Takotsubo cardiomyopathy and QT interval prolongation: who are the patients at risk for torsades de pointes?
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.
Samuelov-Kinori
Liat
L
Department of Internal Medicine D, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel.
Kinori
Michael
M
Kogan
Yevgeni
Y
Swartzon
Michael
M
Shalev
Hadas
H
Guy
Daniel
D
Ferenidou
Fotini
F
Mashav
Noa
N
Sadeh
Ben
B
Atzmony
Lihi
L
Kliuk-Ben-Basat
Orit
O
Steinvil
Arie
A
Justo
Dan
D
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*