What is the recurrence rate of atrial fibrillation (AFib) after cardioversion?

From the Guidelines

The recurrence rate of atrial fibrillation (AFib) after cardioversion is approximately 50-70% within the first year without antiarrhythmic therapy. This high recurrence rate varies based on several factors including the duration of AFib before cardioversion, left atrial size, patient age, and underlying heart disease, as noted in the 2011 ACCF/AHA/HRS guidelines 1. Patients with AFib lasting less than 1 year generally have better outcomes than those with persistent AFib.

Key Factors Influencing Recurrence

• Duration of AFib before cardioversion
• Left atrial size
• Patient age
• Underlying heart disease To reduce recurrence, antiarrhythmic medications are often prescribed following cardioversion.

Management Strategies

• Antiarrhythmic medications such as beta blockers, verapamil, or diltiazem may be used to enhance the likelihood of success and prevent recurrent AF, as suggested by studies 1
• Anticoagulation therapy should be considered based on stroke risk factors
• Addressing underlying risk factors like hypertension, sleep apnea, obesity, and alcohol consumption can significantly improve outcomes The high recurrence rate occurs because cardioversion only restores normal rhythm temporarily but doesn't address the underlying electrical or structural abnormalities in the heart that initially caused the AFib, which is why comprehensive management beyond the procedure itself is essential for long-term success, as indicated by the guidelines 1.

From the Research

Recurrence Rate of Atrial Fibrillation after Cardioversion

• The recurrence rate of atrial fibrillation (AFib) after cardioversion ranges from 40 to 50% despite attempts of electrical cardioversion and administration of antiarrhythmic drugs 2.
• A study found that the risk factors for AFib recurrence within 2 months of cardioversion include no coronary artery disease and an electrocardiographic lead II P-wave duration of > 135 milliseconds 3.
• Another study found that successful electrical cardioversion was associated with a lower rate of one-year recurrence in patients with early recurrent AF after catheter ablation, with a recurrence rate of 56.4% in the ECV group versus 65.4% in the non-ECV group 4.
• Advanced interatrial block is associated with a higher risk of AFib recurrence at 1 year after pharmacological cardioversion, with a recurrence rate of 90.9% in patients with advanced interatrial block 5.
• Factors predicting success rate and recurrence of AFib after first electrical cardioversion include duration of AF < 6 months, patient's weight, treatment with beta blockers or verapamil/diltiazem, and right atrial dimension < 37 mm 6.

Predictors of AFib Recurrence

• Clinical predictors for successful electrical cardioversion and maintenance of sinus rhythm after a first electrical cardioversion include:
  • Duration of AF < 6 months 6
  • Patient's weight 6
  • Treatment with beta blockers or verapamil/diltiazem 6
  • Right atrial dimension < 37 mm 6
• Electrocardiographic predictors include:
  • P-wave duration > 120 ms 5
  • Biphasic morphology (±) in inferior leads 5
• Echocardiographic predictors include:
  • Left atrial diameter > 4.5 cm 3
  • Mitral valve thickening 3
  • Left ventricular ejection fraction < 0.50 3

Management of AFib Recurrence

• Electrical cardioversion can be an effective treatment for AFib recurrence, with a lower rate of one-year recurrence in patients who undergo successful cardioversion 4.
• Pharmacological cardioversion with antiarrhythmic drugs can also be effective, but the recurrence rate is higher in patients with advanced interatrial block 5.
• Treatment with beta blockers or verapamil/diltiazem can help maintain sinus rhythm after cardioversion 6.