Vicious circles in disease / by Jamieson B. Hurry.

  • Jamieson Boyd Hurry
Date:
1913
Catalogue details

Licence: Public Domain Mark

Credit: Vicious circles in disease / by Jamieson B. Hurry. Source: Wellcome Collection.

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    Aortic Stenosis. Amongst the various forms of chronic valvular disease, stenosis and incompetence of the aortic orifice, associated with dilatation of the ventricle, most frequently lead to death. After, perhaps, many years of fairly comfortable life, the compensatory hypertrophy wears out and is replaced by dilatation. The fatal Circle may be summarised as follows :—regurgitation, dilatation, weakened systole, impaired coronary circulation, and increased regurgitation. Terribly sudden may be the syncope : “ Transition from a state of compensation to incompetence seems often very sudden. . . . Insufficiency of the myocardium which develops suddenly is due to the Vicious Cycle created by lowering the pressure in the coronary arteries which occurs directly the ventricle is unable to maintain the required aortic pressure. Thus, at the very time when the heart muscle requires the greatest supply of nutrition, the supply of blood to the myocardium lessens.” 1 Thrombosis. Sudden death is sometimes due to thrombosis or embolism of the heart or large vessels. If not immediately fatal, the embolus or thrombus may cause eddies and obstruction which in their turn lead to rapid and extensive clotting. This steadily adds to the size of the embolus or throm¬ bus, thereby increasing the obstruction. The greater the obstruction the larger the surface on which the blood can coagulate, and the more rapidly does the obstruction grow. The circulation may indeed be completely arrested. 1 Osier and Macrae, System of Medicine, Vol. IV., p. 31.