Ventricular assist devices.

Despite major advances in the treatment of heart failure over the past two decades, improving the natural history of this condition, heart failure continues to be a major source of morbidity and mortality. Although availability of heart donor for transplantation has declined over the past several years, innovations in ventricular assist device (VAD) technology has provided an alternative therapeutic option for patients with advanced heart failure. Initiated as a mechanical option to "bridge" critically ill patients awaiting transplantation, VADs are being increasingly deployed as "destination" devices to provide long-term support. With technical advances resulting in improved mechanical reliability, reduced postoperative morbidity and greater likelihood of patient acceptance, there is interest in expanding the applicability of VAD beyond the current indication, as destination therapy for severely ill patients who are not candidates for transplant. This review examines the rational as well as the technical details of the different generation of VADs for mechanical cardiac support, implanted either surgical or percutaneously. These devices are at various stages of development and clinical investigation. One or more of these newer devices is likely to emerge as an important development in the treatment of patients with advanced heart failure.