Ventricular fibrillation is a chaotic, disorganized rhythm in which the ventricles rapidly and asynchronously quiver. It is fatal and warrants immediate electrical cardioversion; otherwise, asystole is imminent. Mechanisms of ventricular arrythmia include increased automaticity (as occurs with ischemia or hyperkalemia), triggered activity from early or late afterdepolarizations (as occurs with conditions that cause prolonged QT), and reentry (as occurs with a scar from a prior myocardial infarction).
Ventricular Fibrillation
Examples
Ventricular Fibrillation
This is coarse ventricular fibrillation. This patient had a left ventricular assist device, which was keeping him alive. This is the only circumstance in which you should see a 12-lead of ventricular fibrillation.
Ventricular Fibrillation
A 12-lead of ventricular fibrillation should never be obtained unless the patient has a left ventricular assist device. This patient was awake and alert. The rhythm still warrants defibrillation because these patients still rely on right ventricular output.References
- European Heart Rhythm Association, Heart Rhythm Society, Zipes DP, et al. Acc/aha/esc 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the american college of cardiology/american heart association task force and the european society of cardiology committee for practice guidelines(Writing committee to develop guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death). J Am Coll Cardiol. 2006;48(5):e247-346.