A survey of implanters of permanent cardiac pacemakers and ICDs in the United States during 1997 was conducted to identify present and changing patterns in indications for pacing, implantation techniques, pacing-mode selection, follow-up, and opinions regarding pacing and ICD related issues. This report is an update from 1993 of surveys performed every 4 years for the International Cardiac Pacing and Electrophysiology Society (ICPES). Questionnaires were sent to implanting physicians who were members of the North American Society of Pacing and Electrophysiology (NASPE), and who might, therefore, be expected to be more conversant than others with the state of the art. Four major manufacturers also provided estimates of the numbers of pacemakers and ICDs implanted in the United States from 1994 through 1997. In 1997, approximately 182,000 new rhythm management devices, including 153,000 primary pacing systems and 29,000 ICDs, were implanted, an increase of 24% for pacemakers and 90% for ICDs since 1994. In 1997, pacemaker implantations were performed by about 8,600 physicians working in 3,300 hospitals and 1,000 independent "surgi-centers." From 1994 to 1997, sales in the United States of dual chamber pacemakers rose from 58% to 69% of the total, and adaptive rate systems from 74% to 90%. ICD sales increased by about 29% per year from 18,700 to 35,000 units. This study disclosed significant differences among implanter subcategories and between present and earlier practices, and it provided useful insights into trends in pacemaker and defibrillator practice. Future surveys would be facilitated if a standardized implant registry like that used in Europe were established in the United States.