Cardiac Muscle

DURING the past decade chemical studies have been made on the human heart by workers from several laboratories in an effort to correlate heart failure with known facts of muscle chemistry. From these studies has come a consistent agreement among all published data that creatine is usually decreased in the failing heart. Total phosphorus and acid-soluble phosphorus have likewise been found to be decreased, 1 and most workers have found a lowered potassium. To investigate further the chemical changes associated with myocardial insufficiency, Mangun and Roberts 2 studied acid-soluble phosphorus compounds of the dog's heart in aortic insufficiency. No losses were observed in the early stages, but in 2 dogs allowed to progress into the late stages of cardiac failure (approximately one year later) a marked decrease was noted in the adenosinetriphosphate and phosphocreatine content of the left ventricle. These findings made it desirable to investigate