[SCD-FORUM] READING THE LECTURE BY DR. VEENHUYZEN and DR WYSE. THREE EXPERT QUESTIONS BY DR. SERGE BOVEDA

[SCD Symposium]

Reversible Causes of VT/VF: Fact or Fiction? Case presentation and  
review of the literature
G. D. Veenhuyzen, MD
D. George Wyse, MD, PhD


Dr. Serge Boveda (France)
- Your case report clearly shows that transient causes are more  
likely to occur in patients suffering from severe heart disease: most  
of the time they should be implanted with an ICD for primary  
prevention. Don’t you think that guidelines concerning ICD  
implantation among patients with VT/VF due to transient or reversible  
disorders should mainly concern patients with no (or mild) structural  
heart disease?

Dr. George Veenhuyzen and George Wyse (Canada)
- The current guidelines do not advise an ICD for VT/VF with  
transient or reversible causes but are slilent on the issue of co- 
existing heart disease.  It is true our case had extensive heart  
disease and it may be true such patients are more likely to have  
recurrence of the so-called transient or reversible cause as the  
substrate for arrhythmia continues to exist.  The difficulties are   
twofold.  First, in patients with other conditions such as renal and  
lung disease, the transient or correctable causes (electrolyte  
abnormalities and hypoxemia) continue to recurr unpredicatably.   
Second, it is difficult to be sure there is not a continued  
substrate.  For example, in a patient rescued from drowning and found  
to have VF, it may later be difficult to exclude long QT syndrome.   
Thus, as stated in our paper, it requires a great deal of clinical  
judgment to determine if VT/VF had a truly tansient or correctable  
cause and is unlikely to  recur.  I do not think there will ever be a  
simple set of rules or conditions that replace clinical judgment and  
would favor a guideline that is more permissive in this area.

Dr. Serge Boveda (France)
- Concerning the “trigger” of VT/VF, do you think that successful  
ablation of the “triggering VPB’s” (as demonstrated by Michel  
Haïssaguerre for Purkinje or Brugada patients…) should be considered  
as a reversible cause and by the way, avoid ICD implantation in  
patients with no (or mild) structural heart disease?

Dr. George Veenhuyzen (Canada)
- I think it is too early to tell if ablating "triggering" VPBs will  
be complete treatment and in which cases.  So far there has been few  
reports in relatively selected patients.  Brugada and other  
channelopathies are a rather small number of VT/VF cases.  The thing  
about VPBs are they are rather ubquitous, like weeds in your garden.   
When you remove one it is soon replaced by another.  Thus, I am  
doubtful at the moment that this would be a complete solution in many  
patients.

Dr. Serge Boveda (France)
- Regarding with literature data, how long would you consider that VT/ 
VF is a transient or reversible cause after an acute myocardial  
ischemia?

Dr. George Veenhuyzen (Canada)
- I think ischemia is a truly reversible cause mostly in the absence  
of scar (previous infarction) until a defintive treatment like  
revascularization is applied.  The best example is vasospastic angina  
that causes VT/VF in an otherwise normal heart.  Good medical therapy  
(two or more vasodilators and a statin) can be effective treatment.
I have a few such cases with defibrillators who have never had a  
therapy from there ICD in over 10 years.   However, it is important  
to remember that ischemia can return in the case of atherosclerotic  
disease due to progression of disease or incomplete revascularization.


--
Dr. Sergio Dubner
President of Scientific Committee

Dr. Edgardo Schapachnik
President of Steering Committee




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