Device Therapy for Cardiac Arrhythmias

SINCE THE INTRODUCTION OF THE implantable pacemaker in 1958 and the implantable cardioverter defibrillator (ICD) in 1980, implantable devices for rhythm control are now commonly used for treating bradycardia and certain types of ventricular arrhythmias. The first pacemakers and ICDs were large devices (40-200 cm) that required a prolonged hospitalization for implantation and postoperative recovery, and had few programmable features. In contrast, the current devices are significantly smaller (9-45 cm), can be implanted on an outpatient basis, and provide a myriad of programming options to optimize therapy. During the last several years, the actual and potential indications for pacemaker and ICD implantation have expanded significantly as results from several large clinical trials have become available. These advances have led to increased patient and physician acceptance and a steady increase in implantation rates. In 1997, 153000 new pacemakers and 29000 ICDs were implanted in the United States. We summarize the function of and current indications for pacemakers and ICDs. More comprehensive discussions can be found elsewhere.