Intracellular lactate signaling cascade in atrial remodeling of mitral valvular patients with atrial fibrillation

BACKGROUND Atrial remodeling has emerged as the structural basis for the maintenance and recurrence of atrial fibrillation. Lactate signaling cascade was recently linked to some cardiovascular disorders for its regulatory functions to myocardial structural remodeling. It was hypothesized that lactate signaling cascade was involved in the maintenance and recurrence of atrial fibrillation by regulating atrial structural remodeling. METHODS Biopsies of right atrial appendage and clinical data were collected from sex- and age-matched 30 persistent atrial fibrillation, 30 paroxysmal atrial fibrillation, 30 sinus rhythm patients undergoing isolated mitral valve surgery and 10 healthy heart donors. RESULTS Atrial fibrillation groups had higher atrial lactate expression and this upregulated expression was positively correlated with regulatory indicators of atrial structural remodeling as reflected by severe oxidative stress injury and mitochondrial control of apoptosis. CONCLUSIONS The present findings suggest a potential role for lactate signaling cascade in the maintenance and recurrence of atrial fibrillation and possibly represent new targets for therapeutic intervention in this disorder.