AcT	acceleration time
CI	cardiac index
COPD	chronic obstructive pulmonary disease
CTEPH	chronic thromboembolic pulmonary hypertension
HR	heart rate
IQR	interquartile range
IVCex	inferior vena cava expiratory diameter
IVCin	inferior vena cava inspiratory diameter
IVCcoll	inferior vena cava collapsibility index
IRTB	multivariable model based on 4 predictors: IVCin, RAA, TAPSE and NTproBNP
LA	left atrium
MPA	main pulmonary artery diameter
mPAP	mean pulmonary arterial pressure
mRAP	mean right atrial pressure
n	number of cases
NTproBNP	N-terminated type B natriuretic pro-peptide
PAH	pulmonary arterial hypertension
PASP	systolic pulmonary arterial pressure
PH	pulmonary hypertension
PAWP	pulmonary artery wedge pressure
PVR	pulmonary vascular resistance
RAA	right atrium area
RVOT	right ventricle outflow tract
RVIT	right ventricle inflow tract
RV/LV	right ventricle to left ventricle diameters ratio
RV wall	right ventricle wall thickness
6MWD	6-minutes’ walk distance
TAPSE	tricuspid annular plane systolic excursion
TnT	troponin T
TRPG	tricuspid regurgitation peak gradient
SaO2	arterial blood oxygenation
SvO2	mixed venous oxygen saturation
WHO-FC	World Health Organization functional class