After treatment for atrial fibrillation (AFib), do patients typically remain in AFib or convert to a normal sinus rhythm?

Outcome After Atrial Fibrillation Treatment

Most patients treated for atrial fibrillation do NOT stay in normal sinus rhythm long-term, even with aggressive rhythm control strategies—only 39-40% remain in sinus rhythm at one year despite optimal antiarrhythmic therapy. 1

The Reality of Rhythm Control Success Rates

The evidence consistently demonstrates disappointing long-term success rates for maintaining sinus rhythm:

• Only 39% of patients remained in sinus rhythm at one year in the RACE trial despite aggressive rhythm control protocols including multiple cardioversions and antiarrhythmic drugs 1
• Only 40% maintained sinus rhythm at one year in the STAF trial, even with repeated conversion attempts 1
• At 6 months post-cardioversion, success rates varied dramatically by drug: 66% with high-dose dofetilide (500 μg twice daily), 52% with medium-dose, but only 21% with placebo 1
• Amiodarone showed the best long-term results with median time to recurrence of 487 days, compared to 74 days for sotalol and only 6 days for placebo 1

Factors That Determine Whether Patients Stay in Sinus Rhythm

Duration of AF before treatment is the single most important predictor 2:

• AF lasting ≤1 week: Most patients maintain sinus rhythm after conversion 3
• AF lasting >1 week but ≤1 year: 81% maintain sinus rhythm at 6 months, 60% at 24 months 4
• Chronic AF >1 year: Significantly lower success rates 4

Left atrial size strongly predicts outcome 4:

• LA diameter ≤60 mm: Good chance of maintaining sinus rhythm
• LA diameter >60 mm: Poor long-term success even with treatment

Other significant predictors of staying in sinus rhythm 4, 2:

• Conversion with pharmacologic therapy alone (better than requiring electrical cardioversion)
• Absence of mitral valve disease
• Age <75 years
• Use of Class III antiarrhythmic drugs (sotalol, amiodarone)

Clinical Implications: Rate vs. Rhythm Control

The major clinical trials (AFFIRM, RACE, PIAF, STAF) found NO mortality benefit from rhythm control strategies compared to rate control with anticoagulation 1:

• Rhythm control was associated with more hospitalizations (p < 0.001) 1
• Rhythm control showed higher risk for death in older patients, those without heart failure, and those with coronary disease 1
• Stroke rates were identical between strategies; 70% of strokes occurred in patients who stopped anticoagulation or had subtherapeutic INR 1

Rate control with chronic anticoagulation is the recommended strategy for the majority of patients with atrial fibrillation 1. Rhythm control has not been shown superior in reducing morbidity and mortality and may be inferior in some patient subgroups 1.

When Rhythm Control Is Appropriate

Rhythm control should be prioritized in specific clinical scenarios 5:

• First episode of AF or highly symptomatic episodes
• Reversible causes (hyperthyroidism, post-cardiac surgery)
• Young patients with no hypertension, normal left atrium size, and short AF duration
• Patients suitable for ablation therapy (focal AF, atrial flutter)

Rate control is preferred when 5:

• Patients are asymptomatic
• Rhythm control has already failed
• High likelihood of rhythm control failure (older age, LA >60 mm, chronic AF >1 year, hypertension)
• Rhythm control causes adverse effects or requires frequent cardioversions

The Atrial Stunning Phenomenon

Even when sinus rhythm is restored, atrial mechanical function may not immediately return 3:

• After acute AF (≤1 week): Atrial transport function is normal immediately after conversion
• After chronic AF (>1 week): Atrial transport is severely reduced or absent despite normal P waves on ECG
• 36% of chronic AF patients had complete left atrial paralysis (no mechanical contraction) immediately after conversion 3
• Recovery occurs gradually over approximately 48 days on average 3

This "atrial stunning" explains why anticoagulation must continue for at least 4 weeks post-cardioversion regardless of apparent sinus rhythm on ECG 1.

Common Pitfalls to Avoid

Never discontinue anticoagulation based solely on apparent sinus rhythm maintenance 1:

• Most strokes in rhythm control trials occurred when anticoagulation was stopped or subtherapeutic
• Patients may have asymptomatic AF recurrences
• Atrial mechanical dysfunction persists even with electrical sinus rhythm

Do not equate "rhythm control strategy" with "actual maintenance of sinus rhythm" 5:

• 37-74% of patients in rhythm control arms were actually in AF during follow-up
• They received no benefit from sinus rhythm but were exposed to risks of cardioversions and antiarrhythmic drugs

Recognize that antiarrhythmic drugs approximately double sinus rhythm rates compared to placebo, but absolute success remains modest 1.