Mortality rates for heart failure are high, with five year survival rates approximating 30 to 40 percent in patients with mild to moderate symptoms and 0 to 20 percent survival in patients with severe symptoms. The patient with class IV heart failure has a one year survival rate of only 40 to 50 percent. This is despite advances in medical therapy and the availability of ACE inhibitors. While cardiac transplantation is the most viable form of treatment for these patients, it is limited by complications of chronic immunosuppression, the development of graft coronary artery disease and the serious shortage of donor organs. As many as 16,500 patients per year may be suitable candidates for heart transplantation. The actual number of donor hearts procured over the past few years, however, has remained relatively constant at 2,000. Thus, there is a strong rationale for the therapeutic application of left ventricular assist devices (LVADs) as an alternative to cardiac transplantation.