Significance of upright t waves in precordial lead V1 as to its correlation with coronary artery disease and in particular the circumflex coronary artery

Purpose: The T wave in precordial lead V1 is normally inverted in normal adults. The significance of an upright T wave in precordial lead V1 as to the presence of coronary artery disease is controversial and not well studied in the literature. Our purpose is to show the relation between an upright T wave in V1 and the presence of coronary artery disease and specifically that of the circumflex

Material and methods: We studied, retrospectively, 624 consecutive patients referred for cardiac catheterization with normal electrocardiograms excluding patients with acute coronary syndromes, bundle branch blocks, left ventricular hypertrophy, intraventricular conduction delays, pacemakers, ST-T changes, significant valvular heart disease, cardiomyopathies and metabolic disorders. Significant coronary artery stenosis was considered when the stenosis was > 70%; normal or nonsignificant coronary artery stenosis was considered when the coronary stenosis was < 70% [all patients had < 50% coronary stenosis]. The ECG's and coronary arteriographies were reviewed. The 2x2 chi-square was used for statistical analysis

Results: Out of the 624 patients, 380 [60.89%] had normal coronary arteries out of which only 17 [4.47%] had an upright T wave in V1, 244 [39.11%] had significant coronary artery disease out of which 137 [56.14%] had positive T wave in V1, significantly more than the normal population with a p value < 0.0001. A total of 142 patients had significant circumflex stenosis out of whom 128 [90.1%] had a positive T wave in V1; a total of 482 patients had no significant circumflex stenosis, out of whom only 26 [5.39%] had a positive T wave in V1, the difference was highly significant with a p value < 0.00001 as to the presence of a T upright in V1 in patients with significant circumflex stenosis. This significance was maintained when excluding the patients with diabetis mellitus

Conclusion: An upright T wave in V1 is significantly related to the presence of significant coronary artery stenosis and specifically the circumflex coronary artery

Absence of septal Q waves an important predictor of significant coronary artery disease and mainly proximal stenosis of the left anterior descending artery

Aims: 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

Methods: 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

Results: 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%

Conclusion: 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]