Are Prolonged Ventricular Pauses in Atrial Fibrillation a Marker of Poor Prognosis?

Background: In patients with atrial fibrillation (AF), the long-term prognosis of long electrocardiographic pauses in the ventricular action is not well studied. Methods: Consecutive Holter recordings in patients with AF (n = 200) between 2009 and 2011 were evaluated, focusing on pauses of at least 2.5 s. Outcomes of interest were all-cause mortality and pacemaker implantation. Results: Forty-three patients (21.5%) had pauses with a mean of 3.2 s and an SD of 0.9 s. After a median follow-up of 99 months (ranging 89-111), 47% (20/43) of the patients with and 45% (70/157) without pauses were deceased. Pauses of >= 2.5 s did not constitute a risk of increased mortality: HR = 0.75 (95% CI: 0.34-1.66); p = 0.48, neither did pauses of >= 3.0 s: HR = 0.43 (95% CI: 0.06-3.20); p = 0.41. Sixteen percent of patients with pauses underwent pacemaker implantation during follow-up. Only pauses in patients referred to Holter due to syncope and/or dizzy spells were associated with an increased risk of pacemaker treatment: HR = 4.7 (95% CI: 1.4-15.9), p = 0.014, adjusted for age, sex, and rate-limiting medication. Conclusion: In patients with AF, prolonged electrocardiographic pauses of >= 2.5 s or >= 3.0 s are not a marker for increased mortality in this real-life clinical study.