Although the reduction in cardiac function is the cause and central abnormality of heart failure, there is clearly a very wide range of abnormalities in other systems that contribute to both the symptoms and progression of the syndrome of CHF. We must be aware of these changes to use the available therapeutic options to maximal effect, as well as being aware that more effective novel treatment strategies await a better understanding of the cause and effect of these noncardiac abnormalities that constitute the syndrome of CHF.