SVT medication and its consequences

[APeraza]

My son is four years old. He got his first SVT attack when he was 10 months old. Since then he was on and off several types of medications like propranolol and propafenone and others that I don't remember their names. Every time he gets an SVT attack (which was all the time) we had to take him to the ER for him to get the adenosine. He ends up staying at the hospital for observation. After many trials they finally figured out which medication worked best and how much of it. So he then for quite a while was only on propranolol, which they already got to the highest dosage. Since August this year he has been getting the SVT attacks way to often and since they can no longer raise the propranolol dosage they start giving him propafenone. They told us that they thought it would be good for him to get an EP done and perhaps the catheter ablation. But now they have decided not to do that, because they think he is not ready. So they raised the propafenone dosage. They told us that they still have room to raise the dosage should he get SVT attacks again and after that they will see what to do next. Perhaps add another medication or eliminate the two and have a different medication. My worry is that since he has been taking the propafenone he has a lack of appetite. He has always been a very picky eater, but now it has gotten worse. My question is it safe to give a small child all these types of medications? Isn't there an alternative for this? I am not happy that despite him taking these medications he is still having the SVT attack. I do not know what to do. Would it be best to actually do the EP or not? Thanks so much, Adelaida

[Jeffrey R Boris, M.D.]

Dear Adelaida,

This is a difficult situation that your son has, especially since his supraventricular tachycardia (SVT) has been hard to control with medications.  In the end, no medication is completely without side effects.  Propafenone can certainly cause nausea, vomiting, and unusual taste, so it wouldn’t necessarily surprise me if he is experiencing a decreased appetite.  Propranolol can decrease appetite, as well.  However, the question that’s most important here is whether his appetite is so low that he is losing weight.  Certainly, we see plenty of kids with decreased appetite after about 1 to 2 years of age, since they aren’t growing as fast.  However, if he’s losing weight, then this is more than just the picky pre-schooler.

That said, the effects of the medications have to be balanced with the risks of the electrophysiology study with radiofrequency ablation (EPS/RFA).  This is the procedure in which several special catheters with electrodes are placed inside the heart and the heart is electrically mapped.  Then, when the extra abnormal electrical pathway associated with the SVT is found, an ablation catheter is placed on this pathway and a small burn is placed to disrupt the pathway.  The problem is that these burns are not tiny.  Even though the EPS catheters have been made significantly smaller, and urgent EPS/RFA can be done at age 5 years, it is not without greater risk as opposed to if he was 10 years old, or older.  His heart is relatively smaller, so there’s less room for error.  It sounds like your electrophysiologist wants to wait till he’s a bit bigger before considering the intervention to try to reduce that risk.  I would recommend discussing this further with your electrophysiologist to make sure that they are aware of your concerns, but that you are aware of the various risks involved and when the timing will be.