Ventricular fibrillation – A condition in which the ventricles contract in a rapid, unsynchronized fashion. When fibrillation occurs, the ventricles cannot pump blood throughout the body. Ventricular tachycardia – An arrhythmia (abnormal heartbeat) in the ventricle characterized by a very fast heartbeat.
https://www.texasheart.org/heart-health/heart-information-center/topics/a-z/

