By Sara Moraca
The figure of G.B. Morgagni stands out not only in the medical history of the eighteenth century but in that of all times and we owe him the “De Sedibus et Causis Morborum per anatomen investigatis”, a treatise to be counted among the pillars of the entire history of medical science. He was the true founder of the modernly understood pathological anatomy, of which he understood and expressed the great practical utility. His predecessors had dealt with pathological anatomy, but without organicity, without a precise method of investigation and, above all, without constantly having in the foreground the need to research the origins and locations of the morbid phenomena analyzed. With Morgagni, however, pathological anatomy ceases to be a single observation study and becomes part of an immersive and structured medical reasoning. The insistence is placed on the need for a perfect knowledge of normal anatomy as the basis of pathological anatomy and a systemic collection of the greatest possible observations for each individual disease.
On the subject of congenital malformations of the cardiovascular system, Morgagni’s observations are decidedly numerous. These are mostly anomalies of little clinical interest but represent an anatomical and anatomopathological curiosity. A smaller number of data, on the other hand, are of considerable interest both for the clinical phenomena they have determined and for the autoptic description and for the pathogenetic and hemodynamic interpretation. For example, we find a clinical history and a sectoral finding that, without any doubt, deals with what is today called aortic coarctation. In another passage, however, there is a very interesting observation of atheromatous plaques on the walls of the superstructural portion of the aorta. Morgagni attributes the death to the presence of this congenital spoilage of the aorta and explains it with the difficulty that the heart had to find pumping blood into a narrower than normal canal. In another case, we are presented with an episode of interatrial communication, in which, associating a stenosis of the pulmonary artery valves described in an excellent way, today we undoubtedly recognize a “Fallot trilogy” (according to the description provided by Fallot in 1888), thanks to Morgagnana’s interpretation of the vice described and its clinical and functional consequences.
The pathology of valve lesions is extensively treated in the “De Sedibus” and there are numerous anatomopathological references to lesions of the heart valves. Less numerous, but of greater interest, are the dissertations on the hemodynamic and therefore clinical consequences of these lesions. It is of enormous interest that the scholar almost does not conceive the pure, isolated vice of a valve system, that is, pure insufficiency or pure stenosis and that in all or almost all of his observations, the two deficiencies are associated. Only in a case of lesions of the aortic valves does he speak of obstacles to the passage of blood, without mentioning the subsequent regurgitation due to insufficiency of the same valves. Also with regard to tricuspid valves he speaks of pure insufficiency but, in this specific case,
he admits the insufficiency as secondary to an expansion of the right ventricle and not as primitive. All this partly agrees with the acquisitions of modern medicine, according to which we can rarely speak of pure valve insufficiency or stenosis, so much so that we use the terminology “mitral disease”, with regard to mitral valves. Abundant study material is also offered to us about lesions of the aortic valves, in particular on young subjects with symptoms of heart disease and dyspnea, whose autopsy reports allow us to distinguish a form of endocarditic origin, often with association of lesions to the mitral valves and another form of atheromatous origin, in which atheromatous lesions are found in the proximal portion of the aorta. Among the causes of death we find syncopal accidents or intercurrent illnesses, rarely a real cardiovascular failure. Several examples of calcified aortic stenosis and observations related to mitral valve injuries are also listed, to which it refers as an insufficiency mostly caused by dilatation of the left ventricle. But perhaps the most important and interesting topic in this sector is tricuspid insufficiency, where Morgagni deals mostly with the hemodynamics of vice, especially with the pathogenesis of a symptom: the positive venous pulse. Its merit lies in having recognized how the positive pulsations of the jugular veins are a pathognomic sign of the dilation of the right cavity of the heart and of having legitimized Lancisi’s discovery of this true symptom.
Injury of the heart muscle and its vessels
In this field, Morgagni offers us valuable and interesting observations that affect us for their precursor character and because, although not reaching an exact clinical definition of the phenomena, they make it clear that the way of this exact definition was at least glimpsed. Of considerable interest, in an anatomopathological sense, are his description of coronary artery calcification and other similar ones found in the aorta which, albeit with some imperfections, for the first time establish a causal relationship between coronary lesions and some heart disorders. To get an idea of the extent of Morgagni’s work, it is sufficient to mention the access rare permanent pulse syndrome, observed and analyzed by him for the first time, so much so as to take the name of Morgagni-Adams-Stokes Syndrome.
