The RAMER Reviews: ED management of recent onset atrial fibrillation with cardioversion

Written by: Jonathan Jong, DO Edited by: Timothy Khowong, MD, MSEd

The emergency department management of recent onset atrial fibrillation has traditionally involved rate control and anticoagulation, with cardioversion being reserved for unstable patients. Recently, the more aggressive option of cardioverting stable patients has presented itself as an attractive option. The benefits of possibly sparing patients from long-term rate control medication or lifelong anticoagulation are strong considerations for this alternative. The 2006 ACC guidelines recognize this benefit, stating that cardioversion is a useful therapeutic approach, especially in younger patients without structural heart disease.1 Traditional wisdom dictates however that this method carries significant risk, especially of thromboembolic events from an undiagnosed mural thrombus.2 Because of this, cardioversion is reserved for patients with rhythm related symptoms <48 hours as the risk of thromboembolic event is deemed to be low in this subset of patients.3 Despite this, cardioversion of stable atrial fibrillation in the ED has remained a controversial area of management. Vinson et al conducted a study to evaluate the safety and effectiveness of their management of recent onset atrial fibrillation, including cardioversion, in their community emergency departments.4

This was a prospective cohort study with convenience sampling from three community-based emergency departments within the Kaiser Permanente Northern California network of hospitals. 206 patients were enrolled. Type of treatment was at the discretion of the physician and includes pharmacological/electrical cardioversion, no cardioversion, short term observation for spontaneous cardioversion within 48 hours and patients who spontaneously cardioverted in the ED. Outcomes tracked were adverse events in the ED such as bradycardia, hypotension, ventricular tachycardia, etc and short-term arterial embolic events within 30 days of discharge.

In this study, pharmacologic and/or electrical cardioversion was attempted in 115 patients with a success rate of 96%. A total of six adverse events in the ED were reported, four of which were attributed to attempted cardioversion with procedural sedation. Notably two of these patients developed ventricular tachycardia that resolved in the ED. One patient who was cardioverted was diagnosed with CVA during the follow up period. This patient had a prior history of atrial fibrillation and had been recommended to start anticoagulation in the past, however she refused.

In this small, prospective cohort study, cardioversion, either with medications or electricity appears to be a viable and safe option in patients with recent onset atrial fibrillation due to a relatively high success rate of 96% and low rates of adverse events. Limitations include a small sample size and convenience sampling with possible selection bias. Intervention was also done at the discretion of the treating physician. The study does not clarify which patients were chosen for cardioversion versus hope for spontaneous cardioversion with short term follow up. Regardless, candidates for cardioversion should be chosen through careful evaluation of risk factors, prior history and symptom onset. Care should be made to generalize these findings to one’s own practice setting as all patients in this study had reliable and close follow up.

References:

  1. American College of Cardiology/American Heart Association Task Force on Practice Guidelines; Society of Cardiovascular Anesthesiologists; Society for Cardiovascular Angiography and Interventions; Society of Thoracic Surgeons; Bonow RO, Carabello BA, Kanu C, de Leon AC Jr, Faxon DP, Freed MD, Gaasch WH, Lytle BW, Nishimura RA, O'Gara PT, O'Rourke RA, Otto CM, Shah PM, Shanewise JS, Smith SC Jr, Jacobs AK, Adams CD, Anderson JL, Antman EM, Faxon DP, Fuster V, Halperin JL, Hiratzka LF, Hunt SA, Lytle BW, Nishimura R, Page RL, Riegel B. ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (writing committee to revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease): developed in collaboration with the Society of Cardiovascular Anesthesiologists: endorsed by the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons. Circulation. 2006 Aug 1;114(5):e84-231. doi: 10.1161/CIRCULATIONAHA.106.176857. Erratum in: Circulation. 2007 Apr 17;115(15):e409. Erratum in: Circulation. 2010 Jun 15;121(23):e443. PMID: 16880336.

  2. Weigner MJ. Caulfield TA. Danias PG, et al. Risk for clinical thromboembolism associated with conversion to sinus rhythm in patients with atrial fibrillation lasting less than 48 hours. Ann Intern Med. 1997;126:615–20

  3. Kirchhof P, Benussi S, Kotecha D, Ahlsson A, Atar D, Casadei B, Castella M, Diener HC, Heidbuchel H, Hendriks J, Hindricks G, Manolis AS, Oldgren J, Popescu BA, Schotten U, Van Putte B, Vardas P; ESC Scientific Document Group. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J. 2016 Oct 7;37(38):2893-2962. doi: 10.1093/eurheartj/ehw210. Epub 2016 Aug 27. PMID: 27567408.

  4. Vinson DR, Hoehn T, Graber DJ, Williams TM. Managing emergency department patients with recent-onset atrial fibrillation. J Emerg Med. 2012 Feb;42(2):139-48. doi: 10.1016/j.jemermed.2010.05.017. Epub 2010 Jul 15. PMID: 20634022.

 

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