CI
Enter CI, or CO + BSA
Low-flow screen <2.2
The Swan Whisperer
Swan-Ganz Hemodynamic Calculator
Pressures, flow, oxygen delivery—and the pattern they form.
Swan hemodynamics
Enter a snapshot
Time-aligned adult measurements.Measurement modifiers support, TR, ventilation
Integrated pattern · educational
Start with pressures and flow
Enter RAP, verified mean PAWP, and CI (directly or from CO and BSA). Other fields add context; no single index diagnoses shock.PAWP
Enter verified mean PAWP
Mean · filling-pressure screen >15
RAP
Enter RAP / CVP
Marked-elevation screen >15
CPO
Enter CO + MAP
Conventional · cohort reference <0.60
PA SvO₂
Enter true PA saturation
Context 60–80%; demand-dependent
Compare up to three snapshots
In-memory comparison only; values disappear on reload or Clear all values. Use labels such as “Baseline” or “After diuresis,” without identifiers. Keep methods and timing comparable.
Educational use only. This tool and its outputs do not constitute medical advice, diagnosis, or treatment and do not replace clinical judgment. Independently verify the inputs, equations, assumptions, units, and outputs, and confirm that the tool is appropriate for your intended use before relying on a result.
About this tool, equations and measurement guide
Educational deterministic calculations. Patient values remain in this browser; they are not uploaded or saved between visits. This tool does not diagnose shock, prescribe treatment, or independently validate a waveform.
Read The Swan-Ganz Catheter: A Practical Guide for Residents for waveforms, normal values and measurement technique.
A bedside reference
How the hemodynamic markers fit together
Flow, filling pressure, and pulsatility describe different parts of the same snapshot. Start with the measurements, then interpret the markers together.
Right heart
PAPi
PA pulse pressure relative to RAP.
(PASP − PADP) / RAPLower values can support RV dysfunction. Cutoffs depend on the cohort.RVSWI
Indexed stroke volume × pulmonary pressure gradient.
(CI / HR) × (mPAP − RAP)Raw mmHg·L/m²/beat; ×13.6 for g·m/m²/beat.*Mean PAWP estimates LA pressure.
Conceptual flow map · not an anatomical drawing.
Left heart
API
Systemic pulse pressure relative to left-sided filling pressure.
(SBP − DBP) / PAWPThe 1.45 reference comes from selected HF outcome cohorts.Conventional CPO
Flow × mean systemic pressure, expressed in watts.
CO × MAP / 451<0.6 W is a historical prognostic reference in cardiogenic shock.Equations, explainers, and contextual thresholds
The same shared functions calculate these eight markers here and on their individual pages. Thresholds are prognostic references from specific populations; they are not treatment instructions.
Cardiac power output (CPO) ↗
Calculate conventional left ventricular cardiac power output from flow and mean arterial pressure.
CO × MAP / 451W
< 0.6 WHistorical prognostic reference in cardiogenic shock; does not independently diagnose shock or select support.
Pulmonary artery pulsatility index (PAPi) ↗
Calculate PAPi from pulmonary artery pulse pressure and right atrial pressure.
(PASP − PADP) / RAPratio
Population mattersAHA summary: <2. Pre-LVAD study: <1.85. Inferior MI with RV dysfunction: ≤0.9. Loading conditions change the ratio.
LV stroke work index (LVSWI) ↗
Calculate indexed LV work per beat using flow, heart rate, and the systemic-to-left-atrial pressure gradient.
(CI / HR) × (MAP − PAWP) × 13.6g·m/m²/beat
< 20 g·m/m²/beatAssociated with death or deterioration in a transplant-waitlist cohort. No consensus universal cutpoint.
RV stroke work index (RVSWI) ↗
Calculate RV stroke work index in both reporting conventions, with an explicit conversion between them.
(CI / HR) × (mPAP − RAP)mmHg·L/m²/beat · ×13.6 = g·m/m²/beat
0.15–0.33 mmHg·L/m²/beatStudy-specific low-value references, not a normal interval. Equivalent to 2.04–4.49 g·m/m²/beat; compare matching units. Higher work may reflect higher afterload.
