Developed by Dr. Saro Avedikian, MD, MPH — Cardiovascular Disease Fellow
Patient / Constants
yearsm²
g/dLbpm
Access & Equipment
Computation constant must match catheter + injectate in monitor
Why this matters: The TD computation constant programmed in the hemodynamic monitor is specific to catheter size + injectate volume/temperature. A mismatch produces systematic TD CO error. Verify the constant matches your setup. This does not affect Fick or LaFarge calculations.
Pressures (mmHg)
a/v/mean
sys/dia/EDP
sys/dia/mean
a/v/mean
sys/dia/EDP
sys/dia/mean
Oximetry
%% (PA sat)
mmHgmmHg
Enter saturations as percentages (e.g., 92.8 not 0.928). Calculator converts automatically.
SEP = ejection time/beat × HR. Typical: 0.30–0.35 sec/beat → 20–25 sec/min. Measured from AV open to dicrotic notch.
Mitral Valve (MVA)
mmHg (transmitral gradient)
sec/beat→sec/min
DFP = filling time/beat × HR. Typical: 0.40–0.50 sec/beat → 30–40 sec/min. Shortened in tachycardia. Average ≥5 beats in AFib.
Aortic Valve (AVA) — Per-Beat Data
Enter gradient and ejection time for each beat. Minimum 5 beats recommended. Empty rows are ignored.
Beat
ΔP (mmHg)
Eject time (s)
AVA (cm²)
1
—
2
—
3
—
4
—
5
—
6
—
7
—
8
—
9
—
10
—
Mitral Valve (MVA) — Per-Beat Data
Enter gradient and filling time for each beat. Minimum 5 beats recommended. Empty rows are ignored.
Beat
ΔP (mmHg)
Fill time (s)
MVA (cm²)
1
—
2
—
3
—
4
—
5
—
6
—
7
—
8
—
9
—
10
—
Shunt Oximetry Run
Workflow: On routine RHC, draw 1 SVC + 1 PA sample. If PA sat is ≥ 8% higher than SVC → significant L→R shunt suspected → perform full oximetry run below to localize the shunt level and quantify Qp/Qs.
Screening (minimum required)
%%
These two samples alone detect most L→R shunts (≥ 8% step-up = significant).
Full Oximetry Run (for localization & Qp/Qs)
Enter all samples obtained. At minimum, need SVC + IVC (for MV O₂) and PA (for Qp/Qs). More samples = better localization. RA best sampled at mid-RA level.
SVC
%High SVC entered above
IVC (needed for MV O₂)
%At level of diaphragm, beyond renal veins
Right Atrium (step-up here → ASD)
%%%
Mid-RA least affected by IVC/coronary sinus streaming. Multiple samples preferred.
Right Ventricle (step-up here → VSD)
%%
Pulmonary Artery (step-up here → PDA)
PA main entered above in screening%%
PV O₂ & FiO₂
%
If SaO₂ ≥ 95% on room air → no significant R→L shunt → PV O₂ ≈ SaO₂. If R→L shunt suspected, use wedge PA sample or assume 98%.
%Room air = 21%. If > 30%, simplified Qp/Qs is inaccurate — must use full O₂ content with dissolved O₂.
Collect all samples within a few minutes to minimize error from fluctuations in anxiety/wakefulness.