THE PLASMA PROTEINS IN RELATION TO BLOOD HYDRATION: VIII. Serum Proteins in Heart Disease

THE FLOW AND COMPOSITION OF LYMPH IN RELATION TO THE FORMATION OF EDEMA

1. The experimental observations have been summarized at the end of an earlier section. The more important facts only will be recapitulated here. The capacity of the lymphatics for removing fluid from the tissues greatly exceeds the rate at which freshly formed tissue fluid can be made available for removal. Edematous regions can be rendered non-edematous by the application of measures, such as massage, passive motion, or normal exercise, which activate the lymphatics. During continuous activity the rate of lymph flow is first variable and later relatively constant. Constant rates of flow must correspond to the production of fresh lymph. A study of the constant rates indicates that lymph formation in the edematous animal is certainly only slightly greater, and possibly not greater at all, than under conditions of normality. When the protein of plasma decreases, the protein of lymph is also lowered. The loss of protein from lymph takes place at a faster rate than from plasma, so that the ratio of serum protein to lymph protein is greater in the edematous than in the normal animal. In edematous animals the concentration of protein in lymph is of the same order of magnitude as the concentration in edema fluids. The two fluids are not, however, identical in composition. Minor fluctuations in the protein content of lymph always occur during a period of continuous collection. 2. The factors involved in the circulation and accumulation of tissue fluid are discussed. Reasons are given for offering the following suggestions. Significant differences in tissue pressure or tension exist between the states resulting from quiescence and activation of the lymphatics. The differences give rise to variations in the relative areas of capillary wall, functioning for filtration and reabsorption. When the lymphatics are activated it is possible that capillary reabsorption may be completely in abeyance. A decline in the proteins of plasma may be associated with a diminished permeability of the capillaries. Such a lowering of capillary permeability would account for two features, both of which have been demonstrated: (1) failure to observe an appreciably increased rate of lymph formation in the edematous animal, and (2) the extremely low concentration of protein in lymph from edematous animals. Although the difference between the protein concentrations of edema fluid and lymph from the same region is small, the conclusion is not yet justified that a similarly small difference exists between normal tissue fluid and normal lymph.

Cardiac cachexia in early literature: a review of research prior to Medline

Cachexia has been known to physicians since ancient Greek times as a 'signum mali ominis' in various diseases indicating end stage disease and poor quality of life. Cardiac cachexia is recently receiving growing attention as modern treatment options prevent early death from cardiac events and more patients live with chronic compensated heart failure. Nevertheless, observation and clinical documentation of this condition go back as long as medical science itself. Pioneering studies on the reasons and mechanisms of cachexia were performed several decades ago. These studies provide fundamental insights and guidance towards a better understanding of cachexia. This review presents an overview of early thoughts and milestone studies on metabolic abnormalities and cachexia in chronic heart failure.

Contribution of skeletal muscle atrophy to exercise intolerance and altered muscle metabolism in heart failure

BACKGROUND

The purpose of this study was to investigate the prevalence of skeletal muscle atrophy and its relation to exercise intolerance and abnormal muscle metabolism in patients with heart failure (HF).

METHODS AND RESULTS

Peak VO2, percent ideal body weight (% IBW), 24-hour urine creatinine (Cr), and anthropometrics were measured in 62 ambulatory patients with HF. 31P magnetic resonance spectroscopy (MRS) and imaging (MRI) of the calf were performed in 15 patients with HF and 10 control subjects. Inorganic phosphorus (Pi), phosphocreatine (PCr), and intracellular pH were measured at rest and during exercise. Calf muscle volume was determined from the sum of the integrated area of muscle in 1-cm-thick contiguous axial images from the patella to the calcaneus. A reduced skeletal muscle mass was noted in 68% of patients, as evidenced by a decrease in Cr-to-height ratio of less than 7.4 mg/cm and/or upper arm circumference of less than 5% of normal. Calf muscle volume (MRI) was also reduced in the patients with HF (controls, 675 +/- 84 cm3/m2; HF, 567 +/- 112 cm3/m2; p less than 0.05). Fat stores were largely preserved with triceps skinfold of less than 5% of normal and/or IBW of less than 80% in only 8% of patients. Modest linear correlations were observed between peak VO2 and both calf muscle volume per meter squared (r = 0.48) and midarm muscle area (r = 0.36) (both p less than 0.05). 31P metabolic abnormalities during exercise were observed in the patients with HF, which is consistent with intrinsic oxidative abnormalities. The metabolic changes were weakly correlated with muscle volume (r = -0.42, p less than 0.05).

CONCLUSIONS

These findings indicate that patients with chronic HF frequently develop significant skeletal muscle atrophy and metabolic abnormalities. Atrophy contributes modestly to both the reduced exercise capacity and altered muscle metabolism.

Gastrointestinal absorption studies in cardiac cachexia

The nutritional status of 11 patients with severe mitral valve disease was investigated pre-operatively and 3 months post-operatively. It was shown that they were malnourished pre-operatively, and that this appeared to be related mainly to anorexia.