Afib and Max Heart Rates

I touched on this before, wondering if there was a relationship between MHR post ablations. I have had two ablations, the first 14 years ago with good success until a year ago when afib returned. Second ablation a year ago and doing great for the last several months.

My concern was that I couldn't get my MHR above 120 (should be 145 for my age of 75). So the questions is - did afib and two ablations have an impact on my MHR, or was there some other heart issue causing the limitation? I finally got a max stress test and got my HR up to 133 (92% of max). My Electrophysiologist found no ECG issues and didn't believe that there was a relationship between my ablations and my reduction in MHR, or that there was anything wrong with my heart. For those familiar with a treadmill stress test, I made it up to Stage 5 (walking very fast at 4.2 mph up a 18.5% grade). However, only one minute at that level before I gave up. 13 minutes total time on the treadmill. Because of a hip replacement, I did not jog/run. Oxygen saturation steady throughout the test at 98%.

Just an interesting observation: Before my first ablation and before being prescribed any meds, my heart rate while in afib was 180. Prior to my second ablation and taking no meds, my heart rate in afib was 110. There was a 13 year gap between the two, but things changed quiet a bit. Understanding any of this is beyond me. Current resting HR normally between upper 50's and lower 60's.

I was an Olympic swimmer in 1968 and have worked out all my life and still stay quite fit.



Edited 1 time(s). Last edit at 01/08/2021 09:21AM by Ken.

I know of no mechanism that can explain a lowered max heart rate after ablation. Since you didn't mention any, is it safe to assume you're taking no meds?

The one mechanism I do know of that can do that is age.

Before my first ablation, my HR while in afib could avg 160 bpm. I was 57.
It never went that high since that first ablation. In afib, it's now mostly 115-130. Without drugs. I'm now 62.

While exercising, my HR doesn't get high. I might think my ablations set other limits, but the truth is I'm not sure I want or need to push my HR that high. Before having afib, I didn't fear reaching the red line. Now, I'm cautious. This is the reason why I rarely exercise strongly enough to be breathless. I've detrained a lot. It's a mental thing. My last stress test was fine.

Taking no meds. If I have a reoccurring episode of afib, I do take Flecainide (pill in a pocket). Only one breakthrough since May and that was in August. I don't do things that push my heart rate to the max. What brought all this on was my swimming. I hadn't been in the pool for 50 years, but having my hip replaced suggested that I need some aerobic training and swimming was the obvious answer. Getting out of breath while swimming with a heart rate of 120 made me wonder if there was something wrong

Swimming naturally limits breathing compared to jogging or other dry aerobic exercise. I was and still am getting out of breath while swimming. My problem is that it's really hard for me to just swim back and fourth at a slow enough pace to avoid oxygen debt. I do interval training so I can push harder, but need the rest between swims. For example 15 x 100 yd. swims, one every 2.5 minutes. If I swim slow, I get sloppy. 15 years of competitive swimming and 26 years of coaching has me locked in. My hip is almost 100%, so I am considering ending the swimming - it's boring as sin.

I don't know what explains it for sure, but I'm 99% sure it has nothing to do with the ablations. My top suspect would be aging. It's the only thing I can think of that reduces maximum HR without reducing HR across the board. It's a well known phenomenon none of us escape and there's plenty of research about it. For example.

Dang, getting old impacts our physical and aerobic capacity. Nothing new here, but I will continue to push for a 50 year old body, even though mine is 75.

I think I mentioned this before, but my Dad lived to be 97 (passed away in his sleep), got his driver's license renewed at age 95, played golf (always walking) until 94, hiked to the bottom of the Grand Canyon and back out at age 81, walked 2 miles plus every day until age 96, climbed hundreds of mountains including Mt. Whitney at least 6 times.

I am just trying to keep up with the guy.

Ken you inherited good genes

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Ken
Dang, getting old impacts our physical and aerobic capacity. Nothing new here, but I will continue to push for a 50 year old body, even though mine is 75. I am just trying to keep up with the guy.

I get it. I'm typically suggesting the athletes that show up here moderate. I have a subjective limit that I don't cross to stay in afib remission. However I am not afraid to push up to that limit and keep myself in excellent shape. I lift free weights, do body weight exercise, TRX, gymnastic rings, isometrics, yoga, ski, rock climb, hike & moderate cardio per my self imposed restrictions. I'm ten years your junior, but I still understand. I weigh what I did in grade 10 and have a 3 mm skinfold thickness 1" above my right hip. I'm probably lower body fat than I was in grade 10.

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Ken
Getting out of breath while swimming with a heart rate of 120 made me wonder if there was something wrong

All that being said, the urge to breathe is almost always controlled by tolerance to CO2 in the serum (or more accurately the lower pH caused by high CO2). This tolerance is something that can be specifically trained.

