ORIGINAL ARTICLE Differentiating Typical Tako-Tsubo Syndrome from
extensive anterior STEMI: look behind the anterior wall
Abstract
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 2 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 vs -10.2±5.5%
and -9.9 ±4.9% in AMI, respectively (P<0.01 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.