title: Subclinical skeletal muscle abnormalities in patients with hypertrophic cardiomyopathy and their relation to clinical characteristics.
abstract: BACKGROUND
  Some mutations of cardiac sarcomeric proteins causing hypertrophic cardiomyopathy (beta-myosin heavy chain) are associated with skeletal muscle fiber dysfunction, while subclinical skeletal myopathy can be diagnosed by electromyography (EMG) in a substantial proportion of hypertrophic cardiomyopathy patients.
  
  
  METHODS
  In 49 consecutive, unrelated patients with hypertrophic cardiomyopathy, conventional EMG of deltoid, vastus lateralis, tibialis anterior and soleus muscles was performed. No patient had clinically detectable muscle weakness. We compared the clinical and echocardiographic characteristics between patients with normal and patients with myopathic EMG.
  
  
  RESULTS
  Myopathic EMG findings were demonstrated in 13 patients (26.5%), 26 patients (53.1%) had normal findings and 10 patients (20.4%) had indeterminate recordings. There was no significant difference in mean age, maximum wall thickness, left ventricular fraction shortening, NYHA class, the existence of left ventricular outflow tract obstruction, syncope, or the occurrence of nonsustained ventricular tachycardia in the Holter recording among the three groups. Comparison between the myopathic and the normal group revealed that nine patients from the latter (34.6%) had a positive history of sudden death in the family, whereas no patient had such a history in the former group (P=0.015).
  
  
  CONCLUSIONS
  The higher prevalence of a family history of sudden death in patients with normal EMG, although not thoroughly explained by our data, may reflect differences in the genetic substrate produced by the higher prevalence of high-risk mutations that are not expressed in skeletal muscle (e.g. troponin T). Further evaluation in genotyped patients is warranted.
authors.affiliation: Department of Cardiology, University of Athens, Hippokration Hospital, Athens, Greece. fidip@eexi.gr <fidip@eexi.gr>
authors.forename: Aris
authors.initials: A
authors.lastname: Anastasakis
authors.forename: Nikos
authors.initials: N
authors.lastname: Karandreas
authors.forename: Pantelis
authors.initials: P
authors.lastname: Stathis
authors.forename: Angelos
authors.initials: A
authors.lastname: Rigopoulos
authors.forename: Artemisia
authors.initials: A
authors.lastname: Theopistou
authors.forename: Robert
authors.initials: R
authors.lastname: Sepp
authors.forename: Perry M
authors.initials: PM
authors.lastname: Elliott
authors.forename: Demosthenes B
authors.initials: DB
authors.lastname: Panagiotakos
authors.forename: Christodoulos
authors.initials: C
authors.lastname: Stefanadis
authors.forename: Pavlos
authors.initials: P
authors.lastname: Toutouzas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D024741:Cardiomyopathy, Hypertrophic, Familial / Q000150:complications / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D016757:Death, Sudden, Cardiac; D004452:Echocardiography; D004576:Electromyography; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008487:Medical History Taking; D008875:Middle Aged; D018657:Muscle Fibers, Slow-Twitch; D018482:Muscle, Skeletal / Q000002:abnormalities* / Q000503:physiopathology; D009135:Muscular Diseases / Q000150:complications / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D009154:Mutation; D018995:Myosin Heavy Chains / Q000235:genetics; D024723:Ventricular Myosins / Q000235:genetics
chemical_list: D024723:Ventricular Myosins; D018995:Myosin Heavy Chains