DURATION OF ATRIAL FIBRILLATION PREDICTS
CARDIOVERSION PARAMETERS AND SUCCESS. A REPORT FROM THE ACUTE REGISTRY D L. Prior*, W A. Jaber, M Thamilarasan, C R. Asher, P L. Houghtaling,
S E. Jasper, A L. Klein. The Cleveland Clinic Foundation, Cleveland, Ohio,
USA. Previous studies have shown that the duration of atrial
fibrillation (AF) is a determinant of successful cardioversion (CV) and
long-term maintenance of normal sinus rhythm (NSR). Methods: We sought to confirm this in a large prospectively
collected database from the ACUTE registry, which enrolled patients in AF prior
to CV. Furthermore, we assessed the impact of duration of atrial fibrillation
on cardioversion parameters. The study group consisted of 281 patients (M/F =
200/81). Spearman correlation coefficient was used to evaluate the effects of
AF duration (< 3 days, < 30 days, and < 6 months) on CV parameters and
CV success. Results: Mean patient age was (67.7 ± 11.7 yrs). AF
recurred in 66 patients (23.5%) at 24 hours and in 141 patients (50.1%) at one
year. AF duration of less than 3 days did not affect the CV parameters or
recurrence (p = NS). Compared to pts with AF > 30 days and AF > 6 months,
respectively, fewer DC shocks were required in pts with AF < 30 days (Mean =
1.5 ± 0.9, p =
0.001) and AF < 6 months (1.5 ± 0.97, p = 0.01). Similarly, the total and the maximal DC
energy needed for CV was lower in pts in AF < 30 days (p = 0.003, p = 0.004)
and < 6 months (p = 0.0002, p = 0.0002) respectively. RR†,
AF < 30 days RR‡,
AF < 6 months Recurrent
AF at 24 hrs 0.87
(p = 0.06) 0.81
(p = 0.005) Recurrent
AF at 1 year 0.72
(p = 0.025) 0.97
(p = 0.370) † compared to pts with AF >30 days.
‡ compared to pts with AF >6 months. Conclusions:Patients with
shorter duration of AF (< 6 months) require a lower number of shocks with
less DC energy for CV. The analysis from this prospective registry confirms the
positive impact of a shorter duration of AF on the immediate and long-term
success of maintaining NSR.
