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.
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:
- Anticoagulated for three or more weeks.
- 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
- Procainamide 15mg/kg in 500 ml of NS over an hour.
Other agents: Amiodarone, Ibutilide, flecainide, etc.
- Electrical: 150-200 J synchronized. Requires sedation.
If CHADS positive then discharge on DOAC or Warfarin.
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.
- Acute heart failure not improved in the ED
References and Further Reading
- 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 cardiology, 27(1), 38–46. https://doi.org/10.1016/j.cjca.2010.11.014
- 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 medicine, 347(23), 1825–1833. https://doi.org/10.1056/NEJMoa021328
- 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
- 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 Medicine, 26(9), 1034–1043. https://doi.org/10.1111/acem.13703
- 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
- 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