The normal left ventricular human myocardium is a composition of different structural elements. Cardiomyocytes account for about 75% of the normal human myocardial volume. The reminder 25% are allotted to the interstitium or extracellular volume (ECV), which contains blood vessels, nerves, various cells including fibroblasts, a gel-like ground substance composed of glycosaminoglycans and glycoproteins, and fibrillar connective tissue (Mewton et al. 2011; Weber 1989). The fibrillar connective tissue predominantly contains type I and III collagen and is also termed (extracellular) collagen matrix (Weber 1989) accounting for about 2–4% of the total myocardial volume of the left ventricle (Mewton et al. 2011). The collagen fibers provide a scaffolding for the cellular components and blood vessels and play an important role for the even transmission of the contractile force generated by myocytes (Weber 1989; Kong et al. 2014). About 85% of the total collagen is type I collagen, mainly associated with thick fibers that confer tensile strength (Weber 1989; Kong et al. 2014). Type III collagen, representing about 11% of the total collagen, is associated with thin fibers that confer resilience (Weber 1989; Kong et al. 2014).