2. The Myocardial Metabolism in the Congestive Heart Failure

Abstract

The coronary venous and right heart catheterization were performed on the fifty-five cardiac cases including twelve left-sided heart failures. The left ventricular myocardial metabolism and hemodynamic factors were comparatively investigated from the view of left- and right-side overload, in order to clarify the metabolic shift, when they become to fail. The followings are summarized. 1) The elevation of myocardial oxygen ex-traction ratio, i.e. the disturbance of oxygen supply and demand was brought about by de-crease of cardiac index, increase of pressure work and the lowering of the arterial carbon dioxide pressure. 2) The cardiac cases with high myocardial oxygen extraction ratio were supposed to be in the state of latent heart failure, since they had the tendency of decreased systolic ejection rate and maximal dp/dt. 3) The changes of myocardial metabolism in relation to the hemodynamic alterations were different between the left-and right-side over-loaded cases. When the left ventricle began to fail, the myocardium utilized more carbohydrate than fat. On the other hand, the left ventricular myocardium in mitral stenosis utilized more fat with the increase of pulmonary capillary pressure, right atrial pressure and myocardial excess lactate, and also with the decrease of cardiac index and tension time index. These results were discussed. 4) The evidence of the disturbed myocardial metabolism of free fatty acid components in the idiopathic myocardiopathy was presented and discussed.