Electrocardiographic screening for emphysema: The frontal plane P axis

Background: Because the most characteristic and sensitive electrocardiograp hic (ECG) correlate of pulmonary emphysema in-adults is verticalization of the frontal plane P-wave vector (P axis), we investigated its strength as a lone criterion to screen for obstructive pulmonary disease (OPD) in an adu lt hospital population. Methods: In all, 954 consecutive unselected ECGs were required to yield 100 with P axis greater than or equal to +70 degrees (unequivocally negative P in aVL during sinus rhythm) and pulmonary function tests, and 100 with P a xis less than or equal to +50 degrees (unequivocally positive P-aVL). Results: Obstructive pulmonary disease by both pulmonary function test and clinical criteria was present in 89 of 100 patients with vertical P axes an d 4 of 100 patients without OPD. Conclusion: The high sensitivity (89% for this series) and high specificity (96%) makes vertical P axis a useful screening criterion. Its at-a-glance simplicity makes it "user-friendly.".