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The ECG of a (cardio)myopathy: Difference between revisions
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m (New page: {{NHJ| |mainauthor= '''A.A.M. Wilde, Y.M. Pinto''' |edition= 2005:10,373 }} Figure 1|thumb A 33-year-old lady visited the cardiologist because of the...) |
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[[Puzzle 2005_10_373 - Answer|Answer]] | [[Puzzle 2005_10_373 - Answer|Answer]] | ||
The ECG shows sinus rhythm 60 beats/min. The QRS | |||
width is normal (80 msec) and the QRS axis is almost | |||
horizontal. Repolarisation is normal. The primary abnormality | |||
is the prolonged PQ interval (≥300 msec). | |||
In addition, the P wave has a very low amplitude (in | |||
all leads). | |||
The combination of prolonged PQ interval, lowvoltage | |||
P waves and the patient’s history of muscle | |||
weakness should raise the suspicion of a myopathy | |||
associated with conduction disease. The family history | |||
with one sudden death and a pacemaker in first-degree | |||
relatives narrows this down even more to a ‘laminopathy’ | |||
i.e. a disease linked to mutations in the lamin | |||
A/C gene. In that case referral to a recognised ‘muscle | |||
neurologist’ is mandatory. In our patient the neurologist | |||
found clear evidence of proximal myopathy. The | |||
clinical diagnosis limb-girdle disease was made and | |||
molecular diagnostic testing indeed revealed a | |||
mutation in the lamin A/C gene. | |||
The ECG findings are typical for Limb-Girdle disease | |||
type 1b (the variant linked to lamin A/C mutations). | |||
Conduction abnormalities almost always precede signs | |||
of cardiomyopathy, which only progresses to overt dilated | |||
cardiomyopathy in some cases. Particularly the conduction | |||
system is sensitive to damage, most likely increased | |||
fibrosis. In our patient the conduction system is | |||
affected (long PQ interval and undoubtedly a prolonged | |||
HV interval) and it is also likely that the atrial tissue is | |||
abnormal as well (low-amplitude P waves). For a long time | |||
pacemaker therapy was considered sufficient, but in recent | |||
years it has become clear that affected individuals are at | |||
risk for sudden death, even with a pacemaker.<cite>VanBerlo</cite> Prophylactic | |||
ICD therapy at the time a pacemaker is implanted, | |||
usually in the 3rd to 4th decade, is now advocated. | |||
==References== | |||
<biblio> | |||
#VanBerlo pmid=15551023 | |||
</biblio> | |||