I read all of the SVT posts and couldn’t find a similar scenario:
I have been doing Ironmans/Marathons since 1996. My resting HR is super low, and my zones are also quite low (156 bpm AT & I usually do Ironmans at a 130 bpm all day). In 2009, I started experiencing SVT during hard efforts and races but never during rest. I lived with it for a long time, but then it started happening during every sprint tri, and even during Z2/3 workouts. I went to see a cardiologist, wore the monitor, and was diagnosed with SVT. My cardiologist advised me to quit doing long races (sad, but I get it) and to take flecanide the rest of my life. I took the flecanide for about 1.5 years. It worked, but I still had episodes occasionally, especially if stressed at work or dehydrated. I was able to do my sprint tris and workouts without issues. However, being on meds the rest of my life really didn’t sit well with me.
I decided to go see a cardiologist who is a cyclist and is known to treat athletes. He recommended ablation, which I had 6 weeks ago. The surgeon said that the SVT presented itself immediately and he was able to zap it, and that I should be able to work out in 5 days. I waited 7 days, went for an easy jog, and had SVT 4 times. The doc said to give it more time. Over the next few weeks, my heart rate was all over the map and never steady. I even had my first SVT episode at rest which freaked me out. I quit drinking caffeine and started back on the flecanide. The doctor recommended a second ablation. The flecanide helps when I am at rest, but when I try to run my HR goes really high. For example, before the ablation, I could run an 8:30 pace in Z1. Now an 8:30 pace puts me in Z3/4. So, I have to decide whether to go for the 2nd ablation or not. Has anyone else experienced this? Can an ablation totally change your HR zones? Should I become a yogi Zen master and quit all the cardio?
I never noticed SVT, but it showed up on the EKG or whatever.
Doc said I was fine to continue racing and he’d do an ablation a few months later. Did the ablation but every time he went to zap it the svt would stop, so he didn’t know if it was taken care of or not. I took about 3 months off from training at that point since it was the offseason and I was burned out.
Came back and fitness was nonexistant so hr was sky high. Never put in more than 4-5 hours a week so hr stayed super high for any time of intensity. Didn’t have any svt issues.
Took another 6 months off because of time constraints and then started back training and for the first time ever had a noticeable episode for ~5-6 secs while on the trainer in a Zwift race. Spiked at about ~230 or so and then came back down. Have since had one other episode on the bike, hitting 234 for ~10 seconds. Again, I never had these pre-ablation, so I’m guessing it didn’t work the way it was supposed to.
Have since put in more hours (8-12) and hr has come down to ranges that used to be normal, though I’m still lacking about 10% fitness.
So anyway, hr was super high until I really started building back up fitness (and even that took much longer than I anticipated), but this seems to be one of those weird things that affects people differently. I reckon I’ll go through the whole thing and have another ablation at some point, but dropping thousands of dollars on medical procedures that may or may not be effective is a struggle. Maybe I’ll move to another country with better healthcare, first.
Sorry, I did not experience what you did, but I had episodes of super high heart rate, during exercise and at rest, in 2009 as a 39 yr old male. I was diagnosed with SVT and. similar to what you were told, I could take medicine to deal with it long term, or I could get an ablation. I did the ablation, and I think it took a few weeks to feel “normal” again, but I’ve been fine ever since. So there is hope that a second ablation might provide a better result for you.
Hi, I’ll start by saying I’m a physician and I have an intermittent a-fib issue, though I am NOT a cardiologist/electrophysiologist. That said, it is my understanding that a second ablation is frequently required, though I can’t intelligently comment as to how this relates to the changes in heart rate zones that you’ve noticed after the first. However, my primary advice to you is to see another electrophysiologist and get a second opinion, and make sure both electrophysiologists are saying about the same thing. When it comes to important things like this, it sure makes me feel better knowing two experts share nearly the same opinion on things. Best of luck and prayers for great recovery!
Thank you so much for your reply! I haven’t taken that much time off so I don’t think my higher HR is due to poor fitness. I’m wondering if the ablation messes up some well established neuronal pathways that are now disrupted, so the heart has to learn new rhythms, sort of like brain plasticity.
I was diagnosed with persistent afib and SVT a little over 3 years ago, and after being on flecainide and metoprolol for 8 months only partially controlled my symptoms, I was finally approved for ablation at the end of 2017. I remained on the medication for a few months after the ablation, and then was taken off. I was still occasionally having minor episodes, primarily in my sleep,.so after about 2 months I was put back on the flecainide. I finally was taken off it a year ago, and so far haven’t had any more episodes. 2 years ago, my cardiologist was discussing the possibility of needing a second ablation, but at this point he doesn’t think I’ll need it.
My HR zones have changed, but in my case went down. Just before the arrhythmias started, my maximum HR was 174, and I could comfortably sustain mid 160s for 1-2 hour races. After I got off the flecainide, my maximum was 160, and there were a lot of times where I could not get my HR above mid 140s. My FTP is almost back up to what it was 3 years ago, but my HR at a given effort is a lot lower. It also takes me a while to get my HR up. I have to gradually bring it up, if I make a hard effort early in a ride my heart won’t respond and I’ll just go anaerobic at something like 115. But if I take my time, I can gradually bring it up into the 150s, and then if it drops back down during a rest or descent, it’ll quickly go right back up during a hard effort. So even after a year off the medications, I’m still figuring things out…
SBRJen - I can comment as someone who had an ablation for Afib, with a wife who had one for SVT (which is crazy to me that we both had arrhythmias as healthy people!) I seem to remember my cardiologist/surgeon recommending a few weeks off - 1 week seems really quick to me. I do remember a bit of lethargy and some chest tightness for the first week or so. I do recall my doc saying it takes some time for your electrical system to sort things out so perhaps that why you’re still experiencing episodes. But I was also told that repeat procedures are sometimes necessary if they don’t find all the spots to zap.
