Cardiomyopathy or disease of the heart muscle involves abnormal enlargement and a thickened, stiff, or spongy-like appearance of the myocardium. As a result, the function of the myocardium is weakened and does not sufficiently pump blood throughout the body nor maintain a normal pumping rhythm, leading to heart failure. The main types of cardiomyopathies include dilated hypertrophic, restrictive, arrhythmogenic, and noncompaction cardiomyopathy. Abnormal trabeculations of the myocardium in the left ventricle are classified as left ventricular noncompaction cardiomyopathy (LVNC). Myocardial noncompaction most frequently is observed at the apex of the left ventricle and can be associated with chamber dilation or muscle hypertrophy, systolic or diastolic dysfunction, or both, or various forms of congenital heart disease. Animal models are incredibly important for uncovering the etiology and pathogenesis involved in this disease. This chapter will describe the clinical and pathological features of LVNC in humans and present the animal models that have been used for the study of the genetic basis and pathogenesis of this disease.
Part of the book: Preclinical Animal Modeling in Medicine
Most prominent functional abnormalities seen in the failing human heart are impaired contraction and slowed rates of relaxation of cardiac cells in the face of increased neurohormonal activation, sustained inflammation, mechanical and volume overload, and progressive maladaptive remodeling of the myocardium. Mechanical circulatory support devices (MCS) improve cardiac function and outcomes of patients with end-stage heart failure, allowing to bridge to heart transplantation and permitting the removal of MCS device as a bridge to recovery, in some patients with the sufficient recovery of heart function. Numerous reports have demonstrated favorable myocardial recovery and reverse remodeling after prolonged ventricular unloading by MCS. Ventricular unloading by MCS leads to a decreased concentration of peripheral natriuretic peptides in plasma, reduction in cardiac cytokines, kinases, collagens, and proteins involved in hypertrophy, fibrosis, programmed cell death, and necrosis in the heart. This chapter will summarize and review the effects and underlying mechanisms of myocardial remodeling during prolonged MCS in patients with end-stage heart failure. The mechanisms of myocardial recovery are multifactorial and remain to be further explored on cellular, organ, and systems levels.
Part of the book: Ventricular Assist Devices