Monday, January 18, 2016

1672: Vieussens discovers difference between asthma and cardiac asthma

Raymond Vieussens (1635-1715)
Once William Harvey proved blood circulates in 1628, this opened the door for investigators to study the heart, circulation of the blood, and related diseases. Such studies lead to a man named Raymond Vieussens breaking the paradigm that all dyapnea should be classified under the umbrella term asthma.

Vieussens performed a bunch of autopsies, with the specific intent of studying the heart and the circulation of the blood.  Between the years of 1672 and 1676 he came to the conclusion that sometimes dyspnea is caused by heart disease, and such cases of dyspnea should be classified as cardiac asthma, as opposed to pure asthma, explains Fielding Hudson Garrison in his "Introduction to the history of medicine."  Garrison wrote the following about Vieussens:
Vieussens first correctly described the structure of the left ventricle, the course of the coronary vessels*, the valve in the large coronary vein, and the centrum ovale in the brain. In his many autopsies he noted the significance ofpericardial adhesions and the relation of heart disease to asthma and hydrothorax (1672-6)... giving the character of the pulse and the pathological features.
Robert Oswald Moon, in his 1912 book "Prognosis and treatment of diseases of the heart," said:
True, indeed, Raymond Vieussens of Montpellier (1641-1716) was able to recognize disease of the heart as the cause of affections termed asthma and hydrothorax, to note the characteristic pulse of aortic insufficiency and to describe mitral stenosis and the consequent stagnation of the blood in the vessels in the lungs... yet it was not till the invention of the stethoscope and increased practice of percussion that cardiac diseases began to be seriously studied by clinical physicians." (2, page vii, and viii)
According to Oswald, the following are symptoms of heart disease: (2, pages 107-111)
  1. Insomnia (trouble sleeping):  Treatment is hypnotics ( chloralamide, paraldehyde, trionol, etc.).  Morphia is also a good remedy, and also treats any pain that may be present. 
  2. Coughing (early sign): Treatment is drinks of hot water and seltzer; for hacking cough a concoction with codeiae and ipacec is useful
  3. Dyspnea (due to fluid in lungs), and occurs especially at night or when lying down: Treatmenet is avoidance of heavy meals in evening; mustard poltaces and dry cupping over the back and chest are also useful; inhalations of oxygen are useful (usually by mask); morphia; atrophine; digitalis to strenthen heart (increase blood pressure)
  4. Flatulence; treatment is thymol
  5. Vomiting is usually a fatal sign: If severe, abstinence of all food, and peptonized milk with brandy; stop digitalis; large doses of bismuth are beneficial
  6. Dropsy:  It's generally described as the tightening of the skin or body cavity due to an abnormally large quantity of water in the body cavity (6, page 3), such as the lower legs, ankles, etc. It's an old term for what is now referred to as edema.  Treatment is diuresis (make patieint pee); diaphoretics (make patient sweat); a milk diet has a diuretic effect; digitalis also acts as a diuretic; caffeine is also a diuretic; nitrate of potosh; diuretin; theobromine
  7. Wheezing (not noted by Oswald)
As you can well see, many of these symptoms are similar to asthma.  In fact, the symptoms of cardiac disease are so similar to those of asthma that doctors still to this day often confuse the two.  Although, treatment for the two diseases is quite different. 

For a quick review, cardiac disease is now generally referred to as heart failure, and it occurs when the heart becomes a weak pump.  As a result the heart cannot keep up with demands of the body, and blood flowing to the heart (preload) becomes backed up.  This results in increased pressure in the vessels in the lungs, and  pulmonary edema (fluid in the lungs) often results.