I can’t say whether or not this changed my zones, I wasn’t really training hard beforehand, but I don’t think it did. What I can share is that my procedure went fine - there were a lot of trigger points but apparently they got them all because I’ve had no issues to speak of in 4 years. My wife on the other hand was not so fortunate - she ended up in complete heart block and ultimately had to have a pacemaker installed about 4 months after her ablation. So what I would say is be careful, and really weigh the risks. You’ll probably be told it’s something like 1%, which sounds really small - until it happens to you and now you have to deal with a pacemaker install, the risks that come with that, and knowing that you need a new one/new battery every 8-10 years or so.
Question back to you - does the SVT resolve on it’s own for you? If so, maybe it’s just something you live with. My wife’s was intermittent over the months and years, but always resolved within about an hour. Perhaps you can deal with that. My afib scoffed at the notion of the drugs - they tried everything under the sun and nothing worked, so my only solution was cardioversion. I was on 1 or 2 of the drugs for a time but they had quite severe side effects for me that I couldn’t deal with.
Quitting caffeine was also recommended to me, which I did (OK still drink decaf). I remember the ER doc saying the three triggers they know of are booze, caffeine and exhaustion (the latter 2 applied to me at the time). So my 2 cents is that if it’s not severe and isn’t causing harm/resolves on it’s own, maybe just wait a tick before doing anything invasive. The human body is quite a mystery and hopefully things will calm down for your.
I remained on the medication for a few months after the ablation, and then was taken off. I was still occasionally having minor episodes, primarily in my sleep,.so after about 2 months I was put back on the flecainide. I finally was taken off it a year ago, and so far haven’t had any more episodes. 2 years ago, my cardiologist was discussing the possibility of needing a second ablation, but at this point he doesn’t think I’ll need it.
My HR zones have changed, but in my case went down. Just before the arrhythmias started, my maximum HR was 174, and I could comfortably sustain mid 160s for 1-2 hour races. After I got off the flecainide, my maximum was 160, and there were a lot of times where I could not get my HR above mid 140s. My FTP is almost back up to what it was 3 years ago, but my HR at a given effort is a lot lower. It also takes me a while to get my HR up. I have to gradually bring it up, if I make a hard effort early in a ride my heart won’t respond and I’ll just go anaerobic at something like 115. But if I take my time, I can gradually bring it up into the 150s, and then if it drops back down during a rest or descent, it’ll quickly go right back up during a hard effort. So even after a year off the medications, I’m still figuring things out…
Thanks so much for sharing. This makes me hopeful that if I stay on the flecanide for a bit, maybe I can come off someday. I probably just need to be patient and do more wts/yoga/swim for a while.
SBRJen - I can comment as someone who had an ablation for Afib, with a wife who had one for SVT (which is crazy to me that we both had arrhythmias as healthy people!) I seem to remember my cardiologist/surgeon recommending a few weeks off - 1 week seems really quick to me. I do remember a bit of lethargy and some chest tightness for the first week or so. I do recall my doc saying it takes some time for your electrical system to sort things out so perhaps that why you’re still experiencing episodes. But I was also told that repeat procedures are sometimes necessary if they don’t find all the spots to zap.
I can’t say whether or not this changed my zones, I wasn’t really training hard beforehand, but I don’t think it did. What I can share is that my procedure went fine - there were a lot of trigger points but apparently they got them all because I’ve had no issues to speak of in 4 years. My wife on the other hand was not so fortunate - she ended up in complete heart block and ultimately had to have a pacemaker installed about 4 months after her ablation. So what I would say is be careful, and really weigh the risks. You’ll probably be told it’s something like 1%, which sounds really small - until it happens to you and now you have to deal with a pacemaker install, the risks that come with that, and knowing that you need a new one/new battery every 8-10 years or so.
Question back to you - does the SVT resolve on it’s own for you? If so, maybe it’s just something you live with. My wife’s was intermittent over the months and years, but always resolved within about an hour. Perhaps you can deal with that. My afib scoffed at the notion of the drugs - they tried everything under the sun and nothing worked, so my only solution was cardioversion. I was on 1 or 2 of the drugs for a time but they had quite severe side effects for me that I couldn’t deal with.
Quitting caffeine was also recommended to me, which I did (OK still drink decaf). I remember the ER doc saying the three triggers they know of are booze, caffeine and exhaustion (the latter 2 applied to me at the time). So my 2 cents is that if it’s not severe and isn’t causing harm/resolves on it’s own, maybe just wait a tick before doing anything invasive. The human body is quite a mystery and hopefully things will calm down for your.
Oh wow, what happened to your wife sounds like a nightmare! I definitely don’t want that. The SVT does resolve once I quit exercising. It only lasts a few seconds but I feel it go up. Since the ablation and now back on flecanide, it doesn’t go up as high as it used to, but I can feel it start to race. I’ve eliminated the 3 triggers (just decaf, no alcohol and sleeping well). Especially since the quarantine I’ve been sleeping 8 hrs/night and not getting up at 4:30AM every day to hit the gym before work. Thanks for sharing!!!
Not a doctor but was a long-time pacemaker/defib rep working with EPs and have sat in on tons of ablations. SVT is just a chaotic circular pattern of electrical signals, instead of going from top (atrium) to bottom (ventricles) it finds itself going around in circles. What this means is your heart rate may have no correlation to the level of effort so any sort of physiological performance metric you are trying to garner is worthless as it won’t correlate to perceived efforts when in this circular pattern. Just because the EP nabbed one spot doesn’t mean that there is not another spot/pathway that exists that is causing this circular motion. It is very frequent that ablation can take multiple goes so a second procedure is a reasonable approach.