LAUSR

Myotonic dystrophy type 1 (DM 1), also known as Steinert's disease (SD), is the most common muscular dystrophy in adults. It is characterized by multisystemic involvement and the cardiac affectation is the second leading cause of death after the respiratory one. The objective of our work was to study the cardiac involvement by transthoracic echocardiography (TTE) including systolic function, diastolic function and myocardial deformation with global longitudinal strain (GLS) by speckle tracking and trough biomarkers of myocardial damage with high-sensitive cardiac troponin T (hs-cTnT) and NT-proBNP. 24 patients affected by SD were included. The TTE machine used has software to perform GLS with reference values: −20±2%. The normal values of hs-cTnT and NT-proBNP of our central laboratory are: <14 ng/L and 0–250 pg/ml, respectively. The mean age of patients was 52,08±12,14 years and the average age of diagnosis was 31,42 years. There was no gender predilection (12 women, 12 men). In the TTE 55% of patients had a GLS <−18% with a global average of −17,72±4,02%. The 50% of patients with LVEF >50% had a GLS <−18% and the 27,77% had a GLS between −18 and −20%. The diastolic dysfunction assessed by pulsed wave doppler and tissue doppler imaging was present in 26.82%. The 95,83% of the patients had levels of hs-cTnT≥14 ng/L with median of 34,93 ng/L (minimum 3,96 and maximum 429), however only 30,4% of these had values of NT-proBNP above 250 pg/ml with a median of 71,83 pg/ml (minimum 9,37 and maximum 8771). According to our experience GLS and hs-cTnT could be markers of early myocardial damage in patients with SD. We therefore need to develop protocols for the follow-up including these markers in the usual cardiac assessment.