Ventricular fibrillation is a cause of cardiac arrest and sudden cardiac death. The ventricular muscle twitches randomly rather than contracting in a coordinated fashion, so the ventricles fail to pump blood around the body. Because of this, it is classified as a cardiac arrest rhythm, and patients in V-fib should be treated with cardiopulmonary resuscitation (CPR) and prompt defibrillation. Left untreated, ventricular fibrillation is rapidly fatal as the vital organs of the body, including the heart, are starved of oxygen.

Ventricular fibrillation most commonly occurs within diseased hearts and is often due to underlying ischemic heart disease. Ventricular fibrillation is also seen in those with cardiomyopathy, myocarditis, and other heart pathologies. In addition, it is seen with electrolyte imbalance, overdoses of cardiotoxic drugs, and following near drowning or major trauma. It is also notable that ventricular fibrillation occurs where there is no discernible heart pathology or other evident cause. There are hereditary conditions that predispose individuals to developing ventricular fibrillation and sudden cardiac death.

cardiac arrest