Current Axial-Flow Devices—the HeartMate II and Jarvik 2000 Left Ventricular Assist Devices

The increased applicability and excellent results with left ventricular assist devices (LVADs) have revolutionized the treatment options available for patients with end-stage heart failure. Until recently, most patients who have undergone LVAD implantation have been supported by pulsatile devices. Unfortunately, the use of the latter devices is associated with significant comorbidity, primarily as a result of their large size and limited durability. The HeartMate II and the Jarvik 2000 pumps, both of which incorporate axial-flow and rotary pump technology represent the next generation of devices. The clinical use of these newer axial-flow pumps have resulted in superior outcomes, including significantly reduced complication rates with improved durability. However, as with all new technology, axial-flow LVADs have also introduced a different set of management issues, as well as certain complications, into the mechanical circulatory support arena—issues and complications that were previously absent or unimportant with pulsatile LVADs. Concerns include the effects of continuous-flow on the systemic circulation and end-organ function, risk of thromboembolism and pump thrombosis, increased incidence of gastrointestinal bleeding and ventricular arrhythmias, as well as the effects of partial unloading on pulmonary hemodynamics. Different strategies are required to optimize outcomes with these newer devices.