Further Studies on the Creatine Content of Heart Muscle. ∗

Abstract

Creatine in the form of phosphocreatine is thought to play a significant part in muscular activity, and the functional capacity of muscle is apparently reflected by its creatine content. It is of interest to determine in what degree the retention of nitrogenous products influences the level of creatine in heart muscle and how the creatine content is also influenced by clinical and morphological manifestations of cardiac incompetency. A study of the creatine content of heart muscle should therefore offer many interesting possibilities from the standpoint of both creatine metabolism and heart disease which are complementary to each other.

A preliminary report of our work dealing with this subject was presented before this Society in January, 1932, the first publication appearing in April, 1934. 1 The concentration of creatine in the left ventricular muscle of the human was found to exceed that of the right ventricle by about 30%. Attention was also called to certain correlations between creatine content, and age and heart weight.

This general study has been continued, special attention being given to the inclusion of cases with marked nitrogen retention and heart failure. It has been observed that in cases of marked creatinine retention without heart failure there is considerable increase not only in the creatine content of voluntary muscle but also in that of the left and right ventricle. In lobar pneumonia the creatine content of both the voluntary and left ventricular muscle was appreciably increased, due possibly to retention. Low figures for the right ventricle in several cases were suggestive of right heart failure. It was a singular fact that in cases of uremia with heart failure, the creatine content of the voluntary muscle was essentially normal, despite high figures for the blood creatinine, while the creatine concentration of the left and right ventricles was reduced, the reduction being greatest generally in the left ventricle.