Negative T waves (NTWs) in right precordial leads (V-1 to V-3) may be observed on the electrocardiogram (ECG) of healthy subjects but can also represent the hallmark of an underlying arrhytlunogenic right ventricular cardiomyopathy (ARVC). It has been a consistent observation that NTWs usually become upright with exercise in healthy subjects without underlying heart disease. No systematic study has evaluated exercise-induced changes of NTWs in ARVC. We assessed the prevalence and relation to the clinical phenotype of exercise-induced right precordial NTWs changes in 35 patients with ARVC (19 men, mean age 22.2 +/- 6.2 years). Forty-one healthy subjects with right precordial NTWs served as controls. At peak of exercise (mean power 149 +/- 43 W, mean heart rate 83.6 +/- 12.6% of target), NTWs persisted in 3 patients with ARVC (9%), completely normalized in 12 (34%), and partially reverted in 20 (57%). Patients with ARVC with or without NTWs normalization showed a similar clinical phenotype. The overall prevalence of right precordial T waves changes during exercise (normalization plus partial reversal) did not differ between patients with ARVC and controls (92% vs 88%, p = 1.0), whereas there was a statistically nonsignificant trend toward a greater prevalence of complete normalization in controls (56% vs 34%, p = 0.06). In conclusion, our study demonstrated that right precordial NTWs partially or completely revert with exercise in most patients with ARVC, and NTWs normalization is unrelated to the clinical phenotype. Exercise-induced NTWs changes are inaccurate in differentiating between ARVC patients and benign repolarization abnormalities. (C) 2013 Elsevier Inc. All rights reserved.