Risk of arrhythmia in type I myotonic dystrophy: the role of clinical and genetic variables
- P Cudia1,
- P Bernasconi1,
- R Chiodelli2,
- F Mangiola3,
- F Bellocci4,
- A Dello Russo4,
- C Angelini5,
- V Romeo5,
- P Melacini6,
- L Politano7,
- A Palladino7,
- G Nigro8,
- G Siciliano9,
- M Falorni9,
- M G Bongiorni10,
- C Falcone11,
- R Mantegazza1,
- L Morandi1
- 1Muscle Pathology and Neuroimmunology Unit, IRCCS Foundation, Institute of Neurology “Carlo Besta”, Milan, Italy
- 2Arrhythmology Unit, “Monzino” Institute of Cardiology, University of Milan, Italy
- 3Centre for Neuromuscular Diseases, UILDM, Rome, Italy
- 4Institute of Cardiology, Catholic University of the Sacred Heart, Rome, Italy
- 5Department of Neuroscience, University of Padua, Italy
- 6Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Italy
- 7Department of Experimental Medicine, Cardiomyology and Medical Genetics, 2nd University of Naples, Naples, Italy
- 8Department of Cardio-Thoracic Sciences, Unit of Arrhythmology, 2nd University of Naples, Naples, Italy
- 9Department of Neuroscience, University of Pisa, Italy
- 10Institute of Cardiology, Cisanello Hospital, Pisa, Italy
- 11Neuroepidemiology Unit, IRCCS Foundation, Institute of Neurology “Carlo Besta”, Milan, Italy
- Dr L Morandi, Muscular Pathology and Neuroimmunology Unit, IRCCS Foundation, Institute of Neurology “Carlo Besta”, Via Celoria 11, 20133 Milan, Italy; lmorandi{at}istituto-besta.it
- Received 10 September 2008
- Revised 3 December 2008
- Accepted 27 December 2008
- Published Online First 22 February 2009
Abstract
Objective: To examine the association between the presence of arrhythmia in type 1 myotonic dystrophy (DM1) and clinical–genetic variables, evaluating their role as predictors of the risk of arrhythmia.
Methods: 245 patients with genetically proven DM1 underwent clinical and non-invasive cardiological evaluation. Severity of muscular involvement was assessed according to the 5 point Muscular Disability Rating Score (MDRS). Data were analysed by univariate and multivariate models.
Results: 245 patients were examined and cardiac arrhythmias were found in 63 subjects, 40 of whom required a device implant. Statistical analyses revealed that men had more than double the risk of developing arrhythmias compared with women (p = 0.018). Addition of each year of age caused an increased risk of arrhythmia equal to 3% (p = 0.030). Subjects with MDRS 5 had a risk of arrhythmia 12 times higher than patients with MDRS 1–2 (p<0.001). Although all of these variables were significantly associated with cardiac rhythm dysfunction, they had a low sensitivity for the prediction of arrhythmic risk
Conclusion: Male sex, age and muscular disability were strongly associated with the development of arrhythmia in DM1. However, all of these variables were weak predictors of arrhythmic risk. These results suggest that other factors may be involved in the development of cardiac conduction abnormalities in DM1.
Footnotes
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Competing interests: None.
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Funding: Financial support by Telethon-UILDM GUP 02067.
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Ethics approval: The study was approved by all of the ethics committee of the participating centres.
