2026-04-17T06:09:21Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/2241772025-12-05T00:12:45Zcom_2072_1057col_2072_478916col_2072_478917col_2072_478929

00925njm 22002777a 4500 dc Jiménez Sábado, Verónica author Casabella-Ramón, Sergi author Llach, Anna author Gich, Ignasi author Casellas, Sandra author Ciruela Alférez, Francisco author Chen, S.R. Wayne author Guerra, José María author Ginel, Antonino author Benítez, Raul author Cinca, Juan author Tarifa, Carmen author Hove-Madsen, Leif author 2025-11-06T18:54:37Z 2025-11-06T18:54:37Z 2023-02-01 2025-11-06T18:54:37Z Aims: Atrial fibrillation (AF) has been associated with excessive spontaneous calcium release, linked to cyclic AMP (cAMP)-dependent phosphorylation of calcium regulatory proteins. Because β-blockers are expected to attenuate cAMP-dependent signaling, we aimed to examine whether the treatment of patients with β-blockers affected the incidence of spontaneous calcium release events or transient inward currents (ITI). Methods: The impact of treatment with commonly used β-blockers was analyzed in human atrial myocytes from 371 patients using patch-clamp technique, confocal calcium imaging or immunofluorescent labeling. Data were analyzed using multivariate regression analysis taking into account potentially confounding effects of relevant clinical factors RESULTS: The L-type calcium current (ICa) density was diminished significantly in patients with chronic but not paroxysmal AF and the treatment of patients with β-blockers did not affect ICa density in any group. By contrast, the ITI frequency was elevated in patients with either paroxysmal or chronic AF that did not receive treatment, and β-blocker treatment reduced the frequency to levels observed in patients without AF. Confocal calcium imaging showed that β-blocker treatment also reduced the calcium spark frequency in patients with AF to levels observed in those without AF. Furthermore, phosphorylation of the ryanodine receptor (RyR2) at Ser-2808 and phospholamban at Ser-16 was significantly lower in patients with AF that received β-blockers. Conclusion: Together, our findings demonstrate that β-blocker treatment may be of therapeutic utility to prevent spontaneous calcium release-induced atrial electrical activity; especially in patients with a history of paroxysmal AF displaying preserved ICa density. Beta-blocadors Fibril·lació auricular Calci Monofosfat d'adenosina cíclic Adrenergic beta blockers Atrial fibrillation Calcium Adenylic acid Beta-blocker treatment of patients with atrial fibrillation attenuates abnormal electrical activity induced by spontaneous calcium release