#fibrillation.twitch  muscular twitching involving individual muscle fibers acting without coordination
  supertype:  twitch__twitching__vellication  a sudden spasm; especially one caused by a nervous condition
  subtype:  atrial_fibrillation  fibrillation of the muscles of the atria of the heart
  subtype:  ventricular_fibrillation__ventricularfibrillation  fibrillation of heart muscles resulting in interference with rhythmic contractions of the ventricles and possibly leading to cardiac arrest

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