Verticalization of frontal P axis on electrocardiography in patients with acute exacerbation of chronic obstructive pulmonary disease and asthma / 中华全科医师杂志

ABSTRACT

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), FEV 1/FVC( F=39.36), FEV 1( F=28.82), FEV 1%( 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<0.01). P axis was positively correlated with age( r=0.229), total emphysema score( r=0.567), upper lung emphysema score( r=0.542), middle lung emphysema score( r=0.507), lower lung emphysema score( r=0.572)(all P<0.01), and negative correlation with body mass index( r=-0.491), cardiothoracic ratio ( r=-0.396), FEV 1/FVC( r=-0.609), FEV 1( r=-0.389), FEV 1%( r=-0.460), and PEF% ( r=-0.419)(all P<0.01). Taking P axis>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.