Signal Averaged Electrocardiogram (SAECG)
Why is
the doctor performing this procedure?
To evaluate
the heart's functioning by viewing its electrical activity. It is similar
to a standard electrocardiogram (ECG), but provides greater in-depth
information by collecting many heart beats and analyzing them
together—a procedure called signal-averaging.
What
is the procedure?
Similar to
an ECG (See ECG for information on a standard electrocardiogram), the SAECG
is a painless, non-invasive test, with electrodes placed on the skin. These
electrodes are attached to the SAECG machine so that the electrical
activity of the heart is visualized, and then electronically manipulated by
the signal-averaging software for deeper analysis.
The Signal-Averaged Electrocardiogram essentially strengthens some signals
while eliminating "background noise" from other signals. These
signals are then filtered and averaged, providing an analysis that yields
information about patient risk of future ventricular tachycardia (rapid
heart activity) and/or ventricular fibrillation (irregular heart activity).
These weak but very important impulses are called "late
potentials" and are commonly not evaluated in a standard ECG. Late
potentials arise from damaged or scarred areas of heart muscle. Recognizing
the presence of these late potentials can be helpful in the following
situations:
·
To determine risk for ventricular arrhythmia following
heart surgery or a heart attack.
·
To determine the cause of fainting (called syncope).
·
To determine if scar tissue is present from a previous
heart attack.
Where
is the procedure performed?
A
signal-averaged electrocardiogram can be done easily in a number of places
in the hospital (Emergency Room, hospital room, Cath
Lab, the Non-Invasive Cardiology Testing Center). An SAECG can also be
performed in medical offices.
How
long does this procedure take?
A standard
ECG takes about 5 minutes; a SAECG takes a bit longer, usually 5-20
minutes.
|
