Patients with severe depression of left ventricular ejection fraction and high-risk coronary lesions are at risk of developing complications during percutaneous coronary interventions (PCI). Intra-aortic balloon pump (IABP) is a support that helps the interventionalist in such hemodynamic complications during high-risk PCI, but it does not offer complete circulatory support. Instead, TandemHeart (Cardiac Assist, Pittsburg, PA, USA) is a percutaneous left ventricular assist device (pLVAD) that gives total left circulatory support and can be used for patients in cardiogenic shock or for elective PCI at high-risk. TandemHeart is a percutaneous transseptal ventricular assist device that allows a rapid percutaneous left ventricular support without the need for surgical implantation. Between November 2003 and April 2005, 6 patients admitted to our coronary care unit (CCU) underwent either emergency (n = 3) or elective (n = 3) placement of the TandemHeart device before a high-risk procedure. From our initial experience we conclude that the percutaneous transseptal ventricular assist device, TandemHeart, can be easily and rapidly deployed either in emergency or in elective high-risk PCI to achieve complete cardiac assistance.