CINE-ANGIOCARDIOGRAPHIC STUDIES OF THE OUTFLOW TRACT IN ISOLATED PULMONARY VALVULAR STENOSIS

Abstract

Much of the confusion and misunderstanding regarding the nature of the obstruction to the outflow of blood from the right ventricle in patients with pulmonary stenosis is being resolved and the complex nature of the problem more fully recognized. Some five types of obstruction can be defined. First, there may be obstruction due to an abnormal pulmonary valve-pulmonary valvular stenosis. Secondly, there may be obstruction in the infundibular region due to a variety of congenital infundibular lesions such as are commonly seen in patients with Fallot's tetralogy. Thirdly, there may be combined infundibular and valvular lesions, again most commonly seen in Fallot's tetralogy. In these three varieties of pulmonary stenosis, pressure gradients at the sites of obstruction can be demonstrated during cardiac catheterization. The characteristic pressure pulse tracings, pressure artefacts, and possible misinterpretations of the pressure tracings are discussed by numerous authors (Sobin et al.,