1Universitätsklinikum Erlangen Medizinische Klinik 2 Erlangen, Deutschland
BACKGROUND:
Two-dimensional (2D) speckle tracking transthoracic echocardiography (STE) allows detailed analysis of myocardial function and has been used for the diagnosis of acute myocarditis. While cardiac magnetic resonance tomography (MRI) is the non-invasive gold standard to diagnose myocarditis, strain imaging is usually not part of the diagnostic algorithm. Layer-specific strain analysis by cardiac MRI may provide highly detailed information, but the correlation between layer-specific strain in MRI and STE is still not well known.
METHODS:
We analyzed cardiac MRI (MAGNETOM Sola or Aera 1,5T, Siemens Healthineers, Forchheim, Germany) data sets of patients with conformed acute myocarditis and in whom 2D-STE was available. In cardiac MRI; electrocardiographically gated steady-state free precession cine images were acquired in short-axis, four-chamber, two-chamber, and three-chamber views for functional myocardial assessment and strain analysis,. For contrast enhancement (LGE) gadobutrol (Gadovist, Bayer Healthcare) was administered. A semiautomatic software was used to quantify STE (Viewpoint, GE HealthCare) and layer-specific strain by MRI (CVI42, Version 5.11.5, Circle Cardiovascular Imaging). In this analysis, we compare 2D speckle tracking obtained by TTE with layer-specific strain analysis by MRI in patients with acute myocarditis.
RESULTS:
Data sets from 33 patients (36±12 years, 74% male) were available. Overall, for layer-specific strain analyses in cardiac MRI, the mean global peak longitudinal strain was -15.1±2.5%, for global peak circumferential strain -18.8±3.3% and for global peak radial strain 31.5±10.9%. The mean MRI ejection fraction was 56±9% with a mean stroke volume of 100.7±22.9ml and mean LGE fraction of 20.8±6.9%. The average time interval between cardiac MRI and STE was 10±19 days. Mean high sensitive Troponin was 2897.5±3122pg/ml. In echocardiography, a mean global longitudinal strain of -16.2±7%, -17.3±3.4% for the three chamber view, -16.9±4.1% for the four chamber view and -17.5±4.3% for the two chamber view could be demonstrated. The correlation between global longitudinal strain in STE and global peak longitudinal strain in cardiac MRI (r=0,42, p=0.015), the global strain in STE and global peak radial Strain (p=0.024) and the global strain in STE and MRI-EF (p=0.023) was close and significant.
CONCLUSION:
In patients with acute myocarditis, global peak longitudinal and radial strain measured by layer-specific strain analysis in cardiac MRI shows close and significant correlation compared to global longitudinal strain in 2D speckle tracking TTE.