Signal Average Electrocardiogram
A signal average ECG, or "Late Potential Detector" is a microprocessor
based electrocardiogram (ECG). This type of ECG provides the cardiologist
with knowledge about the potential to have a life threatening heart rhythm.
It gives the CCND doctor different information than a 12 lead ECG.
This is a good screening test for detecting patients prone to sustained
ventricular tachycardia. ( a potential life threatening heart beat). If
the test does show the potential to have this rhythm, then a more aggressive
cardiac evaluation is warranted. The test itself only takes about 5 minutes.
Before The Test
There are no dietary
Wear a loose fitting
blouse or shirt, with the buttons in the
Do not wear a one piece jumpsuit.
Do not use lotions or
bath oil on your skin. This will
prevent the electrodes
(sticky patches) from sticking to
During The Test
A trained medical assistant
(or nurse) will place six
electrodes (small sticky
patches) on your chest, and one
on your back. The areas on your chest and
back will be cleansed
with alcohol and an abrasive pad
will be used to ensure
good electrode contact. Men may
need to have areas of
their chest shaved.
The electrodes are connected
by wires to the signal
average ECG machine.
You will be lying on
your back on an exam table. Once
the test has started,
you will be asked to lie very still on
the table, while the
machine is collecting data for the 3
The machine will then
produce a 3 channel ECG for the
doctor to interpret.
After The Test
Immediately after the
test, the physician can give you a
The presence of a "late potential"
been associated with the potential to have an
abnormal heart rhythm.
If the test is abnormal,
your doctor may order additional