A 66-year-old man with cardiogenic shock, severe left ventricle (LV) systolic dysfunction, multiorgan failure and rhabdomyolysis caused by influenza B virus infection was admitted to the Intensive Care Unit. He needed circulatory support with veno-arterial extracorporeal life support, intra-aortic balloon pump, inotropes, and vasopressors. In addition, mechanical invasive ventilation and continuous renal replacement therapy were needed to maintain respiratory function, acid-base equilibrium, and fluid electrolyte balance as well as to treat rhabdomyolysis. Antibiotic and antiviral therapies were tailored by culture and serology. However, after seven days, LV systolic function was not improved, the LV was dilating, and filling pressure was increasing. Thus, the patient underwent left ventricular assist device (LVAD) implantation as bridging therapy to recovery or to transplantation. Initially, the LVAD reduced LV filling pressure and volume, and in the following weeks LV systolic function slowly improved. After two months, LV systolic function recovered completely, the LVAD was removed, and the patient was transferred to a peripheral hospital for rehabilitation.
Ventricular assist devices (VADs) were introduced in clinical practice in the 1980s as mechanical support for the left ventricle (left ventricular assist device [LVAD]), right ventricle (right ventricular assist devices [RVAD]), or both (biventricular assist device [BiVAD]) in patients with end-stage heart failure (HF) headed to transplant or in patients with temporary cardiac shock who were expected to recover ventricular function. Use of these devices increased in the years that followed, and in 2018, VADs, particularly LVADs, are considered a pivotal treatment in patients with HF; these devices have several indications, including bridge to transplant, bridge to candidacy, destination therapy, and bridge to recovery. Moreover, LVAD is considered the only valid alternative treatment when there are not enough organs available for transplant to satisfy the growing need. Indeed, the global HF prevalence, currently estimated between 23 and 26 million people, is expected to increase as a result of the population aging and the improved survival rates associated with other forms of heart disease.1 The huge need for treatment of this population of HF patients easily explains why from 2006 to 2014 more than 15,000 patients in the United States received a VAD implant, with total procedures approaching 2500 per year and with 1- and 2-year survival rates of 80% and 70%, respectively.2
LEFT VENTRICULAR ASSIST DEVICE TYPES
LVADs are composed of an inflow cannula, usually placed in the left ventricular (LV) apex; an outflow cannula, usually anastomosed in the ascending aorta; a propulsion pump that moves the blood provided by the inflow cannula to the aorta through the outflow cannula; and an external controller, which receives and processes information from the pump. According to the pumping mechanisms, LVADs can be classified as either pulsatile or continuous flow. Pulsatile LVADs, the first generation of VADs available, were characterized by a pumping mechanism that simulated the pulsatile action of the heart ...