Ventricular Fibrillation (also known as “V-Fib”) is a very rapid, uncoordinated series of contractions throughout the lower chambers of the heart caused by chaotic electrical impulses. In this case, the rhythm is very fast and irregular causing the heart to effectively stop beating. Ventricular fibrillation is the worst kind of abnormal heart rhythm, and is a form of cardiac arrest.
Damaged heart muscle due to a heart attack or other acute diminution of oxygen supply to the heart can cause ventricular fibrillation. It is may be seen immediately following a heart attack. It may also develop during hypoxia, atrial fibrillation, or improper grounding of electrical devices. An extremely low level of potassium in the blood can also cause ventricular fibrillation.
Ventricular fibrillation is electrically similar to atrial fibrillation, but much graver prognosis. In ventricular fibrillation, the ventricles merely quiver and don’t carry out coordinated contractions.