Heart attack survivors may be at risk of sudden cardiac death. A heart
attack can damage heart tissue causing your heart to misbehave electrically.
Abnormal and dangerously fast electrical signals, or arrhythmias limit your
heart's ability to pump blood to the body and brain.
Risk Factors
Most patients have no obvious symptoms of SCD so it
is important to be familiar with the possible risk factors. Risk factors may
include:
Previous Heart Attack: A heart attack is a mechanical
problem with the plumbing of your heart. A blockage in one of the arteries
nourishing your heart prevents blood and oxygen from reaching your heart
muscle, therefore part of your heart tissue dies.
Impaired Pumping Function of the Heart Muscle: The
pumping function of your heart or "ejection fraction" after a heart attack may
be impaired. This is due to scarring of the tissue of your heart due to the
heart attack.
Rapid Heart Rhythms: You could experience a very
brief period of short bursts of fast heartbeats called nonsustained
ventricular tachycardia (VT). These rapid heartbeats may or may not be
noticeable to you. Nonsustained VT is often the precursor to SCD.
Early identification is key. If you are at risk it is important to talk to
your doctor.
Diagnosis
If you have had a heart attack, your doctor may
perform one or more of the tests below to make a diagnosis.
Echocardiogram [Link to Echocardiogram page] - The
Echocardiogram will determine your heart's pumping function or "ejection
fraction". During this test, ultrasound waves are bounced off your heart
muscle to provide a moving image. Based on the results of this test your
doctor will determine if further testing is needed.
Holter Monitoring [Link to Holter Monitorinig Page]
- A Holter monitor is an external monitor that is worn on a 24-hour
outpatient basis. The monitor records your heart's electrical activity
including any episodes of arrhythmia. Your doctor will analyze the recording
to see if there are any abnormal rhythms, either rapid or slow or irregular.
Electrophysiology (EP) Testing [Link to EP Testing page] - EP testing is
commonly conducted in an electrophysiology lab. Wires will be threaded from
your groin up into your heart. Then, an electrical stimulus will be
delivered through the wires in an attempt to excite your heart into a fast
rhythm. If your heart is stimulated into VT, medications will be
administered intravenously to try and suppress the arrhythmia. While you are
on the medications, the stimulus will be delivered again to see if your
heart can still be induced into VT.
