Assessing the cause of T wave inversion in precordial leads with ECG mapping.

Inversion of the T wave in precordial leads in patients with angina pectoris is a predictor of coronary disease; however, it may also be seen in normal adults. The aim of this study was to assess the cause of T wave inversion by carrying out precordial electrocardiographic (ECG) mapping in 51 patients, who also underwent echocardiography and coronary angiography. The 37 patients in group A had atypical symptoms. They included 11 patients who showed M pattern mapping, of whom 7 had noncoronary cardiac disease and 4 were normal. In 23 other group A patients, whose mappings were in the N pattern, the angiography was normal. In the remaining three patients of this group, mappings were in the I pattern, with angiography revealing coronary disease in two of them and no disease in the third. The 14 group B patients all had typical angina; mappings were in the I pattern in 8 of the patients and in the N pattern in the remaining 6. Angiography revealed coronary artery disease in all patients with the I pattern mapping, while all those with the N pattern were found to be normal. Sensitivity, specificity, and positive predictive value for detecting normal subjects were all 100% for N pattern mapping; for detecting coronary disease, they were 100%, 90%, and 90% for I pattern mapping, respectively. It is concluded that precordial ECG mapping is an accurate method for the assessment of T wave inversion in precordial leads.