The predictive value of a positive T-wave in aVR for the diagnosis of ischemic etiology in patients with cardiomyopathy

Background Ischemic cardiomyopathy (ICM) is a major contributor to left ventricular (LV) dysfunction, and differentiating it from non-ischemic causes is crucial for accurate diagnosis and appropriate management. While cardiac MRI remains the gold standard for diagnosing ICM, the presence of a positive T wave in lead aVR on electrocardiogram (ECG) has been proposed as a potential diagnostic marker (1). However, the diagnostic utility of this T wave for identifying ischemic cardiomyopathy, when compared to cardiac MRI as the reference standard, remains uncertain. Purpose The objective of this study was to evaluate the diagnostic accuracy of a positive T wave in lead aVR for identifying ischemic cardiomyopathy and to investigate factors associated with its presence, specifically whether it results from ischemia or ischemic scars, or whether it is a mirror image from the opposite leads. Methods This prospective, single-center study included patients with a left ventricular ejection fraction (LVEF) of ≤40% who underwent cardiac MRI between May 2020 and June 2024. The primary outcome was the diagnostic accuracy of a positive T wave in lead aVR for diagnosing ischemic cardiomyopathy, using cardiac MRI as the reference standard. Secondary outcomes included identifying factors associated with the presence of a positive T wave in lead aVR. Results Among the 547 patients enrolled, 92 (17%) exhibited a positive T wave in lead aVR. The sensitivity and specificity for diagnosing ischemic cardiomyopathy using a positive T wave in lead aVR were 19.6% and 86.8%, respectively. The positive predictive value was 66%, and the negative predictive value was 45%. Multivariate analysis showed that T wave inversion in leads I, II, and V6 was significantly correlated with the presence of a positive T wave in lead aVR. However, no significant association was found between abnormal MRI findings, including positive perfusion defects or myocardial scars (both ischemic and non-ischemic), and a positive T wave in lead aVR. Conclusion A positive T wave in lead aVR demonstrated low sensitivity but high specificity for diagnosing ischemic cardiomyopathy in patients with LV dysfunction. Additionally, the presence of a positive T wave in lead aVR was more strongly associated with T wave inversions in the opposing leads than with ischemic or scar-related changes in myocardial segments. Further research is needed to explore the clinical utility of this ECG finding in diagnosing ischemic cardiomyopathy.