral of mitral valve (m).
LVOT is Left Ventricle Outflow Tract.
cm
2
Mitral Valve
Area by the
Continuity
Equation using
Pulmonary
Artery
MVA is mitral valve Area (cm
2
).
CSA
PA
is cross-sectional Area of pulmonary artery (cm
2
).
TVI
PA
is the Time Velocity Integral of pulmonary artery (m).
TVI
MV
is the Time Velocity Integral of mitral valve (m).
cm
2
Right Ventricu-
lar Systolic
Pressure from
Tricuspid
Regurgitation
P
RA
is estimated Right Atrial pressure (mmHg).
V
max
is regurgitant Velocity of tricuspid valve (m/s).
mmHg
Right Ventricu-
lar Systolic
Pressure from
Ventricular
Septal Defect
BP
sys
is systolic Blood Pressure (mmHg).
V
max
is maximum Velocity of ventricular septal defect (m/s).
mmHg
TABLE 31. Doppler Formulas (Cardiac)
Type Formula Units
AVA CSA
LVOT
TVI
LVOT
TVI
AoV
--------------------•=
Flow Area π
d
2
4
-----
⎝⎠
⎛⎞
•=
MVA CSA
LVOT
TVI
LVOT
TVI
MV
--------------------•=
MVA CSA
PA
TVI
PA
TVI
MV
---------------•=
RVSP P
RA
4V
max
2
+=
RVSP BP
sys
4V
max
2
–=