An electrocardiogram (EKG, ECG) can be very helpful in determining
the cause of palpitations and may reveal tachycardia if it is happening at the
time the test is given. Since tachycardia may come and go, the EKG more
commonly provides clues about the cause of the palpitations by demonstrating
evidence of underlying heart disease, such as:
- Signs of an old heart attack, which may be
associated with an arrhythmia that originates in the lower heart chambers
(ventricles) as the cause of palpitations.
- Evidence of a bypass
tract, which is an improper electrical connection in the heart.
Why might I need other tests?
If the EKG performed in the office does not reveal conclusive
evidence of the arrhythmia, you may require further testing to determine the
cause of your palpitations if your doctor suspects an arrhythmia based on your
medical history and your physical exam. For example, you may have another heart
condition that can cause an arrhythmia or you may have a family member who has
had an arrhythmia.
How do monitoring devices help identify an arrhythmia as the cause of palpitations?
Various monitoring devices are available to record the electrical
activity of your heart that can show evidence of an arrhythmia when it occurs.
The hope is that the monitor will record an arrhythmia if one occurs while you
are wearing a monitor. Your heart rhythm is recorded and can be matched to the
timing of your symptoms. If an arrhythmia occurs at the time of the symptoms,
your doctor may be able to identify the cause of the palpitations. On the other
hand, if you have a normal heart rhythm during the palpitations, then it is
very unlikely that an arrhythmia is the cause. If the palpitations occur
frequently, they may be "captured" on a 24-hour Holter monitor. If they occur
less frequently, a more prolonged event monitor is preferred because you can
trigger the monitor to record when you feel the palpitations.