ABSTRACT
This chapter identifies the cellular and interstitial changes that are characteristic of the remodeling process, which eventually lead to failure of the hypertrophied human heart. It describes the structural alterations that occur in the human heart during the transition from compensated hypertrophy to cardiac decompensation and it will correlate these findings with clinical functional data. Normal myocardium consists of 90% myocytes and 10% of interstitial tissue. Myocytes are about 80 to 120 µm long and 15 to 20 µm thick. The interstitial tissue represents the scaffold, which provides stability to the continuously contracting myocyte system. It consists of the extracellular matrix, fibroblasts, macrophages, and blood vessels; 75% of all cell nuclei are in the interstitial space. The chapter proposes that significant myocyte hypertrophy and the huge accumulation of fibrosis are the morphological correlate of the disturbed diastolic filling pattern of the hypertrophied left ventricle characterized by impaired relaxation and increased passive stiffness.
