Low Atrial Fibrillatory Rate Is Associated with Poor Outcome in Patients with Mild to Moderate Heart Failure.

BACKGROUND: -Atrial fibrillatory rate (AFR) is a measure of atrial remodeling caused by atrial fibrillation (AF) and its acceleration negatively affects outcome of interventions for persistent AF. However, the prognostic value of AFR in patients with CHF has not been studied. We sought to evaluate whether AFR can predict outcome in patients with mild to moderate (NYHA II-III) congestive heart failure (CHF). METHODS AND RESULTS: -High-resolution 20-min long Holter ECGs obtained from 169 CHF patients with AF at enrollment were analyzed. AFR was estimated using spatiotemporal QRST cancellation and time-frequency analysis. The patients were followed for a median of 44 months with primary endpoint defined as total mortality and secondary endpoints as sudden death and heart failure death. Atrial signal quality was sufficient for AFR estimation in 142 patients (mean age 69±11 years, 101 male). Of those, 48 patients died during follow-up, including 18 due to CHF progression. Mean AFR was 390±60 fpm and decreased with age (r=-0.3, p