Pulmonic stenosis A narrowing of the right ventricular outflow tract that can occur at the pulmonary valve (valvular stenosis), below the pulmonary valve (infundibular stenosis), or above the pulmonary valve (supravalvar stenosis). Pulmonic valve stenosis Narrowing of pulmonic valve HP:0001642 SNOMEDCT_US:56786000 Pulmonary valve stenosis Pulmonary stenosis UMLS:C1956257 Pulmonic stenosis is often seen as a part of Fallot' s tetralogy, in which case the events leading to the formation of the overriding aorta are also believed to be a cause of the pulmonic stenosis. The pulmonic stenosis is the major cause of the malformations seen in patients with Fallot tetralogy, with the other associated malformations acting as compensatory mechanisms to the pulmonic stenosis. The degree of stenosis varies between individuals with TOF, and is the primary determinant of symptoms and severity. Fyler:1611 Abnormal cardiovascular system physiology Abnormal cardiovascular system morphology