LA reverse remodeling as a predictor of the maintenance of sinus
rhythm after bepridil discontinuation
AF causes shortening of the refractory period and conduction delay
(electrical remodeling) in the atrial myocardium due to downregulation
of L-type Ca2+ channels, which leads to contractile and structural
remodeling of the atria.21,22 This remodeling has been
demonstrated to facilitate the initiation and maintenance of AF and to
cause LA enlargement.8,21,23 Like some of our cohort,
active restoration of sinus rhythm could induce anatomic and/or
functional reverse remodeling of the cardiac
chambers.24,25
Bepridil has been reported to have a reverse electrical remodeling
effect, as well as an antiarrhythmic effect, by blocking multiple ion
channels.6 In a canine model, bepridil suppressed
effective atrial refractory period shortening, inducibility, and
duration of AF.9,10 Bepridil has also been reported to
improve calcium handling in the atrial muscle and to promote recovery
from mechanical remodeling.26 The combined use of
bepridil after CA may more potently promote LA reverse remodeling and
may be effective in patients with persistent AF fibrillation and LA
enlargement.18 Conversely, patients without LA reverse
remodeling at follow-up after hybrid therapy may have irreversible
structural remodeling and may be more likely to experience a recurrence
of AF after bepridil discontinuation. For such patients, it may be
better to continue bepridil to maintain sinus rhythm, focusing on its
antiarrhythmic effects rather than reverse remodeling effect. The
assessment of LA reverse remodeling may be useful for predicting the
recurrence of AF after bepridil discontinuation.