Fast atrial activity predicts recurrence of atrial fibrillation after pulmonary vein isolation: results from a prospective randomized study.

Background: Recurrence of atrial fibrillation (AF) after ablative treatment is common. We hypothesized that AF recurrence is heralded by fast ectopic atrial activity occurring after electrical reconnection of previously isolated pulmonary veins.

Methods: Patients with paroxysmal or persistent AF undergoing pulmonary vein isolation (PVI) were followed up by 24-h Holter monitoring every 3 months for the first year and every 6 months thereafter. Antiarrhythmic drugs were withdrawn after a blanking period of 4 weeks for paroxysmal and 3 months for persistent AF. Ectopic atrial activity was defined as a burden of atrial extrasystoles >5% of the total QRS number. Fast atrial activity was present if mean cycle length of ectopic atrial activity was shorter than 50% of the mean cycle length of sinus rhythm in the last ten heartbeats. Patients with symptomatic fast atrial activity but without AF recurrence were randomized to undergo a second PVI procedure or resume antiarrhythmic medication. During follow-up, a 24-h Holter recording was performed every 3 months. Additionally, a 7-day external loop recording was performed in every pt with palpitations and no AF or ectopic atrial activity in the 24-h Holter.

Results: One hundred twenty-four pts with AF (88 paroxysmal, 36 persistent) developed fast atrial activity 6 ± 3 months after PVI. Twenty-two pts were asymptomatic and eight pts refused randomization. Ninety-four pts (61 men, age 57 ± 12 years) were randomized to either receive a second PVI procedure (group I, 48 pts) or antiarrhythmic medication (group II, 46 pts). Re-PVI in group I was performed 10 ± 8 months after the first PVI. During a follow-up of 20 ± 6 months, 11 pts of group I (23%) and 43 pts of group II (93%) had recurrence of AF. The mean time of AF recurrence after appearance of fast atrial activity was 4 ± 2 in group I and 5 ± 3 months in group II.

Conclusions: In patients with atrial fibrillation and after the first PVI procedure, appearance of symptomatic fast atrial activity is associated with a high risk of AF recurrence. Re-isolation of reconnected pulmonary veins in these pts significantly reduces the risk of AF recurrence.