Verticalization of frontal P axis on electrocardiography in patients with acute exacerbation of chronic obstructive pulmonary disease and asthma

Objective To investigate the clinical significance of verticalization of frontal P axis on electrocardiagraphy (ECG) in patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) and asthma. Methods Thirty five COPD patients and 20 asthma patients with acute exacerbation admitted in Jing′an District Central Hospital were enrolled and 20 health subjects served as a control group. The 12 lead ECG examination, pulmonary function test and high resolution CT (HRCT) scan of lung were performed. The P axis in ECG, pulmonary function and CT emphysema score were compared among three groups. The correlation of P axis verticalization with pulmonary function and CT emphysema score was analyzed. Results There were significant differences in P axis(F=24.36), FEV1/FVC(F=39.36), FEV1(F=28.82), FEV1%(F=30.64), FVC%(F=3.45), PEF%(F=13.22), RV/TLC(F=10.46) and total emphysema score (F=50.60) among the three groups (all P 60 ° as cut-off value for screening COPD, the sensitivity was 0.933, specificity was 0.667, positive predictive value was 0.833 and negative predictive value was 0.857. Conclusion The verticalization of frontal P axis on ECG is significantly associated with obstructive ventilation disorder and CT emphysema score, which can be used as a preliminary screening index for COPD. Key words: Pulmonary disease, chronic obstructive; Respiratory function test; Electrocardiography; Vectorcardiography; Pulmonary emphysema