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 Princ...
...1. Genetics, cardiovascular complica...
Duchenne, Becker, and Recessive Limb-girdle Muscular Dystrophies
...Duchenne...
...ble 2. Recessive forms (type 2) of LGMDs...
...Diagnostic testing and...
...nated care of patients with DMD, BMD, or LGM...
...ith DMD, BMD, or LGMD2, guideline-directed evaluat...
...nts with DMD, BMD, or LGMD2, cardiac ev...
...ales who are carriers of a pathogenic or li...
...ith DMD, BMD, or LGMD2 who have sy...
...Bradyc...
...with DMD, BMD, or LGMD2, with documented s...
...with DMD, BMD, or LGMD2 and third-de...
...patients with DMD, BMD, or LGMD2...
...Atrial arrhythmia...
...patients with DMD, BMD, or LGMD2, ant...
...VAs, su...
...patients with DMD, BMD, or LGMD2 with spontane...
...patients with DMD, BMD, or LGMD2 with...
...management and CIED in patients with DMD, BMD, o...
...Table 3. Clini...
...DMDClini...
...al scenario 2 A 31-year-old man with B...
...LGMD2Clinical scenari...
Myotonic Dystrophy Types 1 and 2
...Myotonic Dystrophy Type...
...Diagnostic t...
...d care of patients with DM1 or DM2 should be con...
...s with DM1 or DM2, cardiac evaluation...
...atients with DM1 or DM2 and cardiac conduction d...
...ents with DM1 or DM2 with symptoms cons...
...ts with DM1 or DM2 with symptoms suggestive of ve...
...Br...
...DM1 or DM2 with an LVEF ≤35%, sinus rhy...
...tients with DM1 or DM2 and documented s...
...tients with DM1 or DM2 and third-degree or advanc...
...n patients with DM1 or DM2 and marked f...
...patients with DM1 or DM2 with HV inte...
...Atrial arrhyth...
...with DM1 or DM2, anticoagulation according...
...VAs, sudden cardiac dea...
In patients with DM1 or DM2 in whom ICD...
...nts with DM1 or DM2, who are survivo...
...nts with DM1 or DM2 and an LVEF ≤35%, despite G...
...with DM1 or DM2 in whom clinically rele...
...tients with DM1 or DM2 in whom PPM implantat...
Figure 2. Rhythm management and CIED i...
...Table 4. Clinical...
...cover different degrees of muscle imp...
...D...
...inical scenario 1 A 63-year-old m...
Clinical scenario 2 A 52-year...
...scenario 3 A 72-year-old woman wi...
...enario 4 A 68-year-old woman wi...
Emery-Dreifuss and Limb-girdle Type 1B Muscular Dystrophy
...Emery-Dreif...
...Diagnostic testing...
...ordinated care of patients with EDMD or...
In patients with EDMD or LGMD1B, ca...
...latives of patients with genetically confirmed ED...
In patients with EDMD or LGMD1B, who have sym...
...ts with EDMD or LGMD1B with symptoms consistent w...
...Bradycardia...
...th EDMD or LGMD1B with an LVEF ≤35% desp...
...th EDMD or LGMD1B in whom pacing is indicated an...
...patients with EDMD or LGMD1B, anticoagulatio...
...ents with EDMD, anticoagulation is recommended fo...
...VAs, sudden cardi...
...patients with EDMD or LGMD1B in whom...
...tients with EDMD or LGMD1B who are survivo...
...patients with EDMD or LGMD1B with at le...
...ts with EDMD or LGMD1B with an LVEF ≤35% des...
...h EDMD or LGMD1B in whom clinically re...
...s with EDMD or LGMD1B with LVEF...
...s with EDMD or LGMD1B with at least one...
...ents with EDMD or LGMD1B with symptomatic...
...gure 3. Rhythm management and CIED...
...EDMD
...al scenario 1 A 25-year-old man...
...nario 2 A 64-year-old man with EDMD2 presents...
...cal scenario 3 A 12-year-old boy...
...LGMD1B...
...scenario 4 A 42-year-old woman is admi...
...scenario 5 A 35-year-old man...
Facioscapulohumeral Muscular Dystrophy
Faciosca...
...Diagnostic test...
...patients with FSHD, cardiac evaluation i...
Mitochondrial Myopathies Including Friedreich Ataxia
...Mitochondrial M...
...Diagnostic testi...
...oordinated care of patients with mitoc...
...mitochondrial myopathies includin...
...Bradycardias...
...mitochondrial myopathies including FA...
...ith mitochondrial myopathies including FA and thir...
...patients with FA with an LVEF ≤35% desp...
...s with mitochondrial myopathies includin...
...A...
...patients with mitochondrial myopathies includin...
...VAs, sudden car...
...patients with mitochondrial myopathies including...
...ents with mitochondrial myopathies includi...
...management and CIED implantation in patien...
...T...
...cenario A 30-year-old man with FA is referr...
Shared Decision-making and End-of-life Care
...Shared...
...7. NMDs, use of pacemakers and ICDs, share...
...Share...
...atients with NMD who are considering...
...tients with NMD in whom the presence of conduction...
...s with NMD who are considering ICD r...
...s with NMD who have an ICD and are...
...th NMD who have an ICD and are experiencing VAs...
...n patients with NMD who have a pacemaker or ICD...
...Table 8....
...al scenario 1 A 62-year-old woman w...
...al scenario 2 A 39-year-old woman with Em...
...cenario 3 A 17-year-old adolescent male with...
...nical scenario 4 A 46-year-old woman...