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

J Clin Diagn Res. 2017 Feb;11(2):OC14-OC17. doi: 10.7860/JCDR/2017/21357.9292. Epub 2017 Feb 1.

Abstract

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.

Keywords: Forced Expiratory Volume in First Second; Forced Vital Capacity; PaO2; Pulmonary hypertension.