Abstract
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 6h 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±0.46mV, 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 -aVR and V4-6, whereas negative T waves were rare in lead V1 in TC. Negative T waves in lead -aVR (ie, positive T waves in lead aVR) and no negative T waves in lead V1 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. (Circ J 2012; 76: 462-468)
