Idiopathic Dilatation of the Pulmonary Artery

Abstract

The usual x-ray methods of examination do not give reliable information about the size of the pulmonary artery. In cases in which the pulmonary arch was only slightly prominent we found diameters of 62.5 and 63 mm. by the use of angiocardiography. Angiocardiography is necessary in order to estimate the diameter of the pulmonary artery. Five cases of idiopathic dilatation of the pulmonary artery are presented. Heart catheterization is essential for establishing the diagnosis, for only in this way it is possible to exclude 1) congenital cardiac diseases with a marked increase in the pulmonary flow and 2) an elevated pressure in the pulmonary artery. In idiopathic dilatation the systolic pressure in the right ventricle and the pulmonary artery are equal. The pressure in the right ventricle is not increased and the oxygen saturation in the various parts of the right heart, the pulmonary artery and the superior vena cava does not show significant differences. If the pressure in the right ventricle exceeds that in the pulmonary artery even though it is in the normal range it is still possible that slight pulmonary stenosis is present. The clinical signs are discussed. Now that we are able to establish the diagnosis we may expect to obtain more positive information about the eventual progression and prognosis.