Evaluation and Management of Arrhythmic Risk in Neuromuscular Disorders
Overview
Overview
Top 10 Take-Home Messages
- Shared decision-making among patients, their families, and clinicians is essential whenever diagnostic studies or therapies, particularly those that are invasive, are being utilized or contemplated. Counseling and education may result in patients’ refusal or withdrawal of such measures if inconsistent with their goals of care, and this should be respected.
- Cardiac testing is appropriate in most patients with neuromuscular disorders (NMDs) to evaluate for cardiac involvement. The type of cardiac test and the need for and frequency of repeat testing is governed by the underlying disorder, results of previous or new studies, and the patient’s symptomatic status. It should be noted that skeletal muscle impairment may mask or confound cardiovascular symptoms, requiring heightened vigilance to cardiac involvement and modification of testing.
- Previously published guideline-based indications for cardiovascular implantable electronic device (CIED) use, including cardiac resynchronization therapy (CRT), and for management of cardiomyopathy (CM) and heart failure may be applied in patients with NMDs. For some indications, the level of evidence (LOE) and/or class of recommendation (COR) in the current document have been modified from prior guidelines to reflect the under-representation of patients with NMDs in past studies.
- A patient’s overall prognosis may be affected by the impact of their underlying neuromuscular condition. Condition-specific technical challenges including body habitus (such as kyphoscoliosis), respiratory muscle weakness and sedation-related risks may influence clinical management. These effects may dominate a patient’s clinical picture and prognosis, possibly attenuating the benefit from arrhythmia therapy, particularly CIED implantation, when compared with other patient populations.
- Patients with Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), and recessive forms of limb-girdle muscular dystrophy (LGMD) rarely develop bradyarrhythmias, but CM, heart failure, and ventricular arrhythmias (VAs) may occur with increased frequency. When indicated, CIED therapy in these patients may pose technical challenges and limited benefit, particularly in those with advanced neuromuscular impairment.
- In addition to established indications, pacemaker implantation or, in selected individuals, pacing-capable implantable cardioverter-defibrillator (ICD) placement is indicated in patients with myotonic dystrophy type 1 (DM1) or type 2 (DM2) who have evidence of abnormal atrioventricular (AV) conduction, marked by PR interval ≥240 ms, QRS duration ≥120 ms, and/or HV interval ≥70 ms, even when asymptomatic.
- Patients with Emery-Dreifuss muscular dystrophy (EDMD) or limb-girdle muscular dystrophy type 1B (LGMD1B) with abnormal AV conduction, including PR interval ≥230 ms, or HV interval ≥70 ms, are at higher risk of arrhythmic events including sudden death, even when asymptomatic. Transvenous (or equivalent pacing-capable) ICD placement is indicated in such patients.
- Patients with mitochondrial myopathies, such as Kearns-Sayre syndrome, are susceptible to developing advanced, distal conduction disease. Pacemaker implantation is indicated in these patients who demonstrate AV conduction abnormalities, particularly if progressive, including fascicular block.
- Initiation of oral anticoagulation in patients with NMDs who develop atrial fibrillation (AF) should be based on established risk criteria (e.g., CHA2DS2-VASc, HAS-BLED in adults). Individuals with EDMD or LGMD1B and AF should be treated with oral anticoagulation regardless of CHA2DS2-VASc score because of the association with atrial standstill and suspected heightened risk of thromboembolism.
- Early but limited experience with gene modification in some heritable diseases has been promising and is now being employed in patients with NMDs. The hope for additional advances must be tempered by the complexity of these therapeutics and the small number of patients with NMDs who qualify for such treatment.
General Principles for Arrhythmic Risk in NMDs
...General Principles for Ar...
...s, cardiovascular complications, and NMDs...
Duchenne, Becker, and Recessive Limb-girdle Muscular Dystrophies
...Duchenne, Becker, an...
...sive forms (type 2) of LGMDs associate...
...Diagnostic test...
...are of patients with DMD, BMD, or LGMD2 sho...
...ents with DMD, BMD, or LGMD2, guidelin...
...ents with DMD, BMD, or LGMD2, cardi...
...who are carriers of a pathogenic or likely p...
...n patients with DMD, BMD, or LGMD2 who h...
...Bradycardias,...
...n patients with DMD, BMD, or LGMD2, with...
...patients with DMD, BMD, or LGMD2 a...
...h DMD, BMD, or LGMD2 with an LVEF ≤35% despit...
...Atrial arrhythmias...
...ith DMD, BMD, or LGMD2, anticoagulation...
VAs,...
...tients with DMD, BMD, or LGMD2 with spo...
...th DMD, BMD, or LGMD2 with an LVEF...
