QT prolongation is present in 26-52% of cases of Takotsubo cardiomyopathy (TCM). It has been postulated to result from reduced cardiac repolarization reserve and reflects the transient myocardial insult observed in TCM. Bradycardia-induced QT interval prolongation is amplified by the occurrence of TCM, a combination that potentially carries a significant risk for torsade de pointes (TdP). We present a unique case of an 80-year-old female with TCM-related cardiac arrest. The patient had acquired long QT syndrome in which TCM myocardial insult led to the precipitation of a third-degree atrioventricular (AV) block and subsequent bradycardia-induced TdP. Due to the lack of robust literature, there is no clear guideline in the management of third-degree AV block in the setting of TCM. In our case, because of recurrent ventricular tachycardia (VT) and ventricular fibrillation (VF) arrest, we opted for temporary pacing at a high ventricular rate, followed by a biventricular implantable cardioverter-defibrillator (BiV/ICD). Follow-up 3 months later revealed improvement of left ventricular (LV) dysfunction and resolution of QT prolongation. However, the noticed AV conduction defects persisted. In the available literature, we identified five reported cases that bear similarity with our patient's presentation. The identified cases were middle-aged to elderly females with no significant cardiac history, who exhibited a similar triad of TCM associated with high-grade AV block, acquired long QT syndrome, and a rapid progression of bradycardia-induced TdP, resulting in a near cardiac arrest within the first 24 - 48 h of admission. It is crucial to monitor corrected QT (QTc), correct electrolyte abnormalities, and minimize QT-prolonging medications in patients with TCM. The recognition of AV conduction defects in patients with TCM is critical, especially if it is associated with significant QT prolongation. Such situations are underrecognized, and are potentially fatal, necessitating close monitoring and timely intervention.
Keywords: Biventricular implantable cardiac defibrillator; Cardiac arrest; Complete heart block; Permanent pacemaker; Polymorphic ventricular tachycardia; Stress-induced cardiomyopathy; Takotsubo cardiomyopathy; Torsade de pointes.
Copyright 2022, Awadelkarim et al.