Remodeling of ventricular myocytes during cardiac hypertrophy and heart failure

Cardiac hypertrophy due to pressure or volume overloading leads to changes in myocyte shape which reflect gross anatomical alterations in ventricular geometry. Specifically, pressure overloading causes an increase in wall thickness, little or no change in chamber volume, and an increase in myocyte cross-sectional area only. Hypertrophy due to volume overloading, however, is characterized by a proportional increase in chamber radius and wall thickness and an equal increase in myocyte length and diameter. The underlying cellular changes associated with ventricular dilation and cardiac decompensation, however, have not been clarified. Preliminary myocyte size data collected from failing, explanted human hearts suggests that our current perception of the mechanism of dilation is incorrect. Understanding the true nature of the dilation process associated with congestive heart failure should provide new directions for potential therapies and prevention.