<s>
Multifocal	O
(	O
or	O
multiform	O
)	O
atrial	O
tachycardia	B-Application
(	O
MAT	O
)	O
is	O
an	O
abnormal	B-Application
heart	I-Application
rhythm	I-Application
,	O
specifically	O
a	O
type	O
of	O
supraventricular	B-Algorithm
tachycardia	I-Algorithm
,	O
that	O
is	O
particularly	O
common	O
in	O
older	O
people	O
and	O
is	O
associated	O
with	O
exacerbations	O
of	O
chronic	O
obstructive	O
pulmonary	O
disease	O
(	O
COPD	O
)	O
.	O
</s>
<s>
When	O
a	O
number	O
of	O
different	O
clusters	O
of	O
cells	O
outside	O
the	O
SA	O
node	O
take	O
over	O
control	O
of	O
the	O
heart	O
rate	O
,	O
and	O
the	O
rate	O
exceeds	O
100	O
beats	O
per	O
minute	O
,	O
this	O
is	O
called	O
multifocal	B-Algorithm
atrial	I-Algorithm
tachycardia	I-Algorithm
(	O
if	O
the	O
heart	O
rate	O
is	O
≤100	O
,	O
this	O
is	O
technically	O
not	O
a	O
tachycardia	B-Application
and	O
it	O
is	O
then	O
termed	O
multifocal	O
atrial	O
rhythm	O
)	O
.	O
</s>
<s>
"	O
Multiform	O
"	O
refers	O
to	O
the	O
observation	O
of	O
variable	O
P	B-Algorithm
wave	I-Algorithm
shapes	O
,	O
while	O
"	O
multifocal	O
"	O
refers	O
to	O
the	O
underlying	O
cause	O
.	O
</s>
<s>
Theophylline	O
can	O
cause	O
a	O
number	O
of	O
different	O
abnormal	B-Application
heart	I-Application
rhythms	I-Application
when	O
in	O
excess	O
,	O
and	O
thus	O
further	O
predisposes	O
COPD	O
patients	O
to	O
MAT	O
.	O
</s>
<s>
WAP	O
is	O
positive	O
once	O
the	O
heart	O
generates	O
at	O
least	O
three	O
different	O
P-wave	O
formations	O
from	O
the	O
same	O
ECG	B-Application
lead	O
.	O
</s>
<s>
Then	O
,	O
if	O
the	O
heart	O
rate	O
exceeds	O
100	O
beats	O
per	O
minute	O
,	O
the	O
phenomenon	O
is	O
called	O
multifocal	B-Algorithm
atrial	I-Algorithm
tachycardia	I-Algorithm
.	O
</s>
<s>
Multifocal	B-Algorithm
atrial	I-Algorithm
tachycardia	I-Algorithm
is	O
characterized	O
by	O
an	O
electrocardiogram	B-Application
(	O
ECG	B-Application
)	O
strip	O
with	O
three	O
or	O
more	O
discrete	O
P	B-Algorithm
wave	I-Algorithm
morphologies	O
in	O
the	O
same	O
lead	O
,	O
not	O
including	O
that	O
originating	O
from	O
the	O
sinoatrial	O
node	O
,	O
plus	O
tachycardia	B-Application
,	O
which	O
is	O
a	O
heart	O
rate	O
exceeding	O
100	O
beats	O
per	O
minute	O
(	O
although	O
some	O
suggest	O
using	O
a	O
threshold	O
of	O
90	O
beats	O
per	O
minute	O
)	O
.	O
</s>
<s>
Furthermore	O
,	O
there	O
should	O
be	O
irregular	O
PP	O
intervals	O
,	O
and	O
the	O
baseline	O
should	O
be	O
isoelectric	O
between	O
P	B-Algorithm
waves	I-Algorithm
.	O
</s>
<s>
Other	O
diagnoses	O
that	O
may	O
present	O
with	O
similar	O
findings	O
on	O
electrocardiogram	B-Application
that	O
should	O
be	O
included	O
in	O
the	O
differential	O
diagnosis	O
include	O
sinus	O
tachycardia	B-Application
with	O
frequent	O
premature	O
atrial	O
contractions	O
(	O
this	O
would	O
have	O
regular	O
PP	O
intervals	O
)	O
,	O
atrial	O
flutter	O
with	O
variable	O
AV	O
node	O
conduction	O
(	O
this	O
would	O
have	O
regular	O
PP	O
intervals	O
and	O
flutter	O
waves	O
)	O
,	O
atrial	O
fibrillation	O
(	O
this	O
would	O
not	O
have	O
discrete	O
P-wave	O
morphologies	O
)	O
,	O
and	O
wandering	O
atrial	O
pacemaker	O
which	O
would	O
have	O
a	O
heart	O
rate	O
less	O
than	O
100	O
beats	O
per	O
minute	O
)	O
.	O
</s>
<s>
If	O
arrhythmia	B-Application
persists	O
despite	O
the	O
treatment	O
of	O
underlying	O
medical	O
conditions	O
it	O
may	O
be	O
worth	O
checking	O
a	O
complete	O
blood	O
count	O
and	O
serum	O
chemistry	O
for	O
signs	O
of	O
infection	O
,	O
anemia	O
,	O
or	O
electrolyte	O
abnormalities	O
such	O
as	O
hypokalemia	O
and	O
hypomagnesemia	O
.	O
</s>
<s>
Management	O
of	O
multifocal	B-Algorithm
atrial	I-Algorithm
tachycardia	I-Algorithm
consists	O
mainly	O
of	O
the	O
treatment	O
of	O
the	O
underlying	O
cause	O
.	O
</s>
<s>
A	O
beta-blockers	O
act	O
to	O
suppress	O
ectopic	B-Algorithm
foci	I-Algorithm
by	O
reducing	O
sympathetic	O
stimulation	O
and	O
decreasing	O
conduction	O
through	O
the	O
atrioventricular	O
node	O
,	O
thereby	O
slowing	O
the	O
ventricular	O
response	O
.	O
</s>
<s>
In	O
select	O
cases	O
of	O
refractory	O
multifocal	B-Algorithm
atrial	I-Algorithm
tachycardia	I-Algorithm
,	O
AV	O
node	O
ablation	O
has	O
been	O
performed	O
.	O
</s>
