Original Contributions
An emergency department observation unit protocol for acute-onset atrial fibrillation is feasible*,**,*

Presented at the Society of Academic Emergency Medicine annual meeting, San Francisco, CA, May 2000.
https://doi.org/10.1067/mem.2002.122785Get rights and content

Abstract

Study Objective: We sought to describe the feasibility of an emergency department observation unit (EDOU) treatment protocol for the management of uncomplicated acute-onset atrial fibrillation (AAF). Methods: This descriptive case series took place at a major suburban, university-affiliated teaching hospital. Patients were prospectively enrolled in an EDOU treatment protocol if they had uncomplicated AAF that failed initial ED attempts to convert to sinus rhythm. In the EDOU, patients underwent ECG monitoring, serial creatine kianse MB measurements, and further rate control with optional electrical cardioversion. Primary outcomes measured were EDOU rate of conversion to sinus rhythm, rate of discharge home, length of stay, positive diagnostic outcomes, complications of AAF, and 7-day return visits. Results: Sixty-seven patients were studied. Patients were symptomatic for a median of 4.0 hours, had mean initial ED pulse rates of 137±23 beats/min, and spent 4.7±2.2 hours in the ED before transfer to the EDOU. While in the EDOU, 55 (82%) patients converted to sinus rhythm. Five (7%) patients were admitted because of positive test results: 2 for myocardial infarction, 2 for fever, and 1 for ventricular tachycardia. Twelve (18%) patients remained in atrial fibrillation, with 9 admitted and 3 discharged. Overall, 81% of patients were discharged in 11.8±7.0 hours, and 19% were admitted after 17.6±9.5 hours of observation. Three discharged patients returned within 7 days, 2 for uncomplicated recurrent AAF and 1 for chest pain subsequently found to be noncardiac in origin. There were no major complications attributable to the EDOU protocol. Conclusion: Selected patients with AAF for whom initial ED management fails can subsequently be managed in an EDOU with a high short-term conversion and discharge rate. [Koenig BO, Ross MA, Jackson RE. An emergency department observation unit protocol for acute-onset atrial fibrillation is feasible. Ann Emerg Med. April 2002;39:374-381.]

Introduction

Atrial fibrillation is the most common cardiac arrhythmia managed in the emergency department.1 It results from the chaotic depolarization of atrial tissue.2 It is associated with a reduction in cardiac output3 and an increased risk of stroke. Atrial fibrillation accounts for 30,000 to 40,000 strokes per year in the United States.4

Acute-onset atrial fibrillation (AAF; or new-onset, paroxysmal atrial fibrillation) is defined as atrial fibrillation in which symptoms have lasted for less than 48 to 72 hours. Because atrial fibrillation leads to changes within the heart that perpetuate it (atrial fibrillation begets atrial fibrillation), cardioversion to sinus rhythm is more likely to be successful the sooner it is conducted.5 For this reason, patients presenting to the ED with AAF benefit from timely restoration of sinus rhythm. Traditionally, when initial conversion to sinus rhythm fails, these patients are admitted to the hospital to achieve rate control, to restore sinus rhythm, and to monitor for comorbidities or complications, such as myocardial infarction or embolic events. The incidence of serious cardiovascular complications within this group may be as high as 20%.6 It has been reported that hospital lengths of stay for atrial fibrillation are markedly greater than for any other arrhythmia.7, 8 However, a subset of patients with AAF that may not require inpatient admission has been described. Recent studies suggest that approximately one third of admitted patients with AAF may not have required inpatient admission.9 Others have proposed that stable patients with recent-onset atrial fibrillation may avoid hospitalization by using a combination of initial rate control and various therapies to encourage conversion to sinus rhythm.10

Studies in Canada and Australia have suggested that many patients with AAF may be safely managed in the ED and discharged.11, 12, 13 In the United States, there has been growing interest in the ED observation unit (EDOU) as an alternative to inpatient admission. In this setting, patients with other conditions are aggressively managed with accelerated treatment or diagnostic protocols, resulting in high discharge rates, lower costs, and improved satisfaction.14, 15, 16, 17, 18 It would seem that the EDOU would be an ideal alternative to inpatient admission for the management of stable patients with AAF presenting to the ED. However, there are currently no studies of AAF managed in an EDOU setting.

In this study, we report the outcomes of an EDOU treatment protocol for the management of patients with AAF in whom initial ED therapy has failed.

Section snippets

Materials and methods

This is a prospective descriptive case series of patients enrolled in an EDOU treatment protocol for the management of AAF. This study was conducted in the ED at the William Beaumont Hospital, a high-volume, university-affiliated, suburban teaching hospital. The study was granted an institutional review board exemption at the study hospital. The EDOU has been operational since 1995 and complies with the American College of Emergency Physicians' guidelines for the management of an EDOU.19, 20

Results

Over the study period, 259,175 patients were seen in the ED. Of these, 2,750 (1.06%) had the ICD-9 code for atrial fibrillation coded in their medical record. On chart review, 65% (1,788) were seen for treatment of chronic atrial fibrillation and 35% (125) for AAF, yielding an estimated 962 patients with AAF. Of patients with AAF, 13% converted in the ED and were discharged home, 80% (770) were admitted as an inpatient, and 7% (67 patients) were treated in the EDOU and are detailed in this

Discussion

We found that, for a selected subset of ED patients with uncomplicated AAF, management in an EDOU was a feasible alternative to inpatient admission. We describe a basic protocol for the management of these patients that contains both therapeutic and diagnostic components. By using this protocol, high rates of conversion to sinus rhythm and discharge can be expected, and latent occult pathology may be identified. No previous studies have addressed the treatment of AAF in an EDOU. A previous

Addendum

The recent decision by the Centers for Medicare and Medicaid Services to separately fund observation services for only the 3 most well-studied conditions (chest pain, asthma, and congestive heart failure) underscores the need to further study other conditions that may be amenable to EDOU treatment. A copy of the Federal Register comments made by the Centers for Medicare and Medicaid Services can be accessed at www.hcfa.gov/regs/Pp44671.pdf.26

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    *

    Author contributions are provided at the end of this article.

    **

    Address for reprints: Michael A. Ross, MD, 3601 West Thirteen Mile Road, Royal Oak, MI 48073-6769; 248-551-3080 or 248-551-2016; E-mail [email protected]

    *

    Author contributions: MAR and BOK conceived the study, and REJ worked with them to refine its design. BOK conducted data collection. MAR, REJ, and BOK all analyzed and interpreted the data. MAR and BOK drafted the manuscript, while MAR, BOK, and REJ all contributed to revisions. MAR and BOK take responsibility for the paper as a whole.

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