LAUSR

https://e-kcj.org Detrimental effect of atrial fibrillation (AF) on sinus node (SN) function has been one of the most frequently investigated topics of basic and clinical researches. Ongoing AF could cause direct impairment to the SN function.1-3) Expression of ion channels making pacemaker funny current (If ) in the SN was reported to be downregulated,1) and spontaneous Ca2+ release from sarcoplasmic reticulum was known to become dysfunctional by ongoing AF, deteriorating the SN automaticity.2) In addition, AF-induced atrioventricular dyssynchrony and lack of effective coordinated atrial contraction causes elevation of atrial pressure. The high atrial pressure along with ongoing AF could induce atrial fibrosis.4)5) Significant fibrosis, particularly within SN and perinodal atrial tissues, can predispose patients to sinus node dysfunction (SND). In a recent study using late gadolinium enhancement cardiac magnetic resonance, Akoum et al.6) showed that perinodal and both atrial fibrosis was more extensive in patients with SND compared to those without.