AH intervals

[wmac]

I had a second ep study in sept. 05 At the University of Utah by Doctor Klein. The ep and possible ablation was for NSVT and SVT. Both ep studies they could not induce either one once again. I just got a copy of my report and I have a question. My report says. With programmed stimulation of the right atrium at baseline there was no abrupt increment in AV node conductioin time; there was a gradual prolongation of AH interval preceding AV nodeal echo beats. My question is is the prolongation in AH interval is that normal or is that something to worry about? I dont even understand what that means. Also If a person has had two ep studies both being at a big University hospital and they cannot induce either svt or NSVT is that good enough to quit there or should I try again. I do have documented nsvt and svt on loop recorder and king of hearts monitors. They did however burn my dual av node with 11 burns. During the study junctional tachycardia was induced during several of the RF deliveries. The docs were wondering if I had svt w/abberancy. But now im not sure what they think. They used isoproterenol and esmolol and programmed stimulation and got only single and double echo beats from both the atrium and ventricles.They were able to reproduce AV nodal echo beats, but after the burns no AV nodal echo beats induced post ablation. It was the slow pathway that was burned. Also how long post ablation does it take to know if your fixed if that was my problem. Its four months now and Im still have nsvt runs. Should I be satisfied or try another eps else where. Thanks so much. wmac

[CCF-M.D.-MJM]

Hi WMAC,

Very good questions -- but also very difficult questions to understand.  This is no longer cardiology 101 when you start talking about AH an HV intervals and understanding the AV node to this degree.

My question is is the prolongation in AH interval is that normal or is that something to worry about?

Prolongation of the AV node is expected, especially in someone with AVNRT -- this is how you diagnosis.  You usually see a jump in the  AH interval.  The AH interval measures the time from atrium to AV node and the HV measures the tiem from AV node (his bundle) to the ventricle.

As you stress the AV node by adding progressively more premature complexes, you "tire" out the fast pathway.  The slow pathway then kicks in and gives you "jump" in your AH interval.  This jump can be acute with only a 10 millisec change in intervals or can occur over a series of progressively premature beats.

Also If a person has had two ep studies both being at a big University hospital and they cannot induce either svt or NSVT is that good enough to quit there or should I try again.

We do have cases where cannot induce the  SVT in questions.  In your case they were able to show that you have the physiology consistent with AVNRT and they proceeded to ablate the fast path way to treat this.  This is a reasonable approach.  It is possible that your NSVT is really aberrancy but more like it is just NSVT.  I would not try to ablate an NSVt in a normal ventricle unless it was so frequent as to cause a cardiomyopathy or extremem symptoms.

I would wait to see if it comes back before considering a repeat ablation.

Also how long post ablation does it take to know if your fixed if that was my problem.

After the ablation we usually wait 30 minutes and the repeat the EP study.  The probably showed that the dual pathway phsyiology was gone and felt comfortable with that and you should too.  Now just wait and see if it comes back -- they sometimes do.  Hopefully they got it ;)

Should I be satisfied or try another eps else where.

Wait and see what happens.  If it comes back, go back to your current EP and get their opinion --  you know them already.  At that point you can consider a second opinion, but hopefully it won't come to that.

I hope this helps and here's to an SVT free 2006.

[Bromley]

It sounds like they accomplished what they needed to, and you got through it without complication!!!

I definitely think I would stick with your current doc.