Fibrillation

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Fibrillation

Fibrillation commonly refers to the rapid, irregular, and unsynchronized contraction of the muscle fibers of the heart

Heart

The heart is a muscle organ in all vertebrates responsible for pumping blood through the blood vessels by repeated, rhythmic contractions, or a similar structure in annelids, mollusks, and arthropods....
. There are two major classes of fibrillation: atrial fibrillation

Atrial fibrillation

Atrial fibrillation is a cardiac arrhythmia that involves the two upper chambers of the heart. It can often be identified by taking a pulse and observing that the heartbeats don't occur at regular intervals, but a conclusive indication of AF is the absence of P waves on an electrocardiogram ....
and ventricular fibrillation

Ventricular fibrillation

Ventricular fibrillation is a condition in which there is uncoordinated contraction of the cardiac muscle of the ventricle s in the heart, making them tremble rather than contract properly....
.

Fibrillation may sometimes be used after heart surgery to stop the heart from beating while any minor leaks are stitched up.

In addition to the above use of the term, fibrillation also refers to the spontaneous electrical activity and feeble contraction of individual skeletal muscle fibers.

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Encyclopedia

Fibrillation commonly refers to the rapid, irregular, and unsynchronized contraction of the muscle fibers of the heart

Heart

Atrial fibrillation

Ventricular fibrillation

Ventricular fibrillation is a condition in which there is uncoordinated contraction of the cardiac muscle of the ventricle s in the heart, making them tremble rather than contract properly....
.

Atrial fibrillation
Atrial fibrillation

Atrial fibrillation is a cardiac arrhythmia that involves the two upper chambers of the heart. It can often be identified by taking a pulse and observing that the heartbeats don't occur at regular intervals, but a conclusive indication of AF is the absence of P waves on an electrocardiogram ....
can be a chronic condition, usually treated with anticoagulation and sometimes with conversion
Cardioversion

Synchronized electrical cardioversion is the process by which an abnormally fast heart rate or cardiac arrhythmia is terminated by the delivery of a therapeutic dose of electric current to the heart at a specific moment in the cardiac cycle....
to normal sinus rhythm
Cardiac pacemaker

The contractions of the heart are controlled by chemical impulses, which fire at a rate which controls the beat of the heart.The cell s that create these rhythmical impulses are called pacemaker cells, and they directly control the heart rate....
. This originates in the Atrium and an electrical impulse is "quivering" (fibrillation). An electrical pulse is given off, but is not the optimal way of sending an electrical pulse.

Ventricular fibrillation
Ventricular fibrillation

Ventricular fibrillation is a condition in which there is uncoordinated contraction of the cardiac muscle of the ventricle s in the heart, making them tremble rather than contract properly....
is rapidly fatal if not reversed by defibrillation
Defibrillation

Defibrillation is the definitive treatment for the life-threatening cardiac arrhythmias, ventricular fibrillation and ventricular tachycardia....
. No electrical impulse is given off in this form of dysrhythmia.

Fibrillation may sometimes be used after heart surgery to stop the heart from beating while any minor leaks are stitched up.

In addition to the above use of the term, fibrillation also refers to the spontaneous electrical activity and feeble contraction of individual skeletal muscle fibers. These contractions are never visible under the skin and are detectable only through electromyography

Electromyography

Electromyography is a technique for evaluating and recording the activation signal of muscles. EMG is performed using an medical instrument called an electromyograph, to produce a record called an electromyogram....
(EMG). Fibrillations do not occur in healthy individuals and are often characteristic of lower motor neuron lesions. This is contrasted by fasciculations, which are visible spontaneous contractions involving small groups of muscle fibers. Also, fasciculation does not necessarily denote pathology, as does fibrillation, although it can be seen in lower motor neuron lesions as well.