...gure 1. Rhythm management and CIED in patients...
...Table 3. Clinical s...
...DMDClinical s...
...DClinical scenario 2 A 31-year-o...
...LG...
Myotonic Dystrophy Types 1 and 2
...Myotonic Dystrophy Typ...
...Diagnostic testing and ris...
...care of patients with DM1 or DM2 should...
...n patients with DM1 or DM2, cardiac evaluati...
...ients with DM1 or DM2 and cardiac...
...ients with DM1 or DM2 with symptoms consist...
...DM1 or DM2 with symptoms suggestive of ve...
...Bradycardias, co...
...atients with DM1 or DM2 with an LVEF ≤35%,...
...patients with DM1 or DM2 and documen...
...atients with DM1 or DM2 and third-degree or advan...
...s with DM1 or DM2 and marked first-degree AV...
...ients with DM1 or DM2 with HV interval ≥70 ms on...
...Atr...
...ients with DM1 or DM2, anticoagulation...
...V...
...ith DM1 or DM2 in whom ICD therapy is pl...
...patients with DM1 or DM2, who are...
...nts with DM1 or DM2 and an LVEF ≤35%, despite GD...
...ith DM1 or DM2 in whom clinically relevant V...
...with DM1 or DM2 in whom PPM implan...
...2. Rhythm management and CIED implantatio...
Table 4. C...
...ver different degrees of muscle impai...
...scenario 1 A 63-year-old man with DM1 a...
...scenario 2 A 52-year-old man with DM...
...BMD...
...scenario 3 A 72-year-old woman wit...
...inical scenario 4 A 68-year-old woma...
Emery-Dreifuss and Limb-girdle Type 1B Muscular Dystrophy
Emery-Dr...
...Diagnostic...
...oordinated care of patients with ED...
...patients with EDMD or LGMD1B, cardiac...
...gree relatives of patients with gene...
...ents with EDMD or LGMD1B, who have symptoms o...
...ients with EDMD or LGMD1B with sympt...
...Bradycardia...
...nts with EDMD or LGMD1B with an LVEF ≤35%...
...atients with EDMD or LGMD1B in whom p...
...Atrial arrhy...
...th EDMD or LGMD1B, anticoagulation is rec...
...patients with EDMD, anticoagulation is recommend...
...V...
...patients with EDMD or LGMD1B in who...
...n patients with EDMD or LGMD1B who are...
...patients with EDMD or LGMD1B with at le...
...with EDMD or LGMD1B with an LVEF ≤35%...
...ts with EDMD or LGMD1B in whom clinically relevan...
...patients with EDMD or LGMD1B with...
...with EDMD or LGMD1B with at least on...
...s with EDMD or LGMD1B with symptomatic sinus n...
...3. Rhythm management and CIED implantation i...
...Table 5. Clinical sc...
...EDMD...
...scenario 1 A 25-year-old man presents with...
...ario 2 A 64-year-old man with EDMD2 pre...
...nical scenario 3 A 12-year-old boy with...
...LGMD...
...nical scenario 4 A 42-year-old woma...
...io 5 A 35-year-old man with LGMD...
Facioscapulohumeral Muscular Dystrophy
...Facioscapulohumer...
...Diagnostic t...
...th FSHD, cardiac evaluation including examina...
Mitochondrial Myopathies Including Friedreich Ataxia
...M...
...Diagnostic testing...
...care of patients with mitochondrial my...
...mitochondrial myopathies including FA, cardiac ev...
...Bradycardias...
...n patients with mitochondrial myopathies...
...with mitochondrial myopathies including FA an...
...atients with FA with an LVEF ≤35% despite...
...with mitochondrial myopathies inclu...
...Atrial arrhythmias...
...mitochondrial myopathies including FA, a...
...VAs, s...
...nts with mitochondrial myopathies incl...
...patients with mitochondrial myopa...
...hythm management and CIED implantation in patien...
...Table 6. Clinical...
...cal scenario A 30-year-old man with FA is referr...
Shared Decision-making and End-of-life Care
...Shared Decision-makin...
.... NMDs, use of pacemakers and ICDs, shared decisi...
...Shared decision-making a...
...n patients with NMD who are considering...
...n patients with NMD in whom the presence of con...
...nts with NMD who are considering IC...
...patients with NMD who have an ICD and are un...
...NMD who have an ICD and are experiencin...
...ients with NMD who have a pacemaker...
...Table 8. Clini...
...al scenario 1 A 62-year-old woman with DM1, no...
...l scenario 2 A 39-year-old woman with Emery-Dr...
...al scenario 3 A 17-year-old adolescent...
...ario 4 A 46-year-old woman wit...