Via Reuters, a good illustration of the interconnected nature of the body. It degenerates in the same general way as any complex system - nothing fails in isolation. "The results of a new study suggest that there is an association between heart failure and an increased risk of dementia or Alzheimer's disease in the elderly. ... it may be worth looking at possible biological pathways linking heart failure to dementia, specifically to Alzheimer's disease. The markedly impaired cerebral circulation that results from chronic heart failure, for example, may play a role in the neurodegenerative process, especially in the elderly population. Poor blood circulation in the brain could further promote neurodegeneration by depriving the brain of oxygen." This is why the most effective approach is to prevent or repair the root causes of failure, rather than to continually develop patches for the far greater range of resulting problems.