Abstract 4238: Speckle Tracking Echocardiography can Identify the Location of Myocardial Injury in Acute Myocarditis
Objective. Our aim was to test whether speckle tracking echocardiography (STE) could help for the location of myocardial injury in acute myocarditis. We hypothesized that edema located in areas of acute myocardial injury (defined using MRI as gold standard) increases circumferential strain measured with STE.
Methods. Ten consecutive patients admitted for acute myocarditis, defined as acute chest pain, elevated troponin, normal coronary angiogram and presence of epicardial delayed enhancement with cardiac MRI, were studied. For each patient, left parasternal short axial views were acquired in 2D mode at basal, mid-ventricular and apical levels on the same day as cardiac MRI and divided into a 16-segment model. Circumferential strain (CS) and radial strain (RS) were automatically calculated for each segment (n=160) using a dedicated workstation. We compared strain values between segments with or without epicardial delayed enhancement by cardiac MRI.
Results. Patients had a mean age of 41 years and a mean troponin peak value of 12.7 μg/L. Ten minutes after gadolinium injection, 35 segments had epicardial delayed enhancement with cardiac MRI. Cardiac segments with epicardial delayed enhancement had a lower CS value as compared to segments with no delayed enhancement (−6.4 ± 8.2 % vs. −16.7 ± 7.1 %, respectively; p < 0.05), but similar RS values (37.7 ± 16.8 % vs. 38.4 ± 15.9 %, respectively; p = 0.86). A threshold of CS ≥ −10 % identified segments with epicardial delayed enhancement with a specificity of 87 % and a sensitivity of 71 % (AUC of the ROC curve: 0.78). Therefore, CS on STE is correlated to epicardial delayed enhancement with cardiac MRI.
Conclusion. This pilot study shows that STE can identify myocardial segments with epicardial delayed enhancement on MRI. Further studies will explore the relative diagnostic performance of both techniques for the diagnosis of acute myocarditis.