PATHOLOGICAL ANEURYSM
In this class are included such dilatations as result from weakening of
the arterial coats, combined, in most cases, with a loss of elasticity
in the walls and increase in the arterial tension due to
arterio-sclerosis. In some cases the vessel wall is softened by
arteritis--especially the embolic form--so that it yields before the
pressure of the blood.
Repeated and sudden raising of the arterial tension, as a result, for
example, of violent muscular efforts or of excessive indulgence in
alcohol, plays an important part in the causation of aneurysm. These
factors probably explain the comparative frequency of aneurysm in those
who follow such arduous occupations as soldiers, sailors,
dock-labourers, and navvies. In these classes the condition usually
manifests itself between the ages of thirty and fifty--that is, when the
vessels are beginning to degenerate, although the heart is still
vigorous and the men are hard at work. The comparative immunity of women
may also be explained by the less severe muscular strain involved by
their occupations and recreations.
|