Atrial Fibrillation: An Approach to Diagnosis and Management in the Emergency Department

Table of Contents

 

About This Issue

Patients who present to the ED with atrial fibrillation are 4 to 5 times more likely to have an ischemic stroke, so it is essential that emergency clinicians manage these patients effectively in conjunction with follow-up cardiology. This issue reviews the latest evidence on the initial evaluation of atrial fibrillation in the ED, including:

Determining the underlying causes of AF: structural cardiac issues, hyperthyroidism, sepsis, substance use, thromboembolism, among others.

How treatment will differ depending on whether the patient has been previously diagnosed with AF or if it is new-onset.

The differential for narrow complex tachycardia, and how the specific rhythm disturbance will dictate treatment.

How the diagnosis can be organized based on ECG findings or by symptoms and how these are focused by history, ECG, and cardiovascular examination.

Using the patient’s presentation to dictate the diagnostic studies needed: thyroid function testing, cardiac serum markers, D-dimer, and imaging.

Determining the initial approach for patients who are hemodynamically unstable or critically ill, including IV fluids, electrical cardioversion, and avoiding worsening hypotension.

For stable patients, choosing rate control, rhythm control, or “wait-and-see.”

The circumstances when pharmacologic cardioversion would be favored over electrical cardioversion.

Using the primary tools for stroke and bleeding risk stratification: CHA₂DS₂-VASc and HAS-BLED.

When to prescribe anticoagulation in the ED and when not to.

1. Abstract
2. Case Presentations
3. Introduction
4. Critical Appraisal of the Literature
5. Epidemiology
6. Pathophysiology
7. Differential Diagnosis
8. Prehospital Care
9. Emergency Department Evaluation
   1. History
   2. Physical Examination
10. Diagnostic Studies
    1. Electrocardiogram
       1. Atrial Fibrillation Findings
       2. Atrial Flutter Findings
    2. Laboratory Tests
       1. Magnesium
       2. Thyroid Function Tests
       3. Cardiac Serum Markers
       4. D-Dimer
    3. Imaging Studies
11. Treatment
    1. Initial Approach to Management
       1. Emergent Stabilization of Critically Ill Patients
       2. Urgent Stabilization of Hemodynamically Unstable Patients
    2. Treatment of Stable Patients
       1. Selecting a Treatment Strategy: Rate Control, Rhythm Control, or “Wait-And-See”
       2. Selecting a Rate Control Agent
          • Beta Blockers
          • Nondihydropyridine Calcium-Channel Blockers
          • Digoxin
          • Amiodarone
          • Magnesium
       3. Rhythm Control Strategies
          • Pharmacologic Cardioversion
          • Electrical Cardioversion
       4. Wait-and-See Approach
    3. Putting It All Together
    4. Reducing Stroke Risk
       1. Risk Stratification for Predicting Thromboembolism
       2. Decreasing Thromboembolic Risk
       3. Bleeding Risk with Anticoagulation
       4. Choice of Anticoagulant
       5. Prevention of Postcardioversion Thromboembolism
12. Cutting Edge
13. Disposition
14. Summary
15. Risk Management Pitfalls for Atrial Fibrillation and Atrial Flutter
16. Case Conclusions
17. Clinical Pathways
    1. Clinical Pathway for Initial Approach to the Stable Patient With Atrial Fibrillation With Rapid Ventricular Response
    2. Clinical Pathway for Initial Approach to the Hemodynamically Unstable Patient With Rapid Atrial Fibrillation
18. Tables and Figures
    1. Table 1. Historical Elements That Can Help Identify Underlying Etiology of Atrial Fibrillation/Atrial Flutter
    2. Table 2. Factors Favoring Rhythm Control Over Rate Control
    3. Table 3. Rate Control Therapies for Atrial Fibrillation in the Emergency Department
    4. Table 4. Strategy for Cardioversion Based on the Ottawa Aggressive Protocol
    5. Table 5. CHA2DS2-VASc Score
    6. Table 6. HAS-BLED Score
    7. Table 7. Bleeding Risk Scoring System
    8. Figure 1. Risk Factors for Atrial Fibrillation
    9. Figure 2. Rhythm Strips of Atrial Fibrillation and Atrial Flutter
    10. Figure 3. Sinus Tachycardia on Electrocardiogram
    11. Figure 4. Multifocal Atrial Tachycardia on Electrocardiogram
    12. Figure 5. Atrial Fibrillation on Electrocardiogram
    13. Figure 6. Electrocardiogram of Atrial Fibrillation With Rapid Ventricular Response
    14. Figure 7. Electrocardiogram of Atrial Fibrillation with Wolff-Parkinson-White Syndrome
    15. Figure 8. Electrocardiogram of Atrial Flutter
    16. Figure 9. Pericardial Effusion on Ultrasound
    17. Figure 10. Atrial Thrombus on Ultrasound
    18. Figure 11. Thromboembolism Rate Within 1 Year
    19. Figure 12. One-Year Cumulative Thromboembolic Risk, Stratified by Men and Women
19. References

