Maturation of the Pulmonary Vascular Bed

Abstract
Foreword From anatomical observations, high pulmonary vascular resistance has been predicted for the normal infant. Physiologic data obtained in studies on 44 normal infants and children are used to test this hypothesis. The correlation noted between total pulmonary resistance and pulmonary arteriolar anatomy in the normal child provides a foundation for the better understanding of changes in pulmonary physiology associated with congenital heart disease. In 1927, Moschcowitz1 suggested that pulmonary vascular changes may be a factor in the natural history of congenital heart disease. In more recent years, Edwards,2 Dammann and Ferencz,3 and Heath and Best4 have pointed out a relationship between pulmonary vascular pathology and the intracardiac hemodynamics of congenital heart malformations. The influence of pulmonary vascular changes on the natural history of ventricular septal defects and the effect of these changes on the response of the patient to surgical correction of this defect have been