<s>
In	O
electrocardiography	B-Application
,	O
the	O
atrial	B-Algorithm
action	I-Algorithm
potential	I-Algorithm
are	O
action	B-Algorithm
potentials	I-Algorithm
that	O
occur	O
in	O
the	O
heart	O
atrium	O
.	O
</s>
<s>
They	O
are	O
similar	O
to	O
ventricular	B-Algorithm
action	I-Algorithm
potential	I-Algorithm
with	O
the	O
exception	O
of	O
having	O
a	O
more	O
narrow	O
phase	O
2	O
(	O
plateau	O
phase	O
)	O
due	O
to	O
a	O
smaller	O
calcium	O
influx	O
.	O
</s>
<s>
Also	O
,	O
in	O
comparison	O
to	O
the	O
ventricular	B-Algorithm
action	I-Algorithm
potential	I-Algorithm
,	O
atrial	B-Algorithm
action	I-Algorithm
potentials	I-Algorithm
have	O
a	O
more	O
gradual	O
repolarization	O
period	O
.	O
</s>
