Condition in which the flow of blood from the heart to the lungs is slowed by a deformity on or near the pulmonary valve that controls the blood flow from the right heart to the lungs.
Source: PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 798 (https://doi.org/10.1515/pac-2015-1202)