Diseases of the chest最新文献

Cardiovascular responses to various stress tests have been studied in 13 nonsmokers, 16 moderate (20 cigarettes per day) and 13 heavy (40 cigarettes per day) smokers before and after cigarette smoking. Intra-arterial, pressure, ECG, respiration, and skin temperature were continuously monitored and recorded on tape. Dye dilution cardiac outputs were measured in some of the subjects. The analog data were analyzed on a digital computer using A-D conversion. Blood pressure, heart rate and cardiac output were not different in smokers and nonsmokers before and after smoking. Hyperreactor response to cold immersion by Hines' criteria was extremely frequent (30 percent to 58 percent) in all subjects with the use of continuous pressure measurement. A composite of maximal response, time of return and the area under the pressure curve is suggested for better definition of the cold pressor response. Presyncopal reactions during 40° head-up tilt were more frequent in heavy smokers after smoking.

Eighteen dogs who survived left lung reimplantation were submitted to repeated lung scans at intervals up to six months postoperation. In five dogs the scans were normal or near normal. The reimplanted lungs in these animals appeared grossly normal and the pulmonary angiogram and microscopic appearance were also normal. The lung scans in eight dogs had diminished perfusion of the left upper lobe. In these lungs there was loss of volume of the upper lobe but the angiogram was otherwise normal. Histologic abnormalities were found in some of these upper lobes. Five dogs showed no perfusion of the left lung which emphasized that survival of the animal is not necessarily associated with function of the lung. Lung scans were helpful in evaluating the pulmonary vascular bed of reimplanted lungs and in some cases where the angiograms appeared normal abnormalities were demonstrated in lung scans. In the present study no attempt was made to compare the abnormalities of pulmonary function.

Clinical data for the first 100 operations utilizing saphenous vein graft are presented. Eighty-seven percent of the patients were between 41 and 60 years of age, the youngest being 26 and the oldest 69. A combined simultaneous single internal mammary artery implantation and saphenous vein graft was done in 41 patients with no increase in the operative risk. The operative mortality rate was 5 percent. There were three late deaths. The most common complications were atrial fibrillation in 12 patients and myocardial infarction in seven. Fifty patients underwent postoperative cardiac catheterization. In 40, the graft was patent and the obstruction was totally relieved. Six patients showed significant narrowing, and in four the graft was closed. The grafts remained in good condition without dilatation over a year postoperatively.

The routine study of regional ventilation of the lungs has been hampered by the lack of safe, simple and accurate methods. Radioisotope techniques have made possible the development of such methods. Two varieties of radioactive scanning have been used: radiolabelled particulate material, and radioactive inert gases. We have performed scans using both inhaled technetium-99m albuminate particles and xenon 133 gas. Normal subjects and patients with pulmonary disease were studied. Particle inhalation in normal controls revealed adequate peripheral filling, although upper airway and gastrointestinal deposition occurred. In patients with pulmonary disease, however, underventilated zones of lung appeared totally unventilated with particle scans, while those with ¹³³Xe gas reflected ventilation disturbances more accurately. Further, a dynamic visualization of ventilation could be obtained using ¹³³Xe, while scans with ^99mTc albuminate indicated the cumulative result of several minutes of positive pressure breathing. It is concluded that both methods can offer important information, but each has its own limitations and advantages which should be recognized. Valuable insights into respiratory physiology and pathogenesis of pulmonary diseases can be obtained from these new techniques.