Cardiomyopathy and more specifically the dilated cardiomyopathy, regardless of severity, is associated with activation of neuro-hormonal, cytokine and oxidative stress signaling pathways that alter the structure and function of cardiac myocytes and non-myocyte cells. These cellular alterations culminate in the morphological changes in cardiac structure termed as cardiac remodeling, a maladaptive process that contributes to further left ventricular dysfunction and heart failure development. This pathological progression is mainly driven by circulating mediators, in particular angiotensin II and norepinephrine. Natriuretic peptides, endothelin-1, vasopressin play also an important role in the progression of the cardiomyopathy. Cardiac inflammation, mediated by cytokines such as tumor necrosis factor-α (TNF-α), interleukins 1 (IL-1) and 6 (IL-6), as well as the oxidative stress were also shown to worsen the cardiac function. Although these pathways have been described separately, they are critically inter-dependent in the response to the development and progression of the dilated cardiomyopathy. This chapter reviews the cellular basis for cardiac remodeling and the mechanisms that contribute to these cellular abnormalities and, more broadly, to the pathophysiology of dilated cardiomyopathy, its progression and its potential treatments.
The Role of Neurohormonal Systems, Inflammatory Mediators and Oxydative Stress in Cardiomyopathy