Aims: There is conflicting data about the predictive value of absent septal q wave in patients with significant stenosis of proximal Left Anterior Descending coronary artery. To clarify the exact role of this simple electrocardiographic sign we conducted this prospective descriptive study.

Methods: Patients who were referred for coronary angiography in Milad Hospital between December 2008 and September 2009 were chosen randomly. Standard ECG was performed and reviewed for presence or absence of septal q wave, and then the coronary angiography was done and reported by another cardiologist.

Results: Of 148 patients with absent septal q wave in ECG, 85 patients (57%) had significant stenosis of proximal LAD in coronary angiography. Statistical analysis showed that significant stenosis of proximal LAD could be predicted by absence of septal q wave in ECG with sensitivity of 59% and specificity of 47%. However, Kappa statistic (Kappa = 0.36) showed low agreement between them.

Conclusion: Absence of normal septal q wave in ECG could be a low value predictor of coronary artery disease mainly significant proximal LAD stenosis.