Abstract

Atrial fibrillation is the most common dysrhythmia encountered in the emergency department. In patients aged >65 years, the incidence approaches 10%, and the number of patients with atrial fibrillation is expected to almost double in the next 30 years. Atrial fibrillation and its associated comorbidities also carry significant healthcare cost. Electrocardiogram findings may be subtle at times, but prompt diagnosis is needed to maximize good outcomes, especially when patients are cardiovascularly compromised. This review includes evidence-based recommendations on rate versus rhythm control, discusses pharmacologic versus electrical cardioversion, evaluates thromboembolic risk, and provides options for anticoagulation.

Case Presentations

A 58-year-old man with a history of atrial fibrillation and diabetes on rivaroxaban is complaining of palpitations that started after a bike ride…

• On physical exam, he is afebrile, has a blood pressure of 165/82 mm Hg, and a wide complex irregular heart rate at 160 beats/min.
• You suspect AF with aberrancy or a pre-existing bundle branch block and begin thinking about the best strategy for rate control.
• You wonder whether this anticoagulated patient can be safely cardioverted and discharged home...

A 28-year-old woman arrives via EMS after an episode of syncope…

• She has experienced multiple episodes of syncope in the past, but reports no other medical problems.
• She is usually asymptomatic after episodes and has never been evaluated, but this time, she had persistent chest pain and called EMS.
• ECG shows a wide complex irregular tachycardia with a rate of 200 beats/min.
• You wonder whether this is supraventricular or ventricular, and what the best way to stabilize her would be...

A 67-year-old woman with no cardiac history presents with increasing fatigue for the past 5 days, but is otherwise asymptomatic…

• Her ECG shows AF at a rate of 158 beats/min and her blood pressure is 84/58 mm Hg.
• Your colleague tells you that cardioverting these patients makes him nervous and he asks you how you manage rapid AF in the setting of hypotension…

How would you manage these patients? Subscribe for evidence-based best practices and to discover the outcomes.

Clinical Pathways

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Tables and Figures

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Key References

Following are the most informative references cited in this paper, as determined by the authors.

1. * Naccarelli GV, Varker H, Lin J, et al. Increasing prevalence of atrial fibrillation and flutter in the United States. Am J Cardiol. 2009;104(11):1534-1539. (Retrospective review; 21 million patients) DOI: 10.1016/j.amjcard.2009.07.022

13. * Scheuermeyer FX, Pourvali R, Rowe BH, et al. Emergency department patients with atrial fibrillation or flutter and an acute underlying medical illness may not benefit from attempts to control rate or rhythm. Ann Emerg Med. 2015;65(5):511-522.e512. (Retrospective cohort; 416 patients) DOI: 10.1016/j.annemergmed.2014.09.012

22. * January CT, Wann LS, Calkins H, et al. 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol. 2019;74(1):104-132. (Guidelines) DOI: 10.1161/CIR.0000000000000665

23. * Airaksinen KE, Gronberg T, Nuotio I, et al. Thromboembolic complications after cardioversion of acute atrial fibrillation: the FinCV (Finnish CardioVersion) study. J Am Coll Cardiol. 2013;62(13):1187-1192. (Retrospective cohort; 3143 patients) DOI: 10.1016/j.jacc.2013.04.089

67. * Pluymaekers N, Dudink E, Luermans J, et al. Early or delayed cardioversion in recent-onset atrial fibrillation. N Engl J Med. 2019;380(16):1499-1508. (Randomized, open-label, noninferiority; 437 patients) DOI: 10.1056/NEJMoa1900353

72. * Lee WC, Lamas GA, Balu S, et al. Direct treatment cost of atrial fibrillation in the elderly American population: a Medicare perspective. J Med Econ. 2008;11(2):281-298. (Retrospective; 55,260 patients) DOI: 10.3111/13696990802063425

74. * Amin A, Deitelzweig S. A case-based approach to implementing guidelines for stroke prevention in patients with atrial fibrillation: balancing the risks and benefits. Thromb J. 2015;13:29. (Review) DOI: 10.1186/s12959-015-0056-y

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Keywords: atrial fibrillation, flutter, dysrhythmia, arrhythmia, electrocardiogram, palpitations, tachycardia, ventricular, supraventricular, Wolff-Parkinson-White, WPW, electrical, irregular, heart failure, hyperthyroidism, P wave, rate, rhythm, beta blocker, calcium-channel blocker, cardioversion, current, anticoagulation, DOAC, risk, thromboembolism