When to perform cardioversion in patients with atrial fibrillation (AF)?

From the Guidelines

Cardioversion should be considered in symptomatic patients with persistent atrial fibrillation (AF) as part of a rhythm control approach, and in patients who are hemodynamically unstable, it should be performed as an emergency procedure. When considering cardioversion, it's essential to weigh the benefits of restoring sinus rhythm against the risks of the procedure, including thromboembolism. According to the most recent guidelines 1, direct oral anticoagulants are recommended in preference to vitamin K antagonists (VKAs) in eligible patients with AF undergoing cardioversion for thromboembolic risk reduction.

Key Considerations for Cardioversion

• Anticoagulation: Therapeutic anticoagulation for at least 3 weeks before scheduled cardioversion and continuation for at least 4 weeks afterwards is recommended to prevent procedure-related thromboembolism 1.
• Transesophageal Echocardiography (TEE): TEE can be used if 3 weeks of therapeutic oral anticoagulation has not been provided, for exclusion of cardiac thrombus to enable early cardioversion 1.
• Rhythm Control Strategy: Implementation of a rhythm control strategy should be considered within 12 months of diagnosis in selected patients with AF at risk of thromboembolic events to reduce the risk of cardiovascular death or hospitalization 1.
• Emergency Cardioversion: In cases of hemodynamic instability, cardioversion should be performed immediately without anticoagulation, but anticoagulation should be initiated as soon as possible afterwards.

Procedure and Follow-Up

• Electrical Cardioversion: Typically uses biphasic shocks starting at 120-200 joules.
• Pharmacological Cardioversion: May employ agents like amiodarone, flecainide, or propafenone in patients without structural heart disease.
• Success and Maintenance: The success of cardioversion and maintenance of sinus rhythm depends on factors like AF duration, left atrial size, and underlying heart disease, with shorter duration AF having better outcomes.

Given the most recent and highest quality evidence, the approach to cardioversion in patients with atrial fibrillation should prioritize careful patient selection, appropriate anticoagulation, and consideration of the risks and benefits of the procedure 1.

From the Research

When to Perform Cardioversion in Patients with Atrial Fibrillation (AF)

• Cardioversion should be reserved for patients who are symptomatic despite adequate rate control 2.
• For recent-onset AF (<24 h), pharmacological cardioversion using agents like flecainide can be highly successful, but caution should be exercised in patients with potential structural or coronary artery disease due to the risk of proarrhythmia 2.
• If there is doubt about the suitability of a patient for pharmacological cardioversion, DC cardioversion is the safer option 2.
• The decision to perform cardioversion should take into account the risk of thromboembolic complications, which can be minimized with effective periprocedural anticoagulation and early timing of cardioversion 3, 4.
• Patient characteristics, such as those assessed by the CHA2DS2-VASc score, can help identify individuals at higher risk of thromboembolism and inform the decision to perform cardioversion 4.

Considerations for Cardioversion

• The success rate of cardioversion can be affected by patient- and technique-related variables 5.
• Pharmacological cardioversion options exist and are preferable in specific circumstances, but are associated with the risk of proarrhythmia 5.
• Transoesophageal echocardiography can be useful in clinical scenarios where early cardioversion is desirable due to debilitating clinical symptoms and a short duration of arrhythmia or uncertain adequacy of preceding anticoagulation 3.
• Awareness of clinical aspects influencing cardioversion safety should be raised to minimize the risk of thromboembolic complications 3.