title: Pyridostigmine-induced high grade SA-block in a patient with myasthenia gravis.
abstract: METHODS
  Female, 70 FINAL DIAGNOSIS: SA block induced by pyridostigmine Symptoms: Asymptomatic Medication: Pyridostigmine Clinical Procedure: Pacemaker insertion Specialty: Electrophysiology.
  
  
  OBJECTIVE
  Unusual clinical course.
  
  
  BACKGROUND
  Myasthenia gravis requires a long-term treatment with a parasympathomimetic agent, which may result in bradycardia and asystole. Pharmacologic treatment with a reversible inhibitor of inosine monophosphate dehydrogenase (IMPDH) and Methylprednisolone is seen to improve the muscular symptoms but may reinforce potential bradyarrhythmias. This potential side effect can be treated with the levo isomer of atropine, Hyoscyamine, or Glycopyrollate in an intact conduction system.
  
  
  METHODS
  A 70-year old Caucasian female patient with a family history of myasthenia gravis presented with mild weakness of the bilateral facial muscles, moderate dysarthria, dysphagia, diplopia predominantly on the right side and difficulty tracking ocular movements bilaterally. The treatment with pharmacological agents was initiated. Subsequently she developed asymptomatic bradycardia and SA-block. An improvement on Hyoscyamine failed to appear. A dual chamber pacemaker was placed.
  
  
  CONCLUSIONS
  In symptomatic or asymptomatic bradycardia with significant high grade SA-block in patients with myasthenia gravis the insertion of a permanent pacemaker can be the definitive solution.
authors.affiliation: Department of Internal Medicine, Paul L. Foster School of Medicine,Texas Tech University Health Sciences Center, El Paso, TX, U.S.A.
authors.forename: Sarmad
authors.initials: S
authors.lastname: Said
authors.forename: Chad J
authors.initials: CJ
authors.lastname: Cooper
authors.forename: Haider
authors.initials: H
authors.lastname: Alkhateeb
authors.forename: Sherif
authors.initials: S
authors.lastname: Elhanafi
authors.forename: Jorge
authors.initials: J
authors.lastname: Bizet
authors.forename: Sucheta
authors.initials: S
authors.lastname: Gosavi
authors.forename: Zainul
authors.initials: Z
authors.lastname: Abedin
keywords: SA block; myasthenia gravis; pyridostigmine induced bradycardia
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