Figure 5.

Effect of selective PDE8 inhibition on action potential (AP) properties of human atrial trabeculae. (A) Representative traces of AP at baseline (CON) and after 20 min of exposure to the selective PDE8 inhibitor PF-04957325 (PF, 100 nM) recorded in atrial trabeculae from patients in sinus rhythm (SR) and in persistent (chronic) atrial fibrillation (cAF). (B) Left panel, average resting membrane potentials in trabeculae from five SR, five paroxysmal AF (pAF), and seven cAF patients. Middle panel, individual and mean values of the effects of the selective PDE8 inhibitor (PF) on AP duration at 50% of repolarization (APD₅₀) in the three groups of patients. Right panel, plateau potential before (CON) and after exposure to the selective PDE8 inhibitor (PF). *P < 0.05 vs. SR, # P < 0.05 vs. CON based on ANOVA with a Kruskal–Wallis test.