Practical recommendations relating to parameters measured or derived from right heart catheterisation

Haemodynamic variableMethod of measurementRange in healthy subjects#Range in PAHPractical recommendation
Cardiac output  L·min−1Measure pulmonary blood flow:
1) Using the indicator dilution principle (thermodilution) or
2) Based on oxygen consumption (Fick method) Oxygen consumption can be obtained from blood gas analysis or pulse oximetry
4–6Normal or decreasedThe preferred method is thermodilution, although the indirect Fick technique is acceptable Perform oximetry in patients with a pulmonary artery oxygen saturation >75% and in the event of suspected cardiac left-to-right shunt
Cardiac index L·min−1·m−2Calculated using: Cardiac index=cardiac output/BSA2.4–4Normal or decreased
PAWP mmHgTracings to measure pressure waveforms4–12≤15Inflate the balloon in the right atrium and advance the catheter until it reaches the PAWP position Avoid repeated inflations and deflations of the balloon (and removal when inflated) to minimise risk of pulmonary artery rupture Record PAWP as the mean of three end-expiratory measurements
mPAP mmHgCalculated using: mPAP=diastolic PAP+   (systolic–diastolic PAP)/3Systolic: 15–25 Diastolic: 4–12 mPAP: 14±3mPAP: ≥25
PVR Wood units and PVRI Wood units·m−2Calculated using: PVR=(mPAP–mean PAWP)/cardiac output PVRI=PVR/BSA ≤3PVR: >3 PVRI: ≥6For harmonisation, PVR should be expressed in Wood units It may also be expressed as dyn·s−1·cm−5 (conversion: Wood units×80)
RAP mmHgTracings to measure pressure waveforms1–6Normal or elevated
RVP mmHgTracings to measure pressure waveformsSystolic: 15–25 Diastolic 1–8>30 Normal, or elevated
SVR Wood unitsCalculated using: SVR=(mSAP–RAP)/cardiac output8.8–20PVR/SVR: <0.75In general, a ratio of PVR to SVR >0.75 indicates significant pulmonary vascular disease
TPG mmHgCalculated using: TPG=mPAP–PAWP≤12>12May be used to determine a pre-capillary component in post-capillary PH
DPG mmHgCalculated using: DPG=diastolic PAP–PAWP<6>3May be used to determine a pre-capillary component in post-capillary PH
  • PAH: pulmonary arterial hypertension; PAWP: pulmonary arterial wedge pressure; PAP: pulmonary arterial pressure; PVR: pulmonary vascular resistance; PVRI: pulmonary vascular resistance index; RAP: right atrial pressure; RVP: right ventricular pressure; SVR: systemic vascular resistance; TPG: transpulmonary pressure gradient; DPG: diastolic pressure gradient; BSA: body surface area; mPAP: mean pulmonary arterial pressure; mSAP: mean systemic arterial pressure; PH: pulmonary hypertension. #: values for PVR and PAP have been identified in additional studies of healthy subjects [18, 19]; : information for practical recommendations from [3, 15, 17]. Information from [3, 11–19].