A PATHOLOGICAL study of the lungs and heart in fatal and non-fatal chronic airways obstruction.

The lungs and hearts from 50 patients were examined using morphometric techniques to determine the size of the right ventricle, the amount, type, and distribution of emphysema, the size of the bronchial mucous glands, and the proportion of the lung occupied by small airways of less than 2 mm diameter. The patients were divided into three groups according to the clinical history: 18 died as a result of chronic airways obstruction, 17 had symptoms of chronic chest disease but died from some unrelated cause, and 15 had no symptoms related to the respiratory system. The total amount of emphysema was found to be greater in the fatal than the symptomatic group who in turn had more emphysema than the asymptomatic group. A positive correlation was found between the amount of emphysema and the right ventricular weight. The amount of panlobular emphysema in the lung was found to be greater in the fatal group than in the others but this did not apply to the amount of centrilobular emphysema. The amount of panlobular, but not centrilobular, emphysema showed a positive correlation with right ventricular weight. As the total amount of emphysema increased it was found that there was an increase in each of three zones in the lung-apical, middle, and lower. There was no relationship between the bronchial mucous gland size and either the clinical state of the patients with symptoms or the right ventricular weight. The proportion of lung occupied by the lumen of small airways was significantly reduced in the fatal group as compared to the other two groups and also showed a negative (inverse) correlation with right ventricular weight. The total amount of emphysema, the amount of panlobular emphysema, and reduction in small airways lumen in the lung are the three factors in chronic airways obstruction which are quantitatively related to death in chronic airways obstruction and to right ventricular weight.