The value of the change of QRS voltage in lead aVR on the differential diagnosis of bronchial asthma and cardio-genic asthma

Abstract

Objective To investigate the clinical significance of the change of QRS voltage in lead aVR in the differential diagnosis of bronchial asthma and cardiogenic asthma. Methods The QRS voltage in lead a VR of 69 patients with cardiogenic asthma and 60 patients with bronchial asthma were surveyed before onset, after onset and cure of illness, that of 90 normal adults were measured at latest two checkup, and then the results of its change were analyzed. The accuracy rate, sensitivity rate and specificity of this new algorithm in the differential bronchial asthma and cardiogenic asthma were calculated. Results It is obvious to the change of QRS voltage in lead aVR of patients with cardiogenic asthma between before onset and after onset of illness or between after onset and cure of illness, the difference was statistically significant(P= 0.035), while the QRS voltage in lead aVR of patients with bronchial asthma and normal adults were not change, the difference was not statistically significant(P= 0.185,0.393). The accuracy rate of the new algorithm in the differential diagnosis of bronchial asthma and cardiogenic asthma was 91.67%,specificity was 85.71%,sensitivity was 94.87%,and positive predictive value was 92.50%%,negative predictive value was 90.00%. Conclusion The change of QRS voltage in lead aVR of patients with cardiogenic asthma before onset, after onset and cure of illness was obvious, while that of patients with bronchial asthma was not positive. Change of QRS voltage in lead aVR is associated with excellent accuracy rate, sensitivity rate for differential diagnosis of bronchial asthma and cardiogenic asthma. This algorithm is simple and could be easily learned and applied by physician. Key words: Asthma; ElectroCardiography