neys with heart disease obtains; thus, Dr. Bright has shown that in a hundred cases of this disease, the heart presented lesions in at least thirty-five, a number which would probably have been increased if the condition of this organ had been noted with the same care in all. This proportion has been confirmed by the researches of Dr. Taylor.' The secondary effects produced by the dislocation of lymph from the left side of the heart, in the brain, the spleen, and the kidneys, by blocking up the arteries, and thus altering the nutrition of the parts to which they lead, we have already alluded to. The influence of valvular disease in producing hypertrophy is a point of great importance, and its connection with pericardial and endocardial inflammation has been especially dwelt upon by Bouillaud. Its influence in affecting the circulation in the brain is undeniable, but it is probable that the frequency with which it induces hemorrhage, either in the lungs or in the brain, has been overrated. In many of the cases on record of cerebral apoplexy connected with cardiac hypertrophy, the result was more justly attributable to the coincident arterial disease than to the increased impulse of an enlarged heart. Pulmonary apoplexy appears rather to be connected with the obstructions to its circulation presented by mitral disease than by an hypertrophic condition of the heart. With regard to the liver, we find that in fatty degeneration of the heart it commonly presents a similar concomitant affection, not to speak of the congestion to which it is almost invariably subject when the return of the blood to the heart is in any way impeded; more than any other organ it is enabled by its size and elasticity, as well as by its functions, to serve as a species of reservoir where the balance of the circulation is disturbed, a reservoir which may be frequently overcharged, but from which we are more able to draw off the surplus without too much debilitating the system than from any other organ. Congestions of the venous system of the entire body are frequent in cardiac disease, and manifest themselves by lividity of the cutaneous surface and of the mucous membranes: and the secondary effects of stasis are shown in these tissues by oedema and hemorrhage, while in the serous cavities they are evidenced by an effusion of serum-one form of passive dropsy. Of the latter, we find the peritoneum chiefly prone to suffer, a circumstance which we may fairly attribute to the absence of any compression, such as we find normally exerted upon all the other serous sacs. With these few remarks on a subject which belongs rather to the domain of the history of disease than the records of morbid anatomy, we pass to the consideration of the conditions with which cyanosis is found associated. CYANOSIS. Cyanosis is a term applied to a livid, purplish hue of the cutaneous surface, which is found to accompany some organic and congenital disturbances in the central organ of the circulation, of a more intense character than the slaty tinge which the complexion is very frequently Medico-Chirurg. Trans., vol. xxviii. p. 536. observed to assume in acquired disease of the heart. It was formerly attributed, on theoretical grounds, solely to one lesion, a permanent patency of the foramen ovale; and although this occasionally gives rise to the affection, by allowing an intermixture between the blood of the two sides of the organ, and causing it to be circulated through the system, without having undergone the purifying process to which it ought to be subjected in the lungs; it is satisfactorily demonstrated, both that the foramen ovale may remain open, to a considerable degree, throughout life, without inducing any serious disturbance of the circulation; and on the other hand, that various other irregularities in the heart may give rise to cyanosis. Bizot found the foramen ovale more or less open in forty-four out of 155 subjects, in none of whom there was a trace of the morbus coeruleus. Two openings have been found in the ventricular septum, and no cyanosis resulted; a marked instance of this kind in an individual who attained to the age of eight years, was brought before the Pathological Society, by Dr. Quain, in 1847. In such a case, we are justified in assuming that the forces of the two sides of the heart are so exactly balanced as not to disturb the circulation; and the orifice of the pulmonary and systemic arteries being patent, the contents of each side pass into their proper channel. That this is a prevailing law for many cases of cyanosis, is shown by the fact that it frequently does not manifest itself unless there is some further cause for derangement of the circulation, such as a bronchitic affection, to which, it may be remarked, cyanotic individuals are peculiarly subject. The lesion that appears to be most constantly associated with cyanosis, and which may be regarded as its primary cause, is a contracted state of the pulmonary artery; and, as in that case more than usual pressure will continue to be exerted upon the foramen ovale, this will necessarily remain patulous, and allow a passage of blood from the right to the left auricle; in such a case it may be almost looked upon as a safety valve. Gintrac1 has analyzed fifty cases of cyanosis, and among them found obstruction at the pulmonic orifice in twenty-six; the proportion is stated to be