Critical Care & Hemodynamics

Pulmonary Artery Pulsatility Index (PAPi) Calculator

Calculate PAPi from pulmonary artery pulse pressure and right atrial pressure.Need the full picture? Open the combined Swan-Ganz calculator →

Enter measurements

PA systolic pressure (PASP)

mmHg

PA diastolic pressure (PADP)

mmHg

Right atrial pressure (RAP)

mmHg

Calculated in your browser. Inputs are not saved, added to the URL, or sent by this calculator.

Calculated result

—ratio

(PASP − PADP) / RAP

Enter the required measurements to calculate a result.

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.

What is Pulmonary artery pulsatility index (PAPi)?

PAPi relates pulmonary artery pulse pressure to right atrial pressure. It provides a compact description of right-heart pulsatility relative to filling pressure and has been studied in RV infarction, heart failure, and LVAD assessment.

How is it calculated?

(PASP − PADP) / RAP

PASP and PADP are pulmonary artery systolic and diastolic pressures in mmHg. RAP is mean right atrial pressure in mmHg. The pressure units cancel, producing a ratio.

Result units: ratio.

Clinical interpretation

Lower PAPi can support worse RV performance, but the useful cutoff depends on the population and loading conditions. The AHA supplemental table summarizes a reference below 2; a threshold near 1.85 was studied before LVAD implantation. These are prognostic references in particular cohorts, not universal definitions of RV failure.

Clinical considerations

PAPi is undefined when RAP is zero and becomes unstable as RAP approaches zero. Review the RAP waveform and transducer level before interpreting an extreme ratio.

Diuresis, ventilation, pulmonary vascular load, and vasoactive support alter the inputs. A preserved or elevated PAPi does not rule out RV failure when PA pressures are high.

References

Independently created by MendelMD. These educational calculators are not provided, endorsed, or independently validated by the American Heart Association.