**3. LVAD functioning and care**

An LVAD is a device that supplants the workload of the left ventricle by pumping blood from the heart to the body. The first generation of LVADs were pulsatile pumps with unidirectional valves that were later transitioned to continuous flow systems due to improved rates of adverse events [19, 20]. Continuous flow LVADs are further divided into axial pumps (propelling blood forward) and centrifugal pumps (moving blood away from pump). Centrifugal-flow LVADs are superior with respect to survival after 2.5 years, gastrointestinal bleeding, and pump thrombosis [21, 22]. The MOMENTUM 3 trial summarized that the newer device system of HeartMate 3 was superior to the previous devices with respect to disabling strokes and the need to replace malfunctioning devices [23].

LVAD implantation requires cardiopulmonary bypass during which the centrifugal pump system is connected to a conduit in the ascending aorta. The pump is connected to an external control unit by a cable called the driveline. The driveline is connected to the pump and tunneled through the abdominal subcutaneous tissue and then to an external controller. The control unit includes batteries and a display of pump parameters [24, 25]. Given the gravity of this intervention, preoperative risk assessment is extensive. It requires optimizations of comorbid conditions and physical fitness. Patients with right ventricular or renal dysfunction may be evaluated in the ICU with invasive hemodynamic monitoring to optimize volume status and end-organ perfusion prior to surgery. The need for renal replacement therapy or mechanical support before LVAD placement is an indicator of higher mortality [11].
