[SCD-FORUM] 44E RE: Asymptomatic patient with Brugada syndrome. Dr. Ray Jordan

[SCD Symposium]

Dr. Li,
Has genetic research analysis ruled out genetic allele chimerism (at the
time of organogenesis and embryological differentiation) to explain the
phenotypic variety of channelopathies or numerous clinical  
manifestations? Another
words are some alleles more likely to find or gravitate towards the  
eighth
nerve, RV, vs LV etc., while other regions of pacemaker cells remain  
entirely
normal?
Richar-Ray/dba Richard Ray Jordan, M.D., SFM

--
Dr. Sergio Dubner
President of Scientific Committee

Dr. Edgardo Schapachnik
President of Steering Committee

>
> Then we should ask oursselves why is so Dr. Ramon Brugada. Without  
> a clear understanding of the disease nature, we may be always in  
> the dark in terms of risk stratification. If Brugada syndrome were  
> a primary repolarization disorder, one would expect the  
> repolarization instability such as microvolt T wave alternans prior  
> to the onset of VT/VF. As a matter of fact, the majority of VT/VF  
> patients showed positive late potentials ( Arch Cardiol Mex. 2006  
> Jan-Mar;76(1):52-8 ). Recently Dr. Shimizu's group demonstrated  
> both depolarization and repolarization abnormalities [ Pacing Clin  
> Electrophysiol. 2006 Oct;29(10):1112-21]. In the past our main  
> focus was the consequence of reduced INa to the phase 1  
> repolarization in the RV epicardium and the transmural dispersion  
> of repolarization, which may be part of the story. The slow  
> activation propagation in ROVT region due to reduced sodium current  
> itself should not be overlooked Am J Physiol Heart Circ Physiol.  
> 2006 Jul 28; [Epub ahead of print]
> .
> Channelopathies especially SCN5A mutations can lead to structural  
> abnormalities although many are undetectable by routine work up.  
> Those structural alterations (macroscopic or microscopic) could  
> also be the substrate to re-entrant ventricular tachyarrhythmias  
> and sudden VT/VF death.
>
> Sincerely,
>
> Li Zhang, MD
> LDS Hospital,
> University of Utah School of Medicine
> Salt Lake City, UT
> USA
>
>>
>> No that i know of. There are two studies which looked at TWA  
>> (Japan and
>> Germany) in Brugada syndrome. Neither one showed any correlation  
>> with risk.
>>
>> Dr. Ramon Brugada MD FACC
>> Associate Professor of Medicine
>> Canadian Research Chair Genetics of Arrhythmias
>> University of Montreal
>> Director Clinical Cardiovascular Genetics Center
>> Montreal Heart Institute
>> 5000 Rue Belanger
>> Montreal, QC H1T 1C8
>> Canada
>> ramon at brugada.org
>>
>>
>>
>>>
>>> Dear Dr. Ramon Brugada,
>>> As you have discussed in the answer to the question for an  
>>> asymptomatic
>>> patient with brugada syndrome, the use of EPS to risk stratify
>>> asymptomatic patient is very controversial. The first symptom may be
>>> sudden death in such patients. In such a scenario is there any  
>>> role for
>>> microvolt T wave alternans for risk stratifications and to decide  
>>> the need
>>> for ICD?
>>>
>>> Dr. Sunil Roy.  MD, DM
>>> Senior Lecturer in Cardiology
>>> Medical college, Calicut, Kerala, India
>>> Email: sunilroytn at calicutmedicalcollege.ac.in
>>>
>>>

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