Distribution of Fluid and Electrolytes and Concentration of Actomyocin and Other Proteins in the Myocardium of Dogs With Chronic Congestive Heart Failure

¹ From the Departments of Medicine and Pathology, and Division of Hospital Laboratories, University of Minnesota, Minneapolis; and Hill Family Foundation Surgical Research Laboratory, Ancker Hospital, St. Paul, Minnesota

In 17 dogs with chronic heart failure due to surgically produced pulmonary stenosis and tricuspid insufficiency and 13 control dogs, myocardial concentrations of water, potassium, sodium, chloride, calcium, magnesium, total and alkaline soluble protein, actomyosin, myoglobin and collagen were measured. In 11 of the dogs with heart failure and in 7 control dogs, psoas muscle was also analyzed and in these dogs intracellular and interstitial concentrations of water and electrolytes were calculated by assuming a restricted distribution of chloride. In the dogs with heart failure the following were noted: a 20–33% increase in myocardial and psoas interstitial fluid mass; a slight increase in intracellular sodium concentration but essentially no change in the intracellular concentrations of other electrolytes or of water; decreased myocardial concentration of actomyosin per unit of fat-free solids as judged by the viscosity response of extracted actomyosin to the addition of adenosinetriphosphate; no change in the concentration of actomyosin in psoas muscle. Ratios of intracellular magnesium to actomyosin and of the sum of intracellular sodium and potassium to actomyosin were increased to a variable extent in the myocardium in heart failure.