Infections of Cardiac Implantable Electronic Devices: Etiology, Prevention and Treatment

Abstract

Since the initial use of prosthetic heart valves, the use of cardiac prosthesis and implantable devices has revolutionized the therapeutic options available to patients (de Oliveira et al.,2009). Cardiac Permanent PaceMakers (PPMs) have been implanted since the early 1960s. Over the past 50 years there have been tremendous advances in both the design of the device and the software employed. In the mid 1960s, transvenous leads were developed that could be inserted through a vein and thence into the heart, thus preventing the need for a thoracotomy. The development of ‘active fixation’ leads ensured a better contact with the endocardium and the presence of a steroid eluting tip helped to reduce any inflammation that might result. The introduction of the lithium iodine battery has dramatically increased the battery life to well over ten years. Radiofrequency programming became available in the 1970s, allowing simple adjustments to be made to pacemaker’s settings without the need for surgery. Today, permanent pacemakers and ICD (Implantable Cardiac Defibrillator), together with any adjustments, can be completed within minutes using a portable computer. Information regarding events such as periods of bradycardia, tachycardia or ventricular fibrillation can be stored within the memory of the device and accessed by the specialist during the routine checkup. To maintain atrio-ventricular synchrony, dual chamber pacing was then introduced. Moreover, in the late 1990s, pacemaker technology had improved to the extent that it became possible to increase the pacing rate to match the patient’s activity level (Allen et al., 2007). A wide range of cardiac implantable electronic devices (CIEDs) are now available, including ICDs and cardiac resynchronization systems. PPMs are commonly used in patients with atrioventricular conduction block, sick sinus syndrome, and symptomatic sinus bradycardia, whereas ICDs target primarily patients at risk for life-threatening ventricular arrhythmias. Since clinical trials have consistently demonstrated the ability of the ICD to reduce mortality in selected patients with moderate-to-severe left ventricular systolic