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Short QT Publications
Click here to find an updated list of
Short QT Syndrome
publications that includes a description of each publications content.
Last update: October 2008
Distribution of the 53
reported Cases of Short QT Syndrome
as of October, 2008:

Countries where
patients with Short QT Syndrome have been found:
USA, Italy, Spain, The
Netherlands, Germany, France, Finland, Brazil, Turkey and China
Physicians Section
Updated to reflect
discovery of new gene for SQTS involving
KCNJ2
Last update: August 8, 2005
Patients
Section
Treatment - click here
Updated: August 8, 2005
NEWS – October, 2008
At the
Heart Rhythm Society Meeting in San Francisco, California USA,
May-2008, Preben Bjerregaard, MD, presented the following abstract:
Upper limits of QT/QTc Interval in the Short QT
Syndrome.
Review of the World-Wide Short QT Syndrome
Population and 3 New USA Families.
*Preben Bjerregaard, MD, DMSc, *Jack
L. Collier, MD and **Ihor Gussak, MD, PhD, *VA
Medical Center, Saint Louis, MO and **Boehringer-Ingelheim
Pharmaceuticals, Inc., Ridgefield, CT
Introduction: Short QT Syndrome (SQTS) is a
channelopathy with a high risk of sudden cardiac death (SCD),
characterized by a short QT interval and a propensity to atrial and
ventricular tachy-arrhythmias. In few families a mutation has been found
either in the KCNH2, KCNQ1 or KCNJ2 gene. The upper
limit for QT/QTc in patients with SQTS is unknown, but current research
papers suggest a range of 300-330 msec.
Aim: Based upon world-wide families with
known SQTS and incidental patients discovered within our investigation,
we sought to address the question:” What is the upper cutoff point for
QT/QTc in patients with SQTS?”
Patients: Adding previously unpublished data
from 8 individuals in 3 USA families with SQTS increased the total
number of those with an ECG documented short QT interval in the setting
of SQTS to 53 (21 Female, 32 Male). Two of the patients are babies born
with atrial fibrillation (AFIB). It represents a total of 14 families
and 9 sporadic patients with known SQTS from 10 different countries. A
total of 16 had a history of SCD/aborted SCD, 27 had a family history of
SCD/aborted SCD, 8 had atrial fibrillation only and 2 (both from the
same family) had a genetic mutation (KCNJ2), but no symptoms.
QT, heart rate (HR) and QTc’s (Bazett’s formula)
were obtained from published reports except for the new patients, where
they were measured in the first ECG available.
Results: (Excluding two patients with right
bundle branch block).
|
Patient
Categories |
N |
QT
Msec
Mean ± 2
SD, Range |
HR
Beats/min
Mean, Range |
QTc
Msec
Mean ± 2
SD, Range |
|
Fam. Hx. of SCD |
26 |
291 ± 55#, 240-340 |
70, 54-90 |
312 ± 39, 268-345 |
|
SCD/Aborted SCD |
16 |
271 ± 66, 210-315 |
75, 52-128 |
298 ± 43, 248-325 |
|
AFIB only |
7 |
265 ± 49, 220-300 |
73, 54-105 |
289 ± 46, 283-306 |
|
Mutation Positive |
2 |
|
|
315-320 |
|
TOTAL: |
51 |
282 ± 63, 210-340 |
72, 52-128 |
305 ± 42, 248-345 |
# : p = 0.005 vs patients with SCD or tachy-arrhythmias
Conclusion : Despite being recognized in at
least 10 countries, SQTS remains a rare diagnosis. One likely reason is,
that the currently accepted upper limit for QT/QTc in patients with SQTS
is too low. Even though patients with SQTS and tachy-arrhythmias have
shorter QT intervals than patients without such arrhythmias (vide
supra), the implications of our research indicate, that anyone with
a QT/QTc below 345 msec and their family be ruled out for SQTS.
A
detailed description of the 3 new USA families with SQTS:

A
detailed description of the QT and QTc intervals in the World-Wide
population with SQTS:

Last updated:
04/02/2009 |