Sudden cardiac death in neuromuscular disorders

- Patients with certain neuromuscular disorders carry an increased risk to experience sudden cardiac death
- Risk of SCD is particularly increased in myotonic dystrophy, mitochondrial disorders, laminopathies, and desminopathies.
- Risk factors to develop sudden cardiac death vary considerably between neuromuscular disorders.
- Risk factors for SCD include fibrosis, QT-prolongation, increased QT-dispersion, early repolarization, or T-wave alternans.

ObjectivesThe heart is frequently affected in neuromuscular disorders (NMDs). Some of these patients even experience sudden cardiac death (SCD). In the following review, we summarize recent findings concerning epidemiology, risk stratification, and prevention of SCD in NMDs.MethodsReview of publications about SCD and NMDs by search of MEDLINE applying appropriate search terms.ResultsNMDs in which SCD was most frequently reported include myotonic dystrophy type 1, mitochondrial disorders, laminopathy, desminopathy, Danon disease, and amyotrophic lateral sclerosis. Risk factors for developing SCD vary considerably between NMDs and include positive family history for SCD, palpitations, arterial hypertension, ECG-abnormalities (bundle branch block, bifascicular block, QT-prolongation, increased QT-variability, early repolarization, T-wave alternans, ventricular tachycardia), late gadolinium enhancement as an equivalent of myocardial fibrosis, and noncompaction. NMD patients at risk for SCD require a thorough history, long-term ECG recordings, and cardiac MRI with contrast medium. In case a propensity for ventricular arrhythmias is documented, implantation of an implantable cardioverter defibrillator should be considered.ConclusionsSCD is the cause of death in various NMDs why these patients need to be thoroughly screened for risk factors of SCD. Verification of risk factors for SCD in NMDs requires appropriate management.