Richard T. Cathcart

Some Effects of Digoxin upon the Heart and Circulation in Man Digoxin in Chronic Cor Pulmonale

The effects of acute digitalization upon the dynamics of the circulation were observed in patients with chronic cor pulmonale, using the technic of cardiac catheterization. The state of the circulation was further investigated in the same patients following recovery from failure. The mode of action of intravenous digoxin is discussed, and a tentative concept of the pathogenesis of chronic cor pulmonale is presented.

Hemodynamic Studies in Rheumatic Heart Disease

Hemodynamic studies were made in 42 patients with rheumatic heart disease with various valvular lesions and in different stages of cardiac function. These studies include observations not only at rest, but also during exercise, following the acute administration of Digoxin, and after recovery from failure. The relationship between symptomatology and hemodynamic findings were considered and the importance of differentiating between mechanical block and left ventricular myocardial failure as causes for pulmonary artery hypertension is stressed.

Some effects of digoxin on the heart and circulation in man; digoxin in enlarged hearts not in clinical congestive failure.

The early effect of intravenous Digoxin was observed in 12 patients with cardiac enlargement in whom there was no clinical or physiologic evidence of failure. There was either a fall or no change in the cardiac output and the intracardiac pressures did not alter following administration of the drug. The reaction to Digoxin in this type of patient with heart disease was in no way different from the response seen in two normal subjects included in the study but is in sharp contrast to the response elicited in patients in congestive heart failure.

The oxyhemoglobin dissociation curve in the common hemoglobinopathies

Abstract The in vivo oxyhemoglobin dissociation curve has been studied in twelve patients whose hemoglobin was entirely or partially abnormal. Five had no normal hemoglobin. Three of these five had pure S hemoglobin and sickle cell anemia; two had hemoglobin C-S disease. Of the other 7 patients, 3 had A-S hemoglobin, three A-C hemoglobin and one S-A hemoglobin and thalassemia. Arterial oxygen unsaturation was present in the five patients who had no normal hemoglobin and the oxyhemoglobin dissociation curve was displaced to the right. The degree of displacement was sufficient to explain the observed arterial oxygen unsaturation. The oxyhemoglobin dissociation curve was normal in patients with A-C and A-S hemoglobin and in the one patient with S-A hemoglobin and thalassemia. It is suggested that displacement of the dissociation curve may be related to reduction of the intracellular pH of the red cell. The clinical implications are briefly discussed. A moderate shift of the curve is beneficial in anemia if cardiopulmonary function is normal. A marked shift, however, or even a moderate shift in the presence of significant cardiopulmonary dysfunction, will aggravate the tissue anoxia of the anemic state.

Pulmonary alveolar proteinosis: A correlation of pathological and physiological findings in a patient followed up with serial biopsies of the lung

Abstract A case of pulmonary alveolar proteinosis followed up with serial biopsies of the lung performed over a two and a half year period is presented. Extensive pulmonary function studies during that period are included, with a correlation of the pathological and physiological findings. The patient at the peak of his illness exhibited marked pulmonary insufficiency due both to alveolar-capillary block and increased venous admixture. The pathological, physiological and roentgenographic findings have shown a marked improvement over a two and a half year period. This has been accompanied by progressive improvement in his clinical status to the point that he is now symptom-free. The ultimate prognosis must remain guarded, however, because of the obscure etiology of the disease and our present lack of knowledge as to its course.

Heart block caused by fat infiltration of the interventricular septum (cor adiposum)

Abstract A case of extensive fat infiltration of the right ventricle and interventricular septum of the heart is presented. The clinical manifestations of chronic right-sided heart failure and heart block is attributed to this anatomic change.

Physiologic and clinical aspects of pulmonary alveolar proteinosis.

Excerpt The recently described disease, pulmonary alveolar proteinosis,1has aroused much clinical and pathologic interest. This disease bears a significant mortality (30%) in the reported cases. De...

Clinical and physiological considerations in pulmonary muscular hyperplasia.

Excerpt The presence of increased amounts of smooth muscle in the lung is not rare, in itself. In most instances, however, localized areas of smooth muscle hyperplasia have been described, associat...

Effect of partial and total cardiopulmonary bypass with whole blood or hemodilution priming on pulmonary surfactant activity

Abstract 1. 1. Minimal surface tension of the lungs of dogs was estimated in terms of surfactant activity before, during, and after cardiopulmonary bypass. 2. 2. Surfactant values of normal lungs sampled before the operation ranged from 1.8–11.8 dynes per cm. 2 , averaging 5.1 dynes per cm. 2 3. 3. Animals perfused one or two hours with 50% hemodilution showed little change in surfactant values immediately after the perfusion was completed. However, in those that survived more than fifteen hours the values rose an average of 11.1 dynes per cm. 2 4. 4. 60% of animals perfused with whole blood for one hour had rises in surface tension (average 8.5 dynes/cm. 2 ) both at the completion of bypass and at the time of death. None of these dogs survived more than eight hours. 5. 5. No rise in minimal surface tension was observed in animals placed on controlled ventilation without cardiopulmonary by pass; only one of 6 animals with thoracotomy and heparin showed a persistent rise. 6. 6. Possible explanations for the temporary protection to lung surface afforded by hemodilution as compared to whole blood perfusion are discussed.

Alterations in Pulmonary Function Following Diagnostic Radiological Procedures.

Excerpt The increasing availability and utilization of diagnostic radiologic techniques in internal medicine make the proper evaluation of their hazards and limitations essential. This paper deals ...