The myocardium and hemodynamics in cardiac hyperfunction and insufficiency

In cases withvitium cordis only a part of work done by the ventricle is transformed into its external work. All the work performed by the ventricle may be designated as total work, whereas the ratio of external and total work is designated as mechanical efficiency of the ventricle. The study of the dynamics of external, total work and of the mechanical efficiency of the left ventricle in the process of progressive aortic stenosis development demonstrated that in the given experimental vitium cordis the energy losses for overcoming the blood flow resistance in the area of stenosis lead to a 4-fold reduction in the mechanical efficiency of the left ventricle (as compared to the normal).