René-Théophile-Hyacinthe Laennec (February 17, 1781- August 13, 1826) was a French physician and inventor of the stethoscope. Dr. Laennec was born in Quimper, Brittany and studied medicine at the Hôpital de la Charité, Paris qualifying in 1804. He invented the stethoscope in 1816, while working at the Hôpital Necker.
Laennec is the author of the classic treatise De l'Auscultation Médiate (On Mediate Auscultation), published in August, 1819. This refers to his idea of using an instrument, or mediator, to hear sounds within the body. (The complete title of this book, often referred to as the 'Treatise' is De l’Auscultation Médiate ou Traité du Diagnostic des Maladies des Poumons et du Coeur (On Mediate Auscultation or Treatise on the Diagnosis of the Diseases of the Lungs and Heart).
"In 1816 I was consulted by a young woman labouring under general symptoms of diseased heart, and in whose case percussion and the application of the hand were of little avail on account of the great degree of fatness. The other method just mentioned [direct auscultation] being rendered inadmissible by the age and sex of the patient, I happened to recollect a simple and well-known fact in acoustics, . . . the great distinctness with which we hear the scratch of a pin at one end of a piece of wood on applying our ear to the other. Immediately, on this suggestion, I rolled a quire of paper into a kind of cylinder and applied one end of it to the region of the heart and the other to my ear, and was not a little surprised and pleased to find that I could thereby perceive the action of the heart in a manner much more clear and distinct than I had ever been able to do by the immediate application of my ear."
The origin of this idea occurred when Laennec saw some young children playing near the Louvre listening to the ends of a long piece of wood that transmitted the sounds of pin scratches. The next day, he rolled up a piece of paper, tied it with a string, and listened to his patients' chests with it. Laennec was a carpenter and then built a 25 cm by 2.5 cm hollow wooden cylinder which he also used to listen to the chest sounds of his patients. He later modified this cylinder to have detachable parts. He noted the various sounds that he heard and then correlated them to the anatomical findings at their autopsies. He also used a solid piece of wood to 'listen' to heart sounds. In February 1818, he presented his findings in a talk at the Academie de Medecin, later publishing his findings in 1819 (above).
Laennec may have been motivated by several factors in his invention of the stethoscope: he had discovered that it was a better way to transmit sounds from the chest as opposed to the method in vogue at the time of placing his ear over the chest, especially if the patient was overweight; using a stethoscope avoided the embarrassment of placing his ear against the chest of a woman, as noted in the story above; Laennec was also a student of the newly popular art of percussion in making diagnoses, but this had limitations as noted above if the patient was overweight. (This art of percussion had been emphasized by Laennec's teacher, Corvisart, who in turn popularized the method first described by the Austrian physician Leopold Auenbrugger in 1761 in his work Invent um Novum.)
This new method of auscultation was not readily accepted by some doctors, who preferred the usual method of listening directly to the chest with one's ear (immediate auscultation). Although the New England Journal of Medicine reported the invention of the stethoscope two years later, in 1821, as late as 1885 a professor of medicine stated, "He that hath ears to hear, let him use his ears and not a stethoscope." Even the founder of the American Heart Association, L. A. Connor (1866 - 1950) carried a silk handkerchief with him to place on the wall of the chest for ear auscultation.
He also named this instrument for mediate auscultation the stethoscope, which is derived from the Greek (stethos meaning chest). Laennec often referred to the stethoscope as "the cylinder," and as he neared death, he bequeathed his own stethoscope to his nephew, referring to it as "the greatest legacy of my life."
This book, De l'Auscultation Mediate, was a landmark in the knowledge of chest diseases. Laennec classified and discussed the terms rales, rhonchi, crepitance, and egophony - terms that doctors use on a daily basis during physical exams and diagnoses.
He also made many important contributions about tuberculosis.
Perhaps equally as important a contribution to medicine was his reawakening of the spirit of objective scientific observation. When he published his text in 1819, he included this motto in Greek, "the most important part of an art is to be able to observe properly." His text was held in very high regard by many doctors as a gold standard for the practice of medicine. Professor Benjamin Ward Richardson stated in Disciples of Aesculapius that "the true student of medicine reads Laennec's treatise on mediate auscultation and the use of the stethoscope once in two years at least as long as he is in practice. It ranks with the original work of Vesalius, Harvey and Hippocrates."
Of interest is the fact that very little was known of the actual physiology of the heart when Laennec wrote his treatise. He did describe two heart sounds, but erroneously thought that the first heart sound was due to ventricular systole and the second heart sound was due to atrial systole.
Cirrhosis of the liver is occasionally still called Laennec's cirrhosis, as Laennec was one of the first to recognise this problem as a disease entity. He also has other medical eponyms associated with his name: Laennec's cirrhosis refers to the appearance of regenerated liver, comprising small lobules separated by a fine, fibrous tissue; Laennec's thrombus is an antenatal thrombus in the heart; and Laennec's pearls refer to sputum produced by asthmatics.
Hamman's murmur, which is also known as Laënnec-Hamman symptom or Laënnec-Müller-von Bergmann-Hamman symptom, or Hamman's crunch is a crunching sound heard over the precordium due to spontaneous mediastinal emphysema.
Before his death, he wrote:
"I know that I have risked my life, but the book I'm going to publish will be, I hope, useful enough to be of more value than the life of a man."
On a more personal side, Laennec was a very kind man. Being a Breton, he was a very devout Catholic. Some refer to his charity towards the poor as being proverbial. He was beloved by his colleagues and his students, being especially thoughtful to his English speaking students.
On the exterior wall of the “Hôpital Necker - Enfants Malades”, where Laennec developed “mediate auscultation” with the stethoscope, near the entrance of the hospital in 149, Rue de Sèvres, there is a marble memorial tablet with a graved portrait of Laennec and this inscription: "Dans cet hôpital Laennec découvrit l'auscultation. 1781-1826". Some of the oldest buildings of the hospital can be seen on the same front of this large and modern medical area.