The first reported estimations of the creatine content of human cardiac muscle seem to be those of Constabel,1 who analyzed a total of 38 hearts and obtained values ranging from 60 to 188 mg. per hundred grams for the concentration in the left ventricle. No relation to age or sex was observed, but hearts with fatty and other degenerative changes showed significantly lower values than those that were more nearly normal. In general the creatine concentration was about 10 per cent lower in the right than in the left ventricle.
In 1929 Bodansky, Schwab and Brindley2 reported analyses of various muscles, including the myocardium of the left ventricle of a patient with generalized myositis fibrosa. The heart, which microscopically revealed certain abnormalities, such as enlargement of the fibers, granular cytoplasm, mononuclear inflammatory cells and increased fibrosis, contained 159 mg. of creatine per hundred grams of tissue. There were