Abstract
The stem cells keep us young by endogenously repairing us upon need. They do so bysmartly one step forward towards differentiation while another step backward to nurturethe undifferentiated stem cells. They are building blocks for every organ witha differential rate of repair of worn out tissues. Since stem cells can be cultured with a normal karyo type, they could be the ideal source for heart repair after myocardial infarction. As opposed to lower vertebrates and neonatal mice, cardiac regeneration in adult mammalian heart seems to be difficult to assess with a solid evidence of cytokinesis. It becomes more difficult to quantify the level of regeneration after myocardial infarction injury against a background of a large invasion of proliferating inflammatory cells. The question to beraised is how the renewal of a piece of myocardium follows the time line of picking upcell types in series: cardiomyocytes, endothelial cells, smooth muscle cells, fibroblast, pacemaker cells, conducting and Purkinje cells to bring the orchestration of rhythmically contracting and relaxing heart. This review focuses on where we are onthe status of heart repair and cardiac regeneration.