ABSTRACT
Induced pluripotent stem cells (iPSCs) can be differentiated into cardiomyocytes when they are cultured in fl oating condition. The human iPSC-derived cardiomyocytes provide new approaches to study the cellular properties of human cardiomyocytes, to screen drug effi cacy and toxicity in human cardiomyocytes, to study pathogenesis and potential therapeutic strategy in human iPSC-derived cardiomyocytes from individuals with cardiac diseases, and for cell transplantation therapy. To efficiently achieve these future goals, it is indispensable to characterize the geneexpression profi le and the functional properties of human iPSC-derived cardiomyocytes in details, which provide crucial information on whether human iPSC-derived cardiomyocytes are similar or different from adult human cardiomyocytes in situ. Cardiomyocytes in situ can be classifi ed into several types, such as atrial muscle type, ventricular muscle type, nodal cell type, and His-Purkinje cell type. It is also essential to know which types of cardiomyocytes iPSC-derived cardiomyocytes belong to or whether iPSC-derived cardiomyocytes are a mixture of these various types of cardiomyocytes. Atrial muscle cells, ventricular muscle cells, nodal cells, and His-Purkinje cells each have a unique confi guration of action potential, which is attributed to the expression of specifi c combination of ion channels.
