All Journal Entries Journals
Previous | Next

My experience with ablation for AVNRT SVT

Mar 31, 2015 - 0 comments



















EP study


Cardiac catheterization

This is my experience.  My procedure did not go as smoothly as it could have.  Hopefully this information will be helpful to calming the fears of others who are going for the procedure and are as nervous as I was.  Even though things didn't go according to plan, the experience was still not as unpleasant as I imagined it.

I was pretty nervous to be honest.  I went into the procedure having read this many forum threads, including some here on MedHelp, plus I watched some YouTube videos about the procedure, and basically read up on everything I could to try to calm my fears.  It helped a bit.  I was even more fearful because I am a really heavy guy (enough that I was weighed before the procedure to ensure I was not over the weigh limit of the special cath lab table) and I have hypertension.  Even though my EP doctor did not say that this specifically increased the risks of an EP study / ablation for me, I think it did increase my anxiety more than the average person.  Part of the reason for getting the EP study in the first place is that I have been trying to lose weight and while I have been successful so far, the increased exercise and change in diet caused an uptick in the number of SVT episodes I was experiencing (and I experienced two within 30 days requiring an ambulance).

You will see through this thread and any other reading you do that there are several ways this procedure can be done a little differently, particularly when it comes to if/when you are sedated and how much.  I live in Ontario, Canada so this should mostly apply for anyone from the same area, however your procedure should not differ too much.

I was fortunate enough to be booked first thing in the morning, so I did not have to wait for anyone else in line ahead of me.  I arrived at 6:30 am and probably was on the table by 8:00 am.  Prep was pretty uneventful, matched what I had read here and elsewhere.  No sedation prior to the procedure, but they did apply a numbing cream (presumably to make the freezing inside the cath lab less painful).

As I am a big guy (and tall, too) it took some doing to get me in the right position on the table.  It is quite narrow due to the amount of equipment that needs to move around it, so they basically told me to take some time to find my centre of gravity so that I was comfortable and didn't feel like I was falling off the edge.  Once I was in place they added plastic arm rests to support my arms (otherwise would have been hanging straight down over the edge). The nurses and EP Technologist then got me all hooked up for the procedure.  Standard 12 lead ECG, a large pad on my lower back (I think this acts as a ground for the catheters) plus difribrillator pads just in case (you see below that in my case I'm sure glad they take this precaution!).  Then they applied an antiseptic solution to both possible entry sites (left and right side of groin).

When the doctor arrived he checked over everything and then the first step was to freeze the entry site, which he opted for all 4 catheters in the right side of my groin (I think this is a pretty standard setup for EP specifically).  Thanks to the numbing cream applied earlier there was barely a pinch.  Then he went about getting the catheter sheaths in place. I don't know why but at the time I thought they only needed one, through which all 4 catheters would pass.  Apparently it's one each.  Anyway this was definitely an uncomfortable part of the day.  I kept being worried that some part of this process would be painful and really the freezing worked quite well and it wasn't, but I think due to my size he had a real struggle to get the sheaths into the vein.  One of them took so much pressure to get into place that when it finally did "pop" into place it made me jump an inch off the table haha.  At one point I felt a warm gel run over my right hand and thought maybe that was a secondary antiseptic solution of some kind... I realized I was wrong when I was later able to move my arm again and saw my hand was covered in dried blood.  No big deal though, he controlled the bleeding and they are going in through a pretty large vein, no surprise there's going to be some blood.

Once the sheaths were in place, He threaded each catheter up to what I presume was just short of entering the heart, as the x-ray was not in place yet.  Didn't feel it at all in the vein but I could hear what he was doing.  Next there was a lot of adjusting the table, the x-ray, the monitors, and any other piece of equipment needed nearby.  My EP doctor is a short Korean man so I think he needed everything a little closer by than others.  I had read that other people undergoing EP studies were able to watch the monitors and see the process, and that it was helpful in distracting them from their anxiety.  I was really looking forward to this because I'm a definite technology enthusiast but no such luck.  His final choice of x-ray and monitor placement was such that the upper part of the x-ray machine over my chest blocked my view of the monitors.  Oh well.

Next was the part that was probably the most unnerving for me.  At this point there was still no sedation.  He turned on the x-ray and begain threading the catheters into my heart.  Others had said that they couldn't feel the catheters in the heart but could feel extra/skipped beats as the catheters "tickled" the walls of the heart.  I could both feel the catheters pass into the heart and the skipped beats and everything, but it wasn't too bad.  There was then a few minutes that were pretty uneventful and I believe they were just measuring my normal heart rhythm.  Following this, the next step is to induce SVT and measure again.  This part was extremely uncomfortable for me and I'm not really sure why.  I had chest pain, both my hands and lower arms started to tingle and go numb, I was hyperventilating.  I told the nurses this and they said it was normal.  That made me feel a little less anxious but no more comfortable with the situation haha.  My normal SVT did not ever cause these kinds of symptoms.

Anyway, that part lasted maybe 20 minutes, and then the EP doctor told the nurse they could administer Fentanyl.  I asked the doctor if that meant he had found the problem area and he said yes.  Within 1-2 minutes of receiving the medication I was feeling a lot better.  Not drowsy, but all the other stuff I was experiencing went away.

The next probably 2 hours was spent ablating and testing.  I don't think I ever really felt the ablation itself.  He used RF ablation in the beginning and then as he got closer to the AV node, switched to Cryoablation to avoid damaging the node.  There was a lot of communication between the EP doctor and the technician operating the ablation equipment in the control room, how much power to apply, for how long, and so on.

