Molecular and cellular diversity of heart conduction system myocytes

Conduction system myocytes are a subpopulation of cardiac myocytes that display unique electrophysiologic properties. Significant differences in cellular components of conduction myocytes have been demonstrated by the application of in situ procedures using both immunologic and molecular probes. Although molecular and cellular biology investigations are still at the beginning, they unequivocally show that conduction myocytes are a highly heterogeneous myocyte population, whose difference from working myocytes might reflect both the degree of functional specialization and the origin from a cell lineage distinct from myocardial cells.