Late Breaking Abstract - Electrical Impedance Tomography (EIT) determines the pulmonary ventilation heterogeneity in patients with normal and preserved ratio impairment of lung function

<bold>Purpose:</bold> The purpose of our study was whether EIT can detect spatial and temporal heterogeneity of ventilation during lung function testing in patients with normal one-second rates. <bold>Methods:</bold> This study is a prospective observational study that enrolled 131 patients who presented to Shaw Hospital with respiratory symptoms and required pulmonary function testing between. Based on the pulmonary function test and EIT examination(Figure1EIT analysis images during lung function testing (after bronchodilation test). A: PRISm group;B: normal group). <fig><object-id>erj;64/suppl_68/PA1238/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> <bold>Results:</bold> Compared with the normal group(n=88), the PRISm group(n=26) had higher prevalence of hypertension (p<0.001), CAT score (P=0.019) and SGRQ score (P=0.017). The PRISm group showed greater temporal and spatial heterogeneity in lung ventilation. GI of FVC, FEV1, FEV1/FVC, MEF25-75, T75, and FIVC differentiated PRISm patients from normal patients. In the normal group, EIT could exhibit lung function characteristics partially similar to those observed in the PRISm group. Furthermore, subgroup analysis using a cutoff score of 25 for the SGRQ revealed correlations with EIT- FEV1/FVC abnormal area and GI-FEV1/FVC, time constant. <bold>Conclusion:</bold> With EIT-based lung function assessment, we can sensitively identify spatial and temporal heterogeneity of regional lung function in patients with normal one-second rates.