TABLE 5

Haemodynamic definitions of pulmonary hypertension

DefinitionHaemodynamic characteristics
PHmPAP >20 mmHg
Pre-capillary PHmPAP >20 mmHg
PAWP ≤15 mmHg
PVR >2 WU
IpcPHmPAP >20 mmHg
PAWP >15 mmHg
PVR ≤2 WU
CpcPHmPAP >20 mmHg
PAWP >15 mmHg
PVR >2 WU
Exercise PHmPAP/CO slope between rest and exercise >3 mmHg/L/min

CO, cardiac output; CpcPH, combined post- and pre-capillary pulmonary hypertension; IpcPH, isolated post-capillary pulmonary hypertension; mPAP, mean pulmonary arterial pressure; PAWP, pulmonary arterial wedge pressure; PH, pulmonary hypertension; PVR, pulmonary vascular resistance; WU, Wood units. Some patients present with elevated mPAP (>20 mmHg) but low PVR (≤2 WU) and low PAWP (≤15 mmHg); this haemodynamic condition may be described by the term ‘unclassified PH’ (see text for further details).