Cardiac Effect of Interstitial Lung Disease Correlated with Spirometry and Six Minute Walk Test.

INTRODUCTION: The cardiac effect of different pulmonary functions, six minute walk distance, arterial blood gases and saturation in Interstitial Lung Disease (ILD) is not much known. So this study, a tertiary care hospital experience that entails to know the various factors in Pulmonary Hypertension (PH) mentioned above causing PH and their correlation with PH. AIM: To study the correlation of PH in patients with ILD with spirometry and six minute walk test (6MWT).
MATERIALS AND METHODS: All consecutive patients with confirmed diagnosis of ILD taken over a period of 1½year in tertiary care hospital. 6MWT and spirometry were performed as per the American Thoracic Guidelines. Percent predicted 6 minute walk distance was calculated using Enright et al., and Indian reference equation. PH was diagnosed using 2-D echo. The spirometry variables and 6MWT were then correlated with the mean pulmonary artery pressure.
RESULTS: There were 75 patients. About 66.66 % had PH on 2-D echo. The mean% predicted six minute walk distance as per the Indian reference equation, pre- and post- exercise PaO2 as well as desaturation had a significant correlation with PH. Spirometry variables Forced Expiratory Volume in First Second (FEV1) and Forced Vital Capacity (FVC) did not correlate with PH.
CONCLUSION: Thus, the 6MWT correlated significantly with PH while spirometry did not.