The limitation in number of donor hearts led to the establishment of alternative treatments such as left ventricular assist devices (LVAD), which have been used. Although several reports suggest the native ventricular function recovers after long-term LVAD support - a process called "reverse remodelling" - the underlying biological mechanisms are unclarified. Various molecular pathways of the human myocardium associated with apoptosis, response to stress, or matrix changes are known to be altered under conditions of heart failure and some of them have been shown to be reversible regulated during left ventricular mechanical support. This suggests that the "reverse remodelling" is actually, at least in part, a reverse mechanism. One explanation may be, under mechanical circulatory assist, volume and pressure overload is reduced, and thus ventricular wall stress decreases, leading to improved myocardial blood supply. This may be one explanation for the molecular myocardial changes, and may reflect a possible cause of "reverse remodelling".
