Previously based on a mean pulmonary arterial pressure (mPAP) of ≥25 mmHg measured at right heart catheterisation.
The mPAP cut-off has been reduced to 20 mmHg in the presence of other haemodynamic characteristics. There are 3 haemodynamic definitions:
mPAP – mean pulmonary arterial pressure
PAWP – pulmonary arterial wedge pressure
WU – Wood units, a unit of pulmonary vascular resistance. 1 WU
= 80 dynes/s/cm-5
Gold standard for diagnosis is right heart catheterisation (RHC).
