Cardiac Magnetic Resonance Imaging Guided Left Ventricular Lead Placement

Heart failure is a common, costly, disabling and potentially lethal condition. Despite well recognised and proven drug therapies, many patients remain breathless on exertion. A special pacemaker (cardiac resynchronisation therapy) may help improve symptoms of breathlessness and survival by restoring coordinated beating of the heart. However, despite careful planning and the knowledge of the most appropriate selection criteria, up to a third of patients do not get the desired beneficial effects after the pacemaker has been implanted. The implantation of the special pacemaker requires three leads (wires) to be inserted within the heart. Currently this is undertaken under X-ray guidance. Some patients may have scarring of the heart muscle due to previous heart attacks or their underlying condition. The X-ray technique cannot see this and therefore the doctor may implant the lead in such an area of scar tissue. Cardiac magnetic resonance imaging (CMR) can demonstrate these areas of scar. The study aims to investigate whether CMR can better predict where the wires should be placed. The CMR pictures will be taken before the patient has the special pacemaker implanted.