Congenital heart disease - changes in form and function

Abstract

physiology relation between form and function is the relation between anatomy and physiology; change in one leads to change in the other. By the time of birth, in babies born alive with cardiac malformations, some adaptive changes in the cardiovascular system already may have been superimposed upon the basic structural abnormalities. These alterations in pathological anatomy continue throughout postnatal life but time is needed for the changes to evolve and show their physiological effects. Such alterations may occur as part of the predetermined natural history and may continue after early palliative surgery has extended the time of survival and thus allowed the abnormal heart to change further its form and function. The interdependence of form and function can be examined in the living from either initial aspect. Congenital heart disease is an ideal model and spontaneous alterations in cardiac form can be detected from changing symptoms, signs, and the use of invasive and noninvasive techniques. With growing experience, many changes are predictable from knowledge of the basic disturbance in cardiac morphology. In this lecture it is shown how spontaneous change in form influences the natural history of the common anomaly, ventricular septal defect, and the clinical management of patients with this lesion. The various pathological changes which can develop in malformed hearts are then discussed and it is shown how their occurrence influences the signs and symptoms in patients with specific congenital cardiac anomalies, paticularly complex malformations.