Regional distribution of ventilation and perfusion in the lung has been studied using Xe133 in normal subjects. In 31 subjects seated upright at rest the previous findings of a gradient of ventilation and perfusion distribution from apex to base of the lung, have been confirmed. The results agree well with those obtained using C15O2. In seven normal subjects lying supine, the V/Q distribution from apex to base of the lung is much more uniform, though a perfusion gradient can be shown to exist from front to back. Five normal subjects exercising on a bicycle ergometer in the upright posture were found to have a proportionately much greater blood flow through the upper zone of the lung than when in the same position at rest. One study during induced syncope on standing indicated that this state is accompanied by a progressive decrease in perfusion to the upper zones of the lung. No change in distribution occurred breathing 100% oxygen. xenon 133; posture; exercise; syncope; oxygen Submitted on August 30, 1963

No abstract

Pulmonary vascular topography has been studied at our Institute over the last two years to evaluate more adequately the pulmonary vasculature in obstructive lung disease. This investigation has stressed comparison studies of the various parameters of pulmonary function, full chest laminagraphy, pulmonary angiography and more recently lung scanning. To our knowledge this type of correlation has not been previously reported. Evaluation by lung scanning was made in a preliminary fashion as a further detailed study is in progress.The twofold purpose of this study was: (1) to determine whether there was a correlation of the clinical picture, pulmonary function studies, chest laminagraphy, pulmonary angiography and lung scanning in order to differentiate more adequately bronchial asthma and emphysema, and (2) to delineate more effectively regional impairments of circulation in obstructive lung disease, namely: (a) local (one area-lobe or segment), (b) regional (more than one lobe), (c) unilateral lesions, involving most or all of the one lung and (d) diffuse involvement, with approximately an equal degree of impairment throughout both lungs.By differentiating bronchial asthma from emphysema, we hope to determine more adequately both the diagnosis and prognosis of the types of obstructive lung disease. This is particularly important in younger individuals, in whom the diagnosis of obstructive lung disease is extremely valuable in longterm management. Moreover, by a more exact definition of the extent of abnormal ventilation and perfusion, earlier and more vigorous therapy can be instituted which might possibly prevent or minimize cardiopulmonary complications. Consequently, a greater number of patients might be rehabilitated or maintained as productive workers. Preliminary reports from two medical centers have already lent support to this newer concert.