Acute Atrial Fibrillation in the ED: Almost all goes home

Atrial fibrillation (AF) is the most common dysrhythmia presenting to ED. The management options depend on patient stability, presence of underlying causes and factors in the patient history. In stable patients presenting in AF with a rapid ventricular response, both rate and rhythm control are acceptable approaches. Physicians often tend toward rate control because evidence has shown no mortality benefit between the two approaches. The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial contributed to this trend when it concluded no survival advantage and higher risk of adverse drug effects with rhythm control. However, rhythm control is the preferred approach for the management of acute stable AF in Canadian guidelines. The advantages are a higher rate of symptom resolution, restoration of sinus rhythm and avoiding the need for rate control prescriptions, decreased ED length of stay, and hospital admissions.

In the electrical versus pharmacological cardioversion for emergency department patients with acute atrial fibrillation (RAFF2) trial, it was found that both drug–shock and shock-only strategies were effective, rapid, and safe with 96% of patients discharged home in sinus rhythm. The drug infusion worked for 50% of patients avoiding procedural sedation.

The evidence that supports the management of acute AF in the ED without hospital admission is increasing. Implementing practices to achieve that will markedly decrease the burden on the health care system.

ED Management

Approach of Atrial fibrillation

AF might be secondary to variable causes, including ACS, Heart failure, PE, sepsis and bleeding. In patients with secondary AF, cardioversion might be harmful, and the mainstay of treatment is tackling the underlying cause. Those patients will require hospital admission. For primary AF, if the patient is unstable, electrical cardioversion should be done without delay. Stable primary AF may be managed with rate or rhythm control.

Rate control can be achieved with the following:

CCB: Diltiazim 0.25 mg/kg over ten mins, repeat q15-20 mins, up to three doses (avoid in heart failure)

BB: Metoprolol 2.5-5 mg q15-20 mins

Digoxin: 0.25-0.5 mg loading dose then 0.25 mg q4-6 hs (if hypotension or acute HF occur)

Target is HR <100 at rest or <110 walking

Rhythm control is safe with the following according to The CAEP AF best practice guidelines:

  1. Anticoagulated for three or more weeks.
  2. No valvular heart disease, prior stroke or TIA plus: 
  • Onset in 12 hours or less
  • Onset more than 12 hours but less than 48 hours plus less than two of :
    • Age less than 65, DM, HTN, HF.
  • Cleared by TOE

Methods:

  • Procainamide 15mg/kg in 500 ml of NS over an hour.

Other agents: Amiodarone, Ibutilide, flecainide, etc.

  • Electrical: 150-200 J synchronized. Requires sedation.

Anticoagulation:

If CHADS positive then discharge on DOAC or Warfarin.

Disposition:

Almost all patients can be discharged home after cardioversion or effective rate control with appropriate follow up: within a week if warfarin or rate control agent prescribed, otherwise in 4 weeks.

Patients will require admission if one of the following:

  • Highly symptomatic after treatment.
  • ACS
  • Acute heart failure not improved in the ED

References and Further Reading

  1. Stiell, I. G., Macle, L., & CCS Atrial Fibrillation Guidelines Committee (2011). Canadian Cardiovascular Society atrial fibrillation guidelines 2010: management of recent-onset atrial fibrillation and flutter in the emergency department. The Canadian journal of cardiology27(1), 38–46. https://doi.org/10.1016/j.cjca.2010.11.014
  2. Wyse, D. G., Waldo, A. L., DiMarco, J. P., Domanski, M. J., Rosenberg, Y., Schron, E. B., Kellen, J. C., Greene, H. L., Mickel, M. C., Dalquist, J. E., Corley, S. D., & Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Investigators (2002). A comparison of rate control and rhythm control in patients with atrial fibrillation. The New England journal of medicine347(23), 1825–1833. https://doi.org/10.1056/NEJMoa021328
  3. Baymon, D. E., & Baugh, C. E. (2020). Patients with Atrial Fibrillation in the Emergency Department: Strategies to Achieve Best Outcomes. https://www.hmpgloballearningnetwork.com/site/eplab/patients-atrial-fibrillation-emergency-department-strategies-achieve-best-outcomes
  4. Martín, A., Coll-Vinent, B., Suero, C., Fernández-Simón, A., Sánchez, J., Varona, M., Cancio, M., Sánchez, S., Carbajosa, J., Malagón, F., Montull, E., Del Arco, C., & HERMES-AF investigators (2019). Benefits of Rhythm Control and Rate Control in Recent-onset Atrial Fibrillation: The HERMES-AF Study. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine26(9), 1034–1043. https://doi.org/10.1111/acem.13703
  5. Stiell, I. G., Sivilotti, M., Taljaard, M., Birnie, D., Vadeboncoeur, A., Hohl, C. M., McRae, A. D., Rowe, B. H., Brison, R. J., Thiruganasambandamoorthy, V., Macle, L., Borgundvaag, B., Morris, J., Mercier, E., Clement, C. M., Brinkhurst, J., Sheehan, C., Brown, E., Nemnom, M. J., Wells, G. A., … Perry, J. J. (2020). Electrical versus pharmacological cardioversion for emergency department patients with acute atrial fibrillation (RAFF2): a partial factorial randomised trial. Lancet (London, England)395(10221), 339–349. https://doi.org/10.1016/S0140-6736(19)32994-0
  6. Ian G. Stiell, et al. (2021). 2021 CAEP Acute Atrial Fibrillation/Flutter Best Practices Checklist.https://caep.ca/wp-content/uploads/2021/06/2021-CAEP-AAF-Checklist-FINAL-6-June-2021.pdf
Cite this article as: Israa M Salih, UAE, "Acute Atrial Fibrillation in the ED: Almost all goes home," in International Emergency Medicine Education Project, September 13, 2021, https://iem-student.org/2021/09/13/acute-atrial-fibrillation-in-the-ed-almost-all-goes-home/, date accessed: July 6, 2022

