Now, this morbid growth is evidently connected with the lacerated state of the membrane in the conditions of its production, whereby it is limited to a small space.
It is probable that the membrane is first ruptured; that its lacerated edges inflame, and then throw out unhealthy lymph, or unhealthy granulations, in the shape of these fungous or wart-like excrescences. When they have sprung from a ruptured membrane, they have, in the specimens which I have examined, been larger than when they have arisen under other conditions.
But when such excrescences grow from the surface of the membrane which is thickened and cartilaginous only, but not lacerated, they are more apt to occur in many parts of it at the same time. I have seen the valvular apparatus between the auricles and ventricles on both sides, as well as the aortic valves of the same heart, studded with them. They were all about the size of hemp seeds: they adhered to the membrane with different degrees of tenacity, and wherever they were capable of being detached, they left a rough surface. The lining of the arteries has been known to give origin to morbid growths of the same kind, which have obstructed the passage of blood, and given occasion to the formation of a coagulum, which has obliterated the pulse.
The internal lining of the heart is liable to ulceration, not as a common consequence of simple inflammation, but as an occasional consequence of some of those diseased conditions which have been described.
It is most commonly found around scales and spiculæ of bone, and under such circumstances as to leave no doubt that the bone itself has furnished the source of irritation from which it springs. The ulceration commences from the very border of the bony scale, as if it was a process of nature for detaching it, and to a considerable distance around the ulceration the membrane is reddened, and easily detached from the subjacent structure. Where there are several distinct scales of bone, it is not uncommon to find a circle of ulceration around each of them.
Ulceration is also met with where there is a thickened and cartilaginous state of the membrane without ossification. Under these circumstances, as far as I know, it affects no definite form. It is often a very destructive process of disease, obliterating large portions of the valvular structure, and penetrating deep into the muscular substance of the heart.
Rupture of the internal lining of the heart is not easily distinguished from ulceration. In collections of morbid anatomy, many unquestionable specimens of ulceration are described as specimens of rupture. Rupture must always be looked for in the valvular apparatus of the heart, i. e. in the valves themselves, or in the chordæ tendineæ which are their appendages. It is probably incapable of taking place elsewhere, except as a part of a rupture, which involves the whole organ.
That solution of continuity which is evidently without loss of substance; that of which the separated edges when they are brought together are completely adapted to each other; also that which is unaccompanied by any thickening or other morbid condition of the valve; the solution of continuity which is found under these circumstances, may safely be considered to proceed from rupture, and not from ulceration[7].
But it is probable that these characteristic conditions do not long remain after the occurrence of the rupture. Complete specimens of them are very rare; but specimens are numerous where the solution of continuity, by its form and direction, bespeaks rupture, while its rounded edges and the general thickening of the valve denote ulceration. These, it may be fairly conjectured, do in fact exhibit a compound of both. The membrane was originally ruptured, but disease has subsequently arisen and obscured the character of the mechanical injury.
The greater number of those concretions, which were regarded by the older anatomists as polypi of the heart, were unquestionably portions of mere blood, which had undergone coagulation after death. The blood remaining in the heart after death discharges itself of its colouring matter as it coagulates, and, giving off processes between the muscular fasciculi, assumes a shape which has suggested the name of polypus[8].