Background: The aim of present study was to assess left ventricular myocardial deformation detected by 2D STE in patients with suspected acute myocarditis (AM) early on admission in whom later cardiac magnetic resonance (CMR) evaluation was performed.
Methods: A total of 47 patients with suspected AM based on clinical practice were prospectively enrolled. Coronary angiography was performed on all patients to rule out significant coronary artery disease. CMR confirmed myocardial inflammation, oedema, and regional necrosis meeting the Lake Louise criteria in 25 patients (53%, oedema (+) subgroup). In the remaining patients, only LGE was confirmed in the sub-epicardial or intramuscular localization (22 patients, 47%, oedema (-) subgroup). Early on admission, echocardiography with measurements of global and segmental longitudinal strains (GLS), circumferential strains (GCS) at the endocardial (endocardial GCS) and epicardial (epicardial GCS) layers, transmural GCS, and radial strains (RS) were performed.
Results: Mild reduction of GLS, GRS, and transmural GCS values were found in patients with oedema (+) subgroup. The epicardial GCS turned out to be the diagnostic factor for oedema with a cut-off point of 13,0% (AUC 0.747, p = 0.0005). Twenty-two patients (all but three) with an acute phase of myocarditis and epicardial GCS -13.0% or less had oedema confirmed by CMR.
Conclusions: 2D STE can help to set the diagnosis of AM in patients with acute chest pain with a normal coronary angiogram. The epicardial GCS can serve as a diagnostic factor for oedema in patients with early stage of AM. In patients presenting with signs of AM (oedema in CMR), the epicardial GCS is modified in comparison with a subgroup without oedema; therefore, this parameter could be used to improve the performance of ultrasound.
Keywords: acute myocarditis; cardiac magnetic resonance; two-dimensional speckle-tracking echocardiography.