Pacemaker Therapy

Abstract

January 2008

Section 1 Cardiovascular Medicine

VII Pacemaker Therapy

Nazem W. Akoum, M.D., F.A.C.P.
Cardiovascular Disease fellow, University of Utah School of Medicine

Jonathan Lowy, M.D.
Director of Electrophysiology, St. John's Hospital/North Cascade Cardiology, Bellingham, Washington

Roger A. Freedman, M.D.
Professor of Medicine and Director of Clinical Cardiology, University of Utah School of Medicine

More than 250,000 permanent cardiac pacemakers are implanted each year. This number continues to increase as the population ages and indications for pacemakers expand. This chapter reviews the anatomy and physiology of the normal cardiac electrical system and proceeds to outline the current indications for permanent pacing, including sinoatrial (SA) node dysfunction, acquired atrioventricular (AV) block, chronic bifascicular and trifascicular block, acute myocardial infarction, and cardiac surgery, as well as pacing for neurocardiogenic syncope, hypersensitive carotid syndrome, and cardiac resynchronization. The main components of a pacemaker system (generator, leads, and programmer) are explained, and the basic functions of pacemaker programming are summarized. Selection of a pacing system and program mode are discussed. Key issues surrounding pacemaker implantation (such as care before and after the procedure, vascular access, risks, and long-term follow-up) are addressed. Complications are infrequent but can be serious; they can generally be classified according to whether they mainly affect the pocket, the generator, or the leads. External sources that can interfere with pacemaker signals are also discussed; the most important of these is electromagnetic interference (EMI). Figures illustrate a variety of pacemaker generators and leads, different forms of dual-chamber (DDD) pacing, the appearance of a dual-chamber pacemaker on chest x-ray, and an algorithm for determining which pacemaker patients need a programming change before undergoing procedures involving electrosurgery. Tables list guidelines for permanent pacemaker implantation, the North American Society of Pacing and Electrophysiology–British Pacing and Electrophysiology Group (NASPE-BPEG) generic five-position code for antibradycardia pacing, common findings related to pacemaker problems, and sources of electromagnetic interference that can affect pacemakers. This chapter has 24 references. .

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