results from an additional electrical connection between the upper
chambers of the heart (atria) and the lower chambers of the heart
This extra or ‘accessory’
pathway is seen in approximately 1 in every 300-500 people and sometimes
it allows conduction of the electrical pulse at high speed, generating
an electrical short circuit, which produces a rapid heart rate
(arrhythmia) which can occasionally be dangerous.
WPW is rarely inherited,
however, and runs in families in less than 1% of cases.
People with WPW may never experience
symptoms. In fact, in the majority of people the extra pathway is
completely silent. Palpitations are, however, the main symptom of WPW.
Some people may find these palpitations untroubling,
but in others they may cause chest pain, light-headedness and even
blackouts. They may occur predictably or at any time and people may be
able to control them. One way of doing this is by holding one's breath
as forcibly as possible. The palpitations may remain, however, until
they can be stopped by an injection in an accident and emergency
If a person is a competitive athlete; or
has a particular job such as a pilot or a soldier; or has had
palpitations because of arrhythmia; more invasive tests (EP studies) may
be recommended to assess the way the accessory pathway behaves and
therefore the risk of significant arrhythmias.
The ideal treatment for someone with symptoms of WPW
is to burn the extra electrical pathway using
RF ablation. This is
done at the time of an EP study, by passing a wire into the heart and
locating the pathway. This is destroyed by passing a high current
through it. This takes approximately 1-2 hours and may require one night
Tablets may be preferable to an ablation if the accessory pathway is difficult to treat.