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
...rinciples for Arrhythmic Risk in NMD...
...1. Genetics, cardiovascular complica...
Duchenne, Becker, and Recessive Limb-girdle Muscular Dystrophies
...cker, and Recessive Limb-girdle Muscular D...
...sive forms (type 2) of LGMDs associated with...
...stic testing and risk stratification i...
...oordinated care of patients with DMD, B...
...h DMD, BMD, or LGMD2, guideline-directed...
...DMD, BMD, or LGMD2, cardiac evaluation incl...
...are carriers of a pathogenic or likely pathogenic...
...tients with DMD, BMD, or LGMD2 who hav...
...nduction disorders, and use of pacing or C...
...patients with DMD, BMD, or LGMD2, with d...
...DMD, BMD, or LGMD2 and third-degree...
...ents with DMD, BMD, or LGMD2 with...
...as in Duchenne, Becker, and recessive limb-gi...
...patients with DMD, BMD, or LGMD2, antic...
...ardiac death, and use of ICDs in Duchenne,...
...patients with DMD, BMD, or LGMD2 with spontaneous...
...h DMD, BMD, or LGMD2 with an LVEF ≤35% despite...
...gure 1. Rhythm management and CIED in pati...
...le 3. Clinical scenarios for the manag...
...Clinica...
BMDClinical scenario 2 A 31-year-old man with...
...MD2...
Myotonic Dystrophy Types 1 and 2
...ic Dystrophy Types 1 an...
...iagnostic testing and risk stratification in DM1 a...
...care of patients with DM1 or DM2 should...
...tients with DM1 or DM2, cardiac evaluation incl...
...patients with DM1 or DM2 and cardiac condu...
...tients with DM1 or DM2 with symptoms c...
...with DM1 or DM2 with symptoms sug...
...s, conduction disorders, and use of pacin...
...th DM1 or DM2 with an LVEF ≤35%, sinus...
...ents with DM1 or DM2 and documente...
...h DM1 or DM2 and third-degree or adv...
...nts with DM1 or DM2 and marked fir...
...ts with DM1 or DM2 with HV interval ≥70...
...rhythmias in DM1 and DM2...
...atients with DM1 or DM2, anticoagulation accor...
...sudden cardiac death, and use of IC...
...ith DM1 or DM2 in whom ICD therapy is planned, a...
...ients with DM1 or DM2, who are survivors of...
...ts with DM1 or DM2 and an LVEF ≤35%, despite...
...with DM1 or DM2 in whom clinically relevan...
...nts with DM1 or DM2 in whom PPM implanta...
...2. Rhythm management and CIED implantatio...
Table 4. Clinical scenarios for the management of...
...arios cover different degrees of muscle imp...
DM1
...enario 1 A 63-year-old man with DM1 and minima...
...al scenario 2 A 52-year-old man with DM1...
...MD...
...ical scenario 3 A 72-year-old woman with...
...scenario 4 A 68-year-old woman wi...
Emery-Dreifuss and Limb-girdle Type 1B Muscular Dystrophy
...eifuss and Limb-girdle Type 1B Muscular...
...gnostic testing and risk stratific...
...care of patients with EDMD or LGMD1B should be...
...nts with EDMD or LGMD1B, cardiac ev...
...st-degree relatives of patients wit...
...s with EDMD or LGMD1B, who have sy...
...ts with EDMD or LGMD1B with symptoms...
...adycardias, conduction disorders, and use...
...with EDMD or LGMD1B with an LVEF â...
...with EDMD or LGMD1B in whom pacing is indic...
...al arrhythmias in EDMD and LGMD1B
...ents with EDMD or LGMD1B, anticoagulati...
...s with EDMD, anticoagulation is recommend...
...rdiac death, and use of ICDs in EDMD and L...
...with EDMD or LGMD1B in whom ICD therapy is...
In patients with EDMD or LGMD1B wh...
...EDMD or LGMD1B with at least one of the fol...
...EDMD or LGMD1B with an LVEF ≤35% despite GD...
In patients with EDMD or LGMD1B in w...
...tients with EDMD or LGMD1B with...
...ts with EDMD or LGMD1B with at least one of the...
...atients with EDMD or LGMD1B with symptomatic s...
...Rhythm management and CIED implantation in...
...al scenarios for the management of...
...DMD
...nical scenario 1 A 25-year-old man...
...cal scenario 2 A 64-year-old man wit...
...nical scenario 3 A 12-year-old bo...
...MD1B...
...io 4 A 42-year-old woman is admit...
...l scenario 5 A 35-year-old man with LGMD1B...
Facioscapulohumeral Muscular Dystrophy
...scapulohumeral Muscular Dystrop...
...agnostic testing and risk stratifica...
...s with FSHD, cardiac evaluation including ex...
Mitochondrial Myopathies Including Friedreich Ataxia
...opathies Including Friedreich Ataxia...
...ostic testing and risk stratificatio...
...inated care of patients with mitochon...
...ts with mitochondrial myopathies in...
...adycardias, conduction disorders, and use...
...th mitochondrial myopathies including FA and...
...patients with mitochondrial myopathies inc...
...tients with FA with an LVEF ≤35% de...
...patients with mitochondrial myopathies inclu...
...al arrhythmias in mitochondrial myopathies inclu...
...ith mitochondrial myopathies including FA...
...As, sudden cardiac death, and use of ICDs in mitoc...
...patients with mitochondrial myopathies inc...
...ts with mitochondrial myopathies including FA wi...
...4. Rhythm management and CIED implanta...
...able 6. Clinical scenarios for management of...
...o A 30-year-old man with FA is re...
Shared Decision-making and End-of-life Care
...n-making and End-of-life Care...
...MDs, use of pacemakers and ICDs, shared decisio...
...sion-making and end-of-life decisions...
...n patients with NMD who are considering or...
...NMD in whom the presence of conduction...
...nts with NMD who are considering ICD replacement a...
...h NMD who have an ICD and are unde...
...ith NMD who have an ICD and are exp...
...n patients with NMD who have a pace...
Table 8. Clinical scenarios for end-of-life...
...enario 1 A 62-year-old woman with DM1...
...linical scenario 2 A 39-year-old woman...
...nario 3 A 17-year-old adolescent male with DM...
...cenario 4 A 46-year-old woman with DM1 an...