Do cardiac aneurysms blow out?

The possibility is suggested that cardiac aneurysms are formed when an infarcted region of the ventricular wall becomes elastically unstable and "blows out". The consequence of such a blowout could be a large saccular aneurysm or even cardiac rupture. We use a nonlinear stress-strain relation capable of describing both the passive and active myocardial wall to examine this possibility in terms of large-deformation membrane theory. Ventricular infarcts made of a material having physical properties like rubber would be expected to blow out, but those made of passive myocardium would not.