Cardiac involvement of myotonic dystrophy type II in patients with preserved ejection fraction - Detection by CMR

Methods We prospectively enrolled 32 subjects with a genetically confirmed diagnosis of MD2. Exclusion criteria were known cardiac diseases and contraindication for CMR. We assessed left-ventricular (LV) volumes, mass and function applying state of the art cine imaging using a 1.5 T Scanner. Late enhancement imaging (LGE; slice thickness (sth) 7 mm) was performed to detect myocardial fibrosis 10 minutes after injection of gadoteridol (0.2 mmol/kgbw). We applied T1 Mapping based on MOLLI (TI native 211 ms, TI post-contrast 281 ms, TE 1.08 ms, sth 6 mm) before and 15 minutes after contrast application and assessed resultant extracellular volume fraction (ECV). Fat-water-separated imaging (GRE, TR 944.80 ms, TE 1.53-8.22 ms, sth 6 mm) was performed to identify myocardial fat deposits. Furthermore, we used H magnetic resonance spectroscopy (MRS) (TR 1600 ms, TE 35 ms, septal voxel 20 x 15 x 6 mm3) to quantify myocardial Triglycerides (MTG). Data were analyzed using cvi and standard line-fitting procedure. Results 26 data sets were totally completed (age 53.8 ± 11 y, LVEF 65 ± 0.6 %, 19 women). None of the patients had wall motion abnormalities. LGE was detectable in 6 of 28 subjects (LGE+; 3 women); the location was mostly subepicardial inferolateral basal (Figure 1). In case of LGE+, the T1-values of the enhanced regions were significantly different to remote myocardium in both the native (p = 0.03) and the post-contrast maps (p = 0.03). ECV and T1 values of the remote myocardium were not different between LGE+ and LGE negative (LGE-) groups besides to the inferolateral located ECV (25.6 % vs. 34.3 %, p = 0.03) (Figure 2). Fat deposits were noticeable in 6 of 30 subjects (all women, one with LGE +) in the apical portion of the interventricular septum. The content of MTG in LGE+ and LGEsubjects was not significant different (0.34 % vs. 0.74 %, p = 0.47).