Wearable cardioverter defibrillator prevented sudden cardiac death in a pediatric case of takotsubo cardiomyopathy in Japan

As an alternative to implantable cardioverter defibrillators, the wearable cardioverter defibrillator (WCD; LifeVest®, Asahi KASEI Zoll Medical Co., Tokyo, Japan) is the only noninvasive cardioverter defibrillator available that can be worn directly on the skin. The first consensus statement on WCD use in Japan was published in 2014, and, similar to guidelines in other countries, its recommendations focus on adult patients. Pediatric cases involving WCD remain limited, and appropriate indications for its use in children are yet to be established. Here, we report the first pediatric case in Japan where WCD monitored a patient and delivered an appropriate shock to terminate a life-threatening ventricular tachycardia and ventricular fibrillation episode. During this time, the patient was recovering from takotsubo cardiomyopathy, presumably associated with refeeding syndrome secondary to Crohn's disease. No inappropriate shocks were delivered during the three-month monitoring period, and the WCD use was deemed safe. The continuous monitoring function of WCD aided in understanding the patient's conditions. Following treatment, the patient has recovered from Crohn's disease and his cardiac function has stabilized, and he has not experienced neurological sequelae or heart failure symptoms since. This case highlights the potential of WCD use in pediatric patients. Learning objective: The wearable cardioverter defibrillator (WCD; LifeVest®) is the only noninvasive cardioverter defibrillator available. However, current guidelines around the world primarily focus on adult patients. Cases of pediatric patients who are rescued by an appropriate shock by WCD are still limited and many aspects, such as device set-up, effectiveness, and risks require further study. This case supports that WCD in children can be safe and effective, demonstrating its potential to protect against ventricular tachycardia and ventricular fibrillation and prevent sudden cardiac death.