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
...l Principles for Arrhythmic Risk in NMDs...
...e 1. Genetics, cardiovascular complications, and...
Duchenne, Becker, and Recessive Limb-girdle Muscular Dystrophies
...chenne, Becker, and Recessive Limb-girdle...
...Recessive forms (type 2) of LGMDs associated...
...testing and risk stratification in Duchenne, B...
...ed care of patients with DMD, BMD, or LGMD2 shou...
...th DMD, BMD, or LGMD2, guideline-directe...
...h DMD, BMD, or LGMD2, cardiac evaluation includin...
...n females who are carriers of a pathoge...
...ith DMD, BMD, or LGMD2 who have symptom...
...onduction disorders, and use of pacing or...
...ith DMD, BMD, or LGMD2, with docum...
...nts with DMD, BMD, or LGMD2 and third...
...ith DMD, BMD, or LGMD2 with an LVEF ≤35% des...
...hmias in Duchenne, Becker, and recessive...
In patients with DMD, BMD, or LGMD2,...
...n cardiac death, and use of ICDs in D...
In patients with DMD, BMD, or LGMD2...
...ents with DMD, BMD, or LGMD2 with an LVEF ≤...
...hythm management and CIED in patients with DM...
.... Clinical scenarios for the management...
...Clinica...
...ical scenario 2 A 31-year-old man with BMD is...
...Clinical sce...
Myotonic Dystrophy Types 1 and 2
...ystrophy Types 1 and 2...
...ng and risk stratification in DM1 and DM2...
...d care of patients with DM1 or DM2 s...
...ith DM1 or DM2, cardiac evaluation...
...patients with DM1 or DM2 and card...
...nts with DM1 or DM2 with symptoms consistent wit...
...with DM1 or DM2 with symptoms sugge...
...conduction disorders, and use of pacin...
...with DM1 or DM2 with an LVEF ≤35%, sinus rhyth...
...ents with DM1 or DM2 and documented symptoma...
...tients with DM1 or DM2 and third-degree or...
...with DM1 or DM2 and marked first-degree AV block...
...ts with DM1 or DM2 with HV interval ≥70 ms on E...
...trial arrhythmias in DM1 and DM2...
...patients with DM1 or DM2, anticoagulation accordi...
VAs, sudden cardiac death, and use of ICDs in...
...tients with DM1 or DM2 in whom ICD the...
...nts with DM1 or DM2, who are survi...
...atients with DM1 or DM2 and an LVEF ≤35%, d...
...DM1 or DM2 in whom clinically rel...
...s with DM1 or DM2 in whom PPM implantati...
Figure 2. Rhythm management and CIED implantatio...
...4. Clinical scenarios for the management of arrhy...
...r different degrees of muscle impair...
...M1
...nario 1 A 63-year-old man with DM1 and minimal...
...l scenario 2 A 52-year-old man...
BMD
...scenario 3 A 72-year-old woman with...
...rio 4 A 68-year-old woman with DM1...
Emery-Dreifuss and Limb-girdle Type 1B Muscular Dystrophy
...mery-Dreifuss and Limb-girdle Type 1B Muscula...
...esting and risk stratification in EDMD and LGMD...
...nated care of patients with EDMD o...
...with EDMD or LGMD1B, cardiac evaluation i...
...ee relatives of patients with genetically confir...
...ients with EDMD or LGMD1B, who have symptoms...
...ith EDMD or LGMD1B with symptoms consistent wit...
...rdias, conduction disorders, and use...
...ts with EDMD or LGMD1B with an LVEF ≤35% despit...
...EDMD or LGMD1B in whom pacing is indicated and I...
...rial arrhythmias in EDMD and LGMD1B
...th EDMD or LGMD1B, anticoagulation is recommen...
...patients with EDMD, anticoagulation is recom...
...As, sudden cardiac death, and use of ICDs in ED...
...ents with EDMD or LGMD1B in whom ICD therapy is p...
...ients with EDMD or LGMD1B who are su...
...ith EDMD or LGMD1B with at least one...
...th EDMD or LGMD1B with an LVEF ≤3...
...patients with EDMD or LGMD1B in whom clinicall...
...nts with EDMD or LGMD1B with LVEF...
...EDMD or LGMD1B with at least one of...
...atients with EDMD or LGMD1B with sympto...
Figure 3. Rhythm management and CIED impla...
...5. Clinical scenarios for the management...
EDM...
...al scenario 1 A 25-year-old man presents...
...Clinical scenario 2 A 64-year-old man with...
...rio 3 A 12-year-old boy with EDMD, w...
LGMD1...
Clinical scenario 4 A 42-year-old...
...io 5 A 35-year-old man with LGMD1B pre...
Facioscapulohumeral Muscular Dystrophy
...cioscapulohumeral Muscular Dystr...
...sting and risk stratification in FSHD...
...ith FSHD, cardiac evaluation including...
Mitochondrial Myopathies Including Friedreich Ataxia
...ochondrial Myopathies Including Friedreich Ata...
...sting and risk stratification in mi...
...of patients with mitochondrial myopathies...
...mitochondrial myopathies including FA, card...
Bradycardias, conduction disorders, an...
...s with mitochondrial myopathies inc...
...n patients with mitochondrial myopathi...
...tients with FA with an LVEF ≤35% desp...
...mitochondrial myopathies including FA with prog...
...ial arrhythmias in mitochondrial myopathies...
...nts with mitochondrial myopathies incl...
...cardiac death, and use of ICDs in...
...s with mitochondrial myopathies including FA with...
...with mitochondrial myopathies including FA with...
...hythm management and CIED implantati...
...able 6. Clinical scenarios for management...
...cal scenario A 30-year-old man with FA...
Shared Decision-making and End-of-life Care
...cision-making and End-of-life Ca...
...ble 7. NMDs, use of pacemakers and ICDs, share...
...cision-making and end-of-life decisions...
In patients with NMD who are considering or hav...
In patients with NMD in whom the pr...
...with NMD who are considering ICD replacemen...
In patients with NMD who have an I...
...ts with NMD who have an ICD and are...
...tients with NMD who have a pacemaker or ICD...
...ble 8. Clinical scenarios for end-of-life mana...
...nical scenario 1 A 62-year-old woman with...
...enario 2 A 39-year-old woman with Eme...
...linical scenario 3 A 17-year-old adolescen...
...l scenario 4 A 46-year-old wom...