Arrhythmia susceptibility after chronic β-adrenergic stimulation-induced cardiac hypertrophy.

<p>(A) Representative original tracings showing the induction of atrial fibrillation by programmed electrical stimulation in WT mice 2 weeks after chronic ISO infusion (upper panel) and the resistance of CYP2J2-TG mice treated in the same manner (lower panel). (B) Atrial fibrillation inducibility significantly increased in WT mice after chronic ISO infusion (n = 9) compared with the vehicle control (n = 8) and was significantly higher than in CYP2J2-TG mice (n = 7 and n = 8 for the vehicle and ISO groups). (C) The relative percentage of inducible sustained atrial fibrillation was markedly higher in WT compared with CYP2J2-TG after chronic ISO infusion. For statistical evaluation of arrhythmia inducibilities and severity scoring compare <a href="" target="_blank">Fig. 2</a>. Results represent mean±SEM; ANOVA, Post-Hoc Tukey; *p<0.05 vs. WT+Vehicle; †p<0.05 vs. CYP+Vehicle; <sup>‡</sup>p<0.05 vs. WT+ISO.</p>