The first known person to describe pulmonary edema was Giorgio Baglivi (1668-1707) in 1669.  He described it in his book De Praxi Medica (On the Practice of Medicine), according to Hector O. Ventura and Mandeep R. Mehra in their article (3, page 6).  These authors quote Baglivi as saying:
Next to be considered is a dangerous disease of the lungs which is called suffocative catarrh.  It is caused chiefly by stagnation of the blood in the lungs and about the pericardium... in this kind of catarrh the patient has a cold, and pain in the chest, and difficulty in breathing, also interrupted speech, anxiety, cough, sterter (heavy snoring on inspiration), a widely spaced low pulse, foam at the mouth, and the like... The foam at the mouth is caused by impaired circulation of the blood about the lungs... hence (this kind) of catarrh comes from sudden stagnation of blood in the vicinity of the heart and lungs, and not from phlegm running down from the head as the ancients believed to be the condition in this disease." (3, page 6)
In this way, Baglivi used Harvey's theory that the blood circulates to confirm vieussens theory that cardiac asthma and pure asthma are two distinct diseases.   The remedy used by Baglivi was bloodletting, as noted by Baglivi (per Ventura and Mehra):
An instant cure for this disease during the paroxysm is blood letting... The disease is very precipitous; unless phlebotomy is done immediately the blood coagulates more and stagnates.  Thus the opportunity for cure is lost.  The blood should be reduced in amount, the clotting should be undone, and a bland sweat should be produced.  (3, page 6)
Baglivi likewise believed that if an asthmatic, after three to four hours of sleep, awakens feeling as though he is suffocating, and opens the window for want of air, "consider it certain that he is suffering from dropsy of the chest."  The treatment for this, therefore, would be bloodletting.  The patient should also be encouraged to urinate (although Baglivi writes dysuria instead of diuresis), as lack of urination may lead to asthma, according to Baglivi.  Of course, as noted by Ventura and Mehra, Baglivi here is describing "nocturnal dyspnea" probably due to cardiac asthma. (3, page 6)

By the 1820s investigators had access to the stethoscope to listen to heart sounds and sphygmomenometer to monitor blood pressure.  This set the stage for Dr. James Hope, a cardiologist, who published a book in 1831 titled "A treaties on the diseases of the heart and great vessels."  In the book he described signs and symptoms of heart disease, including a description of how an overworked heart becomes hypertrophied, and  as it poops out blood gets backed up all the way to the capillaries of the lungs where it seeps out and causes pulmonary edema.  (3, page 7-8)

Hope recommended bleeding, emetics, purgatives, and expectorants. (3, page 8)  By the 1930s vodka was used to ease the foam of pulmonary edema (or foaming pulmonary edema, which often presents as pink, frothy secretions), and this was often used in emergency rooms to stabilize the edema bubbles which results in rapid dispersion of the bubbles.  Vodka (or ethyl alcohol) was useful for this until improved diuretics were available in the 1970s and 1980s.  (4, page 417)

The dose of alcohol was 3-5 ml of 30-50% ethanol alcohol (vodka) as needed, and it was diluted with probably 3cc of normal saline and aerosolized via a nebulizer.  It could also be delivered into the endotracheal tube (ETT) as needed.  (5, page 264)  Vodka was no longer used by the time I entered RT school, although I still often heard stories of how well it worked.  I would imagine this therapy was ceased due to possible side effects, and improved diuretics, such as furosimide (laxis).

Despite the revelations of Viessens and Baglivi, and despite many it would be many years before these two disease would be completely separated as unique diseases.  In fact, to this day there remain medical caregivers and practitioners who struggle with differentiating the two prior to further testing, and this often results in cardiac asthma (now called heart failure) being treated as asthma.

Various discoveries regarding the understanding of the heart and

*Arteries that feed oxygen to the heart.

References:
  1. Garrison, Fielding Hudson, "An introduction to the history of medicine," 1921, 3rd edition, Philadelphia and London, W.B Saunders Company
  2. Moon, Robert Oswald, "Prognosis and treatment of diseases of the heart," 1912, London, Longmans, Green and Co. 
  3. Ventura, Hector O, and Mandeep R. Mehra, "Chapter 1: The history of acute heart failure management: how far have we come?" in the book "Managing acute decompensated heart failure," Christopher M. O'Conner, Wendy Gattis Stough, Mihai Gheorghiade, Kirkwood F. Adams Jr., editors, 2005, Taylor and Francis; 
  4. Burton, George G, John Elliot Hodgkin, Jeffrey J. Ward, "Respiratory Care: a guide to clinical practice," 1991, Lippincott
  5. Lough, Marvin D., Robert L. Chatburn, W. Arlen Schrock, "Handbook of Respiratory Care," 1983, Year Book Medical Publishers
  6. Monro, Donald, "An essay on the dropsy and its different species," 2nd edition, 1756, London, Plato's Head in the Strand
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