NEW CORRELATION BETWEEN ANGLES OF WIDE QRS COMPLEX IN ELECTROCARDIOGRAM AND ECHOCARDIOGRAPHIC INDICES

BACKGROUND: Heart failure (HF) due to left ventricular (LV) systolic dysfunction has lesser survival than diastolic HF.We examined the correlation of two new angles(α and β) of QRS complex in the electrocardiogram (ECG) with indices including left ventricular ejection fraction (LVEF),left ventricular end systolic dimension (LVESD) and left ventricular end diastolic di-mension (LVEDD) for predicting LVEF. METHODS: In this cross–sectional study,159 subjects with clinical signs of LV systolic dysfunc-tion who presented to the Al-Zahra hospital in Isfahan, Iran, underwent echocardiography.First,on the ECG,two new angles defined and then these two angles compared manually and with computerized analysis by two different observers blinded to the another data. After confir-mation of excellent correlation between these two forms, then two angles measured manually with protractor in 159 patients (wide QRS complex in 59 and normal in 100 patients). Then, cor-relation between these angles and echocardiographic indices were assessed. RESULTS: Statistical analysis revealed that in normal QRS complex, there was no correlation between any of two angles and echocardiographic indices. In contrast, in wide QRS complex,β angle and β/α ratio was correlated with any three echocardiographic indices (negative correla