<s>
Permanent	B-Algorithm
junctional	I-Algorithm
reciprocating	I-Algorithm
tachycardia	I-Algorithm
(	O
PJRT	B-Algorithm
)	O
is	O
a	O
rare	O
cardiac	B-Application
arrhythmia	I-Application
.	O
</s>
<s>
It	O
is	O
a	O
supraventricular	B-Algorithm
tachycardia	I-Algorithm
,	O
and	O
a	O
cause	O
of	O
atrioventricular	B-Algorithm
reentrant	I-Algorithm
tachycardia	I-Algorithm
(	O
AVRT	B-Algorithm
)	O
.	O
</s>
<s>
PJRT	B-Algorithm
can	O
cause	O
chronic	O
tachycardia	B-Application
that	O
,	O
untreated	O
,	O
leads	O
to	O
cardiomyopathy	O
.	O
</s>
<s>
The	O
cause	O
is	O
an	O
accessory	B-Algorithm
pathway	I-Algorithm
in	O
the	O
heart	O
which	O
conducts	O
from	O
the	O
ventricles	O
back	O
to	O
the	O
atria	O
.	O
</s>
<s>
Unlike	O
the	O
accessory	B-Algorithm
pathway	I-Algorithm
in	O
a	O
more	O
common	O
cause	O
of	O
AVRT	B-Algorithm
,	O
Wolff	O
–	O
Parkinson	O
–	O
White	O
syndrome	O
,	O
the	O
accessory	B-Algorithm
pathway	I-Algorithm
in	O
PJRT	B-Algorithm
conducts	O
slowly	O
.	O
</s>
<s>
This	O
means	O
that	O
the	O
associated	O
tachycardia	B-Application
may	O
be	O
subclinical	O
and	O
only	O
diagnosed	O
at	O
a	O
late	O
stage	O
,	O
after	O
significant	O
damage	O
to	O
the	O
heart	O
has	O
been	O
caused	O
from	O
prolonged	O
and	O
recurrent	O
episodes	O
of	O
AVRT	B-Algorithm
.	O
</s>
<s>
While	O
PJRT	B-Algorithm
generally	O
presents	O
itself	O
in	O
infants	O
,	O
and	O
often	O
immediately	O
after	O
birth	O
,	O
few	O
adults	O
can	O
suffer	O
from	O
a	O
sudden	O
onset	O
of	O
PJRT	B-Algorithm
in	O
which	O
the	O
degrading	O
accessory	B-Algorithm
pathway	I-Algorithm
can	O
more	O
often	O
than	O
not	O
be	O
in	O
a	O
non-posteroseptal	O
site	O
.	O
</s>
<s>
Palpitations	B-Algorithm
during	O
exercise	O
or	O
stress	O
may	O
be	O
the	O
presenting	O
symptom	O
.	O
</s>
<s>
During	O
an	O
episode	O
of	O
AVRT	B-Algorithm
caused	O
by	O
PJRT	B-Algorithm
,	O
the	O
accessory	B-Algorithm
pathway	I-Algorithm
conducts	O
electrical	O
activity	O
from	O
the	O
ventricles	O
directly	O
back	O
to	O
the	O
atria	O
at	O
the	O
end	O
of	O
systole	O
,	O
which	O
triggers	O
the	O
atria	O
to	O
contract	O
,	O
and	O
the	O
current	O
to	O
pass	O
back	O
to	O
the	O
ventricles	O
again	O
via	O
the	O
atrioventricular	O
node	O
(	O
AV	O
node	O
)	O
;	O
see	O
diagram	O
.	O
</s>
<s>
An	O
electrocardiogram	B-Application
(	O
ECG	B-Application
)	O
undertaken	O
during	O
an	O
episode	O
of	O
AVRT	B-Algorithm
demonstrates	O
typical	O
features	O
of	O
retrograde	O
(	O
inverted	O
)	O
p-waves	O
in	O
the	O
inferior	O
leads	O
II	O
,	O
III	O
,	O
aVF	O
,	O
and	O
V4	O
–	O
V6	O
with	O
a	O
long	O
RP′	O
interval	O
.	O
</s>
<s>
Termination	O
of	O
an	O
episode	O
of	O
AVRT	B-Algorithm
in	O
PJRT	B-Algorithm
can	O
be	O
achieved	O
with	O
vagal	O
manouvres	O
,	O
antiarrhythmic	B-Algorithm
medications	I-Algorithm
or	O
DC	O
cardioversion	O
.	O
</s>
