Electrocardiographic disturbances in Takotsubo syndrome have been previously partially described but their consequences remain mostly unknown. Our aim was to describe the prevalence and prognostic significance of different electrocardiographic features in patients with Takotsubo syndrome. Our data come from the Spanish multicenter REgistry of TAKOtsubo syndrome (RETAKO). All patients with an available 12-lead surface electrocardiogram at admission and 48 hours post-admission were included. A total of 246 patients were studied, mean age was 71.3±11.5 and 215 (87.4%) were women. ST-segment elevation was seen in 143 patients (59.1%) and was present in ≥2 wall leads in 97 (39.8%). Exclusive elevation in inferior leads was infrequent (5 - 2.0%). After 48 hours, 198 patients (88.0%) developed negative T waves in a median of 8 leads with a mean amplitude of 0.7±0.5 mV and 137 (60.9%) had pathological Q waves. The mean corrected QT interval was 520±72 ms. Corrected QT interval was independently associated with the primary endpoint of all-cause death and nonfatal cardiovascular events (p=0.002) and all-cause death (p=0.008). A higher heart rate at admission was an independent predictor of the primary endp...