Ventricular Fibrillation (VF)

Ventricular fibrillation (V-fib or VF) is when the heart quivers instead of pumps due to disorganized electrical activity in the ventricles. It results in cardiac arrest with loss of consciousness and no pulse. This is followed by irreversible death in the absence of treatment. Ventricular fibrillation is found initially in about 10% of people in cardiac arrest.

Ventricular fibrillation can occur due to coronary heart disease, valvular heart disease, cardiomyopathy, Brugada syndrome, long QT syndrome, or intracranial haemorrhage. Diagnosis is by an electrocardiogram (ECG) showing irregular unformed QRS complexes without any clear P waves. An important differential diagnosis is torsade's de pointes.

Treatment is with cardiopulmonary resuscitation (CPR) and defibrillation. Biphasic defibrillation may be better than monophasic.