Performance of electrocardiographic criteria to differentiate Takotsubo cardiomyopathy from acute anterior ST elevation myocardial infarction

Background: The initial electrocardiogram (ECG) in Takotsubo cardiomyopathy (TC) can mimic an acute, anterior ST-segment elevation myocardial infarction (STEMI). Given the profound and immediate treatment differences between TC and STEMI, it would be clinically valuable to distinguish them using ECG criteria. Methods: Presenting ECGs for proven cases of TC and acute, anterior STEMI were retrospectively collected. QRS onset and J-point were manually identified using custom software to compute median ST deviation for each lead. Six published ECG criteria were examined for diagnostic accuracy using the clinical diagnosis as the gold standard. Results: 33 TC and 263 acute, anterior STEMI cases were identified. ST-segment deviation differed significantly between groups for all leads except aVR, I, V5, and V6. All six published ECG criteria showed a marked reduction in diagnostic accuracy in our validation cohort, except for a combination of ST-elevation in leads V2 < 1.75 mm and V3 < 2.5 mm (sensitivity 79%, specificity 73% for TC). Conclusion: Our study demonstrates the limited diagnostic accuracy of published ECG rules to distinguish TC from acute, anterior STEMI. Given the rarity of TC and the clinical consequences of a "false positive" TC diagnosis based on ECG criteria alone, such rules should not be used in practice. TC remains a diagnosis of exclusion after emergent angiography in patients with an acute coronary syndrome and significant ST-segment elevation.