Pacemaker and defibrillator lead extraction.

Surgically implanted cardiac devices play an important role in the treatment of heart disease. In the 50 years since the first pacemaker was implanted, technology has improved dramatically, and these devices have saved or improved the quality of countless lives. Pacemakers treat slow heart rhythms by increasing the heart rate or by coordinating the heart’s contraction for some heart failure patients.1 Implantable cardioverter defibrillators stop dangerous rapid heart rhythms by delivering an electric shock.2 As the range of applications widens, the number of patients with cardiac devices continues to increase. Approximately 400 000 devices are implanted each year in the United States, and there 3 million patients with implanted cardiac devices currently. Occasionally, pacemaker and implantable cardioverter defibrillator systems must be removed. The removal of such systems is potentially a high-risk procedure. With the increasing number of implanted devices, removal is required more frequently. To ensure patient safety, the Heart Rhythm Society has published guidelines for safe lead removal or extraction. These guidelines outline the indications for lead extraction, physician qualifications and training, and the tools and techniques used in the procedure.3 One part of the system is the pulse generator, a metal can that contains electric circuits and a battery, usually placed under the skin on the chest wall beneath the collarbone. To replace the battery, the pulse generator must be changed by a simple surgical procedure every 5 to 10 years. The other parts are the wires, or leads, which run between the pulse generator and the heart. In a pacemaker, these leads allow the device to increase the heart rate by delivering small bursts of electric energy to make it beat faster. In a defibrillator, the lead has special coils to allow the device to deliver a highenergy shock and convert dangerous rapid rhythms (ventricular tachycardia or fibrillation) back to a normal rhythm. For both of these functions, leads must be in contact with heart tissue. Most leads pass through a vein under the collarbone that connects to the right side of the heart (right atrium and right ventricle). To remain attached to the heart muscle, most leads have either a small screw or hooks at the end. Within a few months, the body’s natural healing process forms scar tissue along the lead and at its tip, which fastens it even more securely in the patient’s body. Leads usually last longer than device batteries, so leads are simply reconnected to each new pulse generator (battery) at the time of replacement.