Differentiating typical Tako-tsubo syndrome from extensive anterior STEMI: Look behind the anterior wall

Background Tako-tsubo syndrome (TTS) in its most typical form shares common features with anterior ST-segment elevation myocardial infarction (AMI) during acute presentation. Differential diagnosis between the two conditions is often challenging especially if ST-segment elevation is associated with extensive apical akinesis. Methods We sought to systematically analyze ECG and echocardiographic parameters including LV longitudinal strain and two new indexes: the inferior-apex ratio (IAR) and the inferior-lateral-apex ratio (ILAR), to assess if ventricular involvement may be different in TTS and AMI. Results A retrospective cohort study was conducted with two groups: patients with TTS (n = 22) and patients with extensive anterior STEMI (n = 22). Lack of ST elevation in V1 was associated with TTS with sensitivity and specificity of 86%, positive and negative predictive value of 86%. Longitudinal strain in mid inferior and mid inferior-lateral segments were more compromised in TTS: -4.3 +/- 6.4% and -5.4 +/- 5.4% in TTS versus -10.2 +/- 5.5% and -9.9 +/- 4.9% in AMI, respectively (p < .01 for all). By multivariate analysis, both longitudinal strain values, inferior-apical ratio (IAR) < 1 and inferior-lateral-apical ratio (ILAR) < 1 were independently associated with diagnosis of TTS during acute phase. Conclusions Our results suggest that impaired contractility extending beyond apex to mid inferior and inferior-lateral walls can be easily assessed by IAR and ILAR, and these indexes facilitate non-invasive differentiation of TTS from extensive anterior STEMI.