Human iPSCs: atrial versus ventricular cardiomyocytes and their functional and pharmacological differences.

The continuing development and characterisation of human-induced pluripotent stem cell (hiPSC)-derived cell-types has opened up a virtually endless source of human, physiologically relevant cells, available at scale, for scientific research. The technology's maturation and refinement have allowed additional cell-types and sub-types to become available. The first step in adopting these novel cell-types is to properly characterise these cells and compare how they perform against the longer-established cell-types. Parallel to the progress in iPSC-derived cells has been the great strides in the platforms developed to assess and analyse the characteristics and functions of cells. These improved platforms have greatly increased the range, throughput and quality of the functional data that can be obtained from cell-types, including iPSC-derived cells. Research into cardiomyocytes in particular has been greatly enhanced by these platforms as cardiomyocytes not only have the expected cellular markers, proteomics and transcriptomics but are also electrically active and capable of contracting, opening a wide vista of potential assays. If human iPSC-derived cardiomyocytes are to confidently replace and supplement the existing animal and cellular models of the heart, it has to be demonstrated that they correctly replicate (or even improve) upon the functions and pharmacology of the existing heart models used on these new and improved platforms. Therefore, this review compares the functional and pharmacological differences seen between Axol's human iPSC-derived atrial and ventricular cardiomyocyte cells on a range of established and newer platforms demonstrating the advantages of using chamber-specific human iPSC-derived cardiomyocytes and discussing how their use could supplement these emerging techniques.