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Three Part Question

[In patients presenting to the emergency department with acute onset atrial fibrillation over the age of forty five], is [electrical or pharmacological cardioversion] the most effective method of [restoring sinus rhtym?]

Clinical Scenario

A patient over the age of forty five presents to the accident and emergency derpartment with new onset atrial fibrillation. This has been going on for less than 48 hours.

Search Strategy

MEDLINE; [exp atrial fibrillation] AND [exp emergency service, hospital/ or exp emergency medicine or exp acute disease] AND [pharm$.mp.] AND [cardioversion.mp. or electrical cardioversion.mp. or cardioversion.mp. or diect current.mp. or exp electric countershock]. EMBASE; [exp heart, atrium fibrillation] AND [exp acute disease/or acute.mp. or exp emergency ward/ emergency department.mp.] AND [exp cardioversion or automatic cardioversion or exp defibrillation] AND [electrical.mp. or exp direct current] AND [pharm$.mp.] AND [exp cardioversion or exp acute cardioversion or exp defibrillation]. Cochrane library; exp Atrial fibrillation

Search Outcome

One hundred and forty four Papers were found of which four were relevant.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Rachel Danker et al. 2008. Israel.	374 patients; 85 ElectricalCardioversion, 56 Pharmacological cardioversion and 233 Watch and Wait.	Retrospective study	Electrical cardioversion was 2.47 times more successful at converting patients to sinus rhythm than pharmacological cardioversion and 6 times more successful than watchful waiting.	Electrical cardioversion restored sinus rhythm in a larger proportion of patients with fewer complications within two weeks and with more patients discharged home than pharmacological therapy and watchful waiting.	Study of stable atrial fibrillation patients only, and therefore did not include thoose with haemodynamic instability. Some patients may have returned for treatment elsewhere within the 2 week period of the study. The study was not randomised. There was variability between treating physicians in which stratergy to use.
John H Burton et al. 2004. United states.	944 patients. 388 Electrical cardioversion, 30 Pharmacological cardioversion and 266 watch and wait.	Retrospective Cohort study.	Electrical cardioversion was successful in 83% of patients across the study.	Electrical cardioversion resorted sinus rhythm in 73% of patients presenting with acute onset atrial fibrillation.	The results of the Pharmacological cardioversion group were not significant. Many patients underwent failed attempts at either Pharmacological cardioversion or rate control before Electrical cardioversion.
Wyatt W. Decker et al. 2008. United States.	153 patients admitted with Atrial Fibrillation of less than 48 hours duration	Randomized control trial	Electrical cardioversion restored sinus rhythm in 85% in the Emeregency department.	Electrical cardioversion restored sinus rhythm in 85% of patients who were admitted with atrial fibrillation of under forty eight hours duration.	Small study sample due to the stringent exclusion criteria, no distinction was made between new and recurrent atrial fibrillation.
Angelo V. De Paola et al. 2003. Brazil.	169 patients, 72 Randomised to Pharmacological cardioversion and 62 Randomised to Electrical cardioversdion.	Randomised control trial.	The restoration rates for both electrical cardioversion and Pharmacological cardioversion were the same after initial therapy.	Secondary treatment of patients who had unsuccessful attempts with primary therapy were more successful in Electrical cardioversion after Pharmacological cardioversion.	Protocol for Pharmacological cardxioversion and electrical cardioversion not standardised. Admittance after cardioversion left to the discretion of the physician. No long term follow up. Small group of patients.

Comment(s)

All papers suggest that both electrical cardioversion and pharmacological cardioversion were better than placebo at conversion to sinus rhythm. However, when comparing the two, electrical cardioversion is seen to have a higher efficacy in Danker at al1. In De Paola et al4, the efficacy of both methods was seen to be the same after the initial treatment period. Decker et al2 and Burton et al3 report conversion rates of eighty three percent to eighty five percent with electrical cardioversion in the acute setting.

Clinical Bottom Line

: There is no difference between Electrical and pharmacological cardioversion in patients who present with haemodynamically stable ATRIAL FIBRILLATION of less than forty eight hours duration. However, in haemodynamically unstable atrial fibrillation, electrical cardioversion is recommended.

References

1. Rachel Dankner, Amir Shahar , Ilya Novikov, Uri Agmon, Arnona Ziv, Hanoch Hod. Treatment of Stable Atrial Fibrillation in the Emergency Department: A Population-Based Comparison of Electrical Direct-Current versus Pharmacological Cardioversion or Conservative Management. Cardiology 2009;112:270-278.
2. Burton JH, Vinson DR, Drummond K et al. Electrical cardioversion of emergency department patients with atrial fibrillation. Annals of Emergency Medicine. 2004;44(1):20–30.
3. Wyatt W. Decker et al. A Prospective, Randomized Trial of an Emergency Department Observation Unit for Acute Onset Atrial fibrillation. Emerg Med. 2008;52:322-328.
4. De Paola AA, Figueiredo E, Sesso R et al. Effectiveness and costs of chemical versus electrical cardioversion of atrial fibrillation. International Journal of Cardiology. 2003;88(2–3):157–3.