382 DISEASES OF THE HEART. 



which openings have never occasioned any symptoms whatever duriiig 

 life. In the septum of the ventricles, likewise, especially at a point 

 at the upper end, which normally is very thin, it is not uncommon to 

 find imperfections, of more or less magnitude, which have never given 

 rise to any inconvenience. 



In the higher grades of ektopia, in which a greater part of the wall 

 of the chest or belly is wanting, the heart lying in the abdomen or 

 upon the neck, continuance of life is impossible. There are persons 

 alive, however, with smaller imperfections of the bony thorax, fissures 

 m the sternum, etc., and who even have attained an advanced age. 

 In such cases the deformity is covered by the skin, and the subject 

 suffers little inconvenience. 



SYMPTOMS AND COTJKSE. If we keep the effect in view, which 

 congenital malformations of the heart exert upon the circulation, turn- 

 ing first to the most frequent and important of them, that namely, in 

 which the aorta or pulmonary artery with its ventricles is undeveloped, 

 so that the blood passes through the open septum, from one side of the 

 heart to the other, and is carried into the body through the more per- 

 fect trunk alone, it will be apparent that the following derangements 

 hi the distribution of the blood must occur. 



First, the current of the blood-stream is greatly retarded, and hence 

 the blood, tarrying long in the body and rarely returning to the lungs, 

 is overloaded with carbonic acid, and assumes an intensely venous char- 

 acter. Ceteris paribus, the rapidity of the circulation depends upon 

 the volume of blood set in motion by every heart-beat. If the aorta or 

 pulmonary artery be missing, if but one outlet from the heart remain, 

 then, notwithstanding hypertrophy of the ventricle, the volume of 

 blood set in motion must be far too small. The retardation of the cir- 

 culation thus resulting sufficiently explains a series of symptoms ob- 

 servable in congenital imperfections of the heart the lassitude, lan- 

 guor, intellectual apathy, depressed spirits, and, above all, the low 

 temperature of the body. 



If, however, the supply of blood to the greater and lesser circula- 

 tion be furnished by only one of the ventricles, it must follow that the 

 arteries are very scantily filled, and that venous engorgement of great 

 intensity arises, as in all other cases, where the arteries have not their 

 due supply. Accordingly, we find the pulse small, the breathing very 

 short, and, above all, we observe cyanosis, the symptom which we 

 have so often designated as the characteristic one of overloading of 

 the veins. Since cyanosis arises here, as it does elsewhere, from obstruc- 

 tion to the course of the blood through the capillaries and veins, the 

 extreme intensity which it here exhibits must be owing to some other 

 nause, which is to be sought in the excessively dark hue of the blood 



