Coloured frontal X-ray of the chest of a 60 year old male patient who is waiting for a heart transplant. He has a pacemaker (top right) and a left ventricular assist device (LVAD, bottom right) fitted. The left ventricle is the main pumping chamber of the heart, responsible for the circulation of oxygenated blood through the body. When it stops working properly, an LVAD is temporarily implanted to assist blood circulation. A pacemaker is a device that supplies electrical impulses to a malfunctioning heart so that it beats normally.