The mechanics of pulmonary ventilation in patients with heart disease
| Autor: | Richard V. Ebert, Cyrus C. Brown, Donald L. Fry |
|---|---|
| Rok vydání: | 1954 |
| Předmět: |
medicine.medical_specialty
Lung Heart disease business.industry General Medicine Cardiac asthma medicine.disease Umbilical cord respiratory tract diseases Surgery medicine.anatomical_structure Heart failure Internal medicine Respiration medicine Cardiology In patient Lung volumes medicine.symptom business |
| Zdroj: | The American Journal of Medicine. 17:438-446 |
| ISSN: | 0002-9343 |
| DOI: | 10.1016/0002-9343(54)90119-9 |
| Popis: | 1.1. Using intraesophageal pressure as a measure of intrathoracic pressure, the elastic forces of the lung were studied in patients with heart disease. Pressure-volume diagrams were constructed by plotting the degree of lung inflation against the static intrathoracic pressure. An alteration in the elastic forces in the lungs of these patients was shown by the finding of an increase in the pressure required to produce a 100 cc. change in lung volume as compared with normal subjects. 2.2. A high correlation was demonstrated between the reciprocal of the vital capacity and the pressure change per 100 cc. change in lung volume both in normal subjects and patients with heart disease. The lung elasticity curves for normal subjects and patients with heart disease were identical when the level of lung inflation was expressed in terms of per cent of the vital capacity. 3.3. Pressure-flow curves were obtained from patients with heart disease. Comparison of the pressure-flow relationships obtained in these patients when breathing air and argon-oxygen demonstrated that tissue friction was a negligible factor and that the resistance to movement of the lungs was caused by resistance to gas flow. 4.4. Resistance to air flow was evaluated in patients with heart disease. It was found to be increased in certain patients with heart failure and normal in other patients. No correlation was found between resistance to air flow and reduction of vital capacity in these patients. 5.5. There may be no increase of resistance to air flow in patients with cardiac disease and exertional dyspnea. For this reason it appears that exertional dyspnea is most closely related to the reduction in vital capacity and altered elastic properties of the lung. On the other hand, it is likely that increased resistance to air flow plays an important role in the dyspnea of cardiac asthma. |
| Databáze: | OpenAIRE |
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