On some of the causes and effects of valvular diseases of the heart : being the Croonian Lectures of the Royal College of Physicians for 1865 / by Thomas B. Peacock.

  • Peacock, Thomas B. (Thomas Bevill), 1812-1882.
Date:
1865
Catalogue details

Licence: Public Domain Mark

Credit: On some of the causes and effects of valvular diseases of the heart : being the Croonian Lectures of the Royal College of Physicians for 1865 / by Thomas B. Peacock. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    symptoms of chronic bronchitis and emphysema, and fre- quently present also signs of dilatation of the heart and of incompetency of the mitral valve. The pulmonary affections are probably mainly due to the impure air which the men breathe while underground, and to the occurrence of inflammatory affections resulting from exposure to the weather on reaching the surface, when exhausted by labour in hot and close places and wearing the damp clothing in which they work. The cardiac defect I conceive chiefly to arise from the distension and overaction of the heart in the prolonged exertion of climbing. The effect of this must be to interfere with respiration and so prevent the free transmission of blood through the lungs; the right side of the heart will become engorged, the venous system gene- rally congested, and the flow of blood through the arteries being also obstructed, the left ventricle will be distended and stimulated to overaction. The cavities being thus habitually overloaded, the muscular walls must have their contractile power impaired and become permanently dilated; and the dilatation of the left ventricle will prevent the perfect adjustment of the folds of the mitral valve. That this is the correct explanation of the cardiac affections of the Cornish miners I am unable to affirm with certainty, for, though I have carefully investigated the state of a large number of disabled miners during life, I have only once had the opportunity of examining the state of the lungs and heart after death. There can, however, be no doubt that the heart is very frequently dilated and the mitral valve in- the mean period of labour was, on the average, 28*5 years, and the extremes 5 and 53 years.