Question Of The Day #26

question of the day
qod26
38 - atrial fibrillation

Which of the following is the most appropriate next step in management for this patient’s condition?

This patient presents to the emergency department with palpitations, a narrow complex tachycardia (<120msec), and an irregularly irregular rhythm. A close look at this patient’s EKG reveals the absence of discrete P waves and QRS complexes that are spaced at varying distances from each other (most apparent in lead V6). These signs support a diagnosis of Atrial Fibrillation, or “AFib.” Atrial Fibrillation is an arrhythmia characterized by an irregularly irregular rhythm, the absence of P waves with a flat or undulating baseline, and narrow QRS complexes. Wide-QRS complexes may be present in AFib if there is a concurrent bundle branch block or Wolff-Parkinson White Syndrome. AFib is caused by the electric firing of multiple ectopic foci in the atria of the heart. This condition is triggered by a multitude of causes, including ischemic heart disease, valvular heart disease, dilated or hypertrophic cardiomyopathies (likely related to this patient’s congestive heart failure history), sepsis, hyperthyroidism, excess caffeine or alcohol intake, pulmonary embolism, and electrolyte abnormalities.

The main risk in AFib is the creation of thrombi in the atria as they fibrillate, resulting in emboli that travel to the brain and cause a stroke. The CHA2DS2VASc scoring system is used to risk stratify patients and determine if they require anticoagulation to prevent against thrombo-embolic phenomenon (i.e. stroke). This patient has a high CHA2DS2VASc score, so she would require anticoagulation. In addition to anticoagulation, A fib is treated with rate control (i.e. beta blockers or calcium channel blockers), rhythm control (i.e. anti-arrhythmic agents), or electrical cardioversion. Electrical cardioversion (choice A) is typically avoided when symptoms occur greater than 48 hours, since the risk of thrombo-emboli formation is higher in this scenario. An exception to this would be a patient with “unstable” AFib. Signs of instability in any tachyarrhythmia are hypotension, altered mental status, or ischemic chest pain. This patient lacks all of these signs and symptoms. Although this patient lacks signs of instability, this patient’s marked tachycardia should be addressed with medical treatment. General observation (Choice C) is not the best choice for this reason. Intravenous adenosine (Choice D) is the best choice for a patient with supraventricular tachycardia (SVT). This is a narrow-complex AV nodal re-entry tachycardia with rates that range from 120-280bpm. SVT also lacks discrete P waves. A key factor that differentiates A fib from SVT is that SVT has a regular rhythm, while AFib has an irregular rhythm. Intravenous metoprolol (Choice B) is the best treatment option listed in order to decrease the patient’s heart rate.

References

  • Brady W.J., & Glass III G.F. (2020). Cardiac rhythm disturbances. Tintinalli J.E., Ma O, Yealy D.M., Meckler G.D., Stapczynski J, Cline D.M., & Thomas S.H.(Eds.), Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill. https://accessmedicine.mhmedical.com/content.aspx?bookid=2353&sectionid=218687685
  • Burns, E. (2020) Atrial Fibrillation. Life in The Fast Lane. Retrieved from https://litfl.com/atrial-fibrillation-ecg-library/

 

Cite this article as: Joseph Ciano, USA, "Question Of The Day #26," in International Emergency Medicine Education Project, February 12, 2021, https://iem-student.org/2021/02/12/question-of-the-day-26/, date accessed: July 6, 2022