We suggest against the introduction of artifact-filtering algorithms for analysis of electrocardiographic rhythm during CPR unless as part of a research program. We suggest that where EMS systems have already integrated artifact-filtering algorithms into clinical practice, it is reasonable to continue with their use. Values, Preferences, and Task Force Insights In making this recommendation, we placed priority on avoiding the costs of introducing a new technology where the effectiveness or harm on patient outcomes remains to be determined. Where such technologies have already been implemented, we place priority on avoiding the likely costs and inconvenience of their withdrawal from practice. We encourage such systems to report on their experiences to build the evidence base regarding the use of these technologies in clinical practice.