Ventricular tissue from patients with end-stage heart failure had significantly lower myofibrillar protein content and Mg-ATPase activity compared with normal hearts.
Observational
Force development and shortening by cardiac muscle occur as a result of the interaction between actin and myosin within the myofibrillar lattice. This interaction is dependent upon intracellular ionized calcium and is controlled by the troponin-tropomyosin regulatory proteins situated along the actin filament. In this study, we compared the myofibrillar content and myofibrillar Mg-ATPase activity of normal human ventricular muscle with that of ventricular muscle from patients in end-stage failure caused by coronary artery disease or cardiomyopathy and ventricular muscle from patients with heart failure due to mitral valve insufficiency. The results show that the amount of myofibrillar protein (mg/g wet wt ventricle) in hearts in end-stage failure (coronary artery disease and cardiomyopathy) is significantly lower compared with normal hearts and hearts in failure due to mitral valve insufficiency. However, the Mg-ATPase activity of myofibrils from hearts in both end-stage failure and failure due to mitral valve insufficiency is significantly lower compared with myofibrils from normal hearts. The data suggest that the reduction in the amount of myofibrillar protein in ventricular tissue is a pivotal event that may be responsible for the progression of heart disease to the point of end-stage failure.
Pagani et al. (Mon,) conducted a observational in Heart failure (coronary artery disease, cardiomyopathy, mitral valve insufficiency). Ventricular tissue from patients with heart failure vs. Normal human ventricular muscle was evaluated on Myofibrillar content and myofibrillar Mg-ATPase activity. Ventricular tissue from patients with end-stage heart failure had significantly lower myofibrillar protein content and Mg-ATPase activity compared with normal hearts.