Absence of Septal Q Waves an Important Predictor of Significant Coronary Artery Disease and Mainly Proximal Stenosis of the Left Anterior Descending Artery

Data concerning the correlation between the absence of septal q waves and significant stenosis of proximal left anterior descending (LAD) artery shows conflicting results. This retrospective study was conducted to show that absence of septal q waves in leads V5-V6 could be of value in predicting significant coronary artery disease (CAD) and mainly significant proximal LAD coronary artery stenosis.Our study included 500 consecutive patients who had coronary angiography, retrospectively chosen, excluding patients with acute coronary syndromes, and patients with abnormal ECGs (abnormal QRS duration, pathological q waves and hemiblocks). ECG and angiography films were reviewed. For the 2x2 tables analysis, a chi-square test was used.Of the 500 patients, 386 had significant CAD defined as 70% luminal stenosis, and 260 had no septal q wave. Of the 386 patients with significant CAD, 233 (60%) did not have septal q waves. Of 260 who did not have septal q wave, 192 (73%) had significant stenosis of proximal LAD. Statistical analysis shows that significant CAD correlates with the absence of septal q waves, with a sensitivity of 60% and a specificity of 76%, and that stenosis of proximal LAD could be predicted by absence of septal q waves in leads V5-V6 with a sensitivity of 83% and a specificity of 74%.The absence of septal q waves in leads V5-V6 on the ECG correlates with the presence of significant CAD and is of highly predictive value in those with significant stenosis of proximal LAD (p < 0.0001).