Enhancing echocardiographic diagnosis of typical Takotsubo syndrome: validation of IAR and ILAR indexes
Matteo Pernigo, Marco Berti, Emanuele Maria Renga, Fabiana Cozza, Marco Bernardo Sbolli, Antonio MaggiAims
Takotsubo syndrome (TTS) and anterior ST-elevation myocardial infarction (AMI) with apical involvement often present with overlapping clinical and echocardiographic features, making early differential diagnosis challenging. Novel echocardiographic indices may aid rapid, bedside discrimination. The objective of the study was to evaluate the diagnostic accuracy and reproducibility of two new echocardiographic indices – inferior-apex ratio (IAR) and infero-lateral-apex ratio (ILAR) – in distinguishing typical TTS from anterior STEMI. Secondary objectives included comparison with segmental strain values and inter-observer reproducibility.
Methods and results
This retrospective study analyzed 2D and speckle-tracking echocardiography of 50 patients with confirmed TTS and 50 with AMI and apical akinesis. IAR and ILAR were calculated from standard apical views. Diagnostic performance was assessed via receiver-operating characteristic analysis. Longitudinal strain was evaluated in all myocardial segments. Inter-observer reproducibility was tested. ILAR and IAR were significantly lower in TTS vs. AMI (ILAR: 0.78 ± 0.32 vs. 1.99 ± 0.85; IAR: 0.86 ± 0.42 vs. 1.71 ± 0.71;
Conclusions
IAR and ILAR are simple, reproducible, and accurate echocardiographic markers for differentiating TTS from AMI at the bedside. Their use may improve early diagnostic confidence and guide appropriate clinical management.