Defibrillator/monitors allow operators to assess and monitor a patient's ECG and, when necessary, deliver a defibrillating shock to the heart. When integral noninvasive pacing capability is added, the resulting device is referred to as a defibrillator/monitor/pacemaker. In this Update Evaluation, we present our findings for nine such units, including complete Product Profiles for two newly evaluated models and update information for seven other models evaluated in our May-June 1993 and February 1998 studies. We tested the two newly evaluated models using the same basic protocol as in our previous studies. However, we did add some new tests--and revise some old ones--to account for advances in the technology. These advancements include the increasing use of advisory modes and the increasing availability of expanded monitoring capabilities (which allow units to function, at least to some degree, like a physiologic monitor). As in our previous studies, we rated each model separately for three common defibrillation applications: (1) general crashcart use, (2) in-hospital transport use, and (3) prehospital use by emergency medical services (EMS) personnel. Because each application requires its own set of capabilities, it's not surprising that few models are appropriate for all applications. However, we did identify three models that perform well--earning a rating of either Acceptable or Preferred--in all three areas.