still greater by other authors. But the blue disease is not necessarily the result of an admixture of the contents of the two sides of the heart; anything causing an arrest in the return of the venous blood to the heart is sufficient to give rise to it. In the first volume of the Pathological Reports (1847, p. 25), we find a case of marked cyanosis, recorded by Mr. Ebenezer Smith, in which the foramen ovale was perfectly closed, and had evidently been so for some time before birth; there was no inter-ventricular communication, the pulmonary artery was large, but the left auriculo-ventricular opening was small, and the left ventricle was almost obliterated; the walls were contracted on a small cavity at the base, not exceeding two or three lines in diameter. The aortic opening was also very small, being about two lines wide; and the arch was much smaller than the pulmonary artery. The mitral valve was altogether defective in structure, consisting only of two small bands without any curtains. Here, then, there was an evident arrest at the aortic orifice, which reacted upon the pulmonary circulation, and through Sur la Cyanose, Paris, 1824. that upon the systemic capillaries. The lungs were too much charged with blood to perform the duty of aeration effectually, and a congested or cyanotic condition of the surface resulted. Similar instances of the cyanosis being due to contraction at the aortic orifices are on record, but it may also happen without this symptom. Dr. G. A. Rees presented the heart of a child to the Pathological Society, in 1847,1 in which the aortic was much smaller than the pulmonic orifice, and there was no cyanosis. The ductus arteriosus continuing open, allowed the blood to pass from the pulmonic artery, directly to the aorta, so that the blood distributed to the lower part of the body must have been almost entirely venous. One of the most palpable instances that has occurred to us, proving how little we are able to account for cyanosis theoretically, was that of a child that lived to the age of nine weeks, and whose heart, after death, was found to present no auriculo-ventricular opening, on the right side, while there was scarcely any inter-ventricular septum at all. Here there had been no cyanosis, although a thorough intermixture of the venous and arterial blood must have necessarily taken place. Bouillaud' is of opinion that the communication between the two sides of the heart, and the consequent admixture of the arterial and venous blood, has, comparatively, little to do with the purple hue of the complexion, which he considers to result, mainly, from the coincident obstacle offered to the circulation by a malformation of the arterial orifices of the heart. The numerous cases on record, in which not only the foramen ovale was patulous, but in which there was further evidence of the actual passage of the blood, directly from one side of the heart to the other, shows, as Dr. Peacock3 has remarked, that there is a want of just relation between the amount of venous blood entering the general circulation and the degree of cyanosis. The lesions that are found in connection with this symptom, consequently, require to be carefully analyzed, before we can determine the exact part that each bears in its production. They may shortly be enumerated as a patulous condition of the foramen ovale, from the valve not entirely covering the orifice; with this a defective involution of the Eustachian valve is commonly combined; permanent patency of the ductus arteriosus; contraction of the arterial orifices; a deficiency in the intra-ventricular septum; and the malfor mation in which the aorta springs from both ventricles. The effect upon the heart itself in these cases is to produce hypertrophy and dilatation, more especially of the right ventricle. Cyanosis is a disease which generally shows itself at or immediately after birth. The circumstance that it occasionally makes its appearance later in life, has induced Meckel and Abernethy to assume that the foramen ovale may reopen, an hypothesis which is unnecessary, as we now know how frequently a communication exists between the auricles, without producing cyanosis, and that this lesion may, under certain circumstances, as in diseased states of the lungs, induce a disturbance in Reports, 1847-48, p. 203. 2 Traité Clinique, &c. vol. ii. 690, seq. the balance of the circulation, sufficient to force the blood through the auricular septum. Stress has been laid by several authors upon the circumstance that the fingers of cyanotic individuals are found clubbed. We only advert to it, to mention that it is by no means diagnostic of this form of heartdisease, or, in fact, of any distinct malady. A more important point, is an observation that Rokitansky concludes his remarks on the subject with; to the effect that cyanosis is incompatible with tuberculosis, against which he states that it offers a complete protection. We do not deny that this is the prevailing rule, yet it is not as absolute as the author quoted asserts. In the Report of the Pathological Society for 1848 (p. 200), we find a case presented by Dr. Peacock, which refutes the universality of the law. There the post-mortem examination of the individual, a young man, aged twenty, established the following facts: The right lung was extensively permeated by tubercle, and towards the apex exhibited several