ABSTRACT
Following acute myocardial infarction, the necrotic myocardium gives way to non-contractile scar tissue over time. There may be small amounts of myocardial cell regeneration that occur in the border regions of infarcts, but certainly not enough to replace the lost muscle mass that infarcted. Numerous experimental studies have now shown that it is possible to replace or at least partially replace lost myocytes with immature cells, including fetal and neonatal cardiomyocytes, embryonic or mesenchymal stem cells, or skeletal muscle myoblasts.1 The purpose of this chapter is to review our experience with transplantation of fetal and neonatal cardiomyocytes into an experimental myocardial infarct model, with emphasis on long-term effects on the heart. We will also review some early attempts to enhance the transplanted cells with fibroblast growth factor. The overall purpose of our studies was to determine whether immature cardiomyocytes could be injected into normal hearts or hearts with myocardial infarction, survive in a hostile milieu, differentiate, contribute to left ventricular (LV) mass by way of thickening the infarct wall, reduce LV dilatation and remodeling, and ultimately contribute to improved LV ejection fraction.
