A. Representative action potential recordings from ARVMs infected with adenoviruses encoding Ad-GFP and Ad-Kir2.1Δ314–315 at 1 Hz. B,C,D, E, F Average amplitude (B), maximum diastolic potential (C), maximal dV/dt (D), action potential duration to 30, 60 and 90% of repolarization (E) and overshoot (F) (N=3, n=8 and N=3, n=8, respectively, where N is the number of animals and n is the number of cells) *p<0.05, mean±SEM, (t-test).