“…With regards to the pulmonary artery, a measure of stiffness should be included (RV outflow tract acceleration time <105 ms), in addition to an early diastolic pulmonary regurgitation velocity >2.2 mm/s and pulmonary artery diameter >25 mm. PAS as evaluated in the study by Elçioğlu et al may provide additional information as it not only incorporates acceleration time, but also maximal flow velocity 5 . Another reason it may have clinical relevance is that in group 1 PH patients (not POPH), PAS measured on cardiac magnetic resonance was associated with mortality 8 .…”