(m–o) Measurements of cell-wide Ca2+ transient magnitude, TTP (rise time), and dyssynchrony in sham and HF cells in the presence and absence of AIP or PKA (sham: ncells = 41, nhearts = 4; HF: ncells = 59, nhearts = 4; HF + AIP: ncells = 43, nhearts = 4; HF + H89: ncells = 38, nhearts = 3). Here, AIP is linked to hydrops fetalis.