Regional lung perfusion and pulmonary artery pressure in chronic obstructive lung disease

In 22 chronic bronchitics with or without emphysema, the authors measured regional pulmonary perfusion in the supine position and calculated the ratios of radio-active tracer (131I-MAA) concentrations in the lung apices and bases (U/L ratio). This ratio was found to be normal in the right lung and tendentially high (though not to a statistically significant degree) in the left lung, this being probably due to the presence of an enlarged heart (13 patients showed evidence of right ventricle hypertrophy and/or overload). The correlation between the U/L ratio and functional impairment of respiration expressed spirometrically failed to reach statistical significance and the same was true of the correlation between the U/L ratio and mean pulmonary arterial pressure at rest.