small cavities; the left lung contained much solid tubercle; the heart was hypertrophic; the pulmonary artery exhibited a complete diaphragm, formed by adhesion of the valves, leaving only a small triangular aperture; the foramen ovale was very widely patulous. There had been cyanosis during life, but not in a very marked degree. Besides the malformations of which we have just spoken, we find other congenital affections of the central organ of the circulation which are compatible with life, to which we must briefly turn our attention. Those hitherto mentioned have all been instances of an arrest of development; an excess of development is rarely met with in the heart, except as an acquired condition. In all the varieties of congenital arrest, we see a tendency to return to the primitive type of a single pulsating cavity; in itself a sufficient proof, if any be needed, that the organ is not a combination of two originally distinct hearts, but that it arrives at its perfect state by a subdivision of a single cavity. As the growth proceeds through its different stages, from the simplest condition of the pulsating vessel, to the complex mechanism of the perfect heart, we see close resemblances between temporary conditions of the human heart, to permanent conditions of the heart in the lower animals. Thus, the type of the piscine heart is presented in those cases where, in a man, we only find a single auricle and ventricle. Here, an aorta proceeds from the latter, from which the lungs are nourished by the ductus arteriosus, while both venæ cavæ and pulmonary veins discharge into the auricle. Children are known to live several months with this defect, without necessarily presenting any marked symptoms of deranged circulation. In the next degree, we find an analogy with the amphibious heart, the septum ventriculorum being absent, or imperfectly developed, while there are two auricular cavities. A defect in the ventricular septum is commonly associated with that malformation of the aorta, in which it communicates with either side of the heart, the pulmonary artery being displaced, or altogether absent. The defect in the inter-ventricular septum may present various degrees, from a mere rudiment at the apex, to a full development of the partition, with the exception of a minute orifice near the base. A very curious anomaly, a genuine freak of nature, consists in a transposition of the pulmonary artery and the aorta, the former arising from the right, the latter from the left ventricle; an accident which is attributable to an abnormal division being effected in the arterial bulb, at the period of intra-uterine life, when the branchial arches are being converted into the arteries of the upper extremities and head, and into the pulmonary arteries. Again, we are informed by Tommasini' of an instance occurring in a female, aged twenty-five, who had not been cyanotic until the last days of her life, and had enjoyed general good health, in whom a circular orifice in the parietes of the left ventricle, established a permanent and free communication between this cavity and the pulmonary artery. Other varieties, in the configuration of the heart and the distribution of the vessels, are recorded in the works of Meckel and Geoffroy St. Hilaire, which contain a full account of everything relating to the subject. We have adverted to those most frequently met with. The valves of the heart, in these various malformations, generally present some alteration, being thickened, corrugated, or otherwise changed from their normal constitution. An alteration in the caliber and form of the parietes of the heart is not less frequently found to accompany the arrest of development spoken of; hypertrophy of one or more parts is a very common accompaniment. The valves frequently present a congenital arrest, or excess of development, sometimes independent of any other malformation of the heart, but commonly associated with further lesions. In reference to the arterial orifices, Dr. Peacock2 observes that the aperture may be defended by a single valve, protruded forwards in the course of the circulation, a condition seen chiefly in the pulmonic artery, or only two valves appear, owing to two having united at their edges; or again, there may be two fully developed semilunar valves, with an abortive valve intervening. Of forty-one cases of defect in the number of the valves, Dr. Peacock found the malformation at the pulmonic, in nine; in thirty-two, at the aortic orifice. Of fifty cases of malformation of the semilunar valves examined by the same observer, nine were examples of excessive development. Of these, he found that eight were cases in which the pulmonic valves were in excess, and in one only was there more than the natural number of valves at the aortic orifice. "In some cases, the excess in the number of valves seems to be due to the division of one of them into two, such divided valves being smaller in size than the others. In others, there are three valves of nearly equal size, with a smaller supplementary valve interposed between two of them. Occasionally, the aperture is provided with four valves, gradually decreasing in size, and in the other cases there may be four valves of nearly equal size, and natural form." Similar defects are met with in the tricuspid and mitral valve, but more rarely. 1 Quoted by Bouillaud, vol. ii. p. 674, 1841. |