Here's where we get to the part where I was glad they take the precaution of applying the debrillator pads at the start of the procedure.  At 3 different points during the ablation process I went into A-fib.  I don't think I've ever had atrial fibrillation before so this was new to me.  Same sensation as SVT but different heart rhythm.  The doctor later explained that my heart was getting easily irritated and that was causing the A-fib, and he said this may become a more common occurence later in life.  Anyway, on each occasion, the nurse gave me something in the IV to knock me out for a few minutes and then they shocked me and continued with the procedure.  I never felt anything and to be honest, the first 2 times when I woke up I didn't remember falling asleep and wondered if I had imagined the whole "we need to shock you" thing, but the 3rd time I made a conscious effort to pay attention.  They didn't tell me to but I did the whole "count backwards from 10" thing when they injected the drug, and felt myself passing out.  Anyway I guess being on the Fentanyl really helped with regard to the whole de-fibrillation thing.  I was certainly less worried about it than I would have thought I would be.

Towards the end of the procedure there was a lot of switching cryoablation catheters.  My EP doctor later explained that I have an oddly shaped ridge in my heart, near the AV node, and he was having difficulty getting the right angle to ablate the area carefully.

Throughout the procedure there were testing periods where an arrythmic drug is administered and the heart is essentially "driven" with the catheters at increasing heart rates (think of starting with a volume knob at 1 and slowly turning it to 10, then dropping it back to 1 quickly).   This is done to see if the ablation has been effective and SVT does not occur.  It's pretty unnerving to be laying there at rest on the table, and feel your heart race increasing to 150+ bpm and then drop back down to 80 or so, over and over.  It doesn't hurt, but it feels weird.

Finally after 3.5 hours we were done and I was in agony because my back has been flat on this hard, flat table for quite some time, unable to move.  I don't lay on my back usually because my back isn't that straight, and I was definitely ready to get out of that position by then.  The catheters were removed but the sheaths left in place, and I was transferred to a gurney and wheeled back out into the general cath lab prep area.  At this point the nurse (same who did the first prep) explained to me that she would be removing the sheaths. All 4, at once.  It took only half a second and certainly didn't hurt, but following removal, pressure needs to be applied at the site for about 10 minutes.  So there I am with a nurse's hand pressed down on my groin for 10+ minutes.  Luckily she was ready with some small talk to break the tension haha.  It was at this point that I discovered the dried blood all over my right hand from the beginning of the procedure.  After the 10 minutes had passed, she checked that the bleeding had stopped, and then applied a dressing.  Then she left to go begin prep on another patient.

Well, not 30 seconds after she had left me, I felt a warm sensation on my leg and as I reached down to check I felt a very wet bandage.  Then I checked my hand... covered in blood for the second time that day haha.  Called her back over and we did another 3 minutes of pressure on the area, once again the bleeding stopped, then she re-dressed it and put a "sandbag" on it to keep pressure (I later found out it was two bags of IV saline taped together).  This time it held up.

A short while later my EP physician came over to talk to me.  He discussed how things went.  He said that I had AVNRT and that he was quite sure he had managed to ablate the problem area.  He went on to say that unfortunately there was a complication during the procedure because the problem area in my heart was so close to the AV node (and probably also because it was so difficult to reach in its inaccessible location).  Despite his precautionary use of cryoablation in this area, some damage occurred to the healthy tissue near the AV node. As a result I now have First Degree AV Nodal Block.  What this means is that there is a small blockage of the signal from the SA to AV node causing a slight delay the signal getting from SA to AV, but not enough of a problem to need any kind of intervention, such as a pacemaker.  First degree is the least problematic variety and generally there are no symptoms, the only place it can really be noticed is on an ECG printout.  This specific risk was brought up by my EP doctor during the consultation and at the time he mentioned it was a 1 in 500 risk.  Overall, I'd rather have a heart that's 1% less efficient than having to deal with SVT several times a year with possibly multiple trips in an ambulance.  It was a risk worth taking.

He went on to say that he would be keeping me overnight in the Cardiac Short Stay Unit to be observed, both because of the AV nodal block and also because of the A-fib episodes.  I was disappointed not to be going home but it was no big deal.  I had a really fantastic nurse in the CSSU who was constantly checking on me and got me anything I could possibly need.  I was kept on heart monitor and the dressing on my groin was checked every hour until lights out.  Following that, I really didn't need any attention at all, but I didn't sleep too well either.  At 6'4", the bed was not really sized for me to sleep comfortably.  I maybe got 2 hours in.  I spent a lot of time on the internet on my laptop.  On a connection frustratingly too slow for Netflix, even in the middle of the night when 95% of people were probably asleep lol.  I went home in the morning after a brief visit from the EP physician.

Since the procedure, I have not had any SVT but I have had some skipped beats, extra beats, and generally just a few seconds at a time of odd feeling in my chest if I do certain things such as bend over.  I'm having a 48 hour holter monitor test next week and then a follow-up with the EP physician a month later.  I attribute the odd heart beats to my heart still healing.  It's the only muscle in the body that doesn't get a chance to heal at rest following an operation, and it's understandable that the heart would feel a little off for a few weeks afterward.  Some other posts I've read here and elsewhere seem to echo this experience.

So, there is my experience with ablation.  If you're worried about your ablation procedure, my advice is to educate yourself as much as you can.  There are several good videos available on YouTube, and lots of posts such as this where people discuss their experience.  I went into the procedure cautiously worried, and to be honest most of that worrying was due to my weight, and I still came out pretty darned good.  Considering that I went in worrying I wasn't going to come out alive, I was definitely more worried than I needed to be.  The procedure has moments of discomfort, no question, but there is no real pain involved.  It's certainly worth a few hours of discomfort for a lifetime of relief from SVT.

Post a Comment