Changes in the Interstitial Matrix During Myocardial Remodeling
The myocardial extracellular matrix (ECM) was previously thought to serve solely as a means to align cells within the tissue. This chapter introduces the players of the ECM and describes some of the cardiac disease states associated with left ventricular (LV) remodeling, placing a particular emphasis on postmyocardial infarction (MI) remodeling. The basement membrane forms a specialized type of ECM that separates the stroma from the cell membrane. Collagen type IV is the most abundant protein found within the basement membrane where it forms a covalently stabilized polygonal framework. Myocardial remodeling involving changes in the ECM often advances to cause dysfunction and heart failure. Hypertensive heart disease is often characterized by alterations in normal LV filling properties that in aggregate have been referred to as diastolic dysfunction. Increases in collagen content, as well as alterations in collagen crosslinking, have been observed in association with LV hypertrophy, and there is an evidence of biochemical modification of the ECM in this condition.