“Objectives: to assess the prevalence of atrial fibrillation (AF) in our patients with myotonic dystrophy type 1 (MD1), in way to examine the association of clinical features with AF, to detect predisposing and/or influencing prognosis factors.
Materials: a retrospective study was conducted in our Center, including 31 MD1-affected individuals (14 males, aged 38-71, Muscular Impairment Rating Scale MIRS 2-4, E1-E3 as categories related to the molecular changes) undergoing routine cardiac screening with at least one 24h- Holter monitoring between January 2008 and January 2024.
Methods: we retrospectively reviewed their medical history, electrocardiograms, DM1 genetic testing, 2D-color Doppler echocardiogram, and 24h-Holter monitoring, neurological examination and cardiological examination.
Results: 7/31 (1 female) presented at least one episode of AF: all of them were E1-E3, two of them were MIRS 4, two MIRS 3. 1 of them (male, MIRS 3) was affected by paroxysmal atrial fibrillation, the others by the chronic one. None of them was diagnosed with ischemic stroke in a 16-years-follow up.
Discussion: myotonic dystrophy type 1 (MD1) is characterized by cardiac involvement, that predominantly affects the conduction system while the prevalence of AF is 10%, according to the literature; unexpectedly, we found an higher prevalence of 22,5%; male sex seems to represent a predisponing status.
Conclusion: the risk of both chronic or paroxysmal atrial fibrillation is the same between DM1 patients without association to MIRS score. Severity of muscular impairment does not correlate with the risk to develop an atrial fibrillation.”