 Over the last several decades, MCSDs have been developed to augment or supplant failing myocardial performance. This therapy has been used successfully as a bridge to heart transplantation, a bridge to recovery, and as permanent implantation or destination therapy for intractable heart failure. Although heart transplantation offers life-saving therapy for selected patients, its use is limited by a supply of donor organs that currently meets less than one-tenth the need. As a consequence, the number of MCSD implantations has increased in recent years. 