Rene-Theophile Hyacinthe Laennec invented the stethoscope in 1816. His invention revolutionized medicine and opened a new era in the field of cardiology. For the first time in the history, physicians had an investigational tool that would allow them to diagnose a significant number of cardiovascular diseases when their patients were still alive. Laennec used the stethoscope extensively in his daily practice. He was the first to detect abnormal cardiac sounds and to correlate with certain accuracy abnormal cardiac sounds and valvular pathology. Similar to his mentor Corvisart, Laennec was an advocate of clinico-pathological correlation and performed a significant number of autopsies himself.
Laennec performed extensive studies on heart valve diseases and described several cases of aortic, mitral and tricuspid valve alteration with "cartilaginous induration or ossification." He also described the auscultatory findings for these valve lesions.
Laennec also studied and reported several cases of valve lesions compatible with infective endocarditis. He agreed with the concept of vegetation described by his mentor Corvisart. Furthermore, he distinguished two types of vegetation that he called "vegetations verruqueses" and "vegetations globuleuse" or globular. Laennec, however, disagreed with Corvisart regarding the syphilitic origin of these vegetations. In his monograph, Laennec noted that he had seen several patients with valvular vegetations at autopsy that did not have venereal diseases during their lifetime. He also treated numerous patients with venereal diseases who did not suffer from these cardiac vegetations. He also recognized that he did not have any potential explanation for their formations. He then continued with the fact that he had observed these vegetations on all four cardiac valves but he noted that they were often localized on the left side and that the involvement of the right-sided valves was very rare. Finally he noted their presence in the left atrium.
Regarding their hemodynamic consequences, he noted that these vegetations were often small and did not obstruct the orifice of the valves, thus explaining the rarity of findings at mediate auscultation.
In the section of his treatise on valvular vegetations, Laennec reported the case of a 35 year-old male who presented with dyspnea, dizziness, palpitation and hemoptysis. At auscultation, Laennec detected a "bruit de soufflet" (Below sounds). He also detected a "fremissement cataire" (thrill) at palpation of the precordial region. A slighter below sounds was detected on the right side. Laennec diagnosis was "biventricular hypertrophy with vegetations or cartilaginous narrowing of the mitral valve." The clinical situation of this patient deteriorated rapidly and he died.
At the autopsy examination, Laennec noted cardiomegaly and chordae rupture of the mitral valve. Other chordae were thin but not ruptured. Finally, he noted the presence of multiple vegetations (verruquese type) on the free margin of the mitral valve. He described carefully these vegetations that were "numerous and irregular, different in size and shape, often long and thin and very fragile."
In the second part of this section, Laennec commented on the vegetations of globular configuration. He likened the appearance of these vegetations to that of a cyst (round, smooth and regular). He also mentioned that he had seen them only in the right or left atrial appendage and at the apex of the ventricles. As he correctly suspected it, these globular vegetations were thrombus formation. Interestingly, he described three stages for these globular vegetations. The stage one corresponded to new clot formation ("sang a demi liquid" or half liquid blood) and the stage three corresponded to organized, adherent and "old" thrombus. From historical point of view, Laennec's observation is probably the first detailed and accurate description of thrombus formation within cardiac chambers.
The entire chapter of Laennec's treatise on cardiac and valvular vegetations is displayed here.
Until the early 1830's, the detailed accounts of cases of valvular induration and vegetation did not correspond to any clinical entities and most authors did not discuss the etiology of these lesions. A number of clinical symptoms such as fever, fatigue, cough, dyspnea, palpitation, edema, and hemoptysis were described. Valvular lesions such as vegetations, wart-like excrescences, and fungus formation were also identified and it was clarified that they were different from cartilaginous formations. There was, however, no clear understanding of their significance.
The next major progress came from the broader application of techniques of physical diagnosis, percussion and mainly auscultation that would allow physicians to detect some of the abnormalities associated with these valvular lesions. The correlation between the clinical findings and postmortem examination was a critical step which would allow physicians to diagnose these valvular lesions during patient lifetime.