⚠️ Chapter 647 · Rhabdomyolysis, Inherited Disorders & Cardiac Manifestations

Nelson Textbook of Pediatrics 22nd Edition — Triggers of rhabdomyolysis (Fig 647.5), complete causes (Table 647.7), inherited disorders with rhabdomyolysis (Table 647.8), and gene variants with cardiac manifestations (Table 647.9).

🌐 paeds.online — Pakistan's Pediatric Platform

📋 30 Clinical Scenarios — Rhabdomyolysis & Cardiac Manifestations in Neuromuscular Disorders

📇 High‑Yield Review Cards

🩺 Clinical Recognition: Rhabdomyolysis & Cardiac Risk in NMD

Select a presentation for diagnostic clues and management.

📋 Stepwise Management of Rhabdomyolysis & Cardiac Surveillance in NMD

    ⚡ Reflex Prompts — Clinical Decisions

    📊 Fig 647.5 & Tables 647.7, 647.8, 647.9

    Fig 647.5 — Examples of Different Triggers of Rhabdomyolysis

    🏃‍♂️ Strenuous exercise 💉 General anesthesia / Succinylcholine 🦠 Viral illness (influenza, EBV, HIV) 🍔 Fasting / Prolonged exercise (FAO defects) ⚡ Seizures / Status epilepticus 🌡️ Malignant hyperthermia / Heatstroke 💊 Medications (statins, neuroleptics) 🧬 Metabolic myopathy (McArdle, CPTII) 💊 Drugs of abuse (cocaine, amphetamines) ⚡ Crush injury / Compartment syndrome
    Identification of triggers guides genetic testing (RYR1, CPT2, ACADVL, PYGM).

    Table 647.7 — Causes of Rhabdomyolysis

    CATEGORYSPECIFIC CAUSES
    Nontraumatic – NonexertionalAlcohol/drugs (cocaine, heroin, MDMA), medications (statins, fibrates, neuroleptics, SSRIs, fluoroquinolones), toxic agents (CO, snake venom), anesthetics (propofol, succinylcholine in DMD/BMD)
    InfectionsInfluenza A/B, HIV, enterovirus, EBV, CMV, Legionella, Mycoplasma, Streptococcus, Salmonella
    Electrolyte & EndocrineHyponatremia, hypokalemia, hypophosphatemia, hypothyroidism, DKA, hyperaldosteronism
    Temperature extremesHeatstroke, malignant hyperthermia, hypothermia
    Exertional causesExtreme exertion, sickle cell crisis, status epilepticus, severe dystonia
    Traumatic causesCrush injury, electrical injury, burns, prolonged immobility, tourniquets
    Adapted from Zutt R et al. Neuromuscul Disord. 2014.

    Table 647.8 — Inherited Neuromuscular Disorders with Rhabdomyolysis Episodes

    GENEDISEASEBASELINE CKINHERITTRIGGERS
    PYGMMcArdle (GSD V)HighARExercise (minutes)
    CPT2CPT II deficiencyNormalARProlonged exercise, fasting, cold, high fat
    ACADVLVLCAD deficiencyNormalARFasting, prolonged exercise, cold, infection
    RYR1MHS / exertional rhabdomyolysisNormal-mild↑AD/ARAnesthesia, heat, infection, exercise
    DMDDuchenne/Becker MDHighXLExercise, succinylcholine
    ANO5AnoctaminopathyHighAROften unprovoked
    LPIN1Lipin deficiencyNormal-HighARFebrile illness, anesthesia, fasting
    ETFDHMADD (glutaric aciduria II)Mild-mod↑ARExercise, fasting, infection
    From Scalco RS et al. Orphanet J Rare Dis. 2015.

    Table 647.9 — Gene Variants and Cardiac Manifestations of Neuromuscular Disorders

    DISORDERGENECARDIOMYOPATHYECG/CONDUCTIONARRHYTHMIAS
    Duchenne MDDystrophinDilatedShort PR, prolonged QT, deep Q wavesPremature ventricular beats (58% by age 24)
    Becker MDDystrophinDilatedConduction diseaseSimilar to DMD
    Emery-Dreifuss (AD/XL)LMNA / EMDDilated (LMNA)Prolonged PR, sinus bradycardiaAtrial fib/flutter, atrial standstill, VT
    Myotonic dystrophy type 1DMPKHypertrophic / LV noncompactionProlonged PR, widened QRSAtrial fib/flutter, complete heart block
    LGMD2I (FKRP)FKRPDilatedAV block, bundle branch blockAtrial/ventricular arrhythmias
    Friedreich ataxiaFXNHypertrophicT-wave inversion, left axis deviationVentricular arrhythmias
    Data from Hsu DT. Paediatr Respir Rev. 2010; and Nelson 22nd Ed.

    📖 Summary: Rhabdomyolysis & Cardiac Manifestations in Neuromuscular Disorders