Differences in negative T waves among acute coronary syndrome, acute pulmonary embolism, and Takotsubo cardiomyopathy

AIMS: Negative T waves in precordial leads often occur in patients with acute coronary syndrome (ACS), but are also found in acute pulmonary embolism (APE) and Takotsubo cardiomyopathy (TC). Because the clinical features of these two diseases mimic those of ACS, differential diagnosis is essential to select an appropriate treatment strategy improve outcomes. This study aimed to clarify the differences in negative T waves among ACS, APE and TC. METHODS AND RESULTS: We studied admission ECGs in 300 patients (198 patients with ACS caused by the left anterior descending coronary artery disease, 81 with APE and 21 with TC). All patients were admitted within 48 h from symptom onset and had negative T waves ≥1.0 mm without ST-segment elevation in leads V1 to V4. The number and maximal amplitude of negative T waves were greatest in patients with TC, followed by in those with ACS, and were lowest in patients with APE (p < 0.001, respectively). The prevalence of negative T waves significantly differed in all 12 leads among the three groups (p < 0.01, respectively). Negative T waves in both leads III and V1 identified APE with 90% sensitivity and 97% specificity. Negative T waves in lead -aVR (i.e., positive T waves in lead aVR) and no negative T waves in lead V1 identified TC with 95% sensitivity and 97% specificity. These values represented the highest diagnostic accuracies. CONCLUSION: The distributions of negative T waves differed among ACS, APE and TC, and these differences were useful for differentiating among these three diseases.