How is ventricular fibrillation presented on ECG?

A wearable cardiac event monitor may be used to diagnose tachycardia. This type of portable ECG device records heart activity only during episodes of irregular heart rhythms (arrythmias). An electrocardiogram is the most common tool used to diagnose tachycardia .

VF is a WCT caused by irregular electrical activity and characterized by a ventricular rate of usually greater than 300 with discrete QRS complexes on the electrocardiogram (ECG). QRS morphology in VF varies in shape, amplitude, and duration with a prominent irregular rhythm.

Ventricular fibrillation seldom terminates spontaneously , since several re-entrant wavefronts, independent from each other, coexist, and the simultaneous extinction of all the circuits is unlikely.