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
...iples for Arrhythmic Risk in NMDs...
...1. Genetics, cardiovascular complicatio...
Duchenne, Becker, and Recessive Limb-girdle Muscular Dystrophies
..., and Recessive Limb-girdle Muscular Dy...
...ve forms (type 2) of LGMDs associated with CM, lis...
...ng and risk stratification in Duchenne, Becker...
...inated care of patients with DMD, BMD, or LGMD2 sh...
...th DMD, BMD, or LGMD2, guideline-d...
...s with DMD, BMD, or LGMD2, cardiac evaluation...
...who are carriers of a pathogenic or likely pathog...
...atients with DMD, BMD, or LGMD2 who h...
...onduction disorders, and use of pacing or CRT in...
...patients with DMD, BMD, or LGMD2, with do...
...patients with DMD, BMD, or LGMD2 and third-degr...
...with DMD, BMD, or LGMD2 with an LVEF...
...trial arrhythmias in Duchenne, Becker, and recessi...
...h DMD, BMD, or LGMD2, anticoagulation accor...
VAs, sudden cardiac death, and use of ICDs in Duch...
...s with DMD, BMD, or LGMD2 with spontaneously oc...
...with DMD, BMD, or LGMD2 with an LVEF ≤3...
...thm management and CIED in patients...
...ical scenarios for the management of arrhyth...
...Cl...
...nario 2 A 31-year-old man with B...
...Clinic...
Myotonic Dystrophy Types 1 and 2
...tonic Dystrophy Types 1 and 2
...testing and risk stratification in DM1...
...care of patients with DM1 or DM2 should...
...with DM1 or DM2, cardiac evaluation inclu...
...with DM1 or DM2 and cardiac conduction disor...
...tients with DM1 or DM2 with symptoms consistent w...
...DM1 or DM2 with symptoms suggestiv...
Bradycardias, conduction disorders, and use...
...with DM1 or DM2 with an LVEF ≤35%, sinus r...
...h DM1 or DM2 and documented symptomatic bradyca...
...with DM1 or DM2 and third-degree or...
...th DM1 or DM2 and marked first-degree AV block...
...patients with DM1 or DM2 with HV in...
...ythmias in DM1 and DM2...
...DM1 or DM2, anticoagulation according to...
...s, sudden cardiac death, and use of ICDs in DM1 an...
In patients with DM1 or DM2 in whom ICD therapy i...
...s with DM1 or DM2, who are survivor...
...with DM1 or DM2 and an LVEF ≤35%,...
...ients with DM1 or DM2 in whom clinically rel...
...ith DM1 or DM2 in whom PPM implantation is in...
Figure 2. Rhythm management and CIED implan...
...nical scenarios for the management of arr...
...er different degrees of muscle impair...
...M1
...rio 1 A 63-year-old man with D...
...ical scenario 2 A 52-year-old man with DM1 and...
...MD
...nical scenario 3 A 72-year-old woman wit...
...cenario 4 A 68-year-old woman with DM1 and ad...
Emery-Dreifuss and Limb-girdle Type 1B Muscular Dystrophy
...Dreifuss and Limb-girdle Type 1B Muscular...
Diagnostic testing and risk stratific...
Coordinated care of patients with EDMD o...
...ents with EDMD or LGMD1B, cardiac evaluation inclu...
...ree relatives of patients with gen...
...s with EDMD or LGMD1B, who have sym...
...n patients with EDMD or LGMD1B with symptoms...
..., conduction disorders, and use of...
In patients with EDMD or LGMD1B with an LVEF ≤3...
...ts with EDMD or LGMD1B in whom pacing is in...
...ythmias in EDMD and LGMD1B...
...n patients with EDMD or LGMD1B, anticoagulation is...
...nts with EDMD, anticoagulation is recommende...
...As, sudden cardiac death, and use of ICDs in...
...s with EDMD or LGMD1B in whom ICD therap...
...patients with EDMD or LGMD1B who...
...nts with EDMD or LGMD1B with at least one o...
...ts with EDMD or LGMD1B with an LVEF ≤3...
...EDMD or LGMD1B in whom clinically relevant V...
...patients with EDMD or LGMD1B with...
...EDMD or LGMD1B with at least one of th...
...h EDMD or LGMD1B with symptomatic si...
...Rhythm management and CIED implantation in pat...
...e 5. Clinical scenarios for the management of arrh...
EDMD
...linical scenario 1 A 25-year-old man presents...
...scenario 2 A 64-year-old man with EDMD2 prese...
...cenario 3 A 12-year-old boy with EDMD...
LGMD1B
...ario 4 A 42-year-old woman is admit...
...nical scenario 5 A 35-year-old man with L...
Facioscapulohumeral Muscular Dystrophy
...cioscapulohumeral Muscular Dystrophy
...tic testing and risk stratification in FSHD...
...FSHD, cardiac evaluation including examination,...
Mitochondrial Myopathies Including Friedreich Ataxia
...tochondrial Myopathies Including Friedreich Ata...
...ing and risk stratification in mitochondrial...
...ted care of patients with mitochondrial my...
...th mitochondrial myopathies including FA, cardiac...
...onduction disorders, and use of paci...
...mitochondrial myopathies including FA and...
...ents with mitochondrial myopathies i...
...ents with FA with an LVEF ≤35% despite GDMT, wit...
...ients with mitochondrial myopathies...
...trial arrhythmias in mitochondrial myopathies incl...
...ients with mitochondrial myopathies including FA,...
...n cardiac death, and use of ICDs in...
...th mitochondrial myopathies including FA...
In patients with mitochondrial myopathies in...
.... Rhythm management and CIED implan...
...al scenarios for management of patients...
...nical scenario A 30-year-old man with F...
Shared Decision-making and End-of-life Care
...ared Decision-making and End-of-li...
...use of pacemakers and ICDs, shared d...
...decision-making and end-of-life decisions...
...tients with NMD who are considering or have...
...nts with NMD in whom the presence...
...atients with NMD who are considering ICD replac...
...ents with NMD who have an ICD and are...
...h NMD who have an ICD and are experiencing V...
...th NMD who have a pacemaker or ICD and who are ne...
...nical scenarios for end-of-life manag...
...ario 1 A 62-year-old woman with DM...
...al scenario 2 A 39-year-old woman with Em...
...scenario 3 A 17-year-old adolesc...
...al scenario 4 A 46-year-old woman with DM1...