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Diagnostic testing and risk stratification in DM1 and DM2
COR LOE Recommendations
1 C-EO 1. Coordinated care of patients with DM1 or DM2 should be
conducted in a medical setting where there is access to expertise
in the neurological, cardiac, arrhythmic, pulmonary, and genetic
manifestations of these disorders.
1 B-NR 2. In patients with DM1 or DM2, cardiac evaluation including
physical examination, ECG, ambulatory ECG, and cardiac
imaging (echocardiography or CMR) at diagnosis with
periodic retesting is recommended even in the absence of
cardiac symptoms.
1 C-LD 3. In patients with DM1 or DM2 and cardiac conduction disorder,
close monitoring for arrhythmic complications is recommended
when using mexiletine (or other sodium channel blockers).
2a B-NR 4. In patients with DM1 or DM2 with symptoms consistent
with bradycardia and with ECG evidence of mild to moderate
conduction disorder and when noninvasive testing is
nondiagnostic, electrophysiological (EP) testing is reasonable for
risk stratification for AV block and sudden cardiac death.
2b B-NR 5. In patients with DM1 or DM2 with symptoms suggestive of
ventricular tachyarrhythmias and when noninvasive testing
is nondiagnostic, EP testing to assess the risk of sustained
arrhythmias may be considered.
Bradycardias, conduction disorders, and use of pacing or
CRT in DM1 and DM2
COR LOE Recommendations
1 B-R 1. In patients with DM1 or DM2 with an LVEF ≤35%, sinus
rhythm, LBBB with a QRS duration ≥150 ms, and NYHA
class II to class IV symptoms, or suspected RV pacing-induced
CM despite GDMT, CRT is recommended if concordant with
the patient's goals of care and clinical status.
1 B-NR 2. In patients with DM1 or DM2 and documented symptomatic
bradycardia due to any degree of sinus node dysfunction or AV
block, PPM implantation is indicated if concordant with the
patient's goals of care and clinical status.
1 B-NR 3. In patients with DM1 or DM2 and third-degree or advanced
second-degree AV block at any anatomical level, with
or without symptoms, PPM implantation is indicated if
concordant with the patient's goals of care and clinical status.
Myotonic Dystrophy Types 1 and 2