Aortic pulsatility index (API) ↗
Calculate API by relating systemic pulse pressure to mean left-sided filling pressure.
(SBP − DBP) / PAWPratio
< 1.45Associated with adverse outcomes in selected decompensated-HF and transplant-waitlist cohorts; higher values do not exclude LV dysfunction.
RAP-adjusted LV CPO ↗
Account for right atrial pressure when calculating systemic hydraulic power.
CO × (MAP − RAP) / 451W
No established normal rangeAccounts for the systemic pressure gradient. Do not apply the conventional-CPO 0.6 W reference to this adjusted value.
RV cardiac power output ↗
Calculate RV hydraulic power using cardiac output and the mPAP − RAP gradient.
CO × (mPAP − RAP) / 451W
No consensus cutpointUses mPAP − RAP. Pressure load can raise power despite RV dysfunction. This differs from mPAP-based RV power.
LV myocardial performance score (MPS) ↗
Combine aortic pulsatility index and conventional LV cardiac power into the LV myocardial performance score.
API × conventional CPO / 2score
< 0.5Associated with adverse transplant-waitlist outcomes. Emerging LV score; do not substitute RV MPS or the echocardiographic Tei index.
Sources and measurement notes
Use time-aligned measurements, measured MAP when available, and a verified mean PAWP. For stroke work, CI is in L/min/m² and HR in beats/min. SVI expressed in mL/m²/beat uses a 0.0136 conversion factor instead of 13.6.
The integrated screen uses PAPi <2 and RAP / PAWP >0.63, matching the visible result references. These come from different cohorts and do not diagnose RV failure. RVSWI is calculated in both unit conventions but has no universal engine cutoff; it does not vote in the phenotype. Mixed markers prompt review rather than a confirmed RV diagnosis.
The source image also includes RAP numerically exceeding PA saturation. This compares mmHg with saturation entered as a percent (for example, 35 rather than 0.35). It is a rare observational research finding, not a pressure gradient or a validated treatment trigger; it is not used by this calculator’s phenotype engine. Original report ↗
- Belkin et al., AHA scientific statement, 2026 ↗
- Supplemental Table 1 — Advanced Hemodynamic Parameters ↗
- Korabathina et al.: PAPi in acute inferior MI ↗
- Morine et al.: PAPi before LVAD surgery ↗
- Belkin et al.: transplant-waitlist outcomes, 2026 ↗
Original MendelMD schematic, informed by the supplied 2025 review figure and the cited studies. Advanced Markers for Hemodynamic Monitoring in Cardiogenic Shock and End-Stage Heart Failure ↗
Interpretation methods and limitations
What this tool does
More than a collection of equations
A Swan-Ganz calculator can compute cardiac index, PAPi, PVR, SVR, cardiac power output, RVSWI, and other derived values. The clinically useful question is how those measurements fit together. The Swan Whisperer uses an explicit ruleset to describe forward flow, filling pressures, ventricular dominance, pulmonary vascular load, and systemic vascular tone.Phenotype is not diagnosis
The report describes observed invasive hemodynamic physiology. It does not establish shock, determine SCAI stage, identify etiology, or prescribe fluids, medications, or mechanical support.
Measurement quality matters
Waveform review, transducer leveling, respiratory phase, timing, severe tricuspid regurgitation, and cardiac-output method can materially change interpretation.
Wedge safeguards
An end-diastolic wedge is not treated as mean PAWP. PVR, PVRI, gradients, aortic pulsatility index, and PH classification are suppressed until a mean wedge is available.
Traceable outputs
Every derived metric shows its equation, unit, short interpretation, and limitations. Experimental indices are separated visually and never drive the primary phenotype.
Selected methodology references
- JACC: Heart Failure practical guidance for invasive hemodynamic assessment, 2024.
- 2022 ESC/ERS Guidelines for pulmonary hypertension.
- 2025 ACC concise clinical guidance on cardiogenic shock.
- RAP-adjusted cardiac power in the ESCAPE trial.
Review the additional measurement-method sources: ELSO VA-ECMO guidance; thermodilution versus estimated Fick study; oximetry-run sampling guidance. This educational calculator has not undergone independent clinical validation. Verify calculations and waveform quality before clinical use.