The need for vigilance for unexpected clinical deterioration in the emergency department (ED) waiting area and in unmonitored treatment areas of the ED continues to increase. We sought to determine in an observational study the feasibility and relative false-alarm burden of, and satisfaction with, a novel wireless automated clinician alert device for cardiac rate and rhythm derangements in a teaching hospital ED. Patients presenting with a variety of complaints who after ED triage were not placed on conventional telemetric monitoring (by standard triage policy) were considered for inclusion. Those enrolled in the study were then monitored in the waiting room and in the ED proper via a wireless, one-lead ECG device that, through relay hubs installed in the ED ceiling, alerted clinicians via desktop computers at regular ED work stations to the presence of asystole, ventricular fibrillation, and bradycardia and tachycardia in those patients. The device is not a conventional telemetry monitor, in that it does not provide streaming visual monitoring capability; instead, it provides alarms and one-lead ECG data when triggered by specific rate and rhythm deviations.A total of 298 ED patients (30.2% patients triaged after a run-in period) were monitored, for a mean duration of 3.53 hours. Productive clinical alarms (those that prompted a change in patient therapy, location, or intensity of monitoring) occurred in 20 patients (6.7%); the most common response to an alert was earlier transition from the waiting room into a clinical space in the ED. There were 10 false-positive asystole or ventricular fibrillation alarms in 4 patients (1.3%), all of which were readily attributable to nonclinical origins, such as poor lead adherence. There was excellent satisfaction with the device from both patients and clinical personnel. Wireless cardiac event monitoring is feasible in the ED, and improves the throughput of ED patients with worsening vital signs, and may improve overall patient safety, without an onerous burden of nonproductive alarms.