The Changes in the Circulation After Birth

Abstract
Circulatory changes at birth have a profound influence on the physiology of the circulation in normal infants and those with congenital heart disease. Since the concept that cardiac defects are fixed entities is being superseded by an appreciation of the changing nature of physiologic disturbances and their clinical consequence, the course and distribution of the fetal circulation with the influences of the major changes at birth, including changes in pulmonary vascular resistance, and closure of the ductus arteriosus and foramen ovale, require study. This lecture traces these and other changes and discusses their influences on congenital heart disease.