632 



ABNORMAL CONDITIONS OF THE HEART. 



single ventricle and two auricles existed, but 

 along with an imperfect inter-auricular septum. 

 The two auricles, therefore, virtually formed 

 one cavity. A similar case is recorded by 

 \\olff,* and is remarkable from the fact that 

 the individual in whom it was observed lived 

 to the age of twenty-two. These hearts then 

 do not exactly correspond to the tripartite heart 

 of Batrachia, inasmuch as the two auricles 

 communicate. A similar case, shewn by Mr. 

 Lawrence to Dr. Farre,f explains more par- 

 ticularly the true nature of the malformation. 

 It was a deficiency of the septa, both auricular 

 and ventricular, the latter having been alto- 

 gether wanting ; the former consisting only of 

 a small muscular band, which left a large fora- 

 men ovale without a valve, but the venae cavae 

 and pulmonary veins opened into their respec- 

 tive auricles, which externally appeared to be 

 quite separate. The ventricle communicated with 

 the two auricles by a single ostium ventriculi, 

 and the aorta and pulmonary artery, the en- 

 trance of the latter being somewhat contracted, 

 arose side by side from the left part of the 

 ventricle. 



Most of the other defective malformations of 

 the heart consist in preternatural communica- 

 tion between the right and left cavities, resulting 

 from various causes. 1. The communication is 

 direct, either from an open forarm n ovale, or from 

 an imperfection in the septum of the auricles 

 or of the ventricles, or from the co-existence 

 of all three or any two of them. 2. The com- 

 munication is indirect, the septa being perfect, 

 but the ductus arteriosus remaining pervious. 



The open foramen ovale is by far the most 

 common of all the malformations of the heart; 

 numerous examples of it are now on record, 

 as found in persons of all ages. The opening 

 of communication varies considerably as to size, 

 apparently according to the period of develope- 

 nient at which the arrest took place ; the di- 

 ameter of the opening ranges between two and 

 twelve lines. We know that the size of this 

 orifice is inversely as the size of the foetus 

 during intra-uterine life, whence we may infer 

 that the larger the opening is, the earlier must 

 have been the period at which further deve- 

 lopement ceased. In many instances the valve- 

 like portions which bound this opening have 

 acquired their full developcment, and the only 

 defect seems to be the non-adhesion of their 

 margins, so as to close the cavity ; this non- 

 adhesion again may involve the whole extent 

 of the margins of the valves, or only a very 

 small portion, thus leaving a large or small 

 opening of communication between the two 

 auricles. Such a condition of the inter-auri- 

 cular septum does not necessarily occasion 

 that intermixture of the blood which so com- 

 monly accompanies the communication be- 

 tween the right and left cavities ; and where 

 the opening is small, of course this inter- 

 mixture is the less likely to occur. Thus every 

 anatomist must be aware that it is not an un- 

 frequent occurrence to find an opening large 



* In Krcysig's die Kraukeit. Ucrz. B. iii. 

 t Lgc. cit. p. yO, 



enough to introduce a goose-quill in the hearts 

 of adults who during life exhibited no derange- 

 ment of the circulation, and who died of dis- 

 eases totally unconnected with the heart. On 

 the other hand we are often surprised at the 

 amazing size of the opening in the hearts of 

 persons who have lived many years, and have 

 shewn less disturbance of functions than the 

 freedom of the communications between the 

 auricles would warrant us to expect. In many 

 of these cases the absence or mildness of sym- 

 ptoms may be accounted for by the obliquity 

 of the passage of communication, and the 

 overlapping of the margins of the valves, so 

 that at times they completely oppose the flow 

 of the blood from one side of the heart to the 

 other, whilst at other times the passage is left 

 more or less free. In a heart which I lately saw 

 in the Museum of Guy's Hospital, the circumfe- 

 rence of the open foramen ovale was equal to 

 that of a halfpenny, (i. e. about an inch in 

 diameter,) and yet the patient had lived to the 

 adult period; and in a case quoted by Dr. 

 Farre from Corvisart, the foramen ovale was 

 " more than one inch in diameter.'' Such cases 

 strongly favour the opinion that the foramen 

 undergoes considerable enlargement when once 

 all impediment to the passage of the current 

 of blood from one side to the other has been 

 removed.* More rarely we find the fossa 

 ovalis cribriform, and thus several small open- 

 ings of communication exist between the 

 auricles, and sometimes in addition to the un- 

 closed foramen ovale, we have a true imper- 

 fection in the septum, as in the case related by 

 Walter,f and another by Otto.J 



Imperfection in the septum ventriculorum is 

 a much less frequent cause of the communi- 

 cation between the right and left hearts than 

 the open foramen ovale. The opening, varying 

 in diameter from two lines to about an inch, 

 is situated towards the base of the septum, 

 so that the ventricles communicate at their 

 bases ; a fact which evidently indicates that the 

 opening results from the progress of the de- 

 velopement of the septum being arrested near 

 its completion, since the base of the septum 

 is the last portion formed. The orifice of com- 

 munication generally opens upwards towards 

 the orifices of both arteries, and is bounded 

 inferiorly by the rounded smooth edge of the 

 ventricular septum. In these cases the aorta 

 opens into both ventricles and appears to arise 

 from both ; and frequently the orifice of the 

 pulmonary artery is contracted and more rarely 

 obliterated, either from non-developement or 

 from previous morbid action ; moreover, ap- 



* It is not, perhaps, correct to suppose every 

 case of open foramen ovale congenital ; at least 

 it is certain that many patients date their symptoms 

 ironi a tall or blow ; and even without any evi- 

 dence of the occurrence of such violence many 

 cases have been observed which can be explained 

 only by supposing that the foramen ovale had been 

 morbidly re-opened. See Abernethy in Phil. Trans. 

 1798; Otto, Sell. Beobachtungen ; and Pasqualini, 

 Memorie sulla frequente apcrtura del foraniine 

 ovale rinvcnuta nei cadaveri dei tisici. Hum. 1827. 



t Observat. Anatom. 



} Pathol. Anat. by South. 



