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The hallmark of SQTS is a
short QT-interval on the electrocardiogram(ECG). Basic information
about ECGs and Short QT can be found on this website under
What is Short QT.
A short QT-interval can be
overlooked. It is particularly important to focus attention on the
QT-interval in people with family members who have SQTS or have died
suddenly. People with atrial fibrillation at a young age or anyone
presenting with passing out spells of unknown origin should have an ECG
at a time when the heart beats less than 80 beats per minute in order to
look for a short QT interval. It is important to emphasize, that an ECG
taken during a higher heart rate may not show the short QT-interval.
If the diagnosis is questionable from the standard ECG, the next
step is a 24-hour ambulatory ECG recording (Holter monitoring). This is
a continuous ECG recording using a small portable recorder (tape or
digital technique) with 4-6 electrodes applied to the front of the chest
wall. Since the heart rate varies over a 24 hour period, it gives the
physician the opportunity to measure the QT-interval at many different
heart rates. The diagnosis can be made with greatest certainty when the
heart beats between 60-80 beats per minute.
The next step could be an
electrophysiologic study, but the indication for such a study has not
been established yet.
The diagnosis can be firmly
made in cases where one of the genetic defects is found. How often this
will be the case is not known, but many patients have been found to
carry the gene abnormality associated with Short QT Syndrome.
last
updated: 04/02/2009 |
