Upon this subject Hayden60 writes as follows: "Pulmonary apoplexy seeming to require it as a necessary antecedent condition, while hæmoptysis, though generally associated with thrombosis in the last moments of life, frequently does occur independently of it."
60 Dis. of the Heart, vol. i. p. 529.
The doctrine of Ludwig, as supported by Niemeyer,61 that the pulmonary apoplexy is directly due to stasis and deposit in the capillaries of blood-corpuscles, does not appear possible if we accord faith to the researches of Waters,62 who has shown an intercommunication between the bronchial vessels and pulmonary veins; and reasoning upon this basis we have a strong confirmation of Virchow's theory of hemorrhagic infarction (Hayden) consequent upon embolism.
61 A Textbook of Practical Medicine, 1869, vol. i. p. 156.
62 The Human Lung, 1860, p. 201.
PATHOLOGY AND MORBID ANATOMY.—In the great majority of cases clots presenting different physical characters are found in one or more of the cavities of the heart after death. According to the supposed time of their formation, they have been very properly divided into—1, cadaveric (post-mortem); 2, terminal (in actu mortis); 3, ancient (ante-mortem). It is important at the very beginning of the considerations which I shall make in regard to these formations to determine, if possible, the physical characters of cadaveric and terminal clots, so as to be able afterward to more clearly separate from them the true cardiac concretions or those formed at a time more or less removed from the period of death. Without much question, it is owing to the indifference or neglect of later writers in making these necessary distinctions that uncertainty has arisen in the minds of many with respect of the age of many heart-clots. The cadaveric and terminal clots would indeed have but slight pathological interest attached to them were it not that occasionally during life, in a spontaneous manner, cardiac thrombosis suddenly takes place, and is always the cause of symptoms of considerable gravity and which often occasion a fatal termination.
I. Cadaveric Clots.—These present the characters of blood drawn from the arm by venesection and which is allowed to coagulate in a vase. 1. Sometimes they are large, soft, homogeneous, friable masses, distending one or more of the cardiac cavities, and having an appearance very similar to badly-cooked currant-jelly, and there is no apparent separation of the fibrin and the globules. Such an aspect is found particularly when the relative quantity of fibrin is below the normal or the blood is deficient in plasticity. In alkaline poisoning and many adynamic forms of disease this is notably the case.63 It may likewise occur in forms of death in which there has been considerable obstruction to the circulation. 2. In a somewhat similar manner, when the blood is removed from the influences which give it life and stagnates, or is arrested within the heart, coagulation takes place and the blood separates into two layers. The upper is fibrinous, and resembles the buffy coat covering a clot after bloodletting; the under layer is mainly cruoric, and encloses within its meshes by far the larger proportion of the red globules. This latter mass always forms the lowest stratum by relation with the position of the body after death. Between these two layers, and from the fact of their smaller density, we find more of the leucocytes. This formation of blood-clot in distinct strata has been accomplished experimentally by Pasta,64 who poured some blood of an animal into the heart of an ox and allowed it to deposit. The cruoric mass is always soft, and may be readily washed from the fibrin by a stream of water. Frequently these clots distend the cardiac cavities to such an extent that when they are opened at the autopsy a portion will fall upon the table and the rest is readily detached from them. The microscope shows the same condition of globules and fibrin in these coagula as it does in those of a venesection. According to Walshe, these cadaveric coagula are usually voluminous, jelly-like masses of fibrin of a pale straw-color, semi-transparent, and containing a quantity of serum in their meshes. Never do they show the slightest signs of stratification, and are not really adherent to the cardiac walls. Occasionally their prolongations may be intertwined amongst the papillary muscles and fleshy columns. According to Legroux, it appears difficult to understand how these large masses of fibrin become separated from the blood and deposited in the heart during life, and yet he is indisposed to regard them as a strictly post-mortem production. They are for him simply the result of the agony.65 After death the serum is expelled from the clot in larger or smaller quantity, and for a longer or shorter time according to its own spontaneous retractility.
63 Magendie, "Lectures on the Blood," Lancet, 1839.
64 Dict. de Médecine, t. viii. p. 560, Paris, 1868.
65 Gaz. hébdomadaire, 1856.