What is ventricular fibrillation (VF)?

Ventricular fibrillation is an exceedingly fast heart rate in the ventricles, the pumping chambers of your heart. When the ventricles are beating too fast, they start to quiver and can no longer pump oxygen-rich blood to the body and brain. If not treated promptly, ventricular fibrillation can lead to death. ICDs are primarily designed to treat ventricular fibrillation and other life-threatening arrhythmias.