Abnormal Repolarization, Spot Diagnosis?: Difference between revisions

From ECGpedia
Jump to navigation Jump to search
m (New page: {{NHJ| |mainauthor= '''A.A.M. Wilde, N.A. Blom''' |edition= 2007:03,114 }} Figure 1|thumb A boy with a birth weight of 3.030 g was born by caesarean ...)
 
mNo edit summary
Line 18: Line 18:


[[Puzzle_2007_03_114_Answer|Answer]]
[[Puzzle_2007_03_114_Answer|Answer]]
The 12-lead ECG shows sinus rhythm with a frequency
of 98 beats/min. The PQ interval is 140 msec and the
QRS width 60 msec (normal value for a neonate). The
vertical axis is normal for the age. Repolarisation is
grossly abnormal and clearly alternates in morphology
every other beat. This T-wave alternans is visible in
every lead but most clearly in lead V4. The QTc interval
is severely prolonged and varies between 665 and 689
msec. The P wave fuses with the terminal part of the
T wave and intermittently was not conducted (i.e.
functional 2:1 block, not shown).
The combination severe QT-interval prolongation
and syndactyly is classical for type 8 LQTS also referred
to as Timothy syndrome.1 It presents frequently at birth
with life-threatening polymorphic arrhythmias in the
setting of severe QTc prolongation. Besides syndactyly
(present in virtually all cases) extra cardiac features include
congenital defects (ASD, VSD), hypoglycaemia,
and autism. In 20% a hypertrophic cardiomyopathy is
shown, as was also seen in our case on echocardiography.
2 Left ventricular systolic function was decreased
(left ventricular shortening fraction 20%). DNA
analysis in our case also revealed the de novo CaV1.2
missense mutation G406R.<cite>Splawski</cite><cite>LoANjoe</cite>
''Postnatal course''
After one month, he developed recurrent torsades de
pointes and syncope. Mexiletine 15 mg/kg and oral
potassium supplementation were added to the therapy
and an extracardiac single-chamber implantable cardioverter-
defibrillator (ICD) was inserted at 4 months of
age. He received numerous ICD shocks and eventually
died at the age of two years after cervical sympathectomy.
==References==
<biblio>
#Splawski pmid=15454078
#LoANjoe pmid=16360093
</biblio>

Revision as of 20:27, 8 October 2007

Author(s) A.A.M. Wilde, N.A. Blom
NHJ edition: 2007:03,114
These Rhythm Puzzles have been published in the Netherlands Heart Journal and are reproduced here under the prevailing creative commons license with permission from the publisher, Bohn Stafleu Van Loghum.
The ECG can be enlarged twice by clicking on the image and it's first enlargement
Figure 1

A boy with a birth weight of 3.030 g was born by caesarean section at 33 weeks of gestation because of bradycardia and severe foetal hydrops. Physical examination at birth showed a hydropic neonate with a heart rate of 70 beats/min. He had cutaneous syndactyly between the fourth and fifth fingers of the left hand. During the first week of life he suffered from polymorphic ventricular arrhythmias for which β- blocker treatment was started and an epicardial pacemaker (VVI) was implanted. An ECG a few weeks later is shown in the figure. What is your diagnosis?

Answer

Retrieved from "https://en.ecgpedia.org/index.php?title=Abnormal_Repolarization,_Spot_Diagnosis%3F&oldid=5253"