Differentiation of transmural and nontransmural infarction using speckle tracking imaging to assess endocardial and epicardial torsion after revascularization

Abstract

Assessment of transmural extent (TME) of necrosis after acute myocardial infarction (MI) remains a major problem in clinical practice. The study sought to determine whether speckle tracking imaging (STI) could differentiate transmural from nontransmural acute MI by assessment of endocardial and epicardial torsion. TME of infarct was measured by contrast-enhanced magnetic resonance imaging. Patients were divided into two groups according to TME (transmural MI group [TME ≥ 50%, n = 36] and nontransmural MI group [TME < 50%, n = 35]). As a control group, 30 subjects without evidence of structural heart disease were included. Conventional echocardiography and STI were done in controls and patients before and 1 month after percutaneous coronary intervention. Compared with control subjects, endocardial and epicardial torsion in patients with transmural and nontransmural MI were all extremely decreased (all P < 0.01). One month after percutaneous coronary intervention, there was no significant increase in endocardial and epicardial torsion in transmural MI patients. However, apical rotation and left ventricular torsion resumed slightly but significantly in the epicardium (but not endocardium) in patient with nontransmural MI (3.11 ± 0.81 vs. 4.37 ± 1.15°, P < 0.01; 3.69 ± 1.07 vs. 5.52 ± 1.89°, P < 0.01, respectively). The combined evaluation of endocardial and epicardial torsion by STI may be used to differentiate transmural from nontransmural MI after revascularization.