Targeting pathological remodeling: concepts of cardioprotection and reparation.

The myocardium is composed of cardiac myocytes, which are tethered within an extracellular scaffolding of fibrillar collagen. Myocytes are large; they occupy a major portion of tissue space. However, they number only a third of all cells in the myocardium; noncardiomyocytes constitute the remaining two-thirds of cells and include endothelial and vascular smooth muscle cells of the intramural coronary circulation and fibroblasts located in interstitial and perivascular spaces.1,2 Ventricular hypertrophy is based on the growth of cardiac myocytes, which may or may not be accompanied by other iterations in tissue structure. In athletes, the growth of muscular and nonmuscular compartments of the heart are proportionate; tissue homogeneity is preserved. Such adaptive hypertrophy contributes to enhanced cardiac performance.