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.