Multifactorial QT Interval Prolongation and Takotsubo Cardiomyopathy

Abstract

A 71-year-old woman collapsed while working as a grocery store cashier. CPR was performed and an AED revealed torsades de pointes (TdP). She was subsequently defibrillated resulting in restoration of sinus rhythm with a QTc interval of 544 msec. Further evaluation revealed a diagnosis of Takotsubo Cardiomyopathy (TCM) contributing to the development of a multifactorial acquired long QT syndrome (LQTS). The case highlights the role of TCM as a cause of LQTS in the setting of multiple risk factors including old age, female gender, hypokalemia, and treatment with QT prolonging medications. It also highlights the multifactorial nature of acquired LQTS and lends support to growing evidence of an association with TCM.

Figure 1

AED rhythm strip demonstrating: (a) TdP in Leads II and III, (b) resolution of TdP following defibrillation at 200 J, and (c) normal sinus rhythm in Lead II after defibrillation.

Figure 2

(a) ECG on admission to community hospital demonstrating normal sinus rhythm and QT interval prolongation (QTc = 544 msec). (b) ECG two days following admission demonstrating marked T-wave inversion and QT prolongation (QTc = 634 msec). (c) ECG on discharge demonstrating improvement of T-wave inversion abnormalities and shortening of the QT interval (QTc = 514 msec). (d) and (e) Left ventriculography at end-diastole and end-systole, respectively. Note the apical ballooning characteristic of Takotsubo Cardiomyopathy.