HF is also characterized by APD prolongation (Wang and Hill, 2010) and increased risk of afterdepolarizations (Pogwizd and Bers, 2004; Weiss et al., 2010), and we speculate that CaMKII inhibitors and NKA activators might be future antiarrhythmic options in HF even in the absence of hypokalemia. This evidence concerns the gene TAC1 and hydrops fetalis.