How can I differentiate between ventricular fibrillation and other arrhythmias during a cardiac arrest scenario?

During a cardiac arrest scenario, ventricular fibrillation (VF) can be differentiated from other arrhythmias primarily by its characteristic chaotic, irregular, and rapid electrical activity on the ECG without identifiable QRS complexes, P waves, or T waves, indicating disorganized ventricular depolarization. This contrasts with other arrhythmias such as atrial fibrillation, which, although irregular, typically shows discernible QRS complexes and a fibrillatory baseline rather than the coarse or fine fibrillatory waves seen in VF. The UK guidelines emphasize recognising VF as a shockable rhythm requiring immediate defibrillation, identified by its erratic waveform and absence of organized ventricular contractions NICE NG196. Recent literature supports this by highlighting dynamic ECG analysis techniques that help discriminate VF from atrial fibrillation and other lethal ventricular arrhythmias through pattern recognition of repolarization abnormalities and waveform morphology Lévy & Sbragia 2011DeMazumder et al. 2013. Thus, the key differentiator is the absence of organized QRS complexes and the presence of rapid, irregular, and chaotic ventricular electrical activity in VF, guiding urgent defibrillation treatment NICE NG196 Lévy & Sbragia 2011DeMazumder et al. 2013.