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Three Part Question

In [patients in the emergency department with haemodynamically stable atrial fibrillation with symptoms for less than 48h] does [pharmacological or electrical cardioversion] lead to [greater cardioversion rates and fewer complications]?

Clinical Scenario

A 38 year old woman comes to the emergency department with a presenting complaint of palpitations of 8 hours duration. She says she has no chest pain or breathlessness and respiratory examination reveals no abnormalities. Her ECG reveals atrial fibrillation with a heart rate of 101bpm and you decide that prompt restoration of sinus rhythm would be the most suitable treatment. You are told by a senior doctor to chemically cardiovert her but you wonder whether there is any evidence for pharmacological over electrical cardioversion of recent-onset atrial fibrillation.

Search Strategy

Embase 1980 to 2008 Week 24.
Medline 1950 to June Week 2 2008 using ovid interface
Cochrane Central Register of Controlled Trials

[exp electric countershock/ or electrical cardioversion.mp. or DC cardioversion.mp. or DC shock.mp.] AND [exp Atrial Fibrillation/ or atrial fibrillation.mp.] AND [exp anti arrhythmia agents/ or chemical cardioversion.mp. or pharmacological cardioversion.mp or exp Amiodarone/ or amiodarone.mp. or cordarone.mp. or exp Flecainide/ or flecainide.mp. or tambocor.mp. or ibutilide.mp or exp Quinidine/ or quinidine.mp. or exp Procainamide/ or procainamide.mp. or exp Propafenone/ or propafenone.mp. or exp Sotalol/ or sotalol.mp. or dofetilide.mp.] LIMIT to humans

Search Outcome

3182 papers found of which 3180 irrelevant

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
De Paola AAV et al. 2003 Brazil	139 patients with persistent AF lasting less than 6 months (including 83 with AF<48h) randomized to receive either electrical or chemical cardioversion initially. If this attempt failed, restoration of sinus rhythm would then be attempted by the other method.	Multicentre randomized trial	Success of primary cardioversion attempt in subgroup with AF<48h (n=83)	Chemical cardioversion successful in 38 of 47 (81%)	Open labeled protocol Power calculation revealed they needed 140 patients (70 per group). They fell short in the electrical group (n=67) The drugs for chemical cardioversion and sedation, the energy and number of shocks utilized for electrical cardioversion, and the length of stay after antiarythmic drug administration were left to the investigators discretion and not standardized. Patients were not homogenous in terms of duration of AF. Long-term follow up was not performed Did not consider outcomes such as exercise capacity or overall quality of ife
			Conversion rates between strategy beginning with electrical or chemical cardioversion (ie if initial proceadure failed, cardioversion was next attempted using the other method) in subgroup with AF<48h	Strategy starting with chemical cardioversion= 45 of 47 (96%)
			Mild adverse events (of whole study group)	In 50% of patients who underwent electrical. In 12% of patients who underwent chemical.
			Severe adverse events (of whole study group)	Occurred in 4 patients undergoing chemical cardioversion (5%).N.B. all had structural heart disease. None obsereved with electrical procedures
Valencua Martin J et al. 2002 Spain	230 consecutive patients in 2 hospitals with chronic or persistent atrial fibrillation of >48h (mean duration of arrythmia was 25 weeks) Electrical cardioversion (n=144) Vs. Pharmalogical cardioversion (n=86) with Quinidine. All patients received 3 weeks anticoagulation with acenocoumarol prior to cardioversion, maintaining a stable range of INR 2.0-3.0	Prospective Study	Restoration of sinus rhythm	Electrical: 111 of 144, 77%. Pharmacological: 70 of 86, 81% No significant difference	Patients were not randomized Cannot discount selection bias as patients with low probability of success were not included. Groups were not identical at baseline, there was a tendency for certain characteristics to be in each group, though none were significant. Patients already taking antiarrythmics were not excluded from the study (ECV after AAD administration is known to be more successful) Short period of follow-up Did not consider outcome measures such as exercise capacity and quality of life
			Length of hospital stay	Electrical: 1.0 day Pharmacological: 1.96 1.06 days p<0.01

Clinical Bottom Line

The available evidence suggests that pharmacological and electrical cardioversion are equally efficacious in recent onset atrial fibrillation. The advantages and disadvantages of both methods should be discussed with the patient before starting treatment.

References

1. de Paola AA. Figueiredo E. Sesso R. Veloso HH. Nascimento LO. SOCES Investigators. Effectiveness and costs of chemical versus electrical cardioversion of atrial fibrillation. International Journal of Cardiology 2003; 88(2-3):157-66
2. Valencia Martin J. Climent Paya VE. Marin Ortuno F. Monmeneu Menadas JV. Martinez Martinez JG. Garcia Martinez M. Ibanez Criado A. Garcia De Burgos Rico F. Sogorb Garri F. The efficacy of scheduled cardioversion in atrial fibrillation. Comparison of two schemes of treatment: electrical versus pharmacological cardioversion. Revista Espanola de Cardiologia. 2002; 55(2):113-20