I've posted a lot on breathing, but mostly for other indications, not performance. Patrick McKeown is an Irish breathing instructor who has been training others for 20+ years. He originally trained in Russia under Dr. Buteyko, to address asthma and other morbidities. In the last 8-10 years, he has expanded his work to include training athletes. He's trained many olympians, professionals, special operation forces, law enforcement & etc. His book is Oxygen Advantage. Website. FB group YouTube interviews related to sport.

One of my prior breathing posts.

Having used nasal breathing as a limit now for many years, I can be quite active and still breathe through my nose - skiing the steeps hard off piste at 13,000' for example. I have a friend who has trained using the MAF protocol for 20+ years and has run 30 sub 3 hour Boston's (MAF is more heart rate based than breathing, but same concept).

This Oxygen Advantage links have exercises you can do to train CO2 sensitivity.

When someone overbreathes, CO2 is depleted. Because of the Bohr Effect this causes a leftward shift in the oxyhemoglobin dissociation curve. When there is less CO2 in the blood, the blood pH gets more alkaline. This means that hemoglobin will bind more tightly to oxygen and your cells will get less O2.

In my world, there is an epidemic of overbreathing, even among my very fit friends.

I'm pretty sure I touched on this here at some point.
Following my first ablation back in 2009 I experienced what I termed heart reactivity. In other words my heart did not react to efforts on the bike the way they had prior to my ablation. I could still drive my heart rate up but it took much longer to get there.
Things eventually returned to normal but it took a while.

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rocketritch

Things eventually returned to normal but it took a while.

How long was "a while", for you?

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Pompon


Things eventually returned to normal but it took a while.

How long was "a while", for you?

It was a little over a year. I thought that I had gone more in depth about how I was feeling at the time on my blog. I read through some posts last evening but could only find anecdotal statements about it. I just figured it was normal.

I do remember on a ride at some point my heart rate jumped right to where I needed it to be during a sprint on a training ride and things were normal from that point. I also remember the initial frustration when this was happening. I surmised that the normal pathways that allowed my heart rate to climb rapidly had been altered by the burns. And that when things returned to normal that new pathways had been formed. I have no idea if that is even possible but it made it more acceptable in my mind.

More than 2 years since my last ablation, and still not able to exercise "normally".
I know I'm 62, but I've to start very quietly. And, when "warm", I rarely push my heart above 120 bpm if I want to avoid ectopics.
I'm feeling 15 years older than 5 years ago.

I never found a relationship between exercise and afib. I had well over 200 episodes of afib and none happened while exercising.

I don't know if my breathing (which I focus on) is a problem. For example, one of the weight exercises I was doing before my hip replacement that generated the greatest need to breath was squats to a short bench (knees bent to 90 degrees) while holding a 40lb dumbbell to my chest. Legs and core mainly and some arms, chest and back - 20 reps in a set, and I normally have to take a few extra breaths after 15 in order to get to 20. No other weight work I do generates this much need to breath. 20 reps takes about 25+ seconds.

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Ken
I don't know if my breathing (which I focus on) is a problem. For example, one of the weight exercises I was doing before my hip replacement that generated the greatest need to breath was squats to a short bench (knees bent to 90 degrees) while holding a 40lb dumbbell to my chest. Legs and core mainly and some arms, chest and back - 20 reps in a set, and I normally have to take a few extra breaths after 15 in order to get to 20. No other weight work I do generates this much need to breath. 20 reps takes about 25+ seconds.

This simple test will indicate CO2 sensitivity.

In this excellent interview, Phil Maffetone explains his heart rate approach. Really it is about doing more at the same heart rate.

I did the test and got to 45 sec. I could have gone longer with much discomfort. Knowing when to stop and breath is a bit subjective depending on ones "discomfort" tolerance.

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Ken
I did the test and got to 45 sec. I could have gone longer with much discomfort. Knowing when to stop and breath is a bit subjective depending on ones "discomfort" tolerance.

Yes, the point is "the first urge to breathe." Ideally you'd have your first breath after the breath hold be the same as those before. It is not a maximal breath hold test. 45 seconds is excellent, if it is your first urge.

Let's say that I have an urge to breathe at 20 seconds, that would be normal for just about anyone since breathing every 4-5 seconds is in the normal range, and going 4-5 times longer should trigger an "urge". I would think that an urge to breathe after 10-20 seconds would not be unusual. The "first urge" is very subjective.

I just check my old blood tests and found that over the last 8 years, there were a half dozen CO2 tests that were in the high normal range. The most recent 2 years ago was in the low normal range.



Edited 1 time(s). Last edit at 01/12/2021 10:05AM by Ken.