title: Structural and functional cardiac changes in myotonic dystrophy type 1: a cardiovascular magnetic resonance study.
abstract: BACKGROUND
  Myotonic dystrophy type 1 (MD1) is a neuromuscular disorder with potential involvement of the heart and increased risk of sudden death. Considering the importance of cardiomyopathy as a predictor of prognosis, we aimed to systematically evaluate and describe structural and functional cardiac alterations in patients with MD1.
  
  
  METHODS
  Eighty MD1 patients underwent physical examination, electrocardiography (ECG), echocardiography and cardiovascular magnetic resonance (CMR). Blood samples were taken for determination of NT-proBNP plasma levels and CTG repeat length.
  
  
  RESULTS
  Functional and structural abnormalities were detected in 35 patients (44%). Left ventricular systolic dysfunction was found in 20 cases, left ventricular dilatation in 7 patients, and left ventricular hypertrophy in 6 patients. Myocardial fibrosis was seen in 10 patients (12.5%). In general, patients had low left ventricular mass indexes. Right ventricular involvement was uncommon and only seen together with left ventricular abnormalities. Functional or structural cardiac involvement was associated with age (p = 0.04), male gender (p < 0.001) and abnormal ECG (p < 0.001). Disease duration, CTG repeat length, severity of neuromuscular symptoms and NT-proBNP level did not predict the presence of myocardial abnormalities.
  
  
  CONCLUSIONS
  CMR can be useful to detect early structural and functional myocardial abnormalities in patients with MD1. Myocardial involvement is strongly associated with conduction abnormalities, but a normal ECG does not exclude myocardial alterations. These findings lend support to the hypothesis that MD1 patients have a complex cardiac phenotype, including both myocardial and conduction system alteration.
authors: Department of Neurology, Maastricht University Medical Centre, PO box 5800, Maastricht, AZ, 6202, The Netherlands. m.hermans@mumc.nl
authors: Mieke C E
authors: MC
authors: Hermans
authors: Catharina G
authors: CG
authors: Faber
authors: Sebastiaan C A M
authors: SC
authors: Bekkers
authors: Christine E M
authors: CE
authors: de Die-Smulders
authors: Monique M
authors: MM
authors: Gerrits
authors: Ingemar S J
authors: IS
authors: Merkies
authors: Gabriel
authors: G
authors: Snoep
authors: Yigal M
authors: YM
authors: Pinto
authors: Simon
authors: S
authors: Schalla
mesh_terms: D000328:Adult; D000368:Aged; D009202:Cardiomyopathies / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D018450:Disease Progression; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D009223:Myotonic Dystrophy / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D015203:Reproducibility of Results; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D016277:Ventricular Function, Left; D055815:Young Adult