title: Chronic hydroxychloroquine use associated with QT prolongation and refractory ventricular arrhythmia.
abstract: BACKGROUND
  Hydroxychloroquine (HCQ) is used for treatment of lupus erythematosus. The cardiac toxicity of HCQ has focused primarily on acute intoxication. We report a case of chronic use of HCQ associated with torsade de pointes.
  
  
  METHODS
  A 67-year-old female presented with acquired long QT interval syndrome with a refractory ventricular arrhythmia. She was receiving chronic therapeutic doses of HCQ for the treatment of lupus erythematosus. Torsades de pointes was diagnosed in the Emergency Department (ED). After excluding other causes of long QT syndrome, the HCQ was suspected as the cause of her ventricular tachycardia. After discontinuing the HCQ, the QT interval was shorter and the patient recovered after treatment with lidocaine and isoproterenol.
  
  
  CONCLUSIONS
  The chronic use of HCQ for rheumatic diseases, or as an anti-malarial drug, should be balanced against the risk of developing potentially lethal cardiac arrhythmias.
authors.affiliation: Department of Emergency Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan.
authors.forename: Chun-Yu
authors.initials: CY
authors.lastname: Chen
authors.forename: Feng-Lin
authors.initials: FL
authors.lastname: Wang
authors.forename: Chih-Chuan
authors.initials: CC
authors.lastname: Lin
mesh_terms: D000368:Aged; D018501:Antirheumatic Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006886:Hydroxychloroquine / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D008133:Long QT Syndrome / Q000139:chemically induced*; D008180:Lupus Erythematosus, Systemic / Q000188:drug therapy; D013997:Time Factors; D018879:Ventricular Premature Complexes / Q000139:chemically induced*
chemical_list: D018501:Antirheumatic Agents; D006886:Hydroxychloroquine