The heart and nervous system
It must be remembered that Morgagni gave great importance to the influences of the nervous system on the heart and the circulation. It is his opinion that not all heart ailments depend on an injury to the heart or blood vessels but that nervous factors or disturbances of other viscera often come into play which, through nerve connections, are reflected in the heart. These considerations reveal not only a perfect knowledge of human anatomy and physiology, but also an admirable psychological intuition and a remarkable ability to observe.
Although it may seem too modern a definition for a text written in the second half of the eighteenth century, the concept of heart disease dependent on an obstacle to the pulmonary circulation not caused by heart disease is clearly and prophetically expressed in “De Sedibus” and is described with such abundance of details that only accentuate the importance and extraordinary topicality of Morgagni’s analytical ability.
The diseases of the pericardium are, in Morgagnan cardiology, the most extensively treated, with a truly remarkable abundance of news and citations. While not bringing news to the knowledge of its time, its merit lies, also here, in knowing how to transcend the fragmentary and inorganic nature of the observations of others, in being able to grasp the bonds and
differences, by framing these isolated annotations according to a logical plan, systematic and organic. Let us take the example of exudative pericarditis in which the discussions, at that time, were primarily about its existence or not as a disease in itself. Morgagni goes so far as to demonstrate that it exists as an entity in itself, although relatively rare since it usually occurs associated with exudative pleurisy or peritonitis. The references to hemorrhagic pericarditis and hemopericardium due to rupture of the aorta, vena cava and coronary artery are also interesting. The treatment of chronic pericarditis or cardiopericardial and mediastinal pericardium adhesions is quite extensive. It is not possible, in this passage, to keep silent about the hints of pericardium tumors, on which not much information is provided, but the very difficult diagnosis is underlined, often being confused with aortic aneurysms or with an excessive cardiac lumen.
Blood vessel diseases
Here a rich treatment appears, with details and clinical and anatomopathological descriptions, of the pathology of aneurysms. It is necessary to remember that Morgagni uses the term “aneurysm” also referred to the heart, although knowing that it is not an aneurysm, but of dilation. Great importance is given to the symptoms of aortic aneurysms, important considerations are present regarding the distinction between sacciform and fusiform aneurysms and an admirable description of dissecting aneurysm. As regards the origin of the aneurysms, numerous conditions are promoted that favor their onset, such as disorderly life and the profession tiring or exposed to bad weather. But the true origin is only one: the lue. Morgagni’s predecessors had already highlighted the link with syphilis, but here the concept is confirmed once and for all. There is also a description of atheromatous aortitis and numerous observations relating to arteriosclerosis, accompanied by extensive anatomopathological and pathogenetic comments and, in almost all reported cases, the symptomatic picture presents a state of arterial hypertension. For Morgagni, moreover, a very important part in the determinism of those phenomena that we know today under the name of hypertension is played by nervous factors. And these are words of such relevance, despite their inevitable oversemplification, that require no comment. Embolisms are also widely discussed in the discussion, before moving on to post mortem alterations of the heart and the discovery, which is rightly attributed to Morgagni, of the non-pathological nature of the clots found in the heart cavities of the corpses, identified as cardiac “polyps” and brilliantly described and investigating the causes.
The concept of heart failure can be said to be contained in many, if not all, of the eighteenth-century medical authors, but it is an unexpressed concept, not yet clearly formalized and developed, more an intuition than a real discovery of facts and of causes, but immediately there was a connection with the enlargement of the heart. In all the cases mentioned in the “De sedibus”, the observations relating to cardiomegaly report a great profusion of symptoms that all lead, more or less indirectly, to cardiac dilatation.
From this brief examination of Morgagni’s cardiological work, we can see that the importance of this author lies not only in what can be considered his original observation but also in the abundance of notions on the medical literature of his time and time preceding him, which he makes available to the reader. It is from these notions, added to his personal experiences, that he often draws truths that no one had drawn before, despite having observed and described the same peculiarities and clinical situations. He searches for the places and causes of morbid phenomena not in vain reasoning or in sterile reworkings of past doctrines but searches for them where only he can actually find them: in the dissected human body. He truly founds not only pathological anatomy, but general and special pathology. With him, medicine finds a new impulse, a new intent and moves towards modernity