<s>
Fibrillation	B-Algorithm
is	O
the	O
rapid	O
,	O
irregular	O
,	O
and	O
unsynchronized	O
contraction	O
of	O
muscle	O
fibers	O
.	O
</s>
<s>
There	O
are	O
two	O
major	O
classes	O
of	O
cardiac	O
fibrillation	B-Algorithm
:	O
atrial	B-Application
fibrillation	I-Application
and	O
ventricular	O
fibrillation	B-Algorithm
.	O
</s>
<s>
Atrial	B-Application
fibrillation	I-Application
is	O
an	O
irregular	O
and	O
uncoordinated	O
contraction	O
of	O
the	O
cardiac	O
muscle	O
of	O
atria	O
.	O
</s>
<s>
It	O
can	O
be	O
a	O
chronic	O
condition	O
,	O
usually	O
treated	O
with	O
anticoagulation	O
and	O
sometimes	O
with	O
conversion	O
to	O
normal	B-Algorithm
sinus	I-Algorithm
rhythm	I-Algorithm
.	O
</s>
<s>
Ventricular	O
fibrillation	B-Algorithm
is	O
an	O
irregular	O
and	O
uncoordinated	O
contraction	O
of	O
the	O
cardiac	O
muscle	O
of	O
ventricles	O
.	O
</s>
<s>
Fibrillation	B-Algorithm
may	O
sometimes	O
be	O
used	O
after	O
heart	O
surgery	O
to	O
stop	O
the	O
heart	O
from	O
beating	O
while	O
any	O
minor	O
leaks	O
are	O
stitched	O
up	O
.	O
</s>
<s>
Fibrillation	B-Algorithm
also	O
occurs	O
with	O
individual	O
skeletal	O
muscle	O
fibers	O
.	O
</s>
<s>
This	O
happens	O
when	O
muscle	O
fibers	O
lose	O
contact	O
with	O
their	O
innervating	O
axon	O
producing	O
a	O
spontaneous	O
action	O
potential	O
,	O
"	O
fibrillation	B-Algorithm
potential	O
"	O
that	O
results	O
in	O
the	O
muscle	O
fiber	O
's	O
contraction	O
.	O
</s>
<s>
Fibrillations	B-Algorithm
can	O
occur	O
in	O
healthy	O
individuals	O
.	O
</s>
<s>
If	O
the	O
fibrillations	B-Algorithm
have	O
irregular	O
potentials	O
then	O
they	O
do	O
n't	O
have	O
pathological	O
significance	O
.	O
</s>
<s>
The	O
word	O
fibrillation	B-Algorithm
(	O
)	O
is	O
related	O
to	O
the	O
word	O
fibril	O
in	O
the	O
sense	O
of	O
muscle	O
fibrils	O
,	O
the	O
proteins	O
that	O
make	O
up	O
each	O
muscle	O
fiber	O
(	O
muscle	O
cell	O
)	O
.	O
</s>
