At the cellular level, EPAC regulates AP lengthening in rat ventricular cardiomyocytes (Brette et al., 2013), a process which is correlated with the genesis of arrhythmia by predisposing cardiomyocytes to early after depolarization and dispersion of repolarization (Nattel et al., 2007). This evidence concerns the gene RAPGEF4 and cardiac arrhythmia.