This issue of Interventional Cardiology Clinics, Guest Edited by Dr. Brian O'Neill, will focus on Mechanical Circulatory Support. This issue is one of four selected each year by the series Consulting Editor, Dr. Marvin H. Eng. Mechanical circulatory support (MCS) plays an important role in the management of a variety of patients with a range of conditions in interventional cardiology.  As many times the question of MCS arises in the most critical of patients, an understanding of each of the devices along with which patients may potentially benefit is vital.  This issue aims to provide a review of the various options of MCS, as well as a variety of scenarios in which MCS may play a beneficial role in the management of patients.