The murmurs of mitral disease / by Edward Mansfield Brockbank ; with five illustrations.

  • Brockbank, E. M. (Edward Mansfield), 1866-
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: The murmurs of mitral disease / by Edward Mansfield Brockbank ; with five illustrations. 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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    muscular .contraction of the auricle which ordinarily causes the propulsion of the heart's apex against the wall of the chest, and that thus it plays a notable part in the production of the impulse which is felt by the hand applied over the situation of the apex beat. In stenosis of the mitral aperture, this lifting of the apex by the force of the contracting auricle may be greatly exag- gerated (Sansom).1 Samways believes that the abnormally powerful contraction of the left auricle prevents regurgitation in compensated mitral stenosis, and further, that the auricle may even be strong enough to force blood into the ventricle, after con- traction of the latter has begun.2 These same observers believe that this prolonged auricular contraction prevents regurgitation of blood during early ventricular systole, and therefore puts the possibility of the crescendo murmur being systolic in rhythm out of the question. Woods,3 criticising Samways' view that the auricle can contend successfully with the ventricle, when their contractions overlap, and send blood into the ventricle at that time, forms the opinion, from his own observations with similar experiments to those from which Samways drew his conclusions, that such a theory is absurd. He says that there are no valves between the auricle and the lungs, and therefore, raising the intra-auricular pressure during contraction of the ventricle could only result in the blood following the path of least resistance, namely, back into the pulmonary veins. Woods also gives mathe- matical reasons for believing Samways' theory of the greater strength of the auricular compared with that of ventricular con- traction to be absurd. I fail to see how the contracting auricle could possibly prevent the regurgitation of the very small stream, and very small total amount, of blood which alone is necessary to produce many audible crescendo murmurs. And even were this contention unquestionable when the auricular wall is normal or hypertro- phied, it is impossible, to my mind, to understand how the thin atrophied muscle of the auricular wall, so often met with in mitral stenosis, and which, in Sansom's experience, may be represented by only a few muscular fibrillas scattered through a shell of fibrous tissue, can contract so forcibly over the mitral orifice as to prevent the regurgitation of blood through the stenosed valve, under the great force of ventricular systole. 1 Allbutt, System of Medicine, vol. v, p. 1014. 2 Ibid., vol. v. p. 1015. s Brit. Med. Journ., London, 1897, vol. i. p. 627.