Differences in Initial Electrocardiographic Findings of Apical Takotsubo Syndrome According to the Time from Symptom Onset.

No previous study has examined the differences in patient characteristics and initial electrocardiographic findings of Takotsubo syndrome (TTS) according to the time from onset to electrocardiography. Using the Tokyo Cardiovascular Care Unit network registry 2011-2012, we retrospectively identified 106 apical TTS patients in whom symptom onset time was specified, and classified the patients into 5 groups according to the time from onset to the initial electrocardiography: <3 hours (n = 45), 3 to 6 hours (n = 20), 6 to 12 hours (n = 12), 12 to 24 hours (n = 13), and ≥24 hours (n = 16). There was no significant difference across the groups in age, gender, symptoms, triggers, vital signs, blood tests, or in-hospital outcomes. In the electrocardiographic findings, ST-elevation was more frequent in leads V2-V4 than in the other leads, especially in the <24 hour groups, but did not differ significantly across groups. T-wave inversion was more frequent in leads V3-V6, especially in the ≥24 hour group, and differed significantly across groups. The total number of leads with T-wave inversion was significantly larger in the ≥24 hour group than in the <24 hour groups (mean, 5.9 leads vs 1.5 to 2.9 leads; p < 0.001). Isolated ST-elevation was the most frequent pattern of ST-T change in precordial leads (42% to 56%) in the <24 hour groups, while isolated T-wave inversion was the most frequent (44%) in the ≥24 hour group (p = 0.018). Neither ST-elevation nor T-wave inversion was observed in precordial leads in 10 (9%) patients. In conclusion, our results suggest that the initial electrocardiographic findings of apical TTS are affected by the time from onset to electrocardiography and display a wide variation in ST-T changes.