title: Takotsubo cardiomyopathy and QT interval prolongation: who are the patients at risk for torsades de pointes?
abstract: OBJECTIVE
  QT interval prolongation is prevalent among patients with Takotsubo cardiomyopathy (TC), whereas torsades de pointes (TdP) has rarely been reported in these patients. We studied all peer-reviewed reports on TC-associated QT interval prolongation and all peer-reviewed reports on TC-associated TdP to characterize the clinical circumstances leading to TdP in patients with TC.
  
  
  METHODS
  The literature search yielded 14 reports on TC-associated TdP and 26 reports on TC-associated QT interval prolongation. Overall, 15 patients with TC-associated TdP and 86 patients with TC-associated QT interval prolongation were reported. We systematically reviewed each report and recorded the risk factors for TdP as well as the clinical circumstances of TC.
  
  
  RESULTS
  The prevalence of the male sex was higher among patients with TC-associated TdP relative to patients with TC-associated QT interval prolongation (26.7% vs 5.8%; P = .01). There was a trend in the mean maximal corrected QT interval being longer among patients with TC-associated TdP relative to patients with TC-associated QT interval prolongation (679.9 +/- 230.6 vs 555.9 +/- 63.8 milliseconds; P = .06). There were no differences between patients with TC-associated TdP and patients with TC-associated QT interval prolongation in mean age, maximal troponin levels, and lowest ejection fraction. Overall, 12 (80.0%) patients with TC-associated TdP had risk factors for TdP other than the female sex and systolic dysfunction, including suspicion of congenital long QT syndrome, bradycardia, hypokalemia, recent conversion from atrial fibrillation to sinus rhythm, and using QT prolonging agents.
  
  
  CONCLUSIONS
  Men with TC-associated QT interval prolongation are at risk for TdP. Most patients with TC-associated TdP have risk factors for TdP other than the female sex and systolic dysfunction.
authors.affiliation: Department of Internal Medicine D, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel.
authors.forename: Liat
authors.initials: L
authors.lastname: Samuelov-Kinori
authors.forename: Michael
authors.initials: M
authors.lastname: Kinori
authors.forename: Yevgeni
authors.initials: Y
authors.lastname: Kogan
authors.forename: Michael
authors.initials: M
authors.lastname: Swartzon
authors.forename: Hadas
authors.initials: H
authors.lastname: Shalev
authors.forename: Daniel
authors.initials: D
authors.lastname: Guy
authors.forename: Fotini
authors.initials: F
authors.lastname: Ferenidou
authors.forename: Noa
authors.initials: N
authors.lastname: Mashav
authors.forename: Ben
authors.initials: B
authors.lastname: Sadeh
authors.forename: Lihi
authors.initials: L
authors.lastname: Atzmony
authors.forename: Orit
authors.initials: O
authors.lastname: Kliuk-Ben-Basat
authors.forename: Arie
authors.initials: A
authors.lastname: Steinvil
authors.forename: Dan
authors.initials: D
authors.lastname: Justo
mesh_terms: D015897:Comorbidity; D004562:Electrocardiography / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000453:epidemiology*; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D054549:Takotsubo Cardiomyopathy / Q000175:diagnosis* / Q000453:epidemiology*; D016171:Torsades de Pointes / Q000175:diagnosis* / Q000453:epidemiology*