T wave abnormalities identify patients with previous lateral wall myocardial infarction and circumflex artery disease.

Background: The diagnosis of previous lateral myocardial infarction is based on QRS morphology.

Objectives: To explore the diagnostic role of T wave abnormalities.

Methods: We studied 166 patients with known or suspected ischemic heart disease who underwent a 12-lead electrocardiogram, myocardial perfusion scintigraphy, and coronary arteriography within 90days. We excluded patients with bundle-branch block, hypertrophy, or paced rhythm.

Results: Only one patient had a prominent R wave in V1, no patient showed lateral Q waves of necrosis. T wave amplitude in V2-V6 ≥0.6mV, and T wave amplitude in lead 1+V6 ≤0mV detected a lateral infarction (sensitivity 33 and 44%, specificity 83 and 80%). T wave amplitude in lead 1+V6 ≤0mV was the only independent predictor of infarction or LCx occlusion (AUC 0.72 and 0.74). Serum potassium values were not associated with T wave abnormalities.

Conclusion: T wave abnormalities identify previous lateral infarction and LCx disease.