Pulmonary here refers to the valve between the right ventricle of the heart and the pulmonary artery. If this valve is insufficient (incompetant) in its performance, blood sloshes back from the pulmonary artery into the right ventricle.
PULMONARY INSUFFICIENCY
Meaning of PULMONARY INSUFFICIENCY in English
English dictionary of medicine. Английский словарь медицины. 2012