The wearable cardioverter-defibrillator (WCD) consists of a garment containing 3 self-gelling defibrillation patch electrodes, 2 on the back and 1 in the front, and 4 non-adhesive ECG electrodes connected to a monitoring unit (Figure 1). Worn around the chest like a vest, the WCD provides continuous ECG monitoring and automatically delivers up to 5 posterior-anterior defibrillation shocks per ventricular arrhythmia (VA) episode. The WCD proved to be both safe and effective in terminating ventricular tachyarrhythmia in various patient cohorts with primary or secondary prevention indication for sudden cardiac death. The first shock effectiveness varies from 91% in the earlier first-in-human studies to 100% in selected patients at-risk. The device is also able to transmit data via telemonitoring concerning arrhythmia and shock discharge, but also information on therapy compliance/adherence to wear the device. Further clinical information as daily heart rate, step count or cardiac acoustic biomarkers are collected that can potentially assist to monitor heart failure patients.  Kulcsszavak: venticular tachyarrhytmia, VT, VF, wearable cardioverter-defibrillator, sudden cardic death