cath ablation

My son had open heart surgery to repair ASD and PAPVR on June 2010, since then he has develope SVT and is not well control with meds. He will be 4 yrs. old March 8th and weighs 38 lbs. His doctors has recommened a cath ablation in the next few weeks. I am scared to death, after reading all the things about how dangerous this procedure is for children his age. I would like to know in your experience, how successful is this procedure without complication? The type of SVT is AVNRT. Any help to ease my mind on this would be helpful. They did tell me it would be about 70% effective 1st go round for his age and size. This sounds like he will eventually need to have it again.

[Jeffrey R Boris, M.D.]

Dear JW Cherries,

There was a very nice national collection of data for these patients from 2002 that demonstrated that patients who specifically had atrioventricular node re-entry tachycardia (AVNRT) and who were under the age of 5 years had a 100% rate of success in between 1996-1999.  However, there were only 11 patients in that cohort. As well, there was a complication rate of 18%, as compared to 3% for older children.  Without evaluating your child, I cannot say what his specific risks are.  However, I can say that the risks and successes are likely somewhat more in his favor if he is bigger/older.  There are numerous medications that can be used to try to control SVT.  If these have all been tried, however, I would recommend that he have his ablation performed in a center that performs a very large number of these procedures, as 70% sounds as if it may be a little on the lower side.  Certainly, before undergoing a procedure with this increased risk, it may be worthwhile having a second opinion.