Chapter 3: Pathophysiology

The hallmark pathophysiologic feature of dilated cardiomyopathy is systolic dysfunction. Several pathogenetic mechanisms appear to be operative. These include increased hemodynamic overload, ventricular remodeling, excessive neurohumoral stimulation, abnormal myocyte calcium cycling, excessive or inadequate proliferation of the extracellular matrix, accelerated apoptosis, and genetic mutations. Although beneficial in the early stages of heart failure, these compensatory mechanisms eventually lead to a vicious cycle of worsening heart failure. Genetic causes account for 30–40% of DCM and involve genes that encode a heterogeneous group of molecules that participate in force generation, force transmission, sarcomere integrity, cytoskeletal and nuclear architecture, electrolyte homeostasis, mitochondrial function, and transcription. Additional research will improve our understanding of the complex and longitudinal molecular changes that lead from gene mutation to clinical expression