Cellular and Molecular Mechanisms of Atrial Arrhythmogenesis in Patients With Paroxysmal Atrial Fibrillation
Atrial Fibrillation Friday, November 22nd, 2013CIRCULATIONAHA: November 18, 2013
Background—Electrical, structural, and Ca2+-handling remodeling contribute to the perpetuation/progression of atrial fibrillation (AF). Recent evidence has suggested a role for spontaneous sarcoplasmic reticulum Ca2+-release events in long-standing persistent AF, but the occurrence and mechanisms of sarcoplasmic reticulum Ca2+-release events in paroxysmal AF (pAF) are unknown.
Method and Results—Right-atrial appendages from control sinus rhythm patients or patients with pAF (last episode a median of 10–20 days preoperatively) were analyzed with simultaneous measurements of [Ca2+]i (fluo-3-acetoxymethyl ester) and membrane currents/action potentials (patch-clamp) in isolated atrial cardiomyocytes, and Western blot. Action potential duration, L-type Ca2+ current, and Na+/Ca2+-exchange current were unaltered in pAF, indicating the absence of AF-induced electrical remodeling. Read more