The work presented here has three objectives: (1) To determine if reduced co-localisation of JPH and RyR is correlated with the loss of t-tubules and cardiac junctions previously documented in the failing human heart; (2) Determine if there are changes in RyR cluster organisation in human HF that could contribute to disrupted Ca2+ release in human HF; (3) Determine if t-sheets were associated with luminal collagen deposition and changes in RyR cluster organisation. Here, RYR2 is linked to hydrops fetalis.