Differences in Negative T Waves Between Takotsubo Cardiomyopathy and Reperfused Anterior Acute Myocardial Infarction

BACKGROUND: In both takotsubo cardiomyopathy (TC) and reperfused anterior acute myocardial infarction (AMI), negative T waves commonly appear on the ECG in the subacute phase. This study aimed to clarify the ECG differences between these diseases. METHODS AND RESULTS: We compared the ECGs with the greatest amplitude of negative T wave from 34 patients with TC and 237 patients with a first reperfused anterior AMI who were admitted within 6 h of symptom onset and who had no abnormal Q-waves on discharge ECG. Time from symptom onset to recording the ECG did not differ between TC and anterior AMI (2.4 ± 1.5 vs. 2.1 ± 2.0 days, P = 0.48). TC was associated with a greater maximal amplitude of negative T wave (1.00 ± 0.44 vs. 0.79 ± 0.46 mV, P = 0.044), and a greater number of leads with negative T waves (9.5 ± 1.0 vs. 6.0 ± 2.1, P<0.001). Negative T waves were consistently observed in leads -aV(R) and V(4-6), whereas negative T waves were rare in lead V(1) in TC. Negative T waves in lead -aV(R) (ie, positive T waves in lead aV(R)) and no negative T waves in lead V(1) identified TC with 94% sensitivity and 95% specificity, representing the highest diagnostic accuracy. CONCLUSIONS: During the subacute phase, deeper negative T waves were more frequently and broadly distributed, particularly around leads facing the apical region, in TC than in reperfused anterior AMI.