Description of WCD
The WCD consists of a two-channel electrocardiogram that records the front-back and left-right site as bipolar leading to continuous electrocardiographic analysis. If a life-threatening heart rhythm such as ventricular tachycardia (VT) or ventricular fibrillation (VF) is detected, it delivers a shock to restore sinus rhythm. The detection until shock delivery takes 45-55 s including initial detection of VT/VF 5 s to 10 s, tachycardia confirmation 10 s, and alarm time 25 s. Shock can be avoided by pressing the stop button. The WCD has a memory for ECG analysis from 30 s before starting the arrhythmia alarm until 15 s after the alarm stop [13].