Background: U wave inversion and presence of stenosis of left anterior descending/left main coronary remains unclear. When this wave can be considered for diagnosis, influencing factors, and the patients clinical condition, there are still no papers that discuss it. Methods: A systematic search was conducted through PubMed/MEDLINE and ScienceDirect databases. This systematic review used all studies in the field of U wave inversion in correlation with the presence of stenosis of left anterior descending/left main coronary artery indefinitely. Result: The search yielded 22 studies involving a total of 2637 patients were obtained for the present study. About 11 studies reported exercise induced U waves, while 8 studies reported U wave in resting patients. The presence of U wave was frequently found in patients during angina attack, however 6 studies reported U wave in absence of angina attack patients. The incidences of U wave inversion in LAD stenosis were reported in 14 studies, 2 studies reported the presence of prominent U wave in LAD stenosis, and 4 studies reported both waves were found in patients with LAD stenosis. About 13 studies reported angina attack in patients with LAD narrowing. Conclusion: Inverted U waves are associated with the incidence of LAD/LMCA stenosis and are more common than prominent U waves in patients with symptomatic chest pain. These waves can be identified in patients either at rest or during exercise testing.