Ventricular fibrillation is an extremely rapid heart rhythm occurring
in the lower heart chambers, usually at over 300 beats per minute. In
addition to being so very rapid, the electrical activation of the
ventricles does not display a specific and repetitive pattern
Instead, the electrical signals swirl around the heart in a very
chaotic manner. The heart muscle cells are activated without any
coordination so that there is no effective heart beat at all. The
heart is often described as "quivering" since it does not
contract in a meaningful way.
As a result, death usually results in 3-5 minutes unless
